Distance from Africa, not climate, explains within-population phenotypic diversity in humans
Lia Betti1, François Balloux2, William Amos1, Tsunehiko Hanihara3, Andrea Manica1
December 02, 2008
Abstract
The relative importance of ancient demography and climate in determining worldwide patterns of human within-population phenotypic diversity is still open to debate. Several morphometric traits have been argued to be under selection by climatic factors, but it is unclear whether climate affects the global decline in morphological diversity with increasing geographical distance from sub-Saharan Africa. Using a large database of male and female skull measurements, we apply an explicit framework to quantify the relative role of climate and distance from Africa. We show that distance from sub-Saharan Africa is the sole determinant of human within-population phenotypic diversity, while climate plays no role. By selecting the most informative set of traits, it was possible to explain over half of the worldwide variation in phenotypic diversity. These results mirror those previously obtained for genetic markers and show that ‘bones and molecules’ are in perfect agreement for humans.
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Of course, climate, environment, living conditions, random mutation and genetic drift, and globalization [inter-ethnic miscegenation as a consequence of immigration] chime in in varying forms and in complex ways in influencing cranio-morphometric variation, as I've noted here before, but what these folks seem to be observing, at least from the little mentioned in the abstract above, is more diversity in Africa, especially sub-Saharan Africa, vs. that elsewhere. It goes back to that old age basic lesson: non-African groups derived from a subset of Africans, and hence, loss of diversity or a fraction of diversity. Though variations would occur in OOA, as a result of a number of bottleneck events and elements of the aforementioned factors, the overall diversity within the population is very likely to be impacted by that of the "founding" population, notwithstanding subsequent expansion events. The pre-existing variation in the original OOA subgroups was already a fraction of that in the African homeland, and there is reason to suspect that a series of bottlenecks events, that marked the dispersal of OOA migrants, would have led to further losses in diversity along the way.
Posted by Knowledgeiskey718 (Member # 15400) on :
quote: but what these folks seem to be observing, at least from the little mentioned in the abstract above, is more diversity in Africa, especially sub-Saharan Africa, vs. that elsewhere. It goes back to that old age basic lesson: non-African groups derived from a subset of Africans, and hence, loss of diversity or a fraction of diversity.
New Research Proves Single Origin Of Humans In Africa
ScienceDaily (July 19, 2007) — New research published in the journal Nature (19 July) has proved the single origin of humans theory by combining studies of global genetic variations in humans with skull measurements across the world. The research, at the University of Cambridge and funded by the Biotechnology and Biological Sciences Research Council (BBSRC), represents a final blow for supporters of a multiple origins of humans theory.
Competing theories on the origins of anatomically modern humans claim that either humans originated from a single point in Africa and migrated across the world, or different populations independently evolved from homo erectus to home sapiens in different areas.
The Cambridge researchers studied genetic diversity of human populations around the world and measurements of over 6,000 skulls from across the globe in academic collections. Their research knocks down one of the last arguments in favour of multiple origins. The new findings show that a loss in genetic diversity the further a population is from Africa is mirrored by a loss in variation in physical attributes.
Lead researcher, Dr Andrea Manica from the University's Department of Zoology, explained: "The origin of anatomically modern humans has been the focus of much heated debate. Our genetic research shows the further modern humans have migrated from Africa the more genetic diversity has been lost within a population.
"However, some have used skull data to argue that modern humans originated in multiple spots around the world. We have combined our genetic data with new measurements of a large sample of skulls to show definitively that modern humans originated from a single area in Sub-saharan Africa."
The research team found that genetic diversity decreased in populations the further away from Africa they were - a result of 'bottlenecks' or events that temporarily reduced populations during human migration.They then studied an exceptionally large sample of human skulls. Taking a set of measurements across all the skulls the team showed that not only was variation highest amongst the sample from south eastern Africa but that it did decrease at the same rate as the genetic data the further the skull was away from Africa.
To ensure the validity of their single origin evidence the researchers attempted to use their data to find non-African origins for modern humans. Research Dr Francois Balloux explains: "To test the alternative theory for the origin of modern humans we tried to find an additional, non-African origin. We found this just did not work. Our findings show that humans originated in a single area in Sub-Saharan Africa."
Posted by The Explorer (Member # 14778) on :
^Good addition.
Posted by argyle104 (Member # 14634) on :
Ahhhhhh "MA DICK" has created a new post.
And I'm refering to the poster who calls himself The Explorer.
Not something else you may think.
hahahahahaheeeeeeeeeeeeeeeeeeeeeeeeeeeee : )
Posted by akoben (Member # 15244) on :
Hey whiskey, I wonder what ever happened to those OOA Chinese that populated Europe? Records show that the early people of Europe were Chinese. What happened to them? Ah, they lost their history so they died.... Posted by Knowledgeiskey718 (Member # 15400) on :
quote: Hey whiskey, I wonder what ever happened to those OOA Chinese that populated Europe?
False interpretations won't fly, you clown. Europe was populated from East Asia, as all geneticists state and Cavalli states, which is in line with OOA. At this time humans still resembled Oceanic's. Modern day Chinese and European pale phenotype is a recent evolutionary adaptation.
quote: What we know of the occupation of different continents (1) shows that West Asia was first settled around 100,000 years ago, although perhaps not permanently. Oceania was occupied first from Africa, more or less at the same time as East Asia (both probably having been settled by the coastal route of South Asia), and then from East Asia both Europe and America were settled, the latter certainly from the north, via the Bering Strait (then a wide land passage).---Sforza
Posted by akoben (Member # 15244) on :
quote:Originally posted by Knowledgeiskey718:
quote: Hey whiskey, I wonder what ever happened to those OOA Chinese that populated Europe?
False interpretations won't fly, you clown. Europe was populated from East Asia, as all geneticists state and Cavalli states, which is in line with OOA. At this time humans still resembled Oceanic's. Modern day Chinese and European pale phenotype is a recent evolutionary adaptation.
quote: What we know of the occupation of different continents (1) shows that West Asia was first settled around 100,000 years ago, although perhaps not permanently. Oceania was occupied first from Africa, more or less at the same time as East Asia (both probably having been settled by the coastal route of South Asia), and then from East Asia both Europe and America were settled, the latter certainly from the north, via the Bering Strait (then a wide land passage).---Sforza
I'm just going to throw this out. What are his "core populations" his ancestral archetypes?
Posted by Knowledgeiskey718 (Member # 15400) on :
^^^Stop throwing **** out your ass, maybe you'll start making sense.
"The phylogenetic and spatial distribution of its equivalent in Europe (Cruciani et al. 2002), the R1-M173 (xM17) lineage for which considerable data exist (Semino et al. 2000a; Wells et al. 2001; Kivisild et al. 2003) implies that R1b3-M269 was well established throughout Paleolithic Europe, probably arriving from West Asia contemporaneous with Aurignacian culture.
Although the phylogeographic pattern of R1b3-M269 lineages in Europe suggest that R1-M173* ancestors first arrived from West Asia during the Upper Paleolithic, we cannot deduce if R1b3-M269 first entered Anatolia via the Bosporus isthmus or from an opposite eastward direction. However, archeological evidence supports the view of the arrival of Aurignacian culture to Anatolia from Europe during the Upper Paleolithic rather than from the Iranian plateau (Kuhn 2002)." Posted by Boofer (Member # 15638) on :
Interesting, but wasn't this already known? Have you read the whole report?
Posted by The Explorer (Member # 14778) on :
Yes, it was already known, which is why it says "recap" above.
On second thought, it had occurred to me that you might well be referring to the head post. Please clarify!
Posted by rasol (Member # 4592) on :
Excellent thread.
Posted by The Explorer (Member # 14778) on :
Hope it stays that way, which is usually a daunting task these days.
Posted by Boofer (Member # 15638) on :
I was referring to the first post!
Posted by rasol (Member # 4592) on :
^ Then in answer to your question - 'already known'.
"We show that distance from sub-Saharan Africa is the sole determinant of human within-population phenotypic diversity."
^ No, I don't think most people know this.
Many people seem to think the diversity in Africa comes from admixture from Arabs and Europeans.
And diversity in Europe or Arabs would be indigenous.
Or perhaps I should say - 'that's what many people *want* to believe'.
However such wishful thinking makes no sense, and is close to being the exact opposite of what is true. Posted by lamin (Member # 5777) on :
It should be noted that Western anthropologists/geneticists continue to make the faux-race derived concept of "sub-Saharan Africa"--which in reality is a vast area with maximal genetic diversity.
I put it down to their naive and historic "phenotype explains all" mindset they don't ever seem capable of shaking off.
Posted by Knowledgeiskey718 (Member # 15400) on :
quote:Originally posted by rasol: ^ Then in answer to your question - 'already known'.
"We show that distance from sub-Saharan Africa is the sole determinant of human within-population phenotypic diversity."
^ No, I don't think most people know this.
Many people seem to think the diversity in Africa comes from admixture from Arabs and Europeans.
And diversity in Europe or Arabs would be indigenous.
Or perhaps I should say - 'that's what many people *want* to believe'.
However such wishful thinking makes no sense, and is close to being the exact opposite of what is true.
Exactly, what this does is put yet another road block for those who want to promote that all Africans look alike(True Negroes), when in fact as shown, Africa is the continent with the most indigenous phenotypic diversity. The farther humans get from Africa the more those populations(non-Africans) tend to actually look like one another, instead of the falsely attributed and limited genetic and phenotypic diversity given to Africa. Africa, the cradle of mankind and civilization.
Posted by Boofer (Member # 15638) on :
I don't think such a study would negate that back migration from Asia to Africa have influenced the phenotypes of some populations, specifically in northern africa. Perhaps that is why they specified Sub-Saharan.
I tend to think that certain extreme features actually do come from Arabs. Certain groups in Ethiopia actually look kinda like Arabs. I'm assuming that groups with the very light skin and the nearly straight hair have some sort of Arab influence, whereas aquiline features are not necessarily from Europeans or Arab influence.
Posted by Knowledgeiskey718 (Member # 15400) on :
quote:Originally posted by Boofer: I don't think such a study would negate that back migration from Asia to Africa have influenced the phenotypes of some populations, specifically in northern africa. Perhaps that is why they specified Sub-Saharan.
I tend to think that certain extreme features actually do come from Arabs. Certain groups in Ethiopia actually look kinda like Arabs. I'm assuming that groups with the very light skin and the nearly straight hair have some sort of Arab influence, whereas aquiline features are not necessarily from Europeans or Arab influence.
Please present this evidence for a back migration, as well as some pics clarifying exactly what you mean by extreme features. Thanks
Because according to genetic evidence, Arabs didn't invade and influence the north African gene pool until 7th century C.E.
In a recent publication, Bosch et al. (2001) reported on Y-chromosome variation in populations from northwestern (NW) Africa and the Iberian peninsula. They observed a high degree of genetic homogeneity among the NW African Y chromosomes of Moroccan Arabs, Moroccan Berbers, and Saharawis, leading the authors to hypothesize that “the Arabization and Islamization of NW Africa, starting during the 7th century ad, … [were] cultural phenomena without extensive genetic replacement” (p. 1023). H71 (Eu10) was found to be the second-most-frequent haplogroup in that area. Following the hypothesis of Semino et al. (2000), the authors suggested that this haplogroup had spread out from the Middle East with the Neolithic wave of advance. Our recent findings (Nebel et al. 2000, 2001), however, suggest that the majority of Eu10 chromosomes in NW Africa are due to recent gene flow caused by the migration of Arabian tribes in the first millennium of the Common Era (ce).
While you're at it, you can tell me if this guy has any extreme features that make him look non African?
Also of note is that from over 150kya Omo I from Ethiopia, resembles modern Ethiopians and Southern Sudanese today. So much for Ethiopians getting their features from people who weren't even around yet. Good luck explaining that.
quote:"From the size of the preserved bones, we estimated that Omo I was tall and slender, most likely around 5'10" tall and about 155 pounds," University of New Mexico anthropologist Osbjorn Pearson, who co-authored at least two of the new papers, told Discovery News.
Pearson said another, later fossil was also recently found. It too belonged to a "moderately tall -- around 5'9" -- and slender individual."
"Taken together, the remains show that these early modern humans were...much like the people in southern Ethiopia and the southern Sudan today," Pearson said.
Posted by The Explorer (Member # 14778) on :
Boofer,
1)The study was not intended to negate "back-migration". Whether potential back-migration has modified some Africans from a physiological standpoint, is trivial to and has no bearing on what the study is relaying -- greatest autochthonous diversity in Africa, especially sub-Saharan Africa, vs. elsewhere.
2)Likewise, it can be said that the regions you speak of, as original points of the said back-migration, have also been impacted by gene flow from mainland Africa.
3)Though the general idea of greatest diversity in Africa had been already known by some of us well-read and learnt ones, the pattern observed in this study, about the "progressive loss of diversity" in correlation to "progressive increase of distance" away from sub-Saharan Africa is necessarily new information. It ties into loss of diversity attained in bottlenecks that generally mark migration events. "Progressive loss of diversity" obviously speaks to additional bottlenecks linked to further dispersals of OOA migrants. Plus, Rasol makes a good point about persisting ignorance and/or wishful thinking on the matter of African diversity, especially in sub-Saharan Africa.
Posted by rasol (Member # 4592) on :
quote:Originally posted by rasol: ^ Then in answer to your question - 'already known'.
"We show that distance from sub-Saharan Africa is the sole determinant of human within-population phenotypic diversity."
^ No, I don't think most people know this.
Many people seem to think the diversity in Africa comes from admixture from Arabs and Europeans.
And diversity in Europe or Arabs would be indigenous.
Or perhaps I should say - 'that's what many people *want* to believe'.
However such wishful thinking makes no sense, and is close to being the exact opposite of what is true.
quote:I tend to think that certain extreme features actually do come from Arabs.
^ then you contradict your own disclaimer.
the study states: "We show that distance from sub-Saharan Africa is the *sole determinant* of human within-population phenotypic diversity."
^ you protest out of one side of your mouth that everyone knows this, and out of the other - you actually deny this - but based on no data.
Which proves, as I stated: 'that's what many people *want* to believe', even when study after study states the opposite.
Posted by Alive-(What Box) (Member # 10819) on :
quote: Boofer,
3)Though the general idea of greatest diversity in Africa had been already known by some of us well-read and learnt ones, the pattern observed in this study, about the "progressive loss of diversity" in correlation to "progressive increase of distance" away from sub-Saharan Africa is necessarily new information. It ties into loss of diversity attained in bottlenecks that generally mark migration events. "Progressive loss of diversity" obviously speaks to additional bottlenecks linked to further dispersals of OOA migrants. Plus, Rasol makes a good point about persisting ignorance and/or wishful thinking on the matter of African diversity, especially in sub-Saharan Africa.
more:
quote:Recent studies comparing craniometric and neutral genetic affinity matrices have concluded that, on average, human cranial variation fits a model of neutral expectation. While human craniometric and genetic data fit a model of isolation by geographic distance, it is not yet clear whether this is due to geographically mediated gene flow or human dispersal events. Recently, human genetic data have been shown to fit an iterative founder effect model of dispersal with an African origin, in line with the out-of-Africa replacement model for modern human origins, and Manica et al. (Nature 448 (2007) 346-349) have demonstrated that human craniometric data also fit this model. However, in contrast with the neutral model of cranial evolution suggested by previous studies, Manica et al. (2007) made the a priori assumption that cranial form has been subject to climatically driven natural selection and therefore correct for climate prior to conducting their analyses. Here we employ a modified theoretical and methodological approach to test whether human cranial variability fits the iterative founder effect model. In contrast with Manica et al. (2007) we employ size-adjusted craniometric variables, since climatic factors such as temperature have been shown to correlate with aspects of cranial size. Despite these differences, we obtain similar results to those of Manica et al. (2007), with up to 26% of global within-population craniometric variation being explained by geographic distance from sub-Saharan Africa. Comparative analyses using non-African origins do not yield significant results.
Am J Phys Anthropol. 2008 May;136(1):108-13 von Cramon-Taubadel N, Lycett SJ. Leverhulme Centre for Human Evolutionary Studies, University of Cambridge, The Henry Wellcome Building, Fitzwilliam Street, Cambridge CB2 1QH, UK.
Posted by Alive-(What Box) (Member # 10819) on :
quote:Originally posted by akoben: Hey whiskey, I wonder what ever happened to those OOA Chinese that populated Europe? Records show that the early people of Europe were Chinese. What happened to them? Ah, they lost their history so they died....
Wrong thread. Posted by Boofer (Member # 15638) on :
quote:Originally posted by rasol:
quote:Originally posted by rasol: ^ Then in answer to your question - 'already known'.
"We show that distance from sub-Saharan Africa is the sole determinant of human within-population phenotypic diversity."
^ No, I don't think most people know this.
Many people seem to think the diversity in Africa comes from admixture from Arabs and Europeans.
And diversity in Europe or Arabs would be indigenous.
Or perhaps I should say - 'that's what many people *want* to believe'.
However such wishful thinking makes no sense, and is close to being the exact opposite of what is true.
quote:I tend to think that certain extreme features actually do come from Arabs.
^ then you contradict your own disclaimer.
the study states: "We show that distance from sub-Saharan Africa is the *sole determinant* of human within-population phenotypic diversity."
^ you protest out of one side of your mouth that everyone knows this, and out of the other - you actually deny this - but based on no data.
Which proves, as I stated: 'that's what many people *want* to believe', even when study after study states the opposite.
I don't know. I'm not doubting you, but based on this study there doesn't seem to be anyway to say whether certain features are "indigenous" or not. It simply says that africa has alot more diversity than other continents. So when I said "everyone knows this" i mean everyone knows that Africans are extremely diverse, but that doesn't mean that some differences come from interactions from back migration.
Posted by Knowledgeiskey718 (Member # 15400) on :
quote:Posted by boofer: It simply says that africa has alot more diversity than other continents.
Boofer,
It seems you're not understanding what you're reading. Africa is the continent with the widest indigenous phenotypic diversity. The farther humans get from Africa, the more those populations(non-Africans) tend to actually look like one another(little diversity). Meaning all features around the world can be found indigenous to Africa, except the pale skin.
quote: Taking a set of measurements across all the skulls the team showed that not only was variation **highest** amongst the sample from south eastern Africa but that it did **decrease** at the same rate as the genetic data the further the skull was away from Africa.
Do tell how a small pond with limited variation in features, compared to Africa, the cradle, with a phenotypic ocean of features, will contribute to the African variation??
quote: Jean Hiernaux "The People of Africa" 1975
p.53, 54
"In sub-Saharan Africa, many anthropological characters show a wide range of population means or frequencies. In some of them, the **whole world range** is covered in the sub-continent.
Here live the shortest and the tallest human populations, the one with the highest and the one with the lowest nose, the one with the thickest and the one with the thinnest lips in the world. In this area, the range of the **average nose widths** covers **92 percent** of the world range:
**only a narrow range of extremely low means are absent from the African record.** Means for head diameters cover about 80 per cent of the world range; 60 per cent is the corresponding value for a variable once cherished by physical anthropologists, the cephalic index, or ratio of the head width to head length expressed as a percentage....."
Btw, did you even bother reading explorers post??
quote:Originally posted by The Explorer: Boofer,
1)The study was not intended to negate "back-migration". Whether potential back-migration has modified some Africans from a physiological standpoint, is trivial to and has no bearing on what the study is relaying -- greatest autochthonous diversity in Africa, especially sub-Saharan Africa, vs. elsewhere.
2)Likewise, it can be said that the regions you speak of, as original points of the said back-migration, have also been impacted by gene flow from mainland Africa.
3)Though the general idea of greatest diversity in Africa had been already known by some of us well-read and learnt ones, the pattern observed in this study, about the "progressive loss of diversity" in correlation to "progressive increase of distance" away from sub-Saharan Africa is necessarily new information. It ties into loss of diversity attained in bottlenecks that generally mark migration events. "Progressive loss of diversity" obviously speaks to additional bottlenecks linked to further dispersals of OOA migrants. Plus, Rasol makes a good point about persisting ignorance and/or wishful thinking on the matter of African diversity, especially in sub-Saharan Africa.
Posted by xyyman (Member # 13597) on :
quote:Originally posted by Boofer: [QUOTE]Originally posted by rasol: [qb] So when I said "everyone knows this" i mean everyone knows that Africans are extremely diverse, but that doesn't mean that some differences come from interactions from back migration.
Ha! Ha! Ha! Ha! This is funny you guys take Boofer seriously. He probably gets off by sitting at his keyboard making sh1t up to get you guys all excited.
What kind of BS statement is the above. Hey YH!! bump the CULPRIT thread. That is more stimulating.
Posted by rasol (Member # 4592) on :
quote: Posted by boofer: It simply says that africa has alot more diversity than other continents.
^ nope. that's not all it says. your mannner of not -hearing- what the study is saying is a classic example of denial.
Let me make this clear.
The study is suggesting is that Africa is the source of much of physical diversity, and Asia, Arabs, Europeans have lesser diversity derived from that source.
"We show that distance from sub-Saharan Africa is the sole determinant of human within-population phenotypic diversity".
^ Can you explain the meaning of -sole determinant-?
Posted by Boofer (Member # 15638) on :
I'm gonna be frank with everybody. It's not really that I don't understand what's being said. What makes it difficult is my own racial conceptions. It's stubborness, I admit. I have an idea of a "mixed" person (of 1 Afro and 1 Euro parentage) in my head. The image is not unlike some ethiopians I've seen. I have an idea also of arabs and of white people. The image is not unlike many north africans I have seen.
Another problem, when distinguishing phenotypes and ancestries is North Africa. Northern Africa seems to have a great influence from East Africa as well as Eurasia, based on mtdna.
Now based on that, it is hard for me to believe any talk that North Africans are entirely "indigenous", and it also makes it apparent why there is often a distinction between Subsaharan and North African. I also know that Y dna shows a much, much smaller Eurasian influence, but that just shows that there is influence from both.
Posted by Boofer (Member # 15638) on :
quote:Originally posted by The Explorer: [QB] Boofer,
1)The study was not intended to negate "back-migration". Whether potential back-migration has modified some Africans from a physiological standpoint, is trivial to and has no bearing on what the study is relaying -- greatest autochthonous diversity in Africa, especially sub-Saharan Africa, vs. elsewhere.
Rasol seemed to treat it like it DID negate back migration. My comment was sort of directed at that.
quote:Many people seem to think the diversity in Africa comes from admixture from Arabs and Europeans.
And diversity in Europe or Arabs would be indigenous.
Or perhaps I should say - 'that's what many people *want* to believe'.
However such wishful thinking makes no sense, and is close to being the exact opposite of what is true.
In a nutshell, I was basically saying that, though diversity (in physical appearance)is greatest in africa and increasingly less based on the distance from africa, it does not necessarily mean that a fragment of diversity doesn't come from populations who migrated back to africa. Features I'm specifically talking about are skin color and hair texture.
quote:2)Likewise, it can be said that the regions you speak of, as original points of the said back-migration, have also been impacted by gene flow from mainland Africa.
Understood, as it would make total sense for adjacent countries to have african migrants post OOA.
Posted by The Explorer (Member # 14778) on :
Boofer, you are case in point why posting this study was/is necessary, and why rasol's point is warranted.
Quite simply, cranio-metric diversity is *naturally greatest* in Africa than anywhere else, whereby -- ad nauseam now -- within-population phenotypic diversity tends to decrease as one moves *away* from sub-Saharan Africa; and so, you cannot use extra-African immigration to explain away autochthonous intra-African diversity.
Not to leave out that hair thickness or skin color has no bearing on *cranio-metric* indices.
