posted
The way I understand it, North Africans are a gradation of northward expanding African populations and "Eurasians" are a gradation of North and East African populations which is why there's a close genetic relationship between the three. This being the case, where and when did their lighter skin color come into play?
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posted
Similarly, Khoi and San people further away from the equator in SA and Namibia tend to be lighter on average than equatorial Africans. Why you always on skin color?
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quote:Originally posted by Elijah The Tishbite: The way I understand it, North Africans are a gradation of northward expanding African populations and "Eurasians" are a gradation of North and East African populations which is why there's a close genetic relationship between the three. This being the case, where and when did their lighter skin color come into play?
Your description of the genetic situation was discussed many times before with experts like Tishkoff and Cruciani back in the 2001s saying that Eurasians are a subset of Northeast Africans who are in turn a subset of Africans. That said, your last question is somewhat loaded since modern North Africans have admixture from Eurasian back-migrations. But as Lioness points out the Khoisan of Southern Africa also have light skin but the genetics of thier skin color was discussed already.
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quote:Originally posted by Elijah The Tishbite: The way I understand it, North Africans are a gradation of northward expanding African populations and "Eurasians" are a gradation of North and East African populations which is why there's a close genetic relationship between the three. This being the case, where and when did their lighter skin color come into play?
Your description of the genetic situation was discussed many times before with experts like Tishkoff and Cruciani back in the 2001s saying that Eurasians are a subset of Northeast Africans who are in turn a subset of Africans. That said, your last question is somewhat loaded and since modern North Africans have admixture from Eurasian back-migrations. But as Lioness points out the Khoisan of Southern Africa also have light skin but the genetics of thier skin color was discussed already.
I guess what I'm trying to say is were those back-migrating "Eurasians" still dark, or light?
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quote:Originally posted by Elijah The Tishbite: I guess what I'm trying to say is were those back-migrating "Eurasians" still dark, or light?
Depends on which ones you're talking about. IIRC, the Iberomaurisian aDNA samples from Taforalt and the Early Neolithic of Morocco all had ancestral alleles for dark skin despite all the Eurasian admixture they supposedly had, so presumably the Eurasian people their ancestors interbred with were dark as well. The lighter skin you see in the Maghreb today is probably from later incursions, such as the Iberian peninsula during the Neolithic and later.
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ElMaestro in a thread with late user antalas pointed out North Africans light skin is mostly from admixture.
Some North Africans do carry similar mutations around melanin related genes like the Khoisan.
For my metric was the presence of known alleles for pigmentation. You'd have to define Amerindian dark if you want that basis of comparison. Just to save you the details, skin color variation in Africans is complicated, skin color variation outside is simple, Admixed (with Euro) populations lose a whole lot of diversity when it comes to pigmentation related genes. And that's the effect of North Africans today, they have overlap and evidence of selection pressure for the known genes in pigmentation. The lightening was due to admixture.
Introduction to the History of African Civilization: Precolonial Africa Volume 1 By C. Magbaily Fyle · 1999 p 30
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From Every People and Nation A Biblical Theology of Race By J. Daniel Hays · 2016 p.152
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quote: Before the Arabs conquered northwest Africa in the seventh century, Ramzi Rouighi asserts, there were no Berbers. There were Moors (Mauri), Mauretanians, Africans, and many tribes and tribal federations such as the Leuathae or Musulami; and before the Arabs, no one thought that these groups shared a common ancestry, culture, or language. Certainly, there were groups considered barbarians by the Romans, but "Barbarian," or its cognate, "Berber" was not an ethnonym, nor was it exclusive to North Africa. Yet today, it is common to see studies of the Christianization or Romanization of the Berbers, or of their resistance to foreign conquerors like the Carthaginians, Vandals, or Arabs. Archaeologists and linguists routinely describe proto-Berber groups and languages in even more ancient times, while biologists look for Berber DNA markers that go back thousands of years. Taking the pervasiveness of such anachronisms as a point of departure, Inventing the Berbers examines the emergence of the Berbers as a distinct category in early Arabic texts and probes the ways in which later Arabic sources, shaped by contemporary events, imagined the Berbers as a people and the Maghrib as their home.