And if you understand said *bidirectional* gene flow as you proclaim you do, then why do you treat the non-African counterparts as *primary* types, while treating the supposed African counterparts as the recipients of phenotypic modification from gene flow? And for the last time, this has no bearing whatsoever on the premise of the study at hand. Your harping on this, goes to make a case in point for what rasol was telling you, which to borrow, would make it so that you...
seem to think the diversity in Africa comes from admixture from Arabs and Europeans.
And diversity in Europe or Arabs would be indigenous.
...and that that's what you *want* to believe'!
Posted by argyle104 (Member # 14634) on :
Boofer wrote:
------------------------------------ I'm gonna be frank with everybody. It's not really that I don't understand what's being said. What makes it difficult is my own racial conceptions. It's stubborness, I admit. I have an idea of a "mixed" person (of 1 Afro and 1 Euro parentage) in my head. The image is not unlike some ethiopians I've seen. I have an idea also of arabs and of white people. The image is not unlike many north africans I have seen.
Another problem, when distinguishing phenotypes and ancestries is North Africa. Northern Africa seems to have a great influence from East Africa as well as Eurasia, based on mtdna.
Now based on that, it is hard for me to believe any talk that North Africans are entirely "indigenous", and it also makes it apparent why there is often a distinction between Subsaharan and North African. I also know that Y dna shows a much, much smaller Eurasian influence, but that just shows that there is influence from both. ------------------------------------
Then in your own words you are simply a know-nothing numbskull spouting off his fantasy/delusions even when you have evidence that proves your fantasy/delusions are false.
Racially deluded fantasies with regards to typologies, phenotypes, culture, history are your security blanket that gets you through your sorry life.
That is the reason why you take such an unscholarly, anti-intellectual dogma in your views. Unfortunately your trashing up this forum with you're imbecillic lunacy.
Since you're a self admitted dunce who can't learn at even a basic level, it is suggested that no one give this clown anymore attention other than to administer a beatdown.
Posted by Doug M (Member # 7650) on :
quote:Originally posted by Boofer: I'm gonna be frank with everybody. It's not really that I don't understand what's being said. What makes it difficult is my own racial conceptions. It's stubborness, I admit. I have an idea of a "mixed" person (of 1 Afro and 1 Euro parentage) in my head. The image is not unlike some ethiopians I've seen. I have an idea also of arabs and of white people. The image is not unlike many north africans I have seen.
Another problem, when distinguishing phenotypes and ancestries is North Africa. Northern Africa seems to have a great influence from East Africa as well as Eurasia, based on mtdna.
Now based on that, it is hard for me to believe any talk that North Africans are entirely "indigenous", and it also makes it apparent why there is often a distinction between Subsaharan and North African. I also know that Y dna shows a much, much smaller Eurasian influence, but that just shows that there is influence from both.
Boofer, what is being said has nothing to do with skin color. The point being made is about ALL human features combined: skull shape, size, thickness, skeletal features and so on. And it is not about Northern Africa it is about ALL of Africa and specifically places South of the Sahara like CENTRAL and EAST Africa. The GREATEST amount of diversity is found among the populations in this region and it is NOT simply those in East Africa, it is a reference to a BROAD RANGE of people from across Central Africa.
The problem here is that African features have been STEREOTYPED for so long as simply being of ONE TYPE and not DIVERSE both within and across various African ethnic groups. Therefore, this oversimplification causes some people to see certain features as being African and others NON African, without actually KNOWING the diversity of features found around the continent. Congo by itself has hundreds of features among its population and similar things can be said about every other part of Africa. But because some people are operating under stereotypical views of Africa, detailed analysis and documentation of such wide ranging features have not been documented for Africans. Therefore, the stereotypical view of Africans as a single monolithic type are allowed to continue in the publich consciousness.
And it is not about Northern Africa it is about ALL of Africa and specifically places South of the Sahara like CENTRAL and EAST Africa. The GREATEST amount of diversity is found among the populations in this region and it is NOT simply those in East Africa, it is a reference to a BROAD RANGE of people from across Central Africa....
The above seems to be fraught with contradictions; was samples from across the continent studied, or was it just east Africa and central Africa? Do you have a citation from the source?
Posted by Doug M (Member # 7650) on :
While awaiting for the answer or its lack thereof, in the meantime, from another study from pretty much the same authors [albeit sans Lia Betti] but from 2007, it says...
The effect of ancient population bottlenecks on human phenotypic variation
Andrea Manica1, William Amos1, François Balloux2 & Tsunehiko Hanihara3
Abstract
The origin and patterns of dispersal of anatomically modern humans are the focus of considerable debate1, 2, 3. Global genetic analyses have argued for one single origin, placed somewhere in Africa4, 5, 6, 7. This scenario implies a rapid expansion, with a series of bottlenecks of small amplitude, which would have led to the observed smooth loss of genetic diversity with increasing distance from Africa. Analyses of cranial data, on the other hand, have given mixed results8, 9, 10, 11, 12, and have been argued to support multiple origins of modern humans2, 9, 12. Using a large data set of skull measurements and an analytical framework equivalent to that used for genetic data, we show that the loss in genetic diversity has been mirrored by a loss in phenotypic variability. We find evidence for an African origin, placed somewhere in the central/southern part of the continent, which harbours the highest intra-population diversity in phenotypic measurements. We failed to find evidence for a second origin, and we confirm these results on a large genetic data set. Distance from Africa accounts for an average 19–25% of heritable variation in craniometric measurements—a remarkably strong effect for phenotypic measurements known to be under selection.
Posted by Doug M (Member # 7650) on :
quote:Originally posted by The Explorer:
quote:Originally posted by Doug M:
And it is not about Northern Africa it is about ALL of Africa and specifically places South of the Sahara like CENTRAL and EAST Africa. The GREATEST amount of diversity is found among the populations in this region and it is NOT simply those in East Africa, it is a reference to a BROAD RANGE of people from across Central Africa....
The above seems to be fraught with contradictions; was samples from across the continent studied, or was it just east Africa and central Africa? Do you have a citation from the source?
Contradictions of what? How can a sample of Africans across Africa be a contradiction of a report about African diversity?
Please explain.
Posted by The Explorer (Member # 14778) on :
^As highlighted in my post, citing your's.
Posted by Doug M (Member # 7650) on :
How does
quote: Using a large data set of skull measurements and an analytical framework equivalent to that used for genetic data, we show that the loss in genetic diversity has been mirrored by a loss in phenotypic variability. We find evidence for an African origin, placed somewhere in the central/southern part of the continent,
Contradict variation in features across Africa?
Are you claiming that they only used data from central and southern Africa when speaking of diversity ACROSS the continent AND the planet?
Posted by The Explorer (Member # 14778) on :
Doug, I suspect you can read. My question addresses your post, not what I just cited. Now, do you have an answer for the questions therein, or do you not?
What you're citing above, is from an actual paper from the authors in question. Are *you* claiming that you haven't yet read that paper, judging by the character of your question in response to the piece?
Posted by lamin (Member # 5777) on :
Boofer,
A mistake that you and others always seem to make is that something genotypically and phenotypically remarkable happen to humans once they cross over to other areas from the African continent.
But that's not the way how nature operates. For example: the genetic distance between West Africans and, say, the San and Twa would be greater that the genetic distance between West Africans and some non-African groups.
And recall that in terms of genetic distance Africans in general are closer to Europeans than are the former to Melanesians.
In other words, once you accept the OOA hypothesis then you would have to admit that traits that you would consider the result of back migration to Africa could have developed right there in the vast and varied environment of Africa.
If not you would have to explain how was possible for the African phenotype to have been transformed phenotypically into those of Europe and Asia-- unless there were intermediary[in a relative sense]stages that could easily have occurred in Africa proper. Posted by The Explorer (Member # 14778) on :
quote:Originally posted by lamin:
But that's not the way how nature operates. For example: the genetic distance between West Africans and, say, the San and Twa would be greater that the genetic distance between West Africans and some non-African groups.
Please elaborate.
Posted by lamin (Member # 5777) on :
Explorer,
Off the top of my head think of the fact that haplogroup A[not the variants of E] is found among the San of Southern Africa and that the Twa of the Congo, on account of their relatively dimunitive size must have been lived in isolation for several thousands of years.
As you might note greater or lesser relative size are usually markers for genetic isolation.
Posted by Doug M (Member # 7650) on :
quote:Originally posted by The Explorer: Doug, I suspect you can read. My question addresses your post, not what I just cited. Now, do you have an answer for the questions therein, or do you not?
What you're citing above, is from an actual paper from the authors in question. Are *you* claiming that you haven't yet read that paper, judging by the character of your question in response to the piece?
Read your own question. It doesn't make sense.
Across Africa means across Africa. So what is the issue?
Posted by The Explorer (Member # 14778) on :
You don't have to beat around the bush; if you are reading-challenged, simply say so. I'll dumb it down for you, and see if that works...
You said:
And it is not about Northern Africa it is about ALL of Africa and specifically places South of the Sahara like CENTRAL and EAST Africa.
"It is about all of Africa" seems to contradict "specifically places like Central and East Africa"
You added:
it is NOT simply those in East Africa, it is a reference to a BROAD RANGE of people from across Central Africa
...which gives me the impression that you think that these two regions were the focus of the study in question, if not the places that were *actually* tested sans the rest of the continent. You mentioned Central and East Africa twice in that comment, with no mention to any other part of the continent. Hence, these questions:
was samples from across the continent studied, or was it just east Africa and central Africa? Do you have a citation from the source?
Which remain unanswered, as you *pretend* that I'm arguing against the very point of the thread, "greater diversity in Africa vs. that elsewhere", as a smokescreen to stall delivering the answers to those simple questions.
The last abstract I cited was to assist in adding some clarity to the head abstract of the thread. It doesn't absolve you from the questions above, nor was it intended to contradict the head abstract -- i.e. "greatest diversity in Africa", as you *pretend* I'm questioning.
Posted by The Explorer (Member # 14778) on :
quote:Originally posted by lamin:
Explorer,
Off the top of my head think of the fact that haplogroup A[not the variants of E] is found among the San of Southern Africa and that the Twa of the Congo, on account of their relatively dimunitive size must have been lived in isolation for several thousands of years.
As you might note greater or lesser relative size are usually markers for genetic isolation.
I fail to see how haplogroup A being in San, and the size of the Twa, is indicative of greater genetic distance between these groups vs. west Africans than between west Africans vs. some non-Africans. You do realize that haplogroup A occurs in west Africa, albeit in relatively lower frequencies than say in eastern Africa or southern Africa, don't you?
Posted by argyle104 (Member # 14634) on :
More proof that Doug believes in dichotomizing Africans.
Posted by Doug M (Member # 7650) on :
quote:Originally posted by The Explorer: You don't have to beat around the bush; if you are reading-challenged, simply say so. I'll dumb it down for you, and see if that works...
You said:
And it is not about Northern Africa it is about ALL of Africa and specifically places South of the Sahara like CENTRAL and EAST Africa.
"It is about all of Africa" seems to contradict "specifically places like Central and East Africa"
You added:
it is NOT simply those in East Africa, it is a reference to a BROAD RANGE of people from across Central Africa
...which gives me the impression that you think that these two regions were the focus of the study in question, if not the places that were *actually* tested sans the rest of the continent. You mentioned Central and East Africa twice in that comment, with no mention to any other part of the continent. Hence, these questions:
was samples from across the continent studied, or was it just east Africa and central Africa? Do you have a citation from the source?
Which remain unanswered, as you *pretend* that I'm arguing against the very point of the thread, "greater diversity in Africa vs. that elsewhere", as a smokescreen to stall delivering the answers to those simple questions.
The last abstract I cited was to assist in adding some clarity to the head abstract of the thread. It doesn't absolve you from the questions above, nor was it intended to contradict the head abstract -- i.e. "greatest diversity in Africa", as you *pretend* I'm questioning.
I think you lack reading comprehension. The fact that you highlighted a perfectly valid and well formed English sentence and are unable to comprehend what is being said proves that.
ALL of Africa includes Central and East Africa does it not?
Therefore, you can study ALL of Africa and also focus on specific parts at the same time can you not? It isn't like I said study ALL of Africa and focus on South America, which is a contradiction.
Seems to me you are wasting time and space on the thread with nonsense.
The study used data FROM ACROSS THE GLOBE but found specific patterns of diversity in Central and Southern Africa. Is that a contradiction?
You can't call out the fact that Africans are MORE diverse than NON Africans without studying and capturing data for BOTH now can you? And does that not ALSO mean that you must also capture data from ALL Africans?
ALL humans are diverse, so ALL humans were studied, but the VARIATION in Central And Southern Africa is the MOST DIVERSE. Which follows from Sub Saharan Africa has the MOST feature diversity in human populations. No contradiction there at all.
Anything else you are confused about?
Posted by The Explorer (Member # 14778) on :
Doug, you know as a matter of fact, yes; one thing baffles me: the limitlessness of your stupidity.
Let's test who "lack of reading" makes a better fit...
You were supposedly attempting to correct someone else's short-sightedness by emphasizing "north Africa" even though the study deals with "all of Africa", only to replace it with your own:
If the study was focusing on "central and east Africa" as you say, how was that done so, vs. the rest of Africa?
Yes, your "finding specific patterns of diversity in central and southern Africa" would be a contradiction to your earlier "*specifically* central and eastern Africa" in two respects:
1)it doesn't say that the study is "specifically" about "central and southern Africa".
2)"central and southern Africa" is not the same as "central and east Africa".
And third, you read the abstract wrong; it makes reference to "central/southern Africa". "/" sign is not "and" in English grammar.
Posted by Knowledgeiskey718 (Member # 15400) on :
quote:Originally posted by rasol: Excellent thread.
quote:Originally posted by The Explorer: Hope it stays that way, which is usually a daunting task these days.
Posted by rasol (Member # 4592) on :
quote:Rasol seemed to treat it like it DID negate back migration. My comment was sort of directed at that.
^ this is an example of a strawmen used to destract from an 'unpleasant' truth.
the study states that Africa is the *sole determinent* of diversity.
you try to run from this by introducing 'back migration' which by definition of what this study is saying -> is utterly irrelevant.
However you prove precisely why this factual study is necessary - to refute the bias, wishful thinking, and strawman arguments, such as proferred by you.
Posted by rasol (Member # 4592) on :
quote:Comparative analyses using non-African origins do not yield significant results.
^ Boofer, maybe you should try explaing the above?
Why is this?
Posted by The Explorer (Member # 14778) on :
Pretty self-explanatory.
Posted by lamin (Member # 5777) on :
Explorer, But there are many instances of E in Europe--going only with Y haplotypes--so the fact that some trace elements of A are found in West Africa does not dislodge my hypothesis. Consider too the cases of R in Central/West Africa[Cameroon].
But back to my point: if the OOA is correct[the data says it is] then how do you explain the phenotypical transformation of non-Africans such as Europeans and Asians from having original African phenotypes to their present appearances? There must have been intermediary stages--that took place not only outside Africa but also inside Africa. In this regard no need for any fanciful ideas such as back migration.
Just document, using your imagination, the transforamtive steps taken.
Posted by The Explorer (Member # 14778) on :
Lamin, let's first remember that I only commented on haplogroup A, because *you* brought it up, upon being queried to clarify your claim. I did so, with the understanding that you generalized west Africans, and used haplogroup A to argue for isolation and thus, greater distance between them and the San than vs. some non-Africans...in addition to the "size" justification centered on the Twa.
Your "distance" claim, pending clarification, seemed to imply the treating of west Africans as figures of autochthonous ancestry vs. "some non-Africans", the San and Twa as others of respective autochthonous ancestry. In that respect, it had the potential to mislead.
Now, you use E as a basis for your claim about the distance issue:
Firstly, the San are not devoid of Hg E, as you might be inclined to assume.
Secondly, E in Europe marks African ancestry; so of course, in that respect, such non-Africans will be closer to haplogroup E-carrying west Africans than Africans who fall out of that macro-haplogroup, from the Y DNA standpoint.
The fact that you mention Hg R in west Africa to reinforce your claim, which no doubt speaks to the heterogeneity of west Africans, is case in point about the futility of generalization as you did, wittingly or otherwise.
Evolution of phenotype of Europeans or other Asian groups has no bearing on African diversity vs. the non-African; phenotypic variation, including that within-population, remains greatest in Africa.
Posted by Knowledgeiskey718 (Member # 15400) on :
quote:Posted by Lamin: But back to my point: if the OOA is correct[the data says it is] then how do you explain the phenotypical transformation of non-Africans such as Europeans and Asians from having original African phenotypes to their present appearances? There must have been intermediary stages--that took place not only outside Africa but also inside Africa. In this regard no need for any fanciful ideas such as back migration.
Allow me to explain this is "laymen" terms. You're clearly speaking upon the pale phenotype of East Asians and Europeans (since you should already know cranio-facially/phenotypically speaking, Africa pretty much covers the world, I won't go into details on that) . This evolution/mutation is a recent adaptation, considering an evolutionary time line. This occurred due to the fact when humans move into northern latitudes need to be lighter skinned in order to allow UV in to produce Vitamin D(since dark skin was evolved to protect from harmful UV, therefore it prevents from absorbing UV to produce Vitamin D).
Early humans as well as early Europeans were hunter gatherers, in a hunter gatherers diet you will find food which contains adequate amounts of Vitamin D, through fish, meats, egg yolks etc... Absorbing enough of this Vitamin D will provide humans with enough Vitamin D to keep their skin dark with no need to be pale, since their receiving the Vitamin D through their diets. A clear example of a human population which consumes adequate amounts of vitamin d and retains melanin, are Eskimos. If you do some research you will notice that an Eskimos diet consists of rich amounts of Vitamin D, and if they would stop eating this diet, Eskimos would develop Vitamin D deficiencies, which surface as rickets, the reason for this is as explained, when humans move to northern latitudes/lower uv environments they aren't receiving as much sun(obviously) and since dark skin protects from harmful UV rays, it blocks out the ability to produce synthesize UV. The sun is one main source of Vitamin D along with diet. So in northern latitudes under a farmers diet(which doesn't provide an individual with adequate amounts of Vitamin D as a hunter gatherers diet would) humans would have to be lighter skinned, as explained, to allow the synthesis of UV for the production of Vitamin D, since dark skin blocks out the sun
Therefore, as explained light skin was evolved to allow the synthesis of Uv for the production of Vitamin d, but remember early Europeans were hunter gatherers, just as Eskimos are/were, so early Europeans retained their melanin levels as well, until agriculture spread. But agriculture /farming didn't spread into Europe until about 8kya with the Neolitic revolution. This new way of living decreased Europeans intake of vitamin D, since a farmers diet is not full with the adequate amounts of Vitamin D that a hunter gatherers fisher/herders diet consists of.
Therefore during this era, Europeans and East Asians evolved pale skin to allow UV in to produce Vitamin D through synthesis.
quote: Signatures of Positive Selection in Genes Associated with Human Skin Pigmentation as Revealed from Analyses of Single Nucleotide Polymorphisms
KEYWORDS human pigmentation • skin color • positive selection • genetic adaptation • Perlegen database • SNP • EHH test ABSTRACT
Phenotypic variation between human populations in skin pigmentation correlates with latitude at the continental level. A large number of hypotheses involving genetic adaptation have been proposed to explain human variation in skin colour, but only limited genetic evidence for positive selection has been presented. To shed light on the evolutionary genetic history of human variation in skin colour we inspected 118 genes associated with skin pigmentation in the Perlegen dataset, studying single nucleotide polymorphisms (SNPs), and analyzed 55 genes in detail. We identified eight genes that are associated with the melanin pathway (SLC45A2, OCA2, TYRP1, DCT, KITLG, EGFR, DRD2 and PPARD) and presented significant differences in genetic variation between Europeans, Africans and Asians. In six of these genes we detected, by means of the EHH test, variability patterns that are compatible with the hypothesis of local positive selection in Europeans (OCA2, TYRP1 and KITLG) and in Asians (OCA2, DCT, KITLG, EGFR and DRD2), whereas signals were scarce in Africans (DCT, EGFR and DRD2). Furthermore, a statistically significant correlation between genotypic variation in four pigmentation candidate genes and phenotypic variation of skin colour in 51 worldwide human populations was revealed. Overall, our data also suggest that light skin colour is the derived state and is of independent origin in Europeans and Asians, whereas dark skin color seems of unique origin, reflecting the ancestral state in humans.
quote: The genetic architecture of normal variation in human pigmentation: an evolutionary perspective and model
Skin pigmentation varies substantially across human populations in a manner largely coincident with ultraviolet radiation intensity. This observation suggests that natural selection in response to sunlight is a major force in accounting for pigmentation variability. We review recent progress in identifying the genes controlling this variation with a particular focus on the trait's evolutionary past and the potential role of testing for signatures of selection in aiding the discovery of functionally important genes. We have analyzed SNP data from the International HapMap project in 77 pigmentation candidate genes for such signatures. On the basis of these results and other similar work, we provide a tentative three-population model (West Africa, East Asia and North Europe) of the evolutionary–genetic architecture of human pigmentation. These results suggest a complex evolutionary history, with selection acting on different gene targets at different times and places in the human past. Some candidate genes may have been selected in the ancestral human population, others in the ‘out of Africa’ proto European-Asian population, whereas most appear to have selectively evolved solely in either Europeans or East Asians separately despite the pigmentation similarities between these two populations. Selection signatures can provide important clues to aid gene discovery. However, these should be viewed as complements, rather than replacements of, functional studies including linkage and association analyses, which can directly refine our understanding of the trait.
Posted by Boofer (Member # 15638) on :
quote:Originally posted by rasol:
quote:Rasol seemed to treat it like it DID negate back migration. My comment was sort of directed at that.
^ this is an example of a strawmen used to destract from an 'unpleasant' truth.
the study states that Africa is the *sole determinent* of diversity.
you try to run from this by introducing 'back migration' which by definition of what this study is saying -> is utterly irrelevant.
However you prove precisely why this factual study is necessary - to refute the bias, wishful thinking, and strawman arguments, such as proferred by you.
Ehh...ok. I admit to having a biased concept of "race." It isn't so much "wishful thinking" as it is my own logic. I guess, for the sole fact that I've witnessed features around me, I've associated certain ones with certain populations. "Wishful thinking" would imply that I really wished it were that way, but what would be the benefit of it being that way? What would be the benefit in an African American saying "certain populations look a certain way partially because of back migration?
Posted by Knowledgeiskey718 (Member # 15400) on :
quote:I guess, for the sole fact that I've witnessed features around me, I've associated certain ones with certain populations.
The simple notion that you continue to render certain features to be solely independent and specific to populations shows your limited understanding of what is discussed. Only thing unique to Europeans and East Asians is pale skin(besides albinos). Be specific in what features you mean.
Which is why you were asked to post/provide clear pictures/examples of individuals that you deem to look non African. Too much to ask??
Posted by Boofer (Member # 15638) on :
quote:Originally posted by Knowledgeiskey718:
quote:I guess, for the sole fact that I've witnessed features around me, I've associated certain ones with certain populations.
Which is why you were asked to post/provide clear pictures/examples of individuals that you deem to look non African. Too much to ask??
Well, to be honest, it would be foolish to say anyone from africa looks "non-African", but I could have pointed out those who, to my perception, look to have a Eurasian element. Notice I said "could have" since the more I read and the more people I see, the more the African and Non-African line becomes blurred. It would have been a person who looks like:
egyptian man
eritrean woman
eritrean kids
Again, I'm not so adament about my previous argument, but speaking from my own experience, and my own perception of "race" such people either look like "middle eastern peoples" or something like a "mulatto." Neither of which are terms that I like using, but phenotypically this is how I would mentally see them.
Posted by Knowledgeiskey718 (Member # 15400) on :
^^^^^This is a crucial situation and viewpoint to justify for you, since one can not always correlate genotype with phenotype. Would you be willing to establish as you stated the extreme features in these individuals that render them to look phenotypically non African influenced? It would be greatly appreciated.
One thing you have to understand is the near East was influenced not only linguistically but genotypically as well, from Africa, recently post OOA(Out Of Africa), so in a sense some features you might render as non African(since you're not familiar with the diversity of Africa) are actually due to African admixture in these near Easterners.
Posted by Boofer (Member # 15638) on :
quote:Originally posted by Knowledgeiskey718: The simple notion that you continue to render certain features to be solely independent and specific to populations shows your limited understanding of what is discussed. Only thing unique to Europeans and East Asians is pale skin(besides albinos). Be specific in what features you mean.
Honestly, it is not any one feature that I see as "specific to populations". It's a couple of co-existing features that have a tendancy, but I understand this is my way of trying to understand populations and "races." It is not accurate.
In the case of Africans, in acknowledgement of incredible diversity, I would not say that an african with a thin nose or lips or epicanthal folds had a non-african element, under certain conditions.
1. If they were not incredibly light skinned by my standards. 2. If the hair was not nearly straight. 3. If they were "far" from so called Non Sub-African populations, including North Africa
This is how I would have judged africans without stereotypically african features to determine whether there was a non Sub-saharan influence. I now know that this is pretty ridiculous, and it was not so imo until I physically typed my criteria. How's that for admitting to ignorance, inspite of reading to the contrary.? Perhaps the thing that made such thinking hard to abandon, particularly with criteria number 3 was the mtdna map of africa.
Posted by The Explorer (Member # 14778) on :
quote:Originally posted by Boofer:
What would be the benefit in an African American saying "certain populations look a certain way partially because of back migration?
Good question; why would intra-population phenotypic diversity being greatest in Africa vs. elsewhere bother an African American as it does you?
quote:Boofer:
until I physically typed my criteria. How's that for admitting to ignorance, inspite of reading to the contrary.?
Hence, why the study was necessary, and addresses your initial reaction to it.
Ps - picture spamming is irrelevant to theme of the study.
Posted by lamin (Member # 5777) on :
Knowledgeiskey718,
Problem:
You say that the "pale phenotype" of Europeans and North East Asians derives from a recent mutation[actually it's 2 separate mutations].
So maybe you can explain why we have seemingly different allelic expressions of such? Southern Europeans and South East Asians are more pigmented than their more northerly neighbours--as if along some kind of gradient. The question is what is the basis for these mutations having such gradient-like allelic expressions? Example: A Cambodian or Thai is easily spotted in Beijing or Tokyo.
This goes back to my point, which is that mutations occur but it's rarely that you see sudden qualitative jumps from one phenotype to another. Which suggests that there are 2 ways intermediary phenotypes are expressed: one way is hybridity, another way is natural gradient change.
Example: many North Africans look like the offspring of Europeans and Africans but that does not mean that North Africans who have such phenotypes have resulted from some kind of back-migration of such types into Africa. It could just be a natural allelic variation of a particular mutation.
Point: to get to the desert from the forest you must pass through woods, savanah, then scrubland.
Puzzle: the pigmentation of many Africans, as in the case of the San, approximates that of Southern Europeans or South East Asian types.
Posted by rasol (Member # 4592) on :
quote:Point: to get to the desert from the forest you must pass through woods, savanah, then scrubland.
^ It's true that to get from black to white you must past thru intermediate skin colors.
Actually the race paradigm holds that 'black' and 'white' are distinct sub-species - with no intrinsic relation to each other.
Anything that is not 'black' or 'white' would then be the result of mycengenation of the two.
This is incorrect.
What is correct:
- Original populations were melanoderms of Africa.
- Variations in dark skin tone is native to Africa with equatorial populations being darker, and southern temperate zone populations being lighter.
- This native potential for variation in skin color is the basis [root] of the variations that exist today all over the world.
- Original non African popoulations were melanoderms - descendant from equatorial east Africans.
- There skin color genotype and phenotype is best represented today by Melanesians, Oceanics, and Australians, as well as some South Asian and Polynesian populations.
- Northern Eurasians have experienced at least two independant instances of depigmentation - European and NorthEast Asian.
- Populations with with more intermediate skin colors - such as found in much of East Asia and parts of Southern Africa are not the product of myscegenation of 'black' and 'white'.
- Whites - ie leucoderms have provably limited genetic range and phenetic influence - primary restricted to influencing SouthWest Asia and parts of modern North Africa.
- It's unclear what influence they have had in India, and doubtful that they have ever had much influence in tropical Africa, East Asia, or Australia.
Posted by Doug M (Member # 7650) on :
quote:Originally posted by The Explorer: Doug, you know as a matter of fact, yes; one thing baffles me: the limitlessness of your stupidity.
Let's test who "lack of reading" makes a better fit...
You were supposedly attempting to correct someone else's short-sightedness by emphasizing "north Africa" even though the study deals with "all of Africa", only to replace it with your own:
If the study was focusing on "central and east Africa" as you say, how was that done so, vs. the rest of Africa?
Yes, your "finding specific patterns of diversity in central and southern Africa" would be a contradiction to your earlier "*specifically* central and eastern Africa" in two respects:
1)it doesn't say that the study is "specifically" about "central and southern Africa".
2)"central and southern Africa" is not the same as "central and east Africa".
And third, you read the abstract wrong; it makes reference to "central/southern Africa". "/" sign is not "and" in English grammar.
The point is you simply cannot read and are determined to use lack of reading comprehension as the reason exercise contradictions IN YOUR HEAD.
What I said:
quote: And it is not about Northern Africa it is about ALL of Africa and specifically places South of the Sahara like CENTRAL and EAST Africa. The GREATEST amount of diversity is found among the populations in this region and it is NOT simply those in East Africa, it is a reference to a BROAD RANGE of people from across Central Africa.
You just can't read. The only thing it says is that there is a broad range of diverse features among people all across central Africa. It means that you cannot stereotype East Africa as an isolated example of African diversity. It means that Africans all across Africa are diverse, but those in Central Africa, from East to West are more diverse and of course so are those to the South. But for some reason you cannot comprehend this.
Posted by Doug M (Member # 7650) on :
quote:Originally posted by Boofer:
quote:Originally posted by Knowledgeiskey718:
quote:I guess, for the sole fact that I've witnessed features around me, I've associated certain ones with certain populations.
Which is why you were asked to post/provide clear pictures/examples of individuals that you deem to look non African. Too much to ask??
Well, to be honest, it would be foolish to say anyone from africa looks "non-African", but I could have pointed out those who, to my perception, look to have a Eurasian element. Notice I said "could have" since the more I read and the more people I see, the more the African and Non-African line becomes blurred. It would have been a person who looks like:
egyptian man
eritrean woman
eritrean kids
Again, I'm not so adament about my previous argument, but speaking from my own experience, and my own perception of "race" such people either look like "middle eastern peoples" or something like a "mulatto." Neither of which are terms that I like using, but phenotypically this is how I would mentally see them.
And my point is that how common are the features of that woman in Eritrea, versus how common are the features of that male gentleman in Egypt? One or two pictures out of context do not mean anything. To study diversity one must have a LARGE SAMPLE of data in order to NOT BE BIASED.
YOU on the other hand take ONE example of the features in Eritrea and extrapolate that to mean that ALL Eritreans look like this and that ALL Eritreans are therefore mixed Eurasians. That is simply a DUMB STATEMENT. It is like taking a picutre of an Asian American and saying ALL AMERICANS are therefore mixed with Asians. YOU know this and this is why you keep repeating such nonsense. The point is that YOU have no idea what on earth you are talking about and are using HAND PICKED examples of possible Eurasian admixture to try and extrapolate WITHOUT EVIDENCE to support it. As I said, ONE or SOME Asian Americans in America does NOT make ALL Americans mixed with Asians. NO sort of population study EVER pretends that there aren't mixtures of various groups in one population to the next. What populations studies are looking for are patterns and percentages. The percentages of East Africans that are the result of mixing with Eurasians is relatively SMALL versus East Africans whose features are the result of INDIGENOUS African diversity.
The question is what do MOST Eritreans look like and what features do they have. MOST Eritreans are NOT mixed with Eurasians. Sure SOME of them may be, but that is NOT the basis of African diversity in features.
What about this Eritrean woman:
And the simple point is that people like these are where the Eurasians got their features from. The ONLY feature that Eurasians can give to Africans is light skin. Almost ALL OTHER features are indigenous to Africa.
Posted by The Explorer (Member # 14778) on :
While you're obviously bent on suckering me into your infantile Micky Mouse games, as a means to avoid requests, I only have time for this:
Let's test your reading skills further, with this first...
What in the study says that "Central Africa and East Africa" [which you noticeably now changed to "Central Africa, from East to West"] is the most diverse in Africa?
Posted by Doug M (Member # 7650) on :
quote:Originally posted by The Explorer: While you're obviously bent on suckering me into your infantile Micky Mouse games, as a means to avoid requests, I only have time for this:
Let's test your reading skills further, with this first...
What in the study says that "Central Africa and East Africa" [which you noticeably now changed to "Central Africa, from East to West"] is the most diverse in Africa?
Dude. The only one playing mickey mouse games is you. I am not going to teach you how to read. So don't ask me.
Posted by The Explorer (Member # 14778) on :
Not sure what lamin's comments on pigmentation has to do with the study's theme about the observed loss of intra-population cranio-metric diversity [and genetic diversity] in humans with augmentation of distance away from sub-Saharan Africa, but maybe he'll explain.
Posted by The Explorer (Member # 14778) on :
I ask this "know nothing about Africa but likes to talk about Africans" cry baby:
Let's test your reading skills further, with this first...
What in the study says that "Central Africa and East Africa" [which you noticeably now changed to "Central Africa, from East to West"] is the most diverse in Africa?
And his/her answer: I am not going to teach you how to read. So don't ask me.
Translation: I didn't read it anywhere.
"F minus" grade - you fail! Hence, answering my question, in that you are indeed a reading-challenged keyboard whiner.
Posted by Doug M (Member # 7650) on :
All of it is diverse, with places LIKE Central being the most diverse. But that is not saying any one PART of central Africa is the most diverse. It only says that relative to ALL of Africa places like Central Africa are the most diverse. That is also what the study says.
That is the point.
You can't read.
Posted by The Explorer (Member # 14778) on :
Why don't you go spam other threads with your usual "know nothing about Africans but obsessed with the dumb African" cry baby rants, since you are obviously intellectually useless to the topic here?
Posted by The Explorer (Member # 14778) on :
Punching more holes into the keyboard cry baby's "theory" as a self-proclaimed capable reader...
What in the study says that "Central Africa and East Africa" [which you noticeably now changed to "Central Africa, from East to West"] is the most diverse in Africa?
Why did you feel the need to separate East Africa in the former above, before you were forced to modify it to the latter?
Posted by Alive-(What Box) (Member # 10819) on :
quote:Originally posted by rasol:
quote:Rasol seemed to treat it like it DID negate back migration. My comment was sort of directed at that.
^ this is an example of a strawmen used to destract from an 'unpleasant' truth.
the study states that Africa is the *sole determinent* of diversity.
you try to run from this by introducing 'back migration' which by definition of what this study is saying -> is utterly irrelevant.
However you prove precisely why this factual study is necessary - to refute the bias, wishful thinking, and strawman arguments, such as proferred by you.
^Amen.
Posted by akoben (Member # 15244) on :
quote:Why don't you go spam other threads with your usual "know nothing about Africans but obsessed with the dumb African" cry baby rants, since you are obviously intellectually useless to the topic here?
Wow, Ausarianstein this takes me back when I was chasing your dumb ass here.
lol
Posted by Knowledgeiskey718 (Member # 15400) on :
quote:Posted by Lamin: So maybe you can explain why we have seemingly different allelic expressions of such? Southern Europeans and South East Asians are more pigmented than their more northerly neighbours--as if along some kind of gradient.
Damn kid you're a genius..........
Read again
quote:Originally Posted by Knowledgeiskey: Allow me to explain this is "laymen" terms. You're clearly speaking upon the pale phenotype of East Asians and Europeans (since you should already know cranio-facially/phenotypically speaking, Africa pretty much covers the world, I won't go into details on that) . This evolution/mutation is a recent adaptation, considering an evolutionary time line. This occurred due to the fact when humans move into northern latitudes need to be lighter skinned in order to allow UV in to produce Vitamin D(since dark skin was evolved to protect from harmful UV, therefore it prevents from absorbing UV to produce Vitamin D).
Early humans as well as early Europeans were hunter gatherers, in a hunter gatherers diet you will find food which contains adequate amounts of Vitamin D, through fish, meats, egg yolks etc... Absorbing enough of this Vitamin D will provide humans with enough Vitamin D to keep their skin dark with no need to be pale, since their receiving the Vitamin D through their diets. A clear example of a human population which consumes adequate amounts of vitamin d and retains melanin, are Eskimos. If you do some research you will notice that an Eskimos diet consists of rich amounts of Vitamin D, and if they would stop eating this diet, Eskimos would develop Vitamin D deficiencies, which surface as rickets, the reason for this is as explained, when humans move to northern latitudes/lower uv environments they aren't receiving as much sun(obviously) and since dark skin protects from harmful UV rays, it blocks out the ability to produce synthesize UV. The sun is one main source of Vitamin D along with diet. So in northern latitudes under a farmers diet(which doesn't provide an individual with adequate amounts of Vitamin D as a hunter gatherers diet would) humans would have to be lighter skinned, as explained, to allow the synthesis of UV for the production of Vitamin D, since dark skin blocks out the sun
Therefore, as explained light skin was evolved to allow the synthesis of Uv for the production of Vitamin d, but remember early Europeans were hunter gatherers, just as Eskimos are/were, so early Europeans retained their melanin levels as well, until agriculture spread. But agriculture /farming didn't spread into Europe until about 8kya with the Neolitic revolution. This new way of living decreased Europeans intake of vitamin D, since a farmers diet is not full with the adequate amounts of Vitamin D that a hunter gatherers fisher/herders diet consists of.
Therefore during this era, Europeans and East Asians evolved pale skin to allow UV in to produce Vitamin D through synthesis.
Posted by The Explorer (Member # 14778) on :
In a related study conducted in 2007, the authors provide a map [see fig 2a; The Effects of ancient population bottlenecks on human phenotypic diversity] which details the "likely location for a single origin of craniometric phenotype assessed from concentration of diversity, and on it, that location was somewhere in what was enclosed in a light-shaded area demarcated by a dark blue line, almost akin to the above example about possible "point of origin of OOA migration". This enclosed area in fact extended as far as the Ivory Coast area in west Africa, proceeding to the central Africa, southeastern Africa through to southern Africa area. Interestingly, east Africa to as far as the African Horn was left outside of this loop, wherein it appears only Somalia area was sampled. For the genetic data though, attained from "neutral" atDNA markers, the map approximates that of the craniometric counterpart, but this time interestingly leaving southern Africa outside of the loop whilst including a portion of the African Horn.
Posted by The Explorer (Member # 14778) on :
AssOpen, do me a favor: take a hike, or better yet, take your voided skull to the now high-jacked Charlie Bass thread and continue spamming, opening your ass and whatever else it is that you do there.
Posted by Doug M (Member # 7650) on :
quote:Originally posted by The Explorer: Punching more holes into the keyboard cry baby's "theory" as a self-proclaimed capable reader...
What in the study says that "Central Africa and East Africa" [which you noticeably now changed to "Central Africa, from East to West"] is the most diverse in Africa?
Why did you feel the need to separate East Africa in the former above, before you were forced to modify it to the latter?
No what I said was you can't read. And you don't understand geography.
If you did you wouldn't be spamming your own thread with nonsense.
Period.
Posted by The Explorer (Member # 14778) on :
keyboard cry baby, it looks like you love citing people drilling you with simple questions that you're too intellectually under-equipped to answer. You've probably never heard the word before or understood it, but such complete off-tangent panicky reaction to kindergarten level questions is called a "non-sequitur". So, why bother citing these simple questions?
Posted by akoben (Member # 15244) on :
^ simple questions like those pertaining to Dawidowicz, Hilberg and Graf? lol
Posted by argyle104 (Member # 14634) on :
Interesting how the keyboard faux scholars only believe that Africans are diverse when it comes to mounting a desperate defense of the "Ancient Egyptians" be black or when someone claims that Ethiopians (Absynnia) are mixed.
The faux scholars attempt to have it both ways and therefore give the eurocentrics the proof they need to claim Ancient Egypt.
Afterall if the rest of Africans are mixed then why wouldn't Ethiopia and Ancient Egypt?
The faux scholars and their minimal intellect with its dependence on whites to do their research and science for them are just as destructive to Africa as the whites who control them.
Posted by rasol (Member # 4592) on :
quote:Originally posted by The Explorer:
Pretty self-explanatory.
quote:gArgoyal writes: Interesting how the keyboard faux scholars only believe that Africans are diverse when it comes to mounting a desperate defense of the "Ancient Egyptians"
^ Interesting how you make strawman arguments, when you don't like the facts.
Actually it's not really interesting.
It's predictable and boring.
Address this..... We show that distance from sub-Saharan Africa is the sole determinant of human within-population phenotypic diversity, while climate plays no role.
No?
Why? Because you can't?
Then you're a weak troll trying to change the subject as beaten losers always do.
Posted by argyle104 (Member # 14634) on :
Doug M wrote:
quote: The ONLY feature that Eurasians can give to Africans is light skin.
Define "light skin".
and then
Inform us of why:
1. Africans can't have this so called "light skin".
and
2. That the so called "light skin" Africans have it because of eurasians.
Posted by argyle104 (Member # 14634) on :
Obviously this rasol was hit hard by my post that noticed how he and the rest of his fake scholars only defend or say anything positive about Africa if it involves anjuct ejupt.
He knows that his views that outside of Ancient Egypt he believes that Africa has or has achieved nothing.
Now he's kicking and screaming in dismay at my exposure of him. Too bad.
Posted by argyle104 (Member # 14634) on :
Boofer wrote: ------------------------------------ Again, I'm not so adament about my previous argument, but speaking from my own experience, and my own perception of "race" such people either look like "middle eastern peoples" or something like a "mulatto." Neither of which are terms that I like using, but phenotypically this is how I would mentally see them. ------------------------------------
Once again by your own statements, you are merely an intellectual unscholarly backwater who can't handle facts or evidence.
You instead need fantasy and delusions because that is what your tiny mind runs on.
Also since east africans are supposedly mixed with arabs and look like arabs you should have no problem of showing us actual examples of your belief.
We're waiting.
Posted by lamin (Member # 5777) on :
quote:Not sure what lamin's comments on pigmentation has to do with the study's theme about the observed loss of intra-population cranio-metric diversity [and genetic diversity] in humans with augmentation of distance away from sub-Saharan Africa, but maybe he'll explain. --------------------------------------------------------------------------------
I mentioned pigmentation only because it is not significant than other traits in genetic analysis.
But again the analysis in the paper is suspect for the following reasons:
1) Craniometric analysis has had a long history--if only because it just involves measuring crania.
Now according to past studies it was found that the crania of Europeans fell into 3 categories: i)doliocephalic, ii)mesocephalic and iii) brachycephalic.
Nordics were measured as doliocephalic while Central Europeans were measured as mesocephlaic. East Europeans were measured as brachycephalic.
Now here's the rub: Africans in general were measured as primarily doliocephalic while East Asians were measured as brachycephalic. So obviously the diversity increased the further away from Africa one travelled with regard to Europe.
The explanation for the mesocephalic European crania was that the the bearers of such crania were hypbrids of northward migrating Africaoids and westward migrating Eastern Asiatics. The Nordics were supposed to have been too far north to be affected by such hybridisations.
Be that as it may, consider the following hypothesis: Think of Africa as the bicycle wheel with the myriad spokes representing migrations in all directions away from the East African human origins centre. Now if you take each spoke or a cluster of spokes as representing particular lineages then obviously you will have less diversity in any particluar limited area--as Europe proper, which is quite small in area[less than area of the Congo] compared to all of Africa.
The serious error made by Euro anthropologists is that they lump all of the African lineages together--hence you will get greater diversity while they become more specific for the separate areas outside of Africa.
Thus we end up under the illusion that "there is decreasing craniometric variation the further away from Africa one travels". But the same could be said for Africa too--the more one moves away from the central East African origin node.
Posted by The Explorer (Member # 14778) on :
lamin,
Saying that cranio-metric analysis has been around for long does not in any way discredit the study in question.
No, the study at hand does NOT just involve cranio-metric analysis as you say, it also involved DNA analysis.
Your caricatures about cranial indices are not only immaterial to said study, but also lack specificity of independent corroborative source. In fact they directly contrast the point relayed, with regards to African intra-population diversity being greater than that seen elsewhere.
Genetic diversity has nothing to do with the space of geography. It has to do with the simple fact that non-Africans derive from only a fraction of Africans, and hence, the loss of diversity that comes with that.
Losses in intra-population diversity [as observed in said study] with accruement of distance away from sub-Saharan Africa is very likely the effect of further offshoots from OOA migrants and subsequent dispersals, and hence, bottlenecks that generally characterize such events.
Sorting out intra-population diversity requires precisely the opposite of "lumping" specimens together. Pooling specimens together generally has the effect of *obscuring* intra-specimen variation.
Queries for clarification:
Explain how the findings of the said study about loss of intra-population craniometric and genetic diversity with accruement of distance away from sub-Saharan Africa is an "illusion" and not a tangible phenomenon.
Given the maps posted above and as noted, in a related study conducted in 2007, the authors provide a map [see fig 2a; The Effects of ancient population bottlenecks on human phenotypic diversity] which details the "likely location for a single origin" enclosed in an un-shaded area that spans west Africa to as far as Ivory Coast, central Africa, south-eastern Africa and southern Africa area, where is it stated in the study, that "central East Africa" is the origin node?
Posted by The Explorer (Member # 14778) on :
quote:Originally posted by lamin:
I mentioned pigmentation only because it is not significant than other traits in genetic analysis.
How does skin color change the patterns observed in intra-population diversity?
Posted by Clyde Winters (Member # 10129) on :
quote:Originally posted by lamin:
quote:Not sure what lamin's comments on pigmentation has to do with the study's theme about the observed loss of intra-population cranio-metric diversity [and genetic diversity] in humans with augmentation of distance away from sub-Saharan Africa, but maybe he'll explain. --------------------------------------------------------------------------------
I mentioned pigmentation only because it is not significant than other traits in genetic analysis.
But again the analysis in the paper is suspect for the following reasons:
1) Craniometric analysis has had a long history--if only because it just involves measuring crania.
Now according to past studies it was found that the crania of Europeans fell into 3 categories: i)doliocephalic, ii)mesocephalic and iii) brachycephalic.
Nordics were measured as doliocephalic while Central Europeans were measured as mesocephlaic. East Europeans were measured as brachycephalic.
Now here's the rub: Africans in general were measured as primarily doliocephalic while East Asians were measured as brachycephalic. So obviously the diversity increased the further away from Africa one travelled with regard to Europe.
The explanation for the mesocephalic European crania was that the the bearers of such crania were hypbrids of northward migrating Africaoids and westward migrating Eastern Asiatics. The Nordics were supposed to have been too far north to be affected by such hybridisations.
Be that as it may, consider the following hypothesis: Think of Africa as the bicycle wheel with the myriad spokes representing migrations in all directions away from the East African human origins centre. Now if you take each spoke or a cluster of spokes as representing particular lineages then obviously you will have less diversity in any particluar limited area--as Europe proper, which is quite small in area[less than area of the Congo] compared to all of Africa.
The serious error made by Euro anthropologists is that they lump all of the African lineages together--hence you will get greater diversity while they become more specific for the separate areas outside of Africa.
Thus we end up under the illusion that "there is decreasing craniometric variation the further away from Africa one travels". But the same could be said for Africa too--the more one moves away from the central East African origin node.