Key both to Rouighi's understanding of the medieval phenomenon of the "berberization" of North Africa and its reverberations in the modern world is the Kitāb al-'ibar of Ibn Khaldūn (d. 1406), the third book of which purports to provide the history of the Berbers and the dynasties that ruled in the Maghrib. As translated into French in 1858, Rouighi argues, the book served to establish a racialized conception of Berber indigenousness for the French colonial powers who erected a fundamental opposition between the two groups thought to constitute the native populations of North Africa, Arabs and Berbers. Inventing the Berbers thus demonstrates the ways in which the nineteenth-century interpretation of a medieval text has not only served as the basis for modern historical scholarship but also has had an effect on colonial and postcolonial policies and communal identities throughout Europe and North Africa.
________________________________
and this website, you will also see in the table of contents:
The Berber Garamantes Kingdom as well as the rest of berber history
The book Inventing the Berbers does not cover the Garamantes but this one does in depth , read p 431 to 434, this covers
1. THE STEROTYPICAL IMAGE OF THE GARAMANTES
2. THE HISTORIOGRAPHICAL DEBATE
3. THE REAL IMAGE OF THE GARAMANTES
Aghram Nadharif: The Barkat Oasis (Sha'Abiya of Ghat, Libyan Sahara) in Garamantian Times Volume 2 2005, Mario Liverani Mario Liverani (born 1939 ), is an Italian historian and Professor of Ancient Near East History at the University of Rome La Sapienza.
The total population of Tuareg is estimated to be around 4 million and as we can see the whole Berber population is estimated at 36 million but they are spread over a much wider territory than others, also more southerly and thus have a lot of diversity in their population in addition to the wide diversity of so called "Berbers" in general and their sometimes nomadic lifestyle
One of the most problematic aspects is the language and inscriptions attributed to the Garamantes...Sites in the vicinity of Jarma, the Garamantian capital of what is now known as Fazzan, have abundant inscriptions (Fig. 14.7). 67 They are found cut or painted on dark grey amphorae, in the tombs of Garamantian cemeteries, such as those of Saniat bin Huwaydi.68 A recent project under the auspices of the British Library has digitised most of the known inscriptions and these are described in Biagetti et al.69 Although the inscriptions are in Berber characters, only some are decipherable. Various reasons for this have been suggested; either the messages were deliberately coded, so that only specific readers could understand them. Alternatively, they may have had a ‘ludic’ nature. The most exciting possibility is that they were in a non-Berber language, perhaps Nilo-Saharan or something unknown.[14]
Burials, Migration and Identity in the Ancient Sahara and Beyond , pp. 431 - 463 Cambridge University Press: 21 June 2019
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From Every People and Nation A Biblical Theology of Race By J. Daniel Hays · 2016 p.152
First off, modern Berbers are diverse peoples who only have in common related languages and some customs. Thus Berbers range from Nordic looking (pale white with blonde/red hair and blue eyes) to black (chocolate colored) so-called "Hamitic" types, with the majority near the coasts being intermediate or a mix between the two. Such was discussed too many times before like here.
The problem with Snowden is that he subscribes to the racist notion of his time that Ethiopian = 'true Negro' which is hilarious considering that Greco-Roman writers at times included Egyptians in that moniker. Also so-called "Mediterranean" features are common in some Africans like modern day Ethiopians as shown to Antalas here and that so-called "negroid" features were not uncommon among early Iron Age natives of Carthage and Algeria as Antalas admitted here, which does not necessarily mean Sub-Saharan or "true negro" either as I explained on metric data here.