I agree with you lamin. Can anyone post the entire study so we can really see what it contains. An abstract can not really give us a full discussion of the material printed in the article. This is due to the fact that diversity in craniometrics in Africa has always been the case .
quote:Originally posted by Clyde Winters: Can anyone post the entire study so we can really see what it contains. An abstract can not really give us a full discussion of the material printed in the article. This is due to the fact that diversity in craniometrics in Africa has always been the case .
.
Posted by xyyman (Member # 13597) on :
Another try as a jpeg. Got to find a pdf hosting site . . .that works.
more data to come
quote:Originally posted by xyyman: Hope this works:
quote:Originally posted by Clyde Winters: Can anyone post the entire study so we can really see what it contains. An abstract can not really give us a full discussion of the material printed in the article. This is due to the fact that diversity in craniometrics in Africa has always been the case .
.
Posted by xyyman (Member # 13597) on :
more data to come
Posted by xyyman (Member # 13597) on :
and yet more data:
Posted by lamin (Member # 5777) on :
The researchers' choice of skulls no more than 2,000 years old would tend to bias results it seems. There have been many population movements in the world from at least 2,000 YA. East-West and North-South movements on the Eurasian landmass are very obvious cases. Europe's perpetual wars and invasions in the last 2,000 years no doubt would not help the researchers hypothesis. After all, as I mentioned, the craniometric data from Europe shows heterogeneous results from region to region--using the old model of doliocephalic, mesocephalic, brachycephalic.
In sum, the paper yields a mixed bag of results--nothing definite. Though it is noted that the mutiregional hypothesis is mentioned--despite its lack of substance.
Posted by rasol (Member # 4592) on :
quote:In sum, the paper yields a mixed bag of results--nothing definite.
How so?
quote:The researchers' choice of skulls no more than 2,000 years old would tend to bias results it seems
Why?
quote:. Europe's perpetual wars and invasions in the last 2,000 years no doubt would not help the researchers hypothis
Why? All regions have -perpetual wars- that doesn't explain the results.
quote:After all, as I mentioned, the craniometric data from Europe shows heterogeneous results from region to region--using the old model of doliocephalic, mesocephalic, brachycephalic
What study can you reference?
What study can refute the results of this one?
quote:mentioned--despite its lack of substance.
Your post consists of ad hoc conclusions - backed by nothing.
Where is the substance behind your claims?
Posted by xyyman (Member # 13597) on :
Beat me to it. Not sure what Lamin is saying. How about some deeeep analysis Lamin? If you are not sure what to make of it. Take your time and read it several times.. . . then respond.
Posted by The Explorer (Member # 14778) on :
lamin,
Your reckoning that population movements in the last 2,000 years is supposed to be cause for biased results has no merit. Whom is it supposed to be biased against and vice versa? And why?
The authors could well have taken crania from 10,000 years ago, it won't make it any less bias, because populations from that time frame too would have been in movement. Name a time frame when population movements had not occurred, whether within or outside of the African continent, and give me the statistics on the sample size of specimens from that era.
Repeating some *immaterial* claim [which has already been called out above at any rate, with no forthcoming answers from you in sight] about cranial indices, supposedly to point out diversity in Europe, serves what purpose?
Lay out this "mixed bag of results" that you talk of, when in fact the authors have provided us with a *definite result*, which is:
Greatest intra-population diversity in sub-Saharan Africa vs. that elsewhere, and that it [intra-population] decreases with distance incrementation away from sub-Saharan Africa. This parallels what they observed from DNA analysis!
Clyde,
If you agree with lamin and not merely a cheerleader, then perhaps you should answer the questions and issues he left unanswered...which is virtually *all* of the ones I directed at him.
xyyman,
The study you posted is a related one from 2007 by the very same authors, on essentially the same subject matter; however, the abstract in the head post of this thread is from December 3rd 2008!
Posted by lamin (Member # 5777) on :
What is the title of the paper:
The title is "The effect of ancient population bottlenecks on human phenotypic variations.
So if ancient bottlenecks why limit the study to crania no more than 2,000 years old? We know that in the last 2,000 years worldwide there have been significant population movements which would mean some amount of transpopulation genetic exchange. Think of Genghis Khan and his cohorts expanding into Europe proper all the way from Central Asia. Think too of the Northern European barbarians invading Rome and elswhere in Europe. The European crusades into West Asia, the Turkish invasions into North Africa and Europe all led to new population transfers and genetic exchange, etc.
The Multiregional hypothesis pushed by researchers like Wolpoff et al.[1992] and others is based mainly on physical anthropological data rather than DNA analysis. It has very few adherents these days--except those who want to establish great genetic distance between the so-called races.
Note that the authors of the paper speak of ancient bottlenecks which would mean populations that have bootlenecked off a parent population and have multiplied mainly among themselves in relative isolation.
I stated that the hypothesis of the paper would be at variance with this because in the last 2,000 years--on account of wars and invasions--across the Eurasian plains and along the north-south latutudes of Europe and elsewhere, old bootlenecked populations would have experienced much commingling with other populations.
Note too that blog exchanges such as those ES, etc. only require the quick exchange of ideas without the citing of references--which would be more appropriate for specialist academic blog sites. Which is not to deny that references are sometimes useful when there is some clear point of dispute.
It looks like the title of the article does not reflect its contents.
Posted by lamin (Member # 5777) on :
Explorer,
I looked at the papers numbers and they do not demsonstrate any significant support its claims. What the authors fail to recognise in their appeal to a vast area such as so-called "sub-Saharan" Africa is that the distance from the Cape of Good Hope to Mali in West Africa is greater than the distance from Mali to Italy. The distance from Senegal to Mombassa is greater than the distance from Sudan to Turkey.
So what is the point of using "sub-Saharan" Africa as a nodal point of departure for the analysis.
Surely, there must have been "ancient bottlenecks" formed in so-called "sub-Saharan Africa".
Posted by lamin (Member # 5777) on :
Explorer,
Population movements have been more pronounced in the last 2,000 years than previously because of more efficient means of transportation and greater increases in population worldwide.
Posted by The Explorer (Member # 14778) on :
That's not the paper in question, but yes, it is related.
Why in the last 2,000 years? Because 1)as they point out, "deterioration might lead to biased estimates of phenotypic variability", and 2) they are able to get far larger sampling in this time frame [and in relatively more fitting condition] than those prior.
The existing intra-population diversity of the "founding" group of any given descendent population is going to have an impact on the intra-population variability of that population. It is in that respect, that ancient bottlenecks influence existing intra-population diversity.
As for the "population movements", please address what I said to you and asked of you thereof.
Posted by The Explorer (Member # 14778) on :
quote:Originally posted by lamin: Explorer,
I looked at the papers numbers and they do not demsonstrate any significant support its claims.
Which claims, and why not?
quote:lamin:
What the authors fail to recognise in their appeal to a vast area such as so-called "sub-Saharan" Africa is that the distance from the Cape of Good Hope to Mali in West Africa is greater than the distance from Mali to Italy. The distance from Senegal to Mombassa is greater than the distance from Sudan to Turkey.
Okay, and how does that make their observations concerning intra-population diversity wrong?
quote:lamin:
So what is the point of using "sub-Saharan" Africa as a nodal point of departure for the analysis.
They didn't use it as a nodal point; the results suggest that it is so. So, they'd repeated the tests assuming origins outside of Africa, and the results failed to support that assumption. These results again, paralleled the genetic data.
quote: Surely, there must have been "ancient bottlenecks" formed in so-called "sub-Saharan Africa".
Of course, but since OOA came from only a subset of Africans, regardless of whether these bottlenecks occurred in sub-Saharan Africa, the OOA migrants diversity vs. that of Africans would have been reduced. What about this simple mathematical concept, do you find difficult?
quote:Originally posted by lamin: Explorer,
Population movements have been more pronounced in the last 2,000 years than previously because of more efficient means of transportation and greater increases in population worldwide.
So what? See my last post on this issue, and please address it.
Posted by Knowledgeiskey718 (Member # 15400) on :
quote:Note that the authors of the paper speak of ancient bottlenecks which would mean populations that have bootlenecked off a parent population and have multiplied mainly among themselves in relative isolation.
In reference to OOA migrants(non-Africans) in question, who are descended from a small subset of East Africans in the first place so a bottleneck would decrease this small subsets genetic and phenotypic diversity each time even more every time it occurs. One of the reasons for a loss in phenotypic diversity in non-African populations is due to these ancient bottlenecks(decreased size in population), which repeated itself, and should be pretty much self explanatory.
quote: Population movements have been more pronounced in the last 2,000 years than previously because of more efficient means of transportation and greater increases in population worldwide.
And? Do you understand genetics? Do you understand that geneticists are able to tell if a population has received admixture due to population migrations?
What are you saying, are you trying to imply the study put a European as an Australian aborigine, since Europeans are now in Australia? Or are you implying that everyone in this world is mixed between populations to where there are no actual aboriginal representatives of said geographical areas tested in the study, and that this would render the results false?
quote:So what is the point of using "sub-Saharan" Africa as a nodal point of departure for the analysis.
Are you sure you have an understanding of the OOA model? Your posts are suspect. Point is, regardless of where they start, their end results will always be the same. Why? Because again, **ALL** non Africans are descended from a subset of East Africans,
quote: Surely, there must have been "ancient bottlenecks" formed in so-called "sub-Saharan Africa".
Perhaps, but in Sub Saharan Africa where genetic diversity is extreme, a bottleneck in one population will not affect another population.
Ex: Even if an ancient African population was wiped out from an area in Africa, this would not have affected the rest of Africa, as Africa is extremely diverse genetically and has many different populations, and carry many different genetic lineages, while all being related. Whereas, as you already know, non Africans are descended from a **single** population from Africa, who migrated out, so a bottleneck, (decrease in population size), in that East African population who walked OOA, decreased that populations genetic and hence phenotypic diversity(not too many different phenotypes to contribute after a bottleneck), and especially if it repeats itself.
quote:The Cambridge researchers studied genetic diversity of human populations around the world and measurements of over 6,000 skulls from across the globe in academic collections. Their research knocks down one of the last arguments in favour of multiple origins. The new findings show that a loss in genetic diversity the further a population is from Africa is mirrored by a loss in variation in physical attributes.
Lead researcher, Dr Andrea Manica from the University's Department of Zoology, explained: "The origin of anatomically modern humans has been the focus of much heated debate. Our genetic research shows the further modern humans have migrated from Africa the more genetic diversity has been lost within a population.
"However, some have used skull data to argue that modern humans originated in multiple spots around the world. We have combined our genetic data with new measurements of a large sample of skulls to show definitively that modern humans originated from a single area in Sub-saharan Africa."
The research team found that genetic diversity decreased in populations the further away from Africa they were - a result of 'bottlenecks' or events that temporarily reduced populations during human migration.They then studied an exceptionally large sample of human skulls. Taking a set of measurements across all the skulls the team showed that not only was variation highest amongst the sample from south eastern Africa but that it did decrease at the same rate as the genetic data the further the skull was away from Africa.
To ensure the validity of their single origin evidence the researchers attempted to use their data to find non-African origins for modern humans. Research Dr Francois Balloux explains: "To test the alternative theory for the origin of modern humans we tried to find an additional, non-African origin. We found this just did not work. Our findings show that humans originated in a single area in Sub-Saharan Africa."
^^^Pretty self explanatory lamin
Posted by Clyde Winters (Member # 10129) on :
quote:Originally posted by lamin: Explorer,
Population movements have been more pronounced in the last 2,000 years than previously because of more efficient means of transportation and greater increases in population worldwide.
Not only have populations movements been pronounced over the past 2ky during this period we have seen that populations have become relatively stabalized in specific regions of the world.
The major problem with the study is that they use climate as a major variable that determines phenotypic diversity and claims that distance away from africa is a major variable. This is a problem because they make it appear that Africa has a single climate which is false.This suggest that climate may play an important role in phenotypic diversity even in Africa.
When we look at the Tables we notice that in the US phenotypic diversity ranges between .551-.819 a difference of .278. This is greater than the range of phenotypic diversity between Ivory Coast .875 and S Af 1.009 which is only .134. In India the phenotypic diversity ranges from .631-.909, the difference is .278. The statistics make it clear that there is greater diversity outside Africa than within Africa.
The data presented by the researchers does not match their claims. It is a beautiful paper with great graphics but says nothing that we didn't already know. It supports the same old model of the three races: Negroid, Caucasian and Mongoloid nothing more.
.
Posted by Knowledgeiskey718 (Member # 15400) on :
quote:Posted by special ed Clyde: The major problem with the study is that they use climate as a major variable that determines phenotypic diversity and claims that distance away from africa is a major variable. This is a problem because they make it appear that Africa has a single climate which is false.This suggest that climate may play an important role in phenotypic diversity even in Africa.
Clyde, sigh.... The major problem with you is you don't know how to read.
Distance from Africa, **not climate** , explains within-population phenotypic diversity
Gee Clyde, yet another one of those misread papers huh? Let's see if Clyde will admit he was wrong.
Posted by osirion (Member # 7644) on :
Its ridiculous. Climate and diet is a much better explanation, just look at the Negrito people.
Posted by Knowledgeiskey718 (Member # 15400) on :
quote:Originally posted by osirion: Its ridiculous. Climate and diet is a much better explanation, just look at the Negrito people.
Explanation for within-population phenotypic diversity? Seems you don't understand what this actually means.
quote:The research team found that genetic diversity decreased in populations the further away from Africa they were - a result of 'bottlenecks' or events that temporarily reduced populations during human migration. They then studied an exceptionally large sample of human skulls. Taking a set of measurements across all the skulls the team showed that not only was variation highest amongst the sample from south eastern Africa but that it did decrease at the same rate as the genetic data the further the skull was away from Africa.
Climate and diet explains loss of genetic and phenotypic diversity? Elaborate....
Posted by The Explorer (Member # 14778) on :
quote:Originally posted by Clyde Winters:
Not only have populations movements been pronounced over the past 2ky during this period we have seen that populations have become relatively stabalized in specific regions of the world.
Elaborate on this "stabilization"!
In the meantime...
In a related study from 2007, an entire copy of which xyyman posted here and which is *NOT* the one that's the actual subject of this thread, the authors used a statistical approach to assess the effect of the main climatic variables on intra-population cranio-metric variability, as well as identifying traits that produced the highest hereditary values. Why?
This allowed for 1)elimination of climatic effect on intra-population cranio-metric variability over time, while 2)emphasizing on the outgrowth of inherited intra-population variation from "ancient" bottlenecks.
And taken from said related study [published in 2007], the authors say:
Realistic geographic distances between locations were computed as the shortest route through landmass that avoid areas with a mean altitude over 2,000m and assuming the following land bridges; a single connection between Africa and Eurasia via a route through the Sinai to the Levant, the Bering Strait between Eurasia and the Americas, and connections between the Malaysian Peninsula to Melanesia and Oceania.
Why? Simple: for consideration in determining the most parsimonious centroid of likely geographical origins on the basis of greatest intra-population diversity. The probability of a subset of a population having reduced diversity from that of the superset population is high, and hence, serves as a major indicator for identifying the source set.
Cranial series of *aboriginal* populations in the major continents were primarily used, judging from the table; otherwise, relatively conservative inbreeding segments of populations whose ultimate *origins* are clear, were used for analysis.
To ensure all crania were physically fit for analysis, and alleviate bias from "deterioration", a decision was taken not to include those from over 2000 years old.
quote:
The major problem with the study is that they use climate as a major variable that determines phenotypic diversity and claims that distance away from africa is a major variable.
Why is considering climate as having some impact on cranio-morphology a problem?
Distance from Africa was considered a major variable, because only when the centriod of *likely origins* in Africa was used in a covariance assessment with intra-population phenotypic variability, were significant regression or statistics results attained, displaying a correlation between loss of diversity and incrementation of distance from the putative origin. Placing likely origin outside of the continent and thereby applying the intra-population phenotype/distance [geographic] covariance analytical approach didn't generate this result.
In the 2008 study, the authors demonstrated that distance from the putative African origin was the *sole* predictor of intra-population diversity indices, as opposed to climate!
quote: This is a problem because they make it appear that Africa has a single climate which is false.
This is incorrect even going by the 2007 study; the table clearly provides *variable* climatic factors for African data sets.
quote: This suggest that climate may play an important role in phenotypic diversity even in Africa.
Recap from above: In the 2008 study, the authors demonstrated that distance from the putative African origin was the *sole* predictor of intra-population diversity indices, as opposed to climate!
quote: When we look at the Tables we notice that in the US phenotypic diversity ranges between .551-.819 a difference of .278. This is greater than the range of phenotypic diversity between Ivory Coast .875 and S Af 1.009 which is only .134. In India the phenotypic diversity ranges from .631-.909, the difference is .278. The statistics make it clear that there is greater diversity outside Africa than within Africa.
Why are you substracting total within-population phenotypic diversity of 2 populations as supposed overall "phenotypic diversity" [as supposedly disproving greatest within-population diversity in sub-Saharan Africa]? That statistically makes no sense.
*Regression modeling*, particularly "robust regression" [effective in overcoming outliers], were used to graphically generate the pattern of intra-population diversity across *all* data sets, using geographic distance from a putative origin as a predictor. It is not a simple matter of subtracting the total within-population phenotypic diversity of 2 populations [while forgetting about the covariance factor of distance altogether] as you have done.
quote: It is a beautiful paper with great graphics but says nothing that we didn't already know.
The graphs therein are representations of *multivariate* distance-statistics and matrix models that are not affected by scaling units. Statistics and matrices are mathematical which requires one to *think* about what is being measured, and not there simply to appeal to the aesthetic tastes of the reader. The question is, do you understand these mathematical models. If so, what is wrong with their findings, and why?
quote: It supports the same old model of the three races: Negroid, Caucasian and Mongoloid nothing more.
How is distance from sub-Saharan Africa is the sole determinant of human within-population phenotypic diversity a model of "Negroid, Caucasian and Mongoloid" racialist dogma? Elaborate.
Posted by The Explorer (Member # 14778) on :
Likely origin of OOA expansion is estimated from the centroid of the vast unshaded-area with the greatest concentration of intra-population diversity.
Posted by xyyman (Member # 13597) on :
Here is another.
Posted by xyyman (Member # 13597) on :
the end from above:
Posted by The Explorer (Member # 14778) on :
^These last authors are not entirely accurate when they portray Manica et al.'s 2007 anaylsis as only taking into consideration a model that utilized correction for climate.
1) They in fact did *both* models that take the climatic factor into consideration, and one solely on distance as a predictor.
And to reiterate:
2) In the 2008 study, the authors demonstrated that distance from the putative African origin was the *sole* predictor of intra-population diversity indices, as opposed to climate!
However, they do essentially reach the same conclusions as Manica et al., even by their own admission.
Posted by lamin (Member # 5777) on :
What most readers above fail to understand is that 1) the idea of "Africa" is an arbitrary concept, and 2) while generally useful the OOA hypothesis is a bit misleading because it fails to point out that there were also migrations from the restricted East or Southern African node to ALL other parts of the landmass we call Africa.
The OOA hypothesis is useful-as I suggested--but there is a more than a hint of Eurocentrism with it.
This conceptual error would seem to bias the research of anthropologists. Example: If humans have lived on the landmass[a relatively very large area given that early human population was quite small] called Africa more than 3 times that have lived outside that landmass then the number of haplogroupings for Africa would be at least 3 times the number of ALL haplogroups found outside of Africa.
But that is not the case. This is puzzling given that Eurasia has produced more haplogroups than Africa--bearing in mind that haplogroup mutatations occur independently of other considerations.
Maybe a better diversity comaparison would be to actually pinpoint the population node from which all humans descended and compare that node with the rest of the world--which would be the other parts of Africa plus the rest of the world.
Posted by The Explorer (Member # 14778) on :
lamin, it seems to me that you merely make assumptions about the study and not actually bother reading what it says, even in the abstract.
If there is within-population phenotypic diversity in African populations, which has the tendency to decrease as one moves away from the centroid of locations of likely origins within Africa itself before continuing the pattern outside of the continent, what does this mean?
As for haplogroups, once again Africa has the greatest diversity, and it doesn't matter whether subclades here are 3 times the number of those found outside of the continent or not; dare I ask you why...
Posted by lamin (Member # 5777) on :
But again why assume conceptually that there's special about the huge landmass we now call Africa?
Africa has the greatest diversity because humans have there the longest in the history of humanity. But they did not live equal lengths of time in ALL its regions.
In fact, there are parts of Africa where humans have lived for 2K years, 5K years, 15K years, 30K, 80K, 100K years, etc.
Again, what is so special about the African landmass--except that in one very restricted area proto-humans attained the sapiens stage. It is just that one restricted area--not so-called SS-Africa--that must be compared with the rest of the world.
Note that I said that it is puzzling that there are many more haplogroup lineages outside of Africa than within that continent. One would have expected the opposite. I believe what I wrote was misread.
Posted by xyyman (Member # 13597) on :
This may be helpful Lamin. Note *****120 polymorphism****
Posted by The Explorer (Member # 14778) on :
lamin, you are talking past my posts directed at you, not addressing them. And so, what do we get: you repeating yourself unnecessarily, and questionably might I add.
Posted by Clyde Winters (Member # 10129) on :
The Explorer
quote:
Why are you substracting total within-population phenotypic diversity of 2 populations as supposed overall "phenotypic diversity" [as supposedly disproving greatest within-population diversity in sub-Saharan Africa]? That statistically makes no sense.
This was done because in the tables, population phenotypic diversity was identified by phenotype within countries e.g., U.S., India, Africa and etc. The research team supposedly found that diversity decreased in populations the further away from Africa .
By looking at the range of phenotypic variance within populations in each region :U.S., India and Africa, there should theoretically be less diversity within and between phenotypes in the various populations outside Africa, than within Africa. By looking at the range of phenotypes and substracting the least from the greatest average phenotype it is obvious that there is almost two times more diversity in populations outside Africa , then within Africa. This makes it clear that the researchers did not confirm their theory.
The Explorer
quote:
How is distance from sub-Saharan Africa is the sole determinant of human within-population phenotypic diversity a model of "Negroid, Caucasian and Mongoloid" racialist dogma? Elaborate.
This is evident in the fact that we see primarially an examination of Europeans in the Americas and Europe, vs. the so called mongoloids of Asia and negroes of Africa in the study. We also notice that these diverse populations (races) are situated in specific areas which have been long associated with the areas and regions inhabited by specific racial groups.
As a result, we see Europeans as the dominant group in Europe. Mongoloid people dominate Asia. The earliest skeletal remains from these areas were diverse and included mongoloid and negro types in place throughout China, for example, were as by 2kya the populations were more homogenous.
Also Explorer can you post the entire article?
Posted by The Explorer (Member # 14778) on :
quote:Originally posted by Clyde Winters:
This was done because in the tables, population phenotypic diversity was identified by phenotype within countries e.g., U.S., India, Africa and etc.
Don't know how noted fact of "within-population diversity" in the sampled regions in any way justifies your simple "arithmetic" subtraction of "within-population diversity" of [merely] 2 populations as supposed "overall" within-population phenotypic diversity measurements in entire continents, when the graphs that you are supposedly protesting use linear regression stastistics and matrix mathematical models to graph covariance results of distance on land and within-population phenotypic diversity across entire data sets from a putative centroid/origin.
quote: The research team supposedly found that diversity decreased in populations the further away from Africa .
Yes, by fitting either within-population phenotypic coefficient of variance for individual traits or mean standardized within-population phenotypic variance into regression models to produce graphs that reveal the pattern of variation *for all data sets*, when distance is used as the predictor; NOT using the simple arithmetic substraction model that you used [for *2* within-population phenotypic diversity values obtained over all measurements undertaken for distinct craniometric traits].
quote: By looking at the range of phenotypic variance within populations in each region :U.S., India and Africa, there should theoretically be less diversity within and between phenotypes in the various populations outside Africa, than within Africa.