Racist anthropologist Carleton Coon’s photo of a “gracile Mediterranean” Shluh Berber of Morocco
modern day Shluh Moroccan
By the way, ironically enough most linguists agree that the Berber languages diffused and diversified only in the Iron Age, meaning that there were other langauges spoken in the Maghreb before Berber primacy. In fact, Berber is hypothesized to be a branch of a Lybico-Berber subfamily the same way Semitic is a branch of a greater subfamily with Semitic being the only survivor.
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^ Recall the 2013 Metspalu et al. light skin allele SLC245 paper showing the presence of the shared European allele in pre-agricultural India..
^ Note the high concentration of SLC245 in littoral Algeria which corresponds to the settlements of the Neolithic Cardial Ware from Europe as was discussed before.
It is this area that has the highest concentration of white Berbers like Antalas.
quote:Originally posted by Antalas: Most north africans live along the coast and look like me:
Antalas
Though how much of these fair skin alleles in the area are traced to Neolithic immigrants, Medieval Vandals or somewhere in between those periods is another issue.
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Rapid evolution of a skin-lightening allele in southern African KhoeSan
Meng Lin , Rebecca L. Siford, Alicia R. Martin and Brenna M. Henn Edited by Nina G. Jablonski, 2018
Significance Skin pigmentation reflects strong local adaptation to latitude after humans migrated around the globe. In the Northern Hemisphere, the gene SLC24A5 plays a key role in the genetic basis of light skin pigmentation, where a nonsynonymous mutation in the gene has swept to fixation in contemporary Europeans. Although considered European-specific, we find this mutation at an unexpectedly high frequency in light-skinned KhoeSan from South Africa, far exceeding the European gene flow during colonial migration. Using haplotype analysis and comprehensive demographic modeling including positive selection, we show that this is an example of surprisingly strong adaptation of a recently introduced allele, via back-to-Africa migration, which occurred less than 2,000 y ago.
Discussion Here, we have demonstrated that the derived rs1426654*A in SLC24A5 in the KhoeSan has a common origin with Europeans, reflected by the similar tMRCA estimates and identical modal haplotypes. This is consistent with the extended haplotype similarity observed between San from Botswana and Europeans (17). We asked whether the common origin of rs1426654*A haplotype could be due to recent migration between Europe and South Africa, or via an indirect route of migration through eastern Africa. A pastoralist migration from eastern Africa to southern Africa 2 kya is well documented from human genetic and archaeological data, and is likely associated with the introduction of domestic sheep and goats into the region. The summary statistics in our demographically explicit ABC approach clearly discriminate between the East African Source and European Source models, and strongly favor the East African Source model (Materials and Methods and SI Appendix, Supplementary Text). We cannot speculate as to the precise geographic origin of this allele, due to the limited sequencing data from eastern African and Near Eastern populations. Additionally, the allele frequency of rs1426654*A in the KhoeSan exceeds the expected frequency under a neutral, migration-based scenario. Both deterministic modeling and simulation of complex demography suggest strikingly strong positive selection on this allele in far southern Africa (s = 0.04 to 0.05), similar to the strength of its counterpart in Europe at high northern latitudes [s = 0.08 under an additive model (21)]. The modal values of the selection coefficients from our modeling are primarily shaped by the current allele frequency, with minor updates to s from the ABC (SI Appendix, Fig. S7). Our selection coefficients are comparable to or exceed other well-known examples of positive selection, including lactase persistence in Europeans [s = 0.012 (32)] and eastern Africans [s = 0.035 to 0.097 (33)], malaria resistance [s = 0.02 to 0.20 (34)], and other pigmentation genes in Europeans [s = 0.02 to 0.04 (21)]. Furthermore, the selective sweep, albeit incomplete, appears to have occurred in fewer than 1,500 y, making it one of the few examples of selection during very recent human history. We have shown that the phenotypic consequences of rs1426654*A have a large effect on the pigmentation of present-day KhoeSan; individuals who carry the derived homozygote are 14% lighter than the population average. The biological or cultural advantage of the lighter pigmentation phenotype remains to be tested in southern Africa. The southern tip of Africa receives relatively lower ultraviolet radiation intensity (35), which would