And the graphs obtained by the method described by me above show precisely that.
quote: By looking at the range of phenotypes and substracting the least from the greatest average phenotype it is obvious that there is almost two times more diversity in populations outside Africa , then within Africa. This makes it clear that the researchers did not confirm their theory.
What is clear, is that you don't seem to understand how those graphs were generated, revealing the general direction of change in the pattern of within-population diversity in relation to change in distance, which you seem to think is a matter of simple arithmetic subtraction of [merely 2] mean standardized within-population values.
quote: The Explorer
quote:
How is distance from sub-Saharan Africa is the sole determinant of human within-population phenotypic diversity a model of "Negroid, Caucasian and Mongoloid" racialist dogma? Elaborate.
This is evident in the fact that we see primarially an examination of Europeans in the Americas and Europe, vs. the so called mongoloids of Asia and negroes of Africa in the study.
Where does it say that Europeans in the Americas were measured as opposed to other groups? Where does it say anything about just samping so-called Mongloids in Asia, and then plotting that in the sense of Europeans vs Mongoloids vs. Negroes of Africa?
Which group is supposed to be the beneficiary of this study, according to what citation, and how?
quote:
We also notice that these diverse populations (races) are situated in specific areas which have been long associated with the areas and regions inhabited by specific racial groups.
You've lost me totally on this one.
quote: As a result, we see Europeans as the dominant group in Europe. Mongoloid people dominate Asia. The earliest skeletal remains from these areas were diverse and included mongoloid and negro types in place throughout China, for example, were as by 2kya the populations were more homogenous.
You are able to discern mean standardized within-population variation of populations from scanty collections of 2, 3 or 4 or a few specimens found in different regions and dating back to the Upper Paleolithic?
And it doesn't matter what the original phenotypes of the ancestral populations were; the diversity therein would have had an impact on the development of diversity in the descendant population. A superset population is unlikely to ever be outnumbered in diversity by just a small subset of itself. This is just a simple matter of mathematical common sense.
quote: Also Explorer can you post the entire article?
I don't have the entire article for the 2008 study, but xyyman has already posted the entire article of a related one done by the very same authors in 2007. This 2008 publication builds on that 2007 publication.
Posted by Clyde Winters (Member # 10129) on :
quote:
What is clear, is that you don't seem to understand how those graphs were generated, revealing the general direction of change in the pattern of within-population diversity in relation to change in distance, which you seem to think is a matter of simple arithmetic subtraction of [merely 2] mean standardized within-population values.
I understand how the graphs are generated. I have used and taught SPSS for years.
The Explorer
quote:
And it doesn't matter what the original phenotypes of the ancestral populations were; the diversity therein would have had an impact on the development of diversity in the descendant population. A superset population is unlikely to ever be outnumbered in diversity by just a small subset of itself. This is just a simple matter of mathematical common sense.
Your reasoning is illogical. The entire paper is made up of subgroups. The authors make it clear that they are comparing the various phenotypes to the African population.
As a result, there is nothing wrong with comparing any group in the research study outside Africa, to the African phenotype. In critiquing any research paper the first thing you have to do is look at the math and determine if the reasercher confirmed what he was researching.
The problem with the study is that the authors make claims which are not supported by the evidence. If the theory was correct their would be less variance between populations further away from Africa, than within Africa as they hypothesize.
The Explorer
quote:
Where does it say that Europeans in the Americas were measured as opposed to other groups? Where does it say anything about just samping so-called Mongloids in Asia, and then plotting that in the sense of Europeans vs Mongoloids vs. Negroes of Africa?
This is clearly indicated when the populations in the Table are divided into groups based either on ethnic origin or location in a specific country.
quote:
And it doesn't matter what the original phenotypes of the ancestral populations were; the diversity therein would have had an impact on the development of diversity in the descendant population. A superset population is unlikely to ever be outnumbered in diversity by just a small subset of itself. This is just a simple matter of mathematical common sense.
It does matter. If you're talking about ancient populations and the population only dates back 2000 years ago the population probably has nothing to do with the ancient group.
.
Posted by lamin (Member # 5777) on :
Xyyman,
The Wikipedia post is probleamtic on the issue of its definition of "genetic distnace". Consider the Africans and Melanesians. Both groups share practically 100% of their surface phenotypes but in terms of overall genetic distance Melanesians and Africans they do not share haplogroup lineages.
For the sceptics: Assume the following: 1)that all the world's continents except the Americas were compressed into one large square. 2)The world's populations as we know them were exactly the same; and 3) the exact restricted location where Homo Sapiens arose some 160KYA.
Would the analytic jargon be the same in terms of "decreasing diversity" from the local node of human origin?
Posted by The Explorer (Member # 14778) on :
quote:Originally posted by Clyde Winters:
I understand how the graphs are generated. I have used and taught SPSS for years.
If you do, then why do calculate the supposed "overall" phenotypic variability across entire continents as [the simple arithmetic] difference between the coefficient of mean standardized within-phenotypic variation of 2 populations? This stands in contrast to the method used by the study in question, to generate results for distance/within-population phenotypic diversity correlation.
quote: The Explorer
quote:
And it doesn't matter what the original phenotypes of the ancestral populations were; the diversity therein would have had an impact on the development of diversity in the descendant population. A superset population is unlikely to ever be outnumbered in diversity by just a small subset of itself. This is just a simple matter of mathematical common sense.
Your reasoning is illogical. The entire paper is made up of subgroups.
More illogical than not being able to grasp common sense that a within-superset variability in all probability is going to be greater than that of just a subset of itself; which junior school did you learn that from? So, according to you a subset of a superset is likely to sport greater diversity than the superset.
quote: The authors make it clear that they are comparing the various phenotypes to the African population.
No, they make it clear that a sub-Saharan African centroid fitted into regression models for within-population phenotypic diversity and distance covariance offers the most parsimonious results suggestive of the likely location of origin of humanity.
quote: As a result, there is nothing wrong with comparing any group in the research study outside Africa, to the African phenotype.
There is certainly something wrong with subtracting mean standardized within-population phenotypic variability of 2 populations in continent, and comparing that against that of another pair in Africa as supposed indicator of where overall mean within-population phenotypic variability is greatest, and henceforth, the most likely origin of humanity.
It also leaves out the relationship of distance with within-populations phenotypic variation from the centroid.
And it leaves out other data sets of the study that are not involved in your simple substraction, in marked contrast to that attained in the single runs of linear regression *multivariate* comparative measurement.
quote: In critiquing any research paper the first thing you have to do is look at the math and determine if the reasercher confirmed what he was researching.
Which is something that you have appeared to not have done.
quote: The problem with the study is that the authors make claims which are not supported by the evidence.
What claim is not supported by what evidence *other than* the nullified ones you've already professed here, and how?
quote: If the theory was correct their would be less variance between populations further away from Africa, than within Africa as they hypothesize.
Again, plotted linear regression models display precisely loss of diversity vis-a-vis accumulation of distance away from a sub-Saharan centroid. Regression models fitted with a non-African centroid have failed to produce such result [which is indicative of most likely location of origin]. This was essentially repeated by another group of authors, as posted by xyyman.
quote:
The Explorer
quote:
Where does it say that Europeans in the Americas were measured as opposed to other groups? Where does it say anything about just samping so-called Mongloids in Asia, and then plotting that in the sense of Europeans vs Mongoloids vs. Negroes of Africa?
This is clearly indicated when the populations in the Table are divided into groups based either on ethnic origin or location in a specific country.
How in the world does labeling samples according to individual countries of origin become synonymous with the racialist model of Caucasian, Mongloid and Negroid?
quote:
quote:
And it doesn't matter what the original phenotypes of the ancestral populations were; the diversity therein would have had an impact on the development of diversity in the descendant population. A superset population is unlikely to ever be outnumbered in diversity by just a small subset of itself. This is just a simple matter of mathematical common sense.
It does matter. If you're talking about ancient populations and the population only dates back 2000 years ago the population probably has nothing to do with the ancient group.
You are not reading what you cited there. It says that it doesn't matter what the original phenotypic manifestations of the *ancestral* population were; the existing mean within-phenotypic variability of that "founder" group would have had an impact on the development of within-population phenotypic variability of its *descendant* population. Therefore, reduced mean within-population variability characterising most non-Africans vis-a-vis an African source is expected, since entire OOA descendents derived from a subset of Africans that already had a reduced mean within-population than its source population. As OOA expanded further, additional bottlenecks would have reduced the mean within-population variability even further. We see a loss of within-population diversity with accumulation of distance away from the most likely source population(s) even within sub-Saharan Africa itself, but not as acute as that in non-Africans, due to 1)greater within-population variability that was already contained in the continent at prior to and after OOA immigration [OOA derived from a source within an African environment wherein there was already some level of population structuring], and 2)reduced obstructive geological barriers between off-shoot groups. I suspect though, that all this is too complex for you to understand.
Posted by Boofer (Member # 15638) on :
quote:Originally posted by lamin: Note that I said that it is puzzling that there are many more haplogroup lineages outside of Africa than within that continent. One would have expected the opposite. I believe what I wrote was misread.
Aren't all haplogroups outside of Africa derived from a single African macro haplogroup? If that's the case, then it doesn't seem to matter that there are more outside of Africa.
I've also heard that Africa appears to have fewer haplogroups because of lack of funding for research and a lack of curiousity for those who can afford. Eurasian haplogroups appear to be so diverse because there is a general curiosity and more folks able to afford funding. I was under the impression that, had the few african specific haplogroups been "broken down" into subgroups (not sure of the exact terminology) then the amount would more closely match AFrica's supposed great diversity.
Posted by Knowledgeiskey718 (Member # 15400) on :
quote: Posted by Clyde: It does matter. If you're talking about ancient populations and the population only dates back 2000 years ago the population probably has nothing to do with the ancient group.
Step into the new age, old man.
Posted by akoben (Member # 15244) on :
^ wow, look who's talking. the dummy that didn't realise the study he was supporting all this time was actually referring to Chinese.
Posted by rasol (Member # 4592) on :
quote:But again why assume conceptually that there's special about the huge landmass we now call Africa?
^ There is something special about it.
Human beings evolved in Africa 150 thousand years ago.
They did not evolve anywhere else.
They then lived in Africa, and only Africa until as recent as 70 thousand years ago.
This 80 thousand year time period [150 to 70 kya], is a hard fact. It's trying to ignore it, is what is contrived.
Between 70 and 20 thousand years ago, Africa was the most heavily populated part of the world, most of the human population was African.
That's pretty special.
Posted by lamin (Member # 5777) on :
Yes, the human species attained the Sapiens level in a large landmass we we now call Africa--but the species' origins are to be attributed only to a tiny and restricted area of such.
My statement that "there's nothing special about Africa" should be understood only as a geographical statement which has been arbitrarily constructed. After all, what we now call Africa, Asia and Europe are all joined together by land. We could easily say that all 3 arbitrarily defined continents are just 1 single continent.
Continuing with my train of thought: there is no basis for dividing up the Eurasian landmass into 2 continent nor for the continuing arbitrarily imposed Eurocentric idea of Africa itself being divided up into so-called "sub-Saharan" Africa and the rest of the continent arbitrarily grafted on to what they call the "Middle East".
Humans began in a restricted part of the area we now call Africa--for whatever hominid evolutionary reasons. Camels began in some restricted part of West Asia according to similar principles.
Posted by lamin (Member # 5777) on :
Boofer, Precisely--and there should be at least 3 times as many haplogroups in Africa as in the rest of the world combined. The premise here is that DNA mutations occur at approximately the same pace everywhere in the world.
The point is that nature is blind when it comes to the classification of humans. It's humans that classify--not nature.
What we have are human individuals interacting with their specific environments--including themselves--in time according to the randomness of the principles of biological evolution.
The upshot of all this is that each human individual is unique and is unlike any other. Human attempts at human tissue grafting proves my point.
Posted by Knowledgeiskey718 (Member # 15400) on :
quote:Yes, the human species attained the Sapiens level in a large landmass we we now call Africa--but the species' origins are to be attributed only to a tiny and restricted area of such.
Ok humans may have originated in one region of Africa, but they spread out from there and were found throughout Africa before they left. As rasol mentioned, humans lived in Africa over 150kya(there is no doubt they dispersed before 70kya, but they didn't survive). In Africa humans have always survived and modern human behavior and everything else that makes one human is found in Africa, and is NOT restricted to one single area. This amongst others( Distance from Africa, not climate, explains within-population phenotypic diversity), make Africa pretty damn special when it comes to human evolution, behavior, civilization etc... whether one likes to admit it, or not.
quote:Earliest Evidence Of Modern Humans Detected
— Evidence of early humans living on the coast in South Africa, harvesting food from the sea, employing complex bladelet tools and using red pigments in symbolic behavior 164,000 years ago , far earlier than previously documented, is being reported in the journal Nature.
The international team of researchers reporting the findings include Curtis Marean, a paleoanthropologist with the Institute of Human Origins at Arizona State University and three graduate students in the School of Human Evolution and Social Change.
"Our findings show that at 164,000 years ago in coastal South Africa humans expanded their diet to include shellfish and other marine resources, perhaps as a response to harsh environmental conditions," notes Marean, a professor in ASU's School of Human Evolution and Social Change. "This is the earliest dated observation of this behavior."
quote:Discovery Of The Oldest Adornments In The World
ScienceDaily (June 18, 2007) — The discovery of small perforated sea shells, in the Cave of Pigeons in Taforalt, eastern Morocco, has shown that the use of bead adornments in North Africa is older than thought. Dating from 82 000 years ago , the beads are thought to be the oldest in the world. As adornments, together with art, burial and the use of pigments, are considered to be among the most conclusive signs of the acquisition of symbolic thought and of modern cognitive abilities, this study is leading researchers to question their ideas about the origins of modern humans. The study was carried out by a multidisciplinary team made up of researchers at CNRS, working with scientists from Morocco, the UK, Australia and Germany.
quote:World's Oldest Ritual Discovered -- Worshipped The Python 70,000 Years Ago
A startling archaeological discovery this summer changes our understanding of human history. While, up until now, scholars have largely held that man's first rituals were carried out over 40, 000 years ago in Europe, it now appears that they were wrong about both the time and place.
Associate Professor Sheila Coulson, from the University of Oslo, can now show that modern humans, Homo sapiens, have performed advanced rituals in Africa for 70,000 years. She has, in other words, discovered mankind's oldest known ritual.
The archaeologist made the surprising discovery while she was studying the origin of the Sanpeople. A group of the San live in the sparsely inhabited area of north-western Botswana known as Ngamiland.
Coulson made the discovery while searching for artifacts from the Middle Stone Age in the only hills present for hundreds of kilometers in any direction. This group of small peaks within the Kalahari Desert is known as the Tsodilo Hills and is famous for having the largest concentration of rock paintings in the world.
quote: 'Modern' Behavior Began 40,000 Years Ago In Africa, Evidence Suggests
-- Excavations from the Enkapune Ya Muto (EYM) rock shelter in the central Rift Valley of Kenya offer the best evidence yet that modern human behavior originated in Africa more than 40,000 years ago. They also suggest that by that time our earlier selves sealed social alliances and prevailed over others by giving token gifts, in this case, beads. So says archaeologist Stanley Ambrose, a professor at the University of Illinois.
Ambrose, an expert on stone tools, paleoecology and stable isotope biogeochemistry, has found that his EYM site "contains perhaps the earliest example of what we think of as an Upper Paleolithic stone-tool technology, and then later in time, ostrich eggshell-bead technology -- the earliest evidence for ornamentation, which may imply a new kind of adaptive social system."
In one of the oldest layers, Ambrose found the stone tools -- "possibly the oldest example of Later Stone Age or European equivalent Upper Paleolithic stone-tool technology. The blade-based tools are at least 46,000 years old, but may be as much as 50,000 years old -- older than the oldest previously known industry of its kind, from Israel."
quote: This lecture was delivered by Dr. Ian Tattersall at The Metropolitan Museum of Art on the occasion of the symposium "Genesis: Exploration of Origins" on March 7, 2003. This symposium was held in conjunction with the special exhibition, "Genesis: Ideas of Origin in African Sculpture," and was made possible through the support of The Ford Foundation.
"The most remarkable early evidence of symbolic activity in Africa comes in the form of the recent find of engraved ochre plaques, such as this one, from Blombos Cave on the southern coast of Africa (Fig. 10). This is an unequivocally symbolic object, even if we cannot directly discern the significance of the geometric design that the plaque bears; and it is dated to around 70,000 years ago, over 30,000 years before anything equivalent is found in Europe. To evidence such as this can be added suggestions of a symbolic organization of space at the site of Klasies River Mouth (Fig. 11), also near the southern tip of Africa, at over 100,000 years ago. Pierced shells, with the strong implication of stringing for body ornamentation, are known from Porc-Epic Cave in Ethiopia at around 70,000 years ago. Bone tools of the kind introduced much later to Europe by the Cro-Magnons, are found at the Congolese site of Katanda, dated to perhaps 80,000 years ago. Blade tool industries, again formerly associated principally with the Cro-Magnons, are found at least sporadically at sites in Africa that date to as much as a quarter of a million years ago. Also in the economic/technological realm, such activities as flint-mining, pigment-processing and long-distance trade in useful materials are documented in Africa up to about 100,000 years ago. These and other early African innovations are reviewed by McBrearty and Brooks (2000)."
Posted by lamin (Member # 5777) on :
Knowledgeiskey,
What you write is well-known, of course. What it means is just that the environment in Africa was sufficiently propitious to allow human survival and advancement.
Posted by Knowledgeiskey718 (Member # 15400) on :
quote:Originally posted by lamin: Knowledgeiskey,
What you write is well-known, of course. What it means is just that the environment in Africa was sufficiently propitious to allow human survival and advancement.
Well, your question of why Africa is special has been answered. Anyway, what about the environment gave Africa the ability to cradle mankind? Why not Australia, Melanesia etc..? Why didn't humans evolve from homo erectus, OOA? Was it wet weather, hot dry, hot humid etc.. that aided Africa? Why didn't humans survive when they left Africa the first(maybe few?) time/s?
Or you can be more specific into what your point is, and what you're trying to get at.....?
Posted by The Explorer (Member # 14778) on :
quote:Originally posted by Knowledgeiskey718:
Ok humans may have originated in one region of Africa, but they spread out from there and were found throughout Africa before they left.
...which is what I alluded to earlier, when I made mention of already existing population structurings within Africa even before the ancestors of contemporary non-Africans left the continent. Anatomically modern humans had been here by ca. 200 ky ago, and some 120 ky or plus had passed by before the ancestors of contemporary non-African had left the African continent. Hence, while the trend actually begins within Africa itself, such that intra-population phenotypic diversity decreases as one moves away from the centroid placed at the most likely location of origin(s), it is less acute within sub-Saharan Africa from the said location of origin than the trend is with respect to groups outside of and further away sub-Saharan Africa.
Genetic data parallels cranio-metric phenotypic trend; it is more diverse in Africa, particularly sub-Saharan Africa, than elsewhere. The entire gene pool of contemporary non-African males for example, ultimately traces ancestry to a single ancestor with the M168 mutation, but this is not so for Africa. In other words, non-African gene pool draws from only a fraction of the overall African gene pool, and hence loss in diversity. This trend continues onto other parts of the human genome, namely autosomes...a point made in, for example: Monophyletic units - Telling the same story... Posted by lamin (Member # 5777) on :
The reason is that Africa as a very large landmass is situated more than the world's other landmasses in tropical and subtropical latitudes. The hot and expansive East African plains probably favoured the emergence of the protohuman hominids.
Knowledgeiskey, You talk of "sub-Saharan Africa"[the Eurocentrics favourite term when it comes to Africa] without realising that it is a huge area. So why don't you apply your principle of decreasing diversity there too? For example, the distance from Kenya to South Africa is greater than the distance from Kenya to Rome or Turkey.
Whether or not males who descend from places not on the African continent all descend from a single ancestor is debatable--given that there were at least 2 or 3--even many more--migrations out of Africa in the last 50,000 years. Recall that one group travelled East on to Southern Asia then on to places like New Guinea and Australia. Other groups headed due North and crossed over to West Asia by way of the Sinai. Some may also have taken boats and crossed over to the Arabian peninsula.
Again, your points about African and non-African gene pools is compromised by the fact that you assume that there is some kind of natural demarcation between what we call Africa and other landmasses.
Posted by The Explorer (Member # 14778) on :
Whatever the forces behind it, the fact that the African continent was *alone* in being the area wherein modern humanity originated naturally makes it a special case. Otherwise, it would not have been singled out *by nature*. This is simply so, regardless of whether you, I or anyone else deem(s) the continent as not being special or not.
quote:Originally posted by lamin:
You talk of "sub-Saharan Africa"[the Eurocentrics favourite term when it comes to Africa] without realising that it is a huge area. So why don't you apply your principle of decreasing diversity there too? For example, the distance from Kenya to South Africa is greater than the distance from Kenya to Rome or Turkey.
The trend is not as apparent in the greater part of sub-Saharan Africa for the reasons already noted in my last post and the one prior:
1)The area wherein the ultimate source of modern humanity's ancestors lie.
2)The area wherein population structuring had already existed, was most concentrated and thrived for some 120 or plus thousand years *before* ancestors of contemporary non-Africans left...heck, long before the oldest TMRCA of non-Africans even ever exited!
3)The area wherein a *tiny fraction* of the overall African population, as a subset [bearing ancestors of contemporary non-Africans] of *one of* the populations therein then, left the continent for an overseas destination.
Hence, we get plots like this...
What does the shade-indicators, as explained above, tell us about sub-Saharan Africa?
quote: Whether or not males who descend from places not on the African continent all descend from a single ancestor is debatable
Debatable, really? Name a contemporary non-African male group which doesn't trace its ancestry to M168, and name this lineage.
quote: Again, your points about African and non-African gene pools is compromised by the fact that you assume that there is some kind of natural demarcation between what we call Africa and other landmasses.
There is: seas, oceans and the splittings of tetonic plates are natural demarcations.
Since it was I, not Knowledgeiskey, who pressed the issue of African genetic diversity vs. non-African genetic diversity, the above is really a reply to me. See for example: monophyletic units tell the same story. Thus far, all monophyletic units are in harmony, in showing greater micro locus-specific and branch length allelic variation within African than non-African gene pool and by association, in many cases, distinctions characterized in the sense of African vs non-African structuring [which could transcend the issue of comparisons between within-gene pool diversity; like say, certain monophyletic units displaying an overall pattern of differentiation in sense of ancestral vs. derived - e.g. as seen in skin tone alleles, Y and mtDNA markers.]
Posted by Alive-(What Box) (Member # 10819) on :
I'm pulling from patchy memory but don't "the deepest clades" or something like seperate Africans from non-Africans?
I'm a have to watch thi video again on that one but as far as "Africa" [geographically] just being "the landmass we call 'Africa'" lamin definitely has a point.
Posted by akoben (Member # 15244) on :
There is evidence the putative African Eurasian split, as claimed in various studies and touted as fundamental fact, is misleading. A recent study of mtDNA from various human populations shows that the world does not divide into Africans and Eurasians (Penny et al. 1995), rather it divides into a select group of Sub Saharan Africans and others. These others also include Sub Saharan Africans.Keita Posted by lamin (Member # 5777) on :
Exactly my point! Posted by lamin (Member # 5777) on :
I question the M168 hypothesis on grounds of analogical reasoning.
The Native Americans are regarded as having crossed over the Bering Straits into the Americas in at least 3 migrational waves. Other theories claim that other migrating groups may have taken boats all the way from coastal East Asia to cross into the U.S. Pacific North West. And there's the Van Sertima hypothesis about trans-Atlantic crossings from West Africa. And all this was done in no more than 10,000 to 30,000 years.
Now human populations in Africa had at least 50,000 years to cross into other areas outside the continent. It's highly unlikely that they would have migrated out only once---given the Native American record.
Posted by The Explorer (Member # 14778) on :
You, lamin, say that the idea that the entire contemporary non-African male gene pool derives from a single African ancestor is *debatable*, yet you cannot name a supposed alternative ancestry sans the M168 UEP that is supposed to generate this debate?
Genealogical data does in fact show African vs. non-African patterns of divergence, including mtDNA...
The entire autochthonous mtDNA gene pool of contemporary non-Africans derives from L3 ancestry, whereas this is *not* the case with the overall African gene pool.
The entire autochthonous Y-DNA gene pool of contemporary non-Africans derives from M168 ancestry, whereas this is *not* the case with the overall African gene pool.
Yes, I'd say the above mentioned are pretty pristine examples of African vs. non-African difference.
Posted by lamin (Member # 5777) on :
Not as cut and dried as you claim--and I am not a dogmatist when it comes to open-ended scientific research as in the case of archaelogoical genetics.
We really don't know if we have all the data--especially in cases where what we claim to know runs counter to commonsense. There's nothing infallible about those men in white coats.
Posted by Knowledgeiskey718 (Member # 15400) on :
Lamin,
All contemporary Africans, do not descend from that single East African population as do all non Africans, nor as recently. Africans in Africa, as explained, would not all be affected by a bottleneck in a single population. In Africa, it would have to had been a continental bottleneck that affected each population respectively decreasing the size, which did not happen. Whereas, a bottleneck in the *single* African population, who became ancestors of all non Africans, would affect all non Africans who do in fact descend recently from a single population from East Africa. The diversity that is present in Africa, is extreme since humans arose in Africa and have lived in Africa for about 200ky, spreading throughout Africa diversifying into many populations carrying different lineages. This immense time in Africa(over 100kya) gave populations in Africa(who spread out to populate Africa) enough time to diversify into the extreme diversified populations that we see today in Africa, well before the ancestors of contemporary non-Africans even left. So now, add another 80ky to the diversification of the contemporary African gene pool, after the 100ky that Africans have already diversified, and you get additional diversity on top of the already extremely diversified African population. If the population who left Africa wouldn't have experienced subsequent population bottlenecks, there would be a greater genetic diversity in the non African gene pool, probably as diverse as any contemporary African population.
Posted by The Explorer (Member # 14778) on :
quote: A recent study of mtDNA from various human populations shows that the world does not divide into Africans and Eurasians (Penny et al. 1995), rather it divides into a select group of Sub Saharan Africans and others. These others also include Sub Saharan Africans.Keita
Which is why recognizing differences between African and non-African diversity is not tantamount to making a case for racialism...
Non-Africans derive from a *subset* of Africans. So naturally, the variation contained in a *subset of Africans* is going to be a part of well, overall African variation.
In other words, while overall African variation contains that of a subset of Africans, overall African variation is not contained in that of a subset of Africans. To picture this,...
Take the above mentioned L3 lineage example for instance; it *includes* Africans, but it does not include all Africans. However, L3 generally includes all non-Africans. Alternatively, African gene pool contains L3, but L3 does not contain African gene pool.
Posted by The Explorer (Member # 14778) on :
quote:Originally posted by lamin:
Not as cut and dried as you claim
What specifically is not cut and dried as I claim, and how so?
quote: --and I am not a dogmatist
If you are not a dogmatist, then where is your counter genetic matter that is supposed to make single African ancestor of the entire non-African males *debatable*?
When you say something is debatable, then it follows that you have to provide an alternative to that which is being debated against; you have offered none.
Posted by rasol (Member # 4592) on :
quote:Originally posted by lamin: Yes, the human species attained the Sapiens level in a large landmass we we now call Africa
^ this is not what i said, nor does it make any sense, as it is a weasel worded redundancy
The Human species - homo sapien - is sapien by definition.
There is no 'human species' / which attains a 'sapien' level.
This is like saying Lions attain their Lion level in Africa.
The purpose of weasel worded arguments like you are making is to attempt to avoid facts.
Ex:
"Lamin stole the cookies", becomes:
Lamin's hand, may or may not have been in the cookie jar, and the cookies may have later -migrated- from the jar into Lamins mouth.
People use weasel worded arguments to argue things they know are not true, or avoid truths they don't like.
The human species is African in origin, period.
This is why Africa is special to human history.
Acknowledge that - and we can progress with an intelligible discussion.
Posted by rasol (Member # 4592) on :
quote:Originally posted by The Explorer:
quote:Originally posted by lamin:
Not as cut and dried as you claim
What specifically is not cut and dried as I claim, and how so?
quote: --and I am not a dogmatist
If you are not a dogmatist, then where is your counter genetic matter that is supposed to make single African ancestor of the entire non-African males *debatable*?
When you say something is debatable, then it follows that you have to provide an alternative to that which is being debated against; you have offered none.
^ unless you are engaging in weasel worded arguments to avoid facts you don't like but can't refute.
isn't that right, lamin. Posted by lamin (Member # 5777) on :
{quote]There is no 'human species' / which attains a 'sapien' level.{/quote}.
The Neanderthals were members of the human species but they did not attain sapiens level. "Sapiens level" merely means an anatomically and behaviourally modern level. That is the ability to use human languages and to think and create abstractly. On account of their glottal structures it has been concluded that the Neanderthals did not speak humanly cognate languages--despite having cranial capacities greater than those of modern humans.
On the "specialness" of the landmass now called Africa. There is nothing special about that landmass per se. What is special and archaeologically interesting is that in a very restricted area in a particular part of that landmass a conjuncture of evolutionary, ecological and climatic factors led to the gradual transition among a small population of hominids to an anatomically and neurologically complete species we now call homo sapiens or homo sapiens sapiens
Were archaeologists from an alien planet to descend on earth--with no knowledge of the names ascribed to the landmasses we now call continents--and come to the conclusion that the human species began in some restricted area on earth I have no idea what they would say--beyond what they would have observed about the origins of the human species: at point A latitude and longitude a novel species arose because of a propitious set of environmental and biological prompts.
Archaelogy and evolutionary anthropology--as practiced by humans--do attempt to look at available data scientifically--though human bias has gratly influenced how such data is/has been presented--but these 2 disciplines are not "closed conditions" disciplines as laboratory physics or biology--for the very simple reason that the past cannot be replicated. All archaelogy and evolutionary anthropology can do is draw reasonable inferences and frame reasonable hypotheses. That's why I say that the hypothesis that M168 suggests that all males in areas not called Africa descend from members of only one group that migrated east into other areas is just a plausible hypothesis--and not gospel truth science.
Reasoning analogically: I mentioned the more than a single migration from East Asia and possibly elsewhere into the Americas. I add to that claim the notion that on the MtDNA side Europe received at least 7 separate migrations at different times into that Eurasian peninsula. See Brian Sykes--"The Seven Daughters of Eve", for example.
Posted by The Explorer (Member # 14778) on :
You contradict yourself: in one breath, you say there is nothing special about the African continent, and then in another, you go onto state what is special.
Your strawman rambling on about multiple migratory events having taken place has no bearing on the derivation of contemporary non-African male gene pool from a single African ancestor. Proof of this is apparent from the fact that you cannot name the alternative ancestor who is supposed to render *debatable*, the M168-bearing ancestor as the singular oldest TMRCA of non-African males. By association, the M168 ancestry is very real indeed and definitely constitutes what you deem as "gospel truth science"; it exists, whereas your alternative doesn't.
Anyhow, why does the prospect of African origins of humanity or that of greater African within-population diversity seem to bother you & co.? It has to be remembered that these were the very same realities that white supremacy had/has sought to suppress, restricting things African to the "True Negro" philosophy, which science has only fairly recently rendered untenable. What do you suppose Eurocentrist holdouts of the crumbling multi-regionalist hypothesis exist for?
Posted by TheAmericanPatriot (Member # 15824) on :
You may be aware that research just out of the University of Toronto wants to say that primates left africa, went to Europe and returned as humans. That, if correct, would negate that idea that the origin of man was in Africa. Now, it may prove to be incorrect but the lesson in this research is that we are still learning about that process and the jury is not yet in.
Keep in mind that none of thois has anything to do with man as we know him today.
Posted by argyle104 (Member # 14634) on :
TheAmericanPatriot wrote:
quote: You may be aware that research just out of the University of Toronto wants to say that primates left africa, went to Europe and returned as humans.
That is not scholarship. That is ideological dogma.
quote: That, if correct, would negate that idea that the origin of man was in Africa.
If they "want to say" a designated conclusion how can one trust if said conclusion is correct? The answer is they can't, since the conclusion cannot be trusted due to ideological dogma.
quote: Now, it may prove to be incorrect but the lesson in this research is that we are still learning about that process and the jury is not yet in.
How can it prove to be incorrect when it was never proven correct in the first place?
Folks, now that was an intellectual thrashing.
Posted by Mmmkay (Member # 10013) on :
quote:Originally posted by TheAmericanPatriot: You may be aware that research just out of the University of Toronto wants to say that primates left africa, went to Europe and returned as humans.
Where is this study idiot?
Produce it.
But fact is, numerous genetic studies, archeological remains, linguistic studies etc have proven otherwise.
Your right about the fact that they *want* to say that but they can't.
Posted by TheAmericanPatriot (Member # 15824) on :
I posted the study on this board twice, look it up.
Posted by Knowledgeiskey718 (Member # 15400) on :
quote:Originally posted by TheAmericanPatriot: You may be aware that research just out of the University of Toronto wants to say that primates left africa, went to Europe and returned as humans. That, if correct, would negate that idea that the origin of man was in Africa. Now, it may prove to be incorrect but the lesson in this research is that we are still learning about that process and the jury is not yet in.
Keep in mind that none of thois has anything to do with man as we know him today.
Lmao Patriot you're a sad individual. You will believe anything that Eurocentrists who will also go to dire lengths to disconnect themselves, and discredit Africa as the cradle of pretty much everything. It's pitiful, there is no debate. I already refuted your Toronto claim. Take your final nail in your coffin chump, and rest eternally.........The research, at the University of Cambridge and funded by the Biotechnology and Biological Sciences Research Council (BBSRC), represents a final blow for supporters of a multiple origins of humans theory.
New Research Proves Single Origin Of Humans In Africa
ScienceDaily (July 19, 2007) — New research published in the journal Nature (19 July) has proved the single origin of humans theory by combining studies of global genetic variations in humans with skull measurements across the world. The research, at the University of Cambridge and funded by the Biotechnology and Biological Sciences Research Council (BBSRC), represents a final blow for supporters of a multiple origins of humans theory.
Competing theories on the origins of anatomically modern humans claim that either humans originated from a single point in Africa and migrated across the world, or different populations independently evolved from homo erectus to home sapiens in different areas.
The Cambridge researchers studied genetic diversity of human populations around the world and measurements of over 6,000 skulls from across the globe in academic collections. Their research knocks down one of the last arguments in favour of multiple origins. The new findings show that a loss in genetic diversity the further a population is from Africa is mirrored by a loss in variation in physical attributes.
Lead researcher, Dr Andrea Manica from the University's Department of Zoology, explained: "The origin of anatomically modern humans has been the focus of much heated debate. Our genetic research shows the further modern humans have migrated from Africa the more genetic diversity has been lost within a population.
"However, some have used skull data to argue that modern humans originated in multiple spots around the world. We have combined our genetic data with new measurements of a large sample of skulls to show definitively that modern humans originated from a single area in Sub-saharan Africa."
The research team found that genetic diversity decreased in populations the further away from Africa they were - a result of 'bottlenecks' or events that temporarily reduced populations during human migration.They then studied an exceptionally large sample of human skulls. Taking a set of measurements across all the skulls the team showed that not only was variation highest amongst the sample from south eastern Africa but that it did decrease at the same rate as the genetic data the further the skull was away from Africa.
To ensure the validity of their single origin evidence the researchers attempted to use their data to find non-African origins for modern humans. Research Dr Francois Balloux explains: "To test the alternative theory for the origin of modern humans we tried to find an additional, non-African origin. We found this just did not work. Our findings show that humans originated in a single area in Sub-Saharan Africa."
Posted by Knowledgeiskey718 (Member # 15400) on :
quote:Originally brayed by AmericanPatriot: You may be aware that research just out of the University of Toronto wants to say that primates left africa, went to Europe and returned as humans.
Since you're the one proposing this fallacy I hope you have the balls and will also take responsibility to address the following. Omo I and others from over 150kya were much like Ethiopians and Southern Sudanese today.
quote: "From the size of the preserved bones, we estimated that Omo I was tall and slender, most likely around 5'10" tall and about 155 pounds," University of New Mexico anthropologist Osbjorn Pearson, who co-authored at least two of the new papers, told Discovery News.
Pearson said another, later fossil was also recently found. It too belonged to a "moderately tall -- around 5'9" -- and slender individual."
"Taken together, the remains show that these early modern humans were...much like the people in southern Ethiopia and the southern Sudan today," Pearson said.
Or perhaps you'd be able to tell us why humans in African were already behaving modernly and expressing cognitive abstract thinking, 164kya in Africa? Whereas, modern humans didn't even reach Europe until 40-45kya, AmericanPatriot can you explain this? I really doubt you can, I actually doubt you will even address this post. Meanwhile, you have the audacity to call yourself a history teacher.....??
quote:Earliest Evidence Of Modern Humans Detected
— Evidence of early humans living on the coast in South Africa, harvesting food from the sea, employing complex bladelet tools and using red pigments in symbolic behavior 164,000 years ago , far earlier than previously documented, is being reported in the journal Nature.
The international team of researchers reporting the findings include Curtis Marean, a paleoanthropologist with the Institute of Human Origins at Arizona State University and three graduate students in the School of Human Evolution and Social Change.
"Our findings show that at 164,000 years ago in coastal South Africa humans expanded their diet to include shellfish and other marine resources, perhaps as a response to harsh environmental conditions," notes Marean, a professor in ASU's School of Human Evolution and Social Change. "This is the earliest dated observation of this behavior."
quote:Discovery Of The Oldest Adornments In The World
ScienceDaily (June 18, 2007) — The discovery of small perforated sea shells, in the Cave of Pigeons in Taforalt, eastern Morocco, has shown that the use of bead adornments in North Africa is older than thought. Dating from 82 000 years ago , the beads are thought to be the oldest in the world. As adornments, together with art, burial and the use of pigments, are considered to be among the most conclusive signs of the acquisition of symbolic thought and of modern cognitive abilities, this study is leading researchers to question their ideas about the origins of modern humans. The study was carried out by a multidisciplinary team made up of researchers at CNRS, working with scientists from Morocco, the UK, Australia and Germany.
quote:World's Oldest Ritual Discovered -- Worshipped The Python 70,000 Years Ago
A startling archaeological discovery this summer changes our understanding of human history. While, up until now, scholars have largely held that man's first rituals were carried out over 40, 000 years ago in Europe, it now appears that they were wrong about both the time and place.
Associate Professor Sheila Coulson, from the University of Oslo, can now show that modern humans, Homo sapiens, have performed advanced rituals in Africa for 70,000 years. She has, in other words, discovered mankind's oldest known ritual.
The archaeologist made the surprising discovery while she was studying the origin of the Sanpeople. A group of the San live in the sparsely inhabited area of north-western Botswana known as Ngamiland.
Coulson made the discovery while searching for artifacts from the Middle Stone Age in the only hills present for hundreds of kilometers in any direction. This group of small peaks within the Kalahari Desert is known as the Tsodilo Hills and is famous for having the largest concentration of rock paintings in the world.
quote: 'Modern' Behavior Began 40,000 Years Ago In Africa, Evidence Suggests
-- Excavations from the Enkapune Ya Muto (EYM) rock shelter in the central Rift Valley of Kenya offer the best evidence yet that modern human behavior originated in Africa more than 40,000 years ago. They also suggest that by that time our earlier selves sealed social alliances and prevailed over others by giving token gifts, in this case, beads. So says archaeologist Stanley Ambrose, a professor at the University of Illinois.
Ambrose, an expert on stone tools, paleoecology and stable isotope biogeochemistry, has found that his EYM site "contains perhaps the earliest example of what we think of as an Upper Paleolithic stone-tool technology, and then later in time, ostrich eggshell-bead technology -- the earliest evidence for ornamentation, which may imply a new kind of adaptive social system."
In one of the oldest layers, Ambrose found the stone tools -- "possibly the oldest example of Later Stone Age or European equivalent Upper Paleolithic stone-tool technology. The blade-based tools are at least 46,000 years old, but may be as much as 50,000 years old -- older than the oldest previously known industry of its kind, from Israel."
quote: This lecture was delivered by Dr. Ian Tattersall at The Metropolitan Museum of Art on the occasion of the symposium "Genesis: Exploration of Origins" on March 7, 2003. This symposium was held in conjunction with the special exhibition, "Genesis: Ideas of Origin in African Sculpture," and was made possible through the support of The Ford Foundation.
"The most remarkable early evidence of symbolic activity in Africa comes in the form of the recent find of engraved ochre plaques, such as this one, from Blombos Cave on the southern coast of Africa (Fig. 10). This is an unequivocally symbolic object, even if we cannot directly discern the significance of the geometric design that the plaque bears; and it is dated to around 70,000 years ago, over 30,000 years before anything equivalent is found in Europe. To evidence such as this can be added suggestions of a symbolic organization of space at the site of Klasies River Mouth (Fig. 11), also near the southern tip of Africa, at over 100,000 years ago. Pierced shells, with the strong implication of stringing for body ornamentation, are known from Porc-Epic Cave in Ethiopia at around 70,000 years ago. Bone tools of the kind introduced much later to Europe by the Cro-Magnons, are found at the Congolese site of Katanda, dated to perhaps 80,000 years ago. Blade tool industries, again formerly associated principally with the Cro-Magnons, are found at least sporadically at sites in Africa that date to as much as a quarter of a million years ago. Also in the economic/technological realm, such activities as flint-mining, pigment-processing and long-distance trade in useful materials are documented in Africa up to about 100,000 years ago. These and other early African innovations are reviewed by McBrearty and Brooks (2000)."
Posted by Knowledgeiskey718 (Member # 15400) on :
quote: That's why I say that the hypothesis that M168 suggests that all males in areas not called Africa descend from members of only one group that migrated east into other areas is just a plausible hypothesis--and not gospel truth science.
It's not a hypothesis you reject. A hypothesis is an educated **guess**. M168 is a genetic fact. I am pretty sure you're a dogmatist. Man walked with dinosaurs too huh?
quote: Reasoning analogically: I mentioned the more than a single migration from East Asia and possibly elsewhere into the Americas. I add to that claim the notion that on the MtDNA side Europe received at least 7 separate migrations at different times into that Eurasian peninsula. See Brian Sykes--"The Seven Daughters of Eve", for example.
Lamin, how many times does this have to be explained to you? See, you have this old style of thinking, of where you're like Clyde Winters and don't understand genetics and what it can tell us. I implore you to find something that disproves OOA. OOA = recent single origin in East Africa for all non Africans.
Posted by lamin (Member # 5777) on :
quote]History of Haplogroup G
Spencer Wells, in his book, The Journey of Man-A Genetic Odyssey, describes the history of our Y-chromosome. The following is excerpted from Well's book.
Genetic "Adam" Males all over the world have a set of markers, particular letters in the four-letter genetic alphabet, on their Y-chromosomes. Once a particular marker appears by mutation in a man, all of his descendants will also carry that marker. If we compile information on a large set of markers and project them back in time using computer algorithms, we find that the trail of mutations coalesces in a single Y-chromosome whose owner lived, according to the genetic dating, some 60,000 years ago. Actually, this date is rather uncertain since the 95% confidence interval is 40,000 to 140,000 years ago. Other data suggest that the date was probably a little older than 60,000 years ago, perhaps about 100,000 years ago. At that time, a mutation arose, which is now carried by every male on the planet. This man has been dubbed "Genetic Adam," though this is a misnomer since he was certainly not the first male modern human. His father was undoubtedly fully as human as he was. The "silent" nature of mutations in non-functional regions of the Y-chromosome means that none of "Adam's" contemporaries would have thought that there was anything out of the ordinary about him-indeed there probably wasn't. There were also many other males living at the same time, but they did not carry the same mutation and none of the male lines from them survived down to the present.
Genetic Adam lived in Africa, probably on the plains of East Africa. He may have resembled the Han people who live in southern Africa today, though earlier they had lived over a wide area of eastern and southern Africa.
M94 "Adam's" descendant identified by the mutation M94, which we Haplogroup G folk carry, lived on the plains of East Africa some 75,000 years ago. He is the ancestor of the overwhelming majority of males today because it is his progeny who "founded" all the Haplogroups B through R. Only Haplogroup A, which until fairly recently was confined to sub-Saharan Africa, does not carry M94. Everyone else is descended from M94 and carries the M94 mutation. Many of his descendants lived along the northeast African coasts.
M168 "M94's" descendant M168 lived about 60,000 years ago, perhaps in the area of today's Ethiopia. He too is our ancestor and we carry his M168 mutation. His descendants make up Haplogroups C-R. It is believed that increasing ice in the far north dried up the African climate to the extent that at least two different groups of M168's descendants left Africa in search of adequate food supplies, or perhaps just seeking new lands. Everyone outside of Africa, and quite a few people still in Africa, descend from M168. The first wave of his descendants left Africa close to 60,000 years ago and are believed to have followed the southern coastline of Asia eastward. Sea level at the time was as much as 400 feet lower than it is now. They and their descendants ended up in Southeast Asia, Australia, south China, and the Pacific Islands. A few even joined their (by then) distant cousins in North America some 10,000 years ago.
A second wave of M168's descendants went north and east out of the Sahara area (forced out in a period of drying) through Egypt into the Middle East. The ancestors of future Haplogroup G were among them.
M89 M168's descendant M89 lived about 45,000 years ago probably in modern-day Iraq. He was the founder of macro-haplogroup F. His descendants include all members of Haplogroups G-R. That means that he is the ancestor of virtually everyone in Europe and the Middle East, and of the vast majority of Asians and Native Americans.
A large group of M89's descendants moved up into central Asia above the Caspian Sea. It was very cold there near the edge of the great northern ice pack. Life was harsh but food was plentiful. Vast herds of big game thronged the tundra and the grasslands south of the ice pack A new mutation arose here, M9, that founded a new Haplogroup K, the "father" of the Eurasian Haplogroups L-R, whose descentants spread over most of Europe, Asia and the Americas. Half of Europeans today belong to this haplogroup, but our Haplogroup G Y-chromosomes are only cousins of these. Many of M89's descendants stayed in or near the Middle East and perhaps some even returned to northeastern Africa. New mutations among them gave rise to the Haplogroups G-J.
M201-Founder of Haplogroup G The first guy to have the M201 mutation which distinguishes our Haplogroup G is thought to have lived about 30,000 years ago along the eastern edge of the Middle East, perhaps as far east as the Himalayan foothills in Pakistan or India. He has had relatively few descendants. Some of them went east on into Southeast Asia, south China and the Pacific Islands, but most moved back into the Middle East. Then about 10,000 years ago things began to change for the members of the four Haplogroups G-J. Prior to this time all humans were hunter-gatherers. The people of what was known as the "Fertile Cresent" developed agriculture and the world would never be the same again. Population could expand rapidly and farmers began moving out of the Middle East, through the islands and along the shores of the Mediterranean, through Turkey into the Balkans and the Caucasus Mountains.
It was once thought that the advancing farmers must have displaced or eliminated the hunter-gatherers of Europe. However the DNA studies have shown that the spread of agriculture did involve the movement of some people into Europe who had not been there before, but largely the spread of farming was through the adoption of the practice by the existing Europeans. An hypothesis which is growing stronger recently is that these same people at the same time may have introduced the Indo-European language into north India, the mid-East and Europe. Indo-European is the parent language for Greek, Latin, Sanskrit, Germanic and hence of most of the other languages of the mid-east, north India and Europe.