serve as the major driving force of selection on the lighter skin pigmentation of the local populations. Additional selection force may have come from a possible diet shift about 2,000 y ago as evidenced in the Cape and coastal regions, as Khoekhoe populations transitioned from vitamin D-enriched marine fish and terrestrial food, likely including animal liver, to pastoralism (36–38). This decrease of dietary intake of vitamin D could have accelerated depigmentation for more photosynthesis of vitamin D, to promote calcium absorption, bone formation and innate immunity. However, as the ≠Khomani San live in the southern Kalahari and many individuals were still practicing a hunter-gatherer subsistence 100 y ago, it is unclear how the transition to pastoralism might have impacted their ancestors. It is particularly interesting to note that the model of evolution at SLC24A5 is remarkably similar to selection for the eastern African lactase persistence allele in the Nama (11). An alternative hypothesis is that sexual selection for light skin pigmentation drove the allele frequency. We find the third hypothesis unlikely, as this sexual preference would make most sense under the European colonialist regime, but we find that that selection most likely began before European arrival (East Africa Source model; SI Appendix). While the biological cause of the selective event merits further investigation, we have demonstrated an unusually rapid case of selection for lighter skin pigmentation based on a recently introduced allele <2,000 y ago, the first case of pigmentation adaptation from migration in humans.
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quote:Originally posted by Djehuti: In fact, I've always questioned just how Eurasian is the SLC24A5 gene and for good reason.
Pigmentary Diversity: Identifying the genes causing human diversity SLC24A5 has a striking pattern of variation in human populations. A coding variant in the gene has previously been described as one of a set of ancestry-informative markers. The ancestral form encodes alanine at residue 111, whereas a derived allele encodes threonine. Alanine is present at this position in all known members of the SLC24 subfamily of proteins, suggesting the change to threonine has functional consequences. The derived variant is universally present on all European chromosomes analysed, while chromosomes of *African* and Asian origin almost invariably carry the ancestral form. The population difference puts this variant in the top 0.01% of all variants studied. Furthermore, analysis of the HapMap Consortium data6 found that SLC24A5 was within a chromosomal region that has a striking reduction of heterozygosity of SNPs in the European population. In fact, at 150 kb it is the longest such segment identified in the genome.1 Such a long conserved homozygous haplotype indicates that there has been strong selection on a gene or genes, which has swept this segment across the population, and selection for homozygosity eliminated recombination between SNPs, which maintained a long haplotype.
Another solute channel gene SLC45A2, or MATP, which is affected in human, mouse and fish pigmentary mutants, also shows strong association with ethnic ancestry. More than 90% of European chromosomes have a derived allele which is rare or absent in Africans. The small number of people of European descent with the ancestral form of the gene appear to have significantly more pigmented skin and there is clear evidence for a selective sweep of the chromosomal segment around the SLC45A2 in the European population.
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North Africans became light skin the same time as Europeans. Residual/favored mutations after the last ice age. It wasn't during, it wasn't right after it was slowly after. 6000 BC - 1200 BC. Back migrating Eurasians had little to do with it until the Egyptian invasions and Rome's occupation of parts of North Africa.
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posted
This is a topic I feel should be discussed more. You have some good arguments that argue that light skin could be indignous to that part of Africa but that's another story.
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quote:Originally posted by Forty2Tribes: North Africans became light skin the same time as Europeans. Residual/favored mutations after the last ice age. It wasn't during, it wasn't right after it was slowly after. 6000 BC - 1200 BC.
yes but you made that all up
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quote:Originally posted by the lioness,: yes but you made that all up
I made up the conclusion. I didn't make up people living near water and how the northern tip of Africa was a glacier during the Ice Age. North Africans have always had light skin, hair, eye pigment genes. They were just punished for expressing them until the Ice Age.
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Hopefully better techniques to retrieve and analyze DNA from human remains will help to also see how those ancient people looked like. Already now they start to try to assess phenotype from DNA out of just fragments of skeletons, and soon perhaps also from eDNA.
Interesting is that they tried to make some kind of reconstructions from the autosomal DNA from three of the Abusir specimens.
Even the phenotype of the Denisovans has been predicted by DNA analysis
quote: Now, in an impressive feat, Gokhman and his colleagues have mapped out a proposed Denisovan skeleton using information for 32 skeletal features encoded in DNA that was extracted from a pinky bone. The research, published today in the journal Cell, doesn’t give exact values for Denisovan proportions, but it does offer a comparative look at how this mysterious kind of hominin measured up against Homo sapiens and Neanderthals.
quote:Originally posted by Archeopteryx: Hopefully better techniques to retrieve and analyze DNA from human remains will help to also see how those ancient people looked like. Already now they start to try to assess phenotype from DNA out of just fragments of skeletons, and soon perhaps also from eDNA.
Interesting is that they tried to make some kind of reconstructions from the autosomal DNA from three of the Abusir specimens.
Even the phenotype of the Denisovans has been predicted by DNA analysis
quote: Now, in an impressive feat, Gokhman and his colleagues have mapped out a proposed Denisovan skeleton using information for 32 skeletal features encoded in DNA that was extracted from a pinky bone. The research, published today in the journal Cell, doesn’t give exact values for Denisovan proportions, but it does offer a comparative look at how this mysterious kind of hominin measured up against Homo sapiens and Neanderthals.
That DNA study has been discussed here before and such techniques are not necessarily accurate. The only way to prove that this DNA based method works is to take random individuals from around the world and submit their DNA this process in the blind. Meaning have the labs run the DNA and see what skin color it predicts without them actually knowing anything about the individuals being sampled. Then compare their results with reality.
The issue is that reconstructions are always going to be subjective in many aspects. That is why it is always to be taken with a grain of salt, not just for skin color but overall fleshy features and appearance.
Beyond that, Denisovans arent humans and we know what the first humans in Asia looked like. That isnt really a mystery needing to be solved. Not to mention, we also know for a fact that black skin was always present in Northern Africa. The issue is when did white skin become dominant in North Africa, because a few immigrants doesn't change an entire population. And we know for a fact that Africans across the continent have variation in skin tones, without Eurasian influence. So light skin was always present to some degree in North Africa as well. Not to mention "North Africa" as a region covers thousands of square miles and it is impossible to claim that populations along the coast are representative of the entire region in time and space. Populations in Southern Algeria and Libya are on average much darker than those in the North of these countries and have been for quite some time. So lumping all people in Northern Africa together as having the same complexion is just not based on facts or reality.
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Well obviously they were human enough for some of our ancestors to make babies with them. And since they seem to have been able to get fertile offspring it shows that we were very closely related. So in one way we must call them humans, even if somewhat different. In their case we did not know so very much how they looked since we just have a few bones preserved. Hopefully we will find more complete skeletons in the future so we can compare their morphology with what the DNA showed. It seems research about both neanderthals and denisovans have rendered enough interest to motivate a Nobelprize to Svante Pääbo who has sequenced their genomes.
Also in Africa it seems that Homo sapiens mixed with one or more kinds of archaic humans, but we know even less about them than what we know of Denisovans since we can not yet tie them to any skeletons or other human remains.
About light skin in Asia it seems to first have evolved somewhere between 20 000 and 30 000 years ago. Seems that light skin evolved separately in Europeans and Asians since it is partly different genes involved who came under selection. Then it took time before these genes came to dominate in respective area.