To be more specific about where Gs are to be found today: those that went east have very small numbers of living male-line descendant members in China, Indonesia, Taiwan, the Philippines, and the Polynesian Islands of the Pacific. Those that went north have small numbers of living male-line descendant G-folk in Syria (Arab), Russia (Adygeans), Uzbekistan (Tartars and Karakalpaks), Mongolia, and western China (Uygurs). Those that went west and north live today in Italy, Sicily, Hungary, Austria, Germany, France, Norway and Sweden. In the Republic of Georgia (Caucasus Mountains south of Russia, north of Turkey) members of G make up as much as 30% of the population. There are 14% on the island of Sardinia, 10% in north central Italy, 8% in northern Spain, almost 7% in Turkey, and lesser percentages in the Czech Republic, Slovakia, the Ukraine, Lebanon, Greece, Hungary, Albania, Croatia, and Ethiopia. G is still represented in the Middle East--some of these are Arab, some are Jews, many are neither. Across northwestern Europe, G haplotypes occur at a low frequency, 1-3%.
Our Cousins, M52, M170, 12f2.1 The mutations M52, M170, and 12f2.1 gave rise to Haplogroups H, I, and J, which are "brother" haplogroups of G. H is largely confined to the Indian subcontinent. I spread up through central Europe and into Scandinavia, where it is well represented today. J is very common in the Middle East, where many Jews, Arabs, and others belong to it. These three haplogroups probably arose between 20,000 and 30,000 years ago. Haplogroups J2 and E3b, along with G, came to Europe primarily during the spread of agriculture.[/quote]
Thus:
1)Very possibly not just one group of humans migrated out of Africa in the past--both assumedly with the M168 marker dominant. But there would be many others in the migratory groups who would not carry M168.
2)There is a plethora of subsequent mutations for those who migrated to Eurasia and the Americas but relatively very few for those who did not migrate Eastwards from the source land mass of Africa to another.
3) Haplogroup A precedes all the other haplogroups--so the question is why isn't it rather than M94 and M168 seen as the parent lineage of the rest of the world?
4) It should be noted that the Y and MtDNA chromosomes are mere markers and that the bearers of novel sex-linked mutations would also carry the whole cluster of autosomal material of their group. In other words the M168 carrier would not be phenotypically distinguishable from from the kin members of his group.
--
Posted by Knowledgeiskey718 (Member # 15400) on :
quote: Thus:
1)Very possibly not just one group of humans migrated out of Africa in the past--both assumedly with the M168 marker dominant. But there would be many others in the migratory groups who would not carry M168.
Your own post answered your question..... and the reason he states it's a misnomer to call the M168 mutation Adam for all humans, is because all contemporary Africans do not descend from that East African population identified by M168, as explained ad Nauseum.
Actually, this date is rather uncertain since the 95% confidence interval is 40,000 to 140,000 years ago. Other data suggest that the date was probably a little older than 60,000 years ago, perhaps about 100,000 years ago. At that time, a mutation arose, which is now carried by every male on the planet. This man has been dubbed "Genetic Adam," though this is a misnomer since he was certainly not the first male modern human.--Spencer Wells
quote:2)There is a plethora of subsequent mutations for those who migrated to Eurasia and the Americas but relatively very few for those who did not migrate Eastwards from the source land mass of Africa to another.
Lamin, regardless of mutations OOA, all non African lineages can be traced back to the M168 mutation. There is no debate. Sorry.
quote: 3) Haplogroup A precedes all the other haplogroups--so the question is why isn't it rather than M94 and M168 seen as the parent lineage of the rest of the world?
Because Haplogroup CT contains the M168 change, which is present in all Y-chromosome haplogroups except A and B and is therefore the common ancestral type of all early migration out of Africa according to genetics which prove OOA.
quote: 4) It should be noted that the Y and MtDNA chromosomes are mere markers and that the bearers of novel sex-linked mutations would also carry the whole cluster of autosomal material of their group. In other words the M168 carrier would not be phenotypically distinguishable from from the kin members of his group.
Cavalli-Sforza: Genes, Culture, and Human Evolution. Pg 187.
..."In other words, all non-Africans carry M168. Of course, Africans carrying the M168 mutation today are the descendants of the African subpopulation from which the migrants originated.... Thus, the Australian/Eurasian Adam (the ancestor of all non-Africans) was an East African Man." Posted by The Explorer (Member # 14778) on :
quote:Originally posted by lamin:
Haplogroup A precedes all the other haplogroups--so the question is why isn't it rather than M94 and M168 seen as the parent lineage of the rest of the world?
Having edited my initial reply, we have...
M91 (associated with Hg A) is of course the oldest attestable lineage [not necessarily common recent ancestor] of *all* contemporary males.
When one speaks of M168, one is naturally referring to the oldest common recent ancestor of *just* non-African males, even though they share this ancestry with a portion of African male population. The oldest attestable common recent ancestor that non-Africans share with their African M168-descendent counterparts, is associated with M94 and M139 mutations [named Hg BT]
While non-African males essentially descend from the M168-bearing ancestor [regardless of how many mutations had occurred over time], *not* all African males descend from this ancestor; there are Africans who do not have this lineage. There are *major* African male lineages free of M168 ancestry!
Posted by lamin (Member # 5777) on :
Of course the whole thing is geared to the so-called non-African audience--that's why there's all the fuss about the so-called "Eurasian Adam". Unbiased analysis would focus on haplogroup A--and not on M168.
They are all amazed that they made it out of the place they labeled Africa--or so-called "sub-Saharan Africa". I just don't see why they are so worked up about this.
Posted by Knowledgeiskey718 (Member # 15400) on :
quote:Of course the whole thing is geared to the so-called non-African audience--that's why there's all the fuss about the so-called "Eurasian Adam". Unbiased analysis would focus on haplogroup A--and not on M168.
Not really, educated persons will understand that...
Cavalli-Sforza: Genes, Culture, and Human Evolution. Pg 187.
..."In other words, all non-Africans carry M168. Of course, Africans carrying the M168 mutation today are the descendants of the African subpopulation from which the migrants originated.... Thus, the Australian/Eurasian Adam (the ancestor of all non-Africans) was an East African Man."
^^^^The above is why Eurocentrists spend so much time trying to make East Africans into "Caucasoids", or ancient Africans into generalized moderns, which just doesn't hold up under scientific scrutiny.......
quote: "From the size of the preserved bones, we estimated that Omo I was tall and slender, most likely around 5'10" tall and about 155 pounds," University of New Mexico anthropologist Osbjorn Pearson, who co-authored at least two of the new papers, told Discovery News.
Pearson said another, later fossil was also recently found. It too belonged to a "moderately tall -- around 5'9" -- and slender individual."
"Taken together, the remains show that these early modern humans were...much like the people in southern Ethiopia and the southern Sudan today," Pearson said.
Posted by The Explorer (Member # 14778) on :
Well, it comes as no mystery that Europeans are generally interested in anything that more immediately relates to things European, and hence, have the tendency to artificially start from history tied into such. That's where the motivation for the unnecessary "Eurasian Adam" biblical eponym *in science* comes from [the "Greek Miracle" or second-coming "Greek Miracle"/the so-called "Renaissance" rebirth scenario are other examples]. Science should be separated from religion as much as possible. If eurocentric extremists could help it, Africa would be totally out of the picture, where humanity's origin is concerned...or anything else for that matter.
Posted by The Explorer (Member # 14778) on :
quote:Originally posted by lamin: Unbiased analysis would focus on haplogroup A--and not on M168.
Haplogroup A is essentially non-existent in non-Africans, including Europeans, short of any rare occasion of post-OOA migration of Africans carrying this lineage to non-African territory. This being the case, Eurocentric mentality doesn't immediately relate to it, and so, goes back to the point I just made.
Posted by lamin (Member # 5777) on :
Yeh, it's like any movie, film or story set in Africa has to have a "white hero"--no matter how distorted and ridiculous the whole thing becomes.
Cf: Danny Glover and his film on Toussaint of Haiti complaining that he was turned down right and left in the U.S. and Europe when looking for money for the film. He says he was told that there was no "white hero" so he couldn't get the support.
Posted by Alive-(What Box) (Member # 10819) on :
Facts about 'TheAmericanPatriot':
It would rather mention some supposed study than agree with the concensus when it normally agrees with anything it even considers mainstream (so long as it supports its Eurocentric agenda - actually, anything that doesn't or supports the afrocentric agenda 'is not mainstream' - according to its own words).
It would rather not link to or even name the "study" (as it is well aware of its own lack of reading comprehension skills and of the number of times clown scholars have had their own sources directly debunk them).
It would rather not explain *why* the claims of said study are more accurate or make more sense (for obvious reasons), or atleast explain the pros and cons of the OutOfAfrica consensus vs those of the claims of the "study".
So i generally ignore it.
Posted by Alive-(What Box) (Member # 10819) on :
quote:Now, it may prove to be incorrect but the lesson in this research is that we are still learning about that process and the jury is not yet in.
Looks like i made a mistake in ignoring it this time, this time it said somehting different.
Little does it know that there is no final jury in science, other than the perpetual testing of different ideas to learn more and more about something.
quote:Originally posted by lamin: Yeh, it's like any movie, film or story set in Africa has to have a "white hero"--no matter how distorted and ridiculous the whole thing becomes.
Cf: Danny Glover and his film on Toussaint of Haiti complaining that he was turned down right and left in the U.S. and Europe when looking for money for the film. He says he was told that there was no "white hero" so he couldn't get the support.
Wow. It doesn't completely surprise me really, after watching those old movies with my Uncle where they had to play heroes (intangible to bullets) opposite hords of fiendish [non white] others.
Posted by alTakruri (Member # 10195) on :
The relevant point/question is why aren't big money blacks financing it? Finaciers are making an economic investment for return. Apparently black potential investors see "no returns" possibility.
Are they are aware there's no audience for the film thus no profitability? Is their feeling based on statistics of black turnout for docudramas on topics related to long ago history not focusing on sexual abuse/intrigue?
The films on Malcolm X and Ali were exceptional perhaps due to the more current in time nature of the protagonists. This is something RU2 could fill us in on since it's his bag.
Posted by Djehuti (Member # 6698) on :
Excellent article Explorer. This recent study only confirms what anthropological remains and genetics have been saying all along. Since Africa is the original source of human populations, it would make sense that the further away from Africa, the greater the decrease in genetic diversity a population has via genetic drift and bottle-necks.
Oh and LMAO @ Patriot's ridiculous and desperate pleas for Eurocentric lies and wishful thinking! A study in Toronto "wants" to say that primates left Africa to go to Europe to become humans and then returned to Africa??! LMAO That sounded so obviously silly even folks at "Racial Reality" or "Mathilda" would laugh.
Posted by rasol (Member # 4592) on :
^ The guy is just a straight up idiot.
He eventually gets his feelings hurt by all the people telling him this, and runs away.
Don't know why he bothers to come back though.
Posted by DevilNegrokiller_Wolofi (Member # 15898) on :
quote:Originally posted by Knowledgeiskey718:
quote:I guess, for the sole fact that I've witnessed features around me, I've associated certain ones with certain populations.
The simple notion that you continue to render certain features to be solely independent and specific to populations shows your limited understanding of what is discussed. Only thing unique to Europeans and East Asians is pale skin(besides albinos). Be specific in what features you mean.
Which is why you were asked to post/provide clear pictures/examples of individuals that you deem to look non African. Too much to ask??
"Will Smith does not look like a kushite" -Knowledgeiskey718 et al.
LOL you are not fooling anyone dude.
Posted by Knowledgeiskey718 (Member # 15400) on :
quote:Originally posted by DevilNegrokiller_Wolofi:
quote:Originally posted by Knowledgeiskey718:
quote:I guess, for the sole fact that I've witnessed features around me, I've associated certain ones with certain populations.
The simple notion that you continue to render certain features to be solely independent and specific to populations shows your limited understanding of what is discussed. Only thing unique to Europeans and East Asians is pale skin(besides albinos). Be specific in what features you mean.
Which is why you were asked to post/provide clear pictures/examples of individuals that you deem to look non African. Too much to ask??
"Will Smith does not look like a kushite" -Knowledgeiskey718 et al.
LOL you are not fooling anyone dude.
^Actually, Djehuti is the one who made that post, and I agreed, you dumb ignorant insignificant trolling jackass... bwahahahahahaa
Anyway, what did that have to do with my post??
You're not fooling anyone, crackerjack!!
Posted by DevilNegrokiller_Wolofi (Member # 15898) on :
quote:Originally posted by Knowledgeiskey718:
quote: Posted by Clyde: It does matter. If you're talking about ancient populations and the population only dates back 2000 years ago the population probably has nothing to do with the ancient group.
Step into the new age, old man.
Who the hell are you to talk to Clyde like that. He is a very respectful and mature poster that has contributed to Africana Studies for years.
What the hell have you done but cut and paste as a butler on a web site for the past 6 months?
How dare you as a mesteeeeeeeezo spic ridicule an African scholar I am starting to think that you are really Jaime and are playing the same Jekyl and Hyde game that the white dude Betty boo plays to get dumb negros on his side only to squash them with racism hmmmmm
Still mad that Winters said Olmecs were blacks huh lol
Posted by Knowledgeiskey718 (Member # 15400) on :
quote: Who the hell are you to talk to Clyde like that. He is a very respectful and mature poster that has contributed to Africana Studies for years.
Lol, you mean contributed to pseudo scholarship and old 19th century racist anthropology, where he still believes in Caucasoids Negroids and Mongoloids? So according to Clyde, all Africans who are not "true negro" or prognathous are actually result of admixture? According to Clyde Winters logic, the Ancient Egyptians were "Caucasoids". Yea I can see your uneducated ass backing Clyde up all day long.... Crackerjack!! bwahahahahahaa Posted by DevilNegrokiller_Wolofi (Member # 15898) on :
quote:Originally posted by Knowledgeiskey718:
quote:Originally posted by TheAmericanPatriot: You may be aware that research just out of the University of Toronto wants to say that primates left africa, went to Europe and returned as humans. That, if correct, would negate that idea that the origin of man was in Africa. Now, it may prove to be incorrect but the lesson in this research is that we are still learning about that process and the jury is not yet in.
Keep in mind that none of thois has anything to do with man as we know him today.
Lmao Patriot you're a sad individual. You will believe anything that Eurocentrists who will also go to dire lengths to disconnect themselves, and discredit Africa as the cradle of pretty much everything. It's pitiful, there is no debate. I already refuted your Toronto claim. Take your final nail in your coffin chump, and rest eternally.........The research, at the University of Cambridge and funded by the Biotechnology and Biological Sciences Research Council (BBSRC), represents a final blow for supporters of a multiple origins of humans theory.
New Research Proves Single Origin Of Humans In Africa
ScienceDaily (July 19, 2007) — New research published in the journal Nature (19 July) has proved the single origin of humans theory by combining studies of global genetic variations in humans with skull measurements across the world. The research, at the University of Cambridge and funded by the Biotechnology and Biological Sciences Research Council (BBSRC), represents a final blow for supporters of a multiple origins of humans theory.
Competing theories on the origins of anatomically modern humans claim that either humans originated from a single point in Africa and migrated across the world, or different populations independently evolved from homo erectus to home sapiens in different areas.
The Cambridge researchers studied genetic diversity of human populations around the world and measurements of over 6,000 skulls from across the globe in academic collections. Their research knocks down one of the last arguments in favour of multiple origins. The new findings show that a loss in genetic diversity the further a population is from Africa is mirrored by a loss in variation in physical attributes.
Lead researcher, Dr Andrea Manica from the University's Department of Zoology, explained: "The origin of anatomically modern humans has been the focus of much heated debate. Our genetic research shows the further modern humans have migrated from Africa the more genetic diversity has been lost within a population.
"However, some have used skull data to argue that modern humans originated in multiple spots around the world. We have combined our genetic data with new measurements of a large sample of skulls to show definitively that modern humans originated from a single area in Sub-saharan Africa."
The research team found that genetic diversity decreased in populations the further away from Africa they were - a result of 'bottlenecks' or events that temporarily reduced populations during human migration.They then studied an exceptionally large sample of human skulls. Taking a set of measurements across all the skulls the team showed that not only was variation highest amongst the sample from south eastern Africa but that it did decrease at the same rate as the genetic data the further the skull was away from Africa.
To ensure the validity of their single origin evidence the researchers attempted to use their data to find non-African origins for modern humans. Research Dr Francois Balloux explains: "To test the alternative theory for the origin of modern humans we tried to find an additional, non-African origin. We found this just did not work. Our findings show that humans originated in a single area in Sub-Saharan Africa."
LOL R.I.P to Europe? Ummm wouldn't that be 70 percent of your own Genome Paco?
Posted by Knowledgeiskey718 (Member # 15400) on :
^^^According to whom Bill? And that's R.I.P Euro-centrism, not Europe, so you don't have to be so upset about it, your place of origin(Europe) still lives. Crackerjack!!! Bwahahahaaa
Posted by DevilNegrokiller_Wolofi (Member # 15898) on :
quote:Originally posted by alTakruri: The relevant point/question is why aren't big money blacks financing it? Finaciers are making an economic investment for return. Apparently black potential investors see "no returns" possibility.
Are they are aware there's no audience for the film thus no profitability? Is their feeling based on statistics of black turnout for docudramas on topics related to long ago history not focusing on sexual abuse/intrigue?
The films on Malcolm X and Ali were exceptional perhaps due to the more current in time nature of the protagonists. This is something RU2 could fill us in on since it's his bag.
Thats because big money blacks are successful and don't need movies to boost their self esteem like beat down blacks and WHITES do and they realize movies are NOT reality and make no material difference in people's lives lol.
Does that answer your question?
Posted by Knowledgeiskey718 (Member # 15400) on :
^^^Topic: Distance from Africa, not climate, explains within-population phenotypic diversity
Care to discuss it? If not, then get off the board....
Posted by akoben (Member # 15244) on :
quote:Originally posted by Knowledgeiskey718:
quote: Who the hell are you to talk to Clyde like that. He is a very respectful and mature poster that has contributed to Africana Studies for years.
Lol, you mean contributed to pseudo scholarship and old 19th century racist anthropology, where he still believes in Caucasoids Negroids and Mongoloids?
Aren't you the one who parrots racial divergence theories and Coonian scholars? Why do you keep projecting your racialism onto others? You believe in population differentiation between Kushites and Egyptians, population differentiation (racial divergence) between Africans (Forest Negros) and east Asians (Chinese). Who are you to talk about old 19th century racist anthropology?
Posted by Knowledgeiskey718 (Member # 15400) on :
^^^Another one......
Topic: Distance from Africa, not climate, explains within-population phenotypic diversity
Care to discuss it? If not, then get off the board....
^^^Continue your thrashing here.
Posted by zarahan (Member # 15718) on :
quote:Originally posted by The Explorer: Distance from Africa, not climate, explains within-population phenotypic diversity in humans
Lia Betti1, François Balloux2, William Amos1, Tsunehiko Hanihara3, Andrea Manica1
December 02, 2008
Abstract
The relative importance of ancient demography and climate in determining worldwide patterns of human within-population phenotypic diversity is still open to debate. Several morphometric traits have been argued to be under selection by climatic factors, but it is unclear whether climate affects the global decline in morphological diversity with increasing geographical distance from sub-Saharan Africa. Using a large database of male and female skull measurements, we apply an explicit framework to quantify the relative role of climate and distance from Africa. We show that distance from sub-Saharan Africa is the sole determinant of human within-population phenotypic diversity, while climate plays no role. By selecting the most informative set of traits, it was possible to explain over half of the worldwide variation in phenotypic diversity. These results mirror those previously obtained for genetic markers and show that ‘bones and molecules’ are in perfect agreement for humans.
=======
Of course, climate, environment, living conditions, random mutation and genetic drift, and globalization [inter-ethnic miscegenation as a consequence of immigration] chime in in varying forms and in complex ways in influencing cranio-morphometric variation, as I've noted here before, but what these folks seem to be observing, at least from the little mentioned in the abstract above, is more diversity in Africa, especially sub-Saharan Africa, vs. that elsewhere. It goes back to that old age basic lesson: non-African groups derived from a subset of Africans, and hence, loss of diversity or a fraction of diversity. Though variations would occur in OOA, as a result of a number of bottleneck events and elements of the aforementioned factors, the overall diversity within the population is very likely to be impacted by that of the "founding" population, notwithstanding subsequent expansion events. The pre-existing variation in the original OOA subgroups was already a fraction of that in the African homeland, and there is reason to suspect that a series of bottlenecks events, that marked the dispersal of OOA migrants, would have led to further losses in diversity along the way. [/QB][/QUOTE]
Excellent data, and a needed corrective against assorted "Mediterranean" climate theories that would use climate as a way to spin an artifical division between peoples of Africa. Some of the darkest people in the world live in cooler "Mediterranean" climates, and have narrow noses to boot, along with tight 'nappy' hair. And they have been found from very old times, not being subjects of any recent gene flow.
Likewise the dry air of desert areas was suppsoed to have excluded "negroid" types, according to anthropologists such as Strouhal in the 1970s who held that said negroid types could not possibly have been in Egypt or in the nearby Sahara due to their supposed inability to adapt to drier climates! Apparently, such "types" could only be "truly" found somewhere far south in a sweltering jungle locale. But this claim likewise has been debunked on these forums. Plenty of such dark-skinned peoples live in the dry desert, with both broad AND narrow noses.
Artifical climate separator approaches (darker negroes way down south in sweltering tropical heat, versus the lighter "Caucasoid" people up nawth there in a cooler "Mediterranean" climate), are also undermined by the limb proportion studies of Zakrewski et al showing that the AEs had a tropical body plan, and that the Nile Valley was not settled by cold adapted peoples. Such a finding holds even for northern Egypt, claimed by some to be a hotbed of "Caucasoid" settlement based on the Palestine and Lebanon area. Unfortunately, those pesky "negroid" features just won't go away. Quote:
[i\... "sample populations available from northern Egypt before the 1st Dynasty (Merimda, Maadi and Wadi Digla) turn out to be significantly different from sample populations from early Palestine and Byblos, suggesting a lack of common ancestors over a long time. If there was a south-north cline variation along the Nile valley it did not, from this limited evidence, continue smoothly on into southern Palestine. The limb-length proportions of males from the Egyptian sites group them with Africans rather than with Europeans." (Ancient Egypt Anatomy of a Civilisation, Barry Kemp, Routledge; 2 ed, 2005, pp. 30-67)[/i]
Explorer's post reinforces the fact of the built in genetic diversity of Africans. Climate could play part in local areas- i.e thin, cold mountain zones tend to have people with narrower noses, but in diverse Africa, you will find broad nosed people living on the upper slopes of Kilimanjaro, as neighbors of the narrow nosed folks, without the need for any "white blood" to explain the difference. It takes more than climate to make African people vary in how they look.
Posted by Djehuti (Member # 6698) on :
^ As insane as it sounds Knowledge is correct, that because of the very fact that humans originated in African and specifically all *non-Africans* originated in East Africa, that Eurocentrics are now trying to turn East Africans into "caucasoids"! LMAO
If you don't believe me, you can have a look at websites such as 'Racial Reality' by the Greek psuedo-scholar and pseudo-intellectual Dienekes Pontikos. We even had one of his lackeys as our resident troll who tried to propagate his psychotic nonsense of "prehistoric East African caucasoids"!
This reminds me of Americanpatriot's claim of "ancient North African caucasoids". Cacazoids, cacazoids, everywhere in Africa but no blacks. LOL Posted by Djehuti (Member # 6698) on :
Here is Herto Man, the second oldest known modern human about 160,000 years old.