With better methods of analysing aDNA, and with more samples we will of course get a more detailed knowledge about when and where. That also goes for other physical traits.
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Well obviously they were human enough for some of our ancestors to make babies with them. And since they seem to have been able to get fertile offspring it shows that we were very closely related. So in one way we must call them humans, even if somewhat different. In their case we did not know so very much how they looked since we just have a few bones preserved. Hopefully we will find more complete skeletons in the future so we can compare their morphology with what the DNA showed. It seems research about both neanderthals and denisovans have rendered enough interest to motivate a Nobelprize to Svante Pääbo who has sequenced their genomes.
Also in Africa it seems that Homo sapiens mixed with one or more kinds of archaic humans, but we know even less about them than what we know of Denisovans since we can not yet tie them to any skeletons or other human remains.
Thats fine and dandy but the point still stands Denisovans aren't human and we know how humans got to Asia. And Denisovans are not a key to human migration to or evolution in Asia, which is implied by this statement. Aboriginal Australians and the Aborigines of the Andamans do not have any Denisovan DNA and those two groups are some of representatives of the oldest human populations in Asia. Not to mention the fact that MOST of the mixing between humans and ancient hominids took place in Africa because that is the birthplace of the hominid family tree to begin with.
quote:Originally posted by Archeopteryx: About light skin in Asia it seems to first have evolved somewhere between 20 000 and 30 000 years ago. Seems that light skin evolved separately in Europeans and Asians since it is partly different genes involved who came under selection. Then it took time before these genes came to dominate in respective area.
With better methods of analysing aDNA, and with more samples we will of course get a more detailed knowledge about when and where. That also goes for other physical traits.
Using DNA to determine skin color is not an exact science because skin color varies and there is no singe DNA value that is going to tell you the exact skin complexion of a person. There are multiple various DNA codes that relate to skin color and how they combine for a specific tone or complexion is not fixed but varies across populations and individuals. Not to mention, "light skin" is not a single color but a range of complexions just like "dark skin" isn't a single value but a range of values. So like I was saying before, until we get a study showing an exact correlation between skin color genes and specific tones in a living person, it will remain ambiguous at best. Most of the times these kinds of studies using statistical models use reference populations but those populations are not "universal" and cannot provide the kind of accuracy required for ancient populations across the globe.
Also the evolution of "lighter skin" in Africa did not start with Eurasians but that doesn't necessarily mean as light as the lightest Europeans. And most people obsessing with light skin in North Africa are specifically focusing on Eurasian arrival into North Africa.
quote: While many have turned to science to falsely support the notion of a biological construct of race, modern research has demonstrated genetics has little to do with it. Now, as Ed Yong at The Atlantic reports, a large-scale study of skin pigmentation demonstrates that humans with both light and dark skin pigmentation have co-existed for hundreds of thousands of years.
A long-standing assumption about the evolution skin color was that Homo sapiens started out in Africa with darkly pigmented skin, full of melanin to protect from the intense ultraviolet radiation from the sun. As humans migrated out of Africa, it was believed that mutations led to lighter skin that can supposedly regulate vitamin D production in lower sunlight levels. But the new study, published in the journal Science, shows that the evolution of skin color is much more complex.
A team of researchers led by Sarah Tishkoff at the University of Pennsylvania and her postdoctoral fellow Nicholas Crawford measured the skin pigmentation of over 2,000 genetically and ethnically diverse people across Tanzania, Ethiopia and Botswana. They analyzed the genome of nearly 1,600 of those people, which allowed them to identify eight key areas in the DNA associated with skin pigmentation.
As Colin Barras at New Scientist reports, each of these sites had genetic variants associated with paler skin and ones associated with darker skin. Seven genetic variants associated with lighter skin developed at least 270,000 years ago and four more than 900,000 years ago. Considering our species, Homo sapiens, did not evolve until around 200,00 to 300,000 years ago, the discovery suggests that the genes responsible for lighter skin tones were present into the genetic material of our hominin ancestors—hundreds of thousands of years before the first humans walked the Earth.
quote:Originally posted by Doug M: Thats fine and dandy but the point still stands Denisovans aren't human and we know how humans got to Asia. And Denisovans are not a key to human migration to or evolution in Asia, which is implied by this statement. Aboriginal Australians and the Aborigines of the Andamans do not have any Denisovan DNA either and those two groups are be representative of the oldest human populations in Asia. Not to mention the fact that MOST of the mixing between humans and ancient hominids took place in Africa because that is the birthplace of the hominid family tree to begin with.
Actually Australian aborigines do have Denisovan DNA, but the Andamanese have not. Most Denisovan DNA has a people in the Philippines. People from Papua New Guinea also have a high percentage of Denisovan DNA.
Homo sapiens mixed with archaic humans in Africa, we also mixed with neanderthals in the Middle East and Europe and we mixed probably more than one time with Denisovans in different parts of Asia. Perhaps we mixed with three different groups of Denisovans who had slightly genetical differencies from each other.
Also Denisovans and Neanderthals seem to have mixed with each other.
When it concerns if Denisovans were human or not one can only imagine if they would have managed to survive until today. Would we have regarded them as humans or not? They belonged to the same genus as we and they could get fertile offspring with us, so I would regard them as humans.
quote: Originally posted by Doug M: Using DNA to determine skin color is not an exact science because skin color varies. "Light skin" is not a single color but a range of complexions just like "dark skin" isn't a single value but a range of values. So like I was saying before, until we get a study showing an exact correlation between skin color genes and specific tones in a living person, it will remain ambiguous at best. Also the evolution of "lighter skin" in Africa did not start with Eurasians but that doesn't necessarily mean as light as the lightest Europeans. And most people obsessing with light skin in North Africa are specifically focusing on Eurasian arrival into North Africa. While many have turned to science to falsely support the notion of a biological construct of race, modern research has demonstrated genetics has little to do with it. Now, as Ed Yong at The Atlantic reports, a large-scale study of skin pigmentation demonstrates that humans with both light and dark skin pigmentation have co-existed for hundreds of thousands of years.
A long-standing assumption about the evolution skin color was that Homo sapiens started out in Africa with darkly pigmented skin, full of melanin to protect from the intense ultraviolet radiation from the sun. As humans migrated out of Africa, it was believed that mutations led to lighter skin that can supposedly regulate vitamin D production in lower sunlight levels. But the new study, published in the journal Science, shows that the evolution of skin color is much more complex. https://www.smithsonianmag.com/smart-news/genetic-study-shows-skin-color-just-skin-deep-180965261/
A big study in South America has looked at the genetics behind skin color and one can see that light skin color arose separately in Europeans and Asians, and probably before that in Africa. But hopefully the methods to assess skin color from DNA will get better so we can know more in detail when, where and why we have different skin tones.
quote:The study, published in the journal Nature Communications, found that the variation of light skin among Eurasian people evolved independently from different genetic backgrounds.
The genetic study analysed pigmentation in over 6,000 Latin Americans, who have a mix of Native American, European and African ancestry.
It is well established that Native Americans are genetically closely related to East Asians, the initial settlement of the Americas occurring some 15-20,000 years ago, through migration from Eastern Siberia into North America. As a consequence, genetic variations in Native Americans are often shared with East Asians.
This study identifies five new associated regions involving skin, eye and hair colour. Genes affecting skin colour in Europeans have been extensively studied, but here researchers identified an important variation in the gene MFSD12 seen uniquely in East Asians and Native Americans.
They show it was under natural selection in East Asians after they split from Europeans around 40,000 years ago, and was then carried over to America by ancient migrations of Native Americans. It is the first time this gene has been linked to skin colour in Native Americans and East Asians.
Dr Kaustubh Adhikari (UCL Genetics Institute