Very Caucasoid huh? Either that or 'generalized' modern. Posted by zarahan (Member # 15718) on :
On Dinekes blog, he asserts the following: Quote:
The finding that the anterior region of the cranium is more informative in terms of reduced diversity is actually consistent with selection and not with bottlenecks, since it is in this part, in nasal features, facial flatness, prognathism, etc. that populations have developed strongly differentiated types under selection.
Furthermore, in this paper the study is limited to skulls from the last 2,000 years. But, if bottlenecks are indeed responsible for the reduction of diversity, then this reduction of diversity would be visible in the earliest Homo sapiens skulls from the various regions, as these would be descended from the few bottlenecked migrants. Are Upper Paleolithic Europeans, for example, more or less diverse than Africans of equivalent age, or even modern Africans?
On the contrary, recent skulls may be less diverse than the earliest ones, due to a longer period of selection, i.e., the tens of thousands of years between the earliest Homo sapiens in Europe or Asia and the ones of the last 2,000 years. Moreover, this selection ought to have been strongest in regions further from Africa, as this is correlated with different environments (although not necessarily the 3 climate variables considered here).
In conclusion: -Within-population variance decreases with distance from Africa, but this does not measure between-population difference in mean trait values
-Both bottlenecks and selection result in reduced variance
-A stronger variance-reduction signal in the anterior cranium is more consistent with selection than with bottlenecks
The bottlenecks theory should be more visible in early, not recent skulls as those studied in this paper. Recent skulls should have reduced variance compared to their more ancient counterparts due to a long period of selection.
However there seem to be several weaknesses in his arguments. The study found that the anterior cranium traits were most informative in finding that diversity decreased the greater the distance from sub-Saharan Africa. Dienekes argues that this is consistent with selection rather than bottlenecks. But is this necessarily so? If the dispersed OOA population, containing a fraction of the variability from the original source met with a bottleneck, would not the diversity also come to a standstill without things like climate necessarily kicking in, as noted elsewhere?
In other words, for example only, if say a group leaving Africa met a huge sea or unpassable mountain range as a bottleneck, would not they become isolated and over time, as inbreeding within that group produced LESS diversity than was present back home in Africa? Climate need not enter into this scenario at all in terms of reducing diversity.
Furthermore it is argued that the “bottlenecks theory should be more visible in early, not recent skulls as those studied in this paper. Recent skulls should have reduced variance compared to their more ancient counterparts due to a long period of selection.”
But again, is this necessarily so? Could not bottlenecked data from say recent populations on isolated islands show the effect of reduced diversity? As for recent skulls having less diversity perhaps this might apply to say a Scandanavia versus Congo region comparison. But within Africa, would not the impact of climate factors be less due to the original built-in diversity in place already? Hence jet-black tribes with broad noses appear in cool climates, and more narrow nosed ones like the Fulani stroll easily through hot sweltering ones. The “climate as destiny” approach breaks down within ultra diverse Africa it seems.
Posted by Knowledgeiskey718 (Member # 15400) on :
quote:In other words, for example only, if say a group leaving Africa met a huge sea or unpassable mountain range as a bottleneck, would not they become isolated and over time, as inbreeding within that group produced LESS diversity than was present back home in Africa? Climate need not enter into this scenario at all in terms of reducing diversity.
Yes, your example is correct. This is what is explained in this study as result of these bottlenecks, the farther non African populations moved from Africa, the more you see a loss in the genetic and phenotypic diversity of that non African population, which is result of population reduction. Which is represented by All non Africans carrying M168,(which represents a subset of East African diversity) as does the population they descend from, in East Africa. Which is how we know that the people who populated the world (60+kya) was a subset of East Africans, represented by this marker which indicates all non Africans carry a small subset of African diversity, which is OOA.
Note, if the continents were populated by subsequent migrations directly from Africa, or arose, in situ from Erectus(multi-regional model), than the genetic diversity of non Africans would be much greater than what it is, but this is not the case, and all non Africans lose diversity phenotypically, and genetically, the farther the population is from Africa.
Posted by Djehuti (Member # 6698) on :
^ It is basic fact of evolutionary genetics. Unfortunately many people here are either too unintelligent or are willing not to learn to understand it.
Posted by Clyde Winters (Member # 10129) on :
KIK718
quote:
Yes, your example is correct. This is what is explained in this study as result of these bottlenecks, the farther non African populations moved from Africa, the more you see a loss in the genetic and phenotypic diversity of that non African population, which is result of population reduction. Which is represented by All non Africans carrying M168,(which represents a subset of East African diversity) as does the population they descend from, in East Africa. Which is how we know that the people who populated the world (60+kya) was a subset of East Africans, represented by this marker which indicates all non Africans carry a small subset of African diversity, which is OOA.
How do you explain this diversity among Filipinos
Posted by Knowledgeiskey718 (Member # 15400) on :
What diversity do you see besides lightskin and dark skin? Definitely not much phenotypic diversity......
Anyway, as the study proves, the further the population has moved from Africa is represented by a loss in phenotypic diversity. Filipinos don't possess as much phenotypic diversity as say, Melanesians, or Australians, nor do Filipinos compare to their ancestors who originally migrated from East Africa.
Posted by akoben (Member # 15244) on :
quote:What diversity do you see besides lightskin and dark skin?
Which one is "dark skin"? And are these your Euro-Asian who were changing in Europe? lol
Posted by Knowledgeiskey718 (Member # 15400) on :
quote:Originally posted by akoben:
quote:What diversity do you see besides lightskin and dark skin?
Which one is "dark skin"?
Posted by Djehuti (Member # 6698) on :
^ And all of that is besides the point since even *all* native Filipinos whether non-black like the ones above or black Aeta (aboriginals) are equally Asian and equally have decreased genetic diversity via great distance from Africa (the hearth).
Posted by akoben (Member # 15244) on :
quote:Originally posted by Knowledgeiskey718:
quote:Originally posted by akoben:
quote:What diversity do you see besides lightskin and dark skin?
Which one is "dark skin"?
Wow! Are these what your Euro-Asains looked like Clueless718?!! Makes sense! Lmao!!!
Posted by Djehuti (Member # 6698) on :
^ LOL Nope, but as usual you twist things into senselessness to cover your ass. But it doesn't work with your boyfriends in real life and it ain't working here in this forum. Posted by rasol (Member # 4592) on :
LOL Nope, but as usual you twist things into senselessness to cover your ass
-> It's called DEFEATED DONKEY syndrome:
Posted by rasol (Member # 4592) on :
quote:How do you explain this diversity among Filipinos?
quote:Originally posted by Knowledgeiskey718: What diversity do you see besides lightskin and dark skin? Definitely not much phenotypic diversity......
^ He doesn't understand. Actually I'm sure you can find better photos of genuine diversity within any population. But Winters chooses groups of people who vary only in skin color, which shows he isn't paying attention to the study in the parent thread.
I've noticed Dr. Winters has tremendous difficulty with any new idea, or any idea outside the box of his race ideology.
Old age is tough.
Posted by akoben (Member # 15244) on :
quote:Originally posted by rasolowitz: Old age is tough.
^ Yeh, I mean who in their right mind would argue for Asia and Europe as "alleged racial groups"? Posted by rasol (Member # 4592) on :
^ "Alleged" for everyone but you.
You actually tried to claim that Europeans 'really are' a race.
Tried and *failed*, as you only ended up humiliating yourself.
quote:Originally posted by rasolowitz: You actually tried to claim that Europeans 'really are' a race.
^ So we're back to the genisis of your beat down. LOL
What I say and still I maintain is that race as a social construct is real. That there are physical differences between whites and blacks. You agree too [New E3b paper totally destroys East African "Caucasoid" myth, posted 05 September, 2008 06:17 PM, posted 06 September, 2008 02:38 AM], you even see "mixed" Sicilians as still white. Give it up rasolowitz, you got baited and then owned.
quote:"Alleged" for everyone but you.
So do you see them as "alleged racial groups"? Posted by rasol (Member # 4592) on :
quote:What I say and still I maintain is that race as a social construct is real.
We we are discussing biology, not sociological beliefs so this comment is a non-sequitur.
A 'real' social construct is merely anything that you believe in, no matter how stupid it may be.
Witches, ghosts, vampires are 'real' social constructs.
Your NAZI beliefs are "real" social constructs, as is your laughably oxymoronic praying to the Jewish/Rabbi Jesus whom you believe to be God.
None of which has any relevance to biology.
It's amazing that in hundreds of posts your dumb jackass self, has hardly managed even a single intelligible sentense.
You should really leave this forum now, since you contribute only retardation to it.
quote:So do you see them as "alleged racial groups"?
This comment is also retarded, as it indicates that you don't understand the meaning of the word alleged.
But you're a jackass, and the meaning of words generally elludes you.
You seem to think that being a retarded jackass is a technique for debate, when it is really only an impulse towards self-humiliation on your part.
Maybe it's some sort of homosexual mashochist thing, for you? I don't know.
Anyway, here is what else everyone can see:
quote:Originally posted by Djehuti: LOL Nope, but as usual you twist things into senselessness to cover your ass
-> It's called DEFEATED DONKEY syndrome:
^ Do you see this?
Posted by rasol (Member # 4592) on :
^ Smells like defeated donkey in here.
Posted by akoben (Member # 15244) on :
Again, an unintelligent response...why do I even bother?
quote:Your NAZI beliefs are "real" social constructs
Btw speaking of Nazis, I'm still waiting on your "proof" that Jews were gassed at Dachau... Posted by Knowledgeiskey718 (Member # 15400) on :
quote:Originally posted by akoben:
quote:Originally posted by rasolowitz: Old age is tough.
^ Yeh, I mean who in their right mind would argue for Asia and Europe as "alleged racial groups"?
You might want to ask Keita this question.....
quote:
quote:Originally posted by akoben: [QB] [QUOTE] The Dravidian sample shows shifts between Europe and Asia. Translation: Dravidians show sifts between two major racial groups. Pay attention little bitch....
Oh come now, clueless718, you know you're talking bullshit! Why are you doing this?! So Europeans are an alleged racial group now?
Tell Keita that Dravidians shifting between Europe and Asia, is not shifting between alleged major racial groups, because according to Keita. The Dravidian sample shows shifts between Europe and Asia. Translation: Dravidians show shifts between two major racial groups. Pay attention little bitch....
Bwahahahahahahaa
quote: A Dravidian sample from Southern India likewise shifts between European and Asian populations, not attaining significance by standard bootstrap criteria.-- Keita
The Berber and Dravidian examples show shifts between the major racial groups as traditionally and currently defined by scholars--Keita
Posted by Djehuti (Member # 6698) on :
^ You should have bolded the part that said "as traditionally and currently defined by scholars"! Watch, now the jackass will go back to saying Keita espouses 'races'! LOL
Why not, since the dumb donkey does not know what a social construct is as opposed to a real measurable scientific entity! Posted by Knowledgeiskey718 (Member # 15400) on :
Na, he knows better than that (I think). Right now, he is desperately scrambling through Keita's paper trying to find out a way to distort and say Keita did not say Dravidian samples shows shifts between Europe and Asia. Which then translates to Dravidians showing shifts between two major racial groups.
But of course he won't be able to distort, as the statements are clear as day.
Posted by Djehuti (Member # 6698) on :
^ All the sorry ass can do is distort, but all in vain. His so-called 'arguments' are null and void.
Sohini Ramachandran*†, Omkar Deshpande‡, Charles C. Roseman§, Noah A. Rosenberg¶, Marcus W. Feldman*, and L. Luca Cavalli-Sforza†
Abstract
Equilibrium models of isolation by distance predict an increase in genetic differentiation with geographic distance. Here we find a linear relationship between genetic and geographic distance in a worldwide sample of human populations, with major deviations from the fitted line explicable by admixture or extreme isolation. A close relationship is shown to exist between the correlation of geographic distance and genetic differentiation (as measured by FST) and the geographic pattern of heterozygosity across populations. Considering a worldwide set of geographic locations as possible sources of the human expansion, we find that heterozygosities in the globally distributed populations of the data set are best explained by an expansion originating in Africa and that no geographic origin outside of Africa accounts as well for the observed patterns of genetic diversity. Although the relationship between FST and geographic distance has been interpreted in the past as the result of an equilibrium model of drift and dispersal, simulation shows that the geographic pattern of heterozygosities in this data set is consistent with a model of a serial founder effect starting at a single origin. Given this serial-founder scenario, the relationship between genetic and geographic distance allows us to derive bounds for the effects of drift and natural selection on human genetic variation.
Results
Testing whether a serial founder effect could give rise to the decay of expected heterozygosity with distance observed in Fig. 4A requires appropriate demographic models for calculating the effect of drift. We performed simulations of evolutionary processes to assess whether we could recover a similar pattern to what was computed from the data as shown in Fig. 4A (37). Assume for simplicity that we begin with a parental population, and there are n serial bottleneck episodes starting at the origin (the location of the parental population). In each bottleneck, a sample of individuals of size Nb founds the next colony, which is established at some distance from the previous colony and which remains isolated from all other colonies. This subsampling generates a succession of colonies in time, each of which grows to a large size K before generating the next colony in the chain. Each bottleneck episode decreases expected heterozygosity in the new colony by a factor of 1 1(2Nb) (39). To be precise, this computation includes the drift effect only of the first generation after the bottleneck. Based on this simple model of n bottlenecks with Nb founders at each bottleneck, an approximation for the total loss of expected heterozygosity from the beginning to the end of the expansion from the parental population due to the sequence of bottlenecks alone will be Regressing heterozygosity on distance from the parental colony, we can estimate Hby calculating the difference between the intercept of the regression line and the fitted value for the last population in the expansion (the furthest population from the origin). In Fig. 4A, the observed H is 0.12. Because n and Nb are unknown, Eq. 8 only allows the estimation of their ratio. Moreover, this simple model assumes no intermigration among colonies after their founding; it only accounts for genetic drift that occurs as a result of the bottlenecks in the serial founder effect, ignoring genetic drift (i) during the growth period where the founding population increases in size to carrying capacity and (ii) while the population stays at carrying capacity as the subsequent colonies are formed. These components will increase the amount of drift experienced by populations over that which would ensue from a population of constant size K. Simulation enables the evaluation of these components of the evolutionary process by using estimable quantities, such as the mutation rate of microsatellites and the sizes of populations (see Supporting Text, which is published as supporting information on the PNAS web site, for more discussion). Fig. 4B shows that simulation can produce heterozygosity values similar to those observed in the data set, giving a simulated value for H of 0.12, very close to the observed value. Hsim will differ from H˜ in Eq. 8 (see Supporting Text). The main assumption in the simulation (Fig. 4B) is that Nb, the number of founders at each bottleneck, is of the order of a hunter–gatherer tribe (35, 36).
Discussion
Geographic distance is a good predictor of genetic distance on a global scale (Fig. 1). The pattern’s robustness is indicated by our ability to reasonably explain anomalies (Fig. 2) based on what is generally believed to have occurred during the past 100,000 years of modern human history (29). We also find a close relationship between the correlation of FST and geographic distance (Fig. 1) and the geographic pattern of heterozygosity across populations (Fig. 4A). An increase in genetic distance with geographic distance has been observed in the past and has been attributed to equilibrium models of isolation by distance, but simulation results show that the geographic pattern of heterozygosities in the HGDP-CEPH populations is consistent with a serial founder effect starting at a single origin. Further, the observed pattern of within-population diversity is best explained by an origin in Africa (Fig. 5). By studying the relationship between genetic and geographic distance, we can assess the relative importance of genetic drift and natural selection in determining the genetic variation observed among human populations. The average contribution of drift generated by the serial founder effect might be estimated from the properties of the regression in Figs. 1B and 4A. Because our regressions explain 76–78% of the observed genetic variation, this quantity is therefore an estimate of the minimum influence that drift, due to the serial founder effect, has on the total variation observed. In other words, the fraction of the variation in heterozygosity across human populations that is explained by drift is at least 76–78%. If stabilizing selection has been a major force in human evolution, then the decrease of average heterozygosity would be reduced, and the slope in Fig. 4A would be less negative (by an unknown amount). The residual 22–24% of genetic variation not explained by the regression is generated by population-specific selection, drift, and mutational histories. The deviation from the regression of each individual population (Fig. 4A) or of each population pair (Fig. 2) is a consequence of each population’s particular demographic history (40). But it is clear that part of these deviations also may be due to different selective conditions met by these populations in the different environments to which they have been exposed. Therefore, we estimate that 76–78% can be considered a lower bound on the effect of drift, and 22–24% an upper bound on the effect of selection, in the genetic differentiation of human populations. Posted by MindoverMatter718 (Member # 15400) on :
From above, a rather well exampled elaboration on the effects of population bottlenecks and result thereof....
quote:Assume for simplicity that we begin with a parental population, and there are n serial bottleneck episodes starting at the origin (the location of the parental population). In each bottleneck, a sample of individuals of size Nb founds the next colony, which is established at some distance from the previous colony and which remains isolated from all other colonies. This subsampling generates a succession of colonies in time, each of which grows to a large size K before generating the next colony in the chain. Each bottleneck episode decreases expected heterozygosity in the new colony by a factor of 1 1(2Nb) (39). To be precise, this computation includes the drift effect only of the first generation after the bottleneck. Based on this simple model of n bottlenecks with Nb founders at each bottleneck, an approximation for the total loss of expected heterozygosity from the beginning to the end of the expansion from the parental population due to the sequence of bottlenecks alone will be Regressing heterozygosity on distance from the parental colony, we can estimate Hby calculating the difference between the intercept of the regression line and the fitted value for the last population in the expansion (the furthest population from the origin). In Fig. 4A, the observed H is 0.12. Because n and Nb are unknown, Eq. 8 only allows the estimation of their ratio. Moreover, this simple model assumes no intermigration among colonies after their founding; it only accounts for genetic drift that occurs as a result of the bottlenecks in the serial founder effect, ignoring genetic drift (i) during the growth period where the founding population increases in size to carrying capacity and (ii) while the population stays at carrying capacity as the subsequent colonies are formed. These components will increase the amount of drift experienced by populations over that which would ensue from a population of constant size K.
Posted by MindoverMatter718 (Member # 15400) on :
quote:Geographic distance is a good predictor of genetic distance on a global scale (Fig. 1). The pattern’s robustness is indicated by our ability to reasonably explain anomalies (Fig. 2) based on what is generally believed to have occurred during the past 100,000 years of modern human history (29). We also find a close relationship between the correlation of FST and geographic distance (Fig. 1) and the geographic pattern of heterozygosity across populations (Fig. 4A). An increase in genetic distance with geographic distance has been observed in the past and has been attributed to equilibrium models of isolation by distance, but simulation results show that the geographic pattern of heterozygosities in the HGDP-CEPH populations is consistent with a serial founder effect starting at a single origin.
Posted by The Explorer (Member # 14778) on :
^Interesting additions. From a DNA phylogenetic standpoint, as heterozygosity increases, linkage disequilibrium tends to decrease; and vice versa, as heterozygosity decreases in a dataset, chances are the same dataset will be marked by greater linkage disequilibrium. African samples generally tend to sport more heterozygosity; the authors in the following, for example, saw this as well:
Global Haplotype Diversity in the Human Insulin Gene Region John D.H. Stead1,3,4, Matthew E. Hurles2 and Alec J. Jeffreys1
The insulin minisatellite (INS VNTR) has been intensively analyzed due to its associations with diseases including diabetes. We have previously used patterns of variant repeat distribution in the minisatellite to demonstrate that genetic diversity is unusually great in Africans compared to non-Africans. Here we analyzed variation at 56 single nucleotide polymorphisms (SNPs) flanking the minisatellite in individuals from six populations, and we show that over 40% of the total genetic variance near the minisatellite is due to differences between Africans and non-Africans, far higher than seen in most genomic regions and consistent with differential selection acting on the insulin gene region, most likely in the non-African ancestral population. Linkage disequilibrium was lower in African populations, with evidence of clustering of historical recombination events. Analysis of haplotypes from the relatively nonrecombining region around the minisatellite revealed a star-shaped phylogeny with lineages radiating from an ancestral African-specific haplotype. These haplotypes confirmed that minisatellite lineages defined by variant repeat distributions are monophyletic in origin. These analyses provide a framework for a cladistic approach to future disease association studies of the insulin region within both African and non-African populations, and they identify SNPs which can be rapidly analyzed as surrogate markers for minisatellite lineage.
The insulin minisatellite, located within the promoter of the human insulin gene, has been intensely investigated for nearly two decades due to its associations with diseases such as diabetes (Bell et al. 1984; Bennett and Todd 1996). Most studies have analyzed populations of European descent where low diversity at the minisatellite combined with strong linkage disequilibria in flanking regions make it difficult to distinguish between etiological and associated variants (Bennett and Todd 1996; Doria et al. 1996). The identification of etiological polymorphisms in the insulin region may therefore require analysis of a range of different populations, in particular those showing a greater range of haplotype diversity than that seen in Europeans...
Franck Prugnolle1, Andrea Manica2 and François Balloux1
A leading theory for the origin of modern humans, the ‘recent African origin’ (RAO) model [1], postulates that the ancestors of all modern humans originated in East Africa and that, around 100,000 years ago, some modern humans left the African continent and subsequently colonised the entire world, displacing previously established human species such as Neanderthals in Europe [2,3]. This scenario is supported by the observation that human populations from Africa are genetically the most diverse [2] and that the genetic diversity of non-African populations is negatively correlated with their genetic differentiation towards populations from Africa [3]. Here we add further compelling evidence supporting the RAO model by showing that geographic distance — not genetic distance as in [3] — from East Africa along likely colonisation routes is an excellent predictor for genetic diversity of human populations (R2 = 85%). Our results point to a history of colonisation of the world characterised by a very large number of small bottlenecks [4] and limited subsequent gene flow. The pattern of decrease in genetic diversity along colonisation routes is very smooth and does not provide evidence for major genetic discontinuities that could be interpreted as evidence for human ‘races’ [2,5]. Posted by Djehuti (Member # 6698) on :
^ Yet Assopen chooses to stalk me in every other thread other than the ones that really count to him like this one...
Assopen just begs me and pleads me to screw him, but again I'm not one of his boy-lovers.
If he wants to get screwed here again, just present him the FACTS as usual. Posted by meninarmer (Member # 12654) on :
^ Why are you constantly interrupting the flow of the thread with talk of men screwing?
Doug posted some great photos which I was digging only to yet again see you posting your deviate thoughts, as if a Robot could screw man or woman. I have no desire to form the picture in mind of a Robot performing homosexual acts with a human male. Please stop, or better yet, Please take horrible vision to one of Egmond's threads where it will be appreciated.
Posted by Djehuti (Member # 6698) on :
^ Sorry but I am merely addressing a sour member of the Aprasscee gang that the fag who keeps stalking me belongs to.
I'm not a homosexual, neither do I have anything against homosexuals.
But since I wasn't even addressing you I don't know why you seemed so vexed unless the such talk 'touches' you deeply so to speak.
Posted by Djehuti (Member # 6698) on :
Who wants to play smash the ass in the face?...
Posted by Djehuti (Member # 6698) on :
I see there are no replies from the ass in threads like this that really matter. Yet the ass chooses to make his issue pertaining to this topic in other threads and worse-- stalk me like the deranged schoolgirl he identifies with in his mind...
Posted by MindoverMatter718 (Member # 15400) on :
^upped
wished there were actual moderators to delete the few posts which have no pertinence to the topic on this thread, but hey, for those reading can learn something...
Topic: Distance from Africa, not climate, explains within-population phenotypic diversity
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Good luck explaining that.
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I'm a have to watch thi video again on that one but as far as "Africa" [geographically] just being "the landmass we call 'Africa'" lamin definitely has a point.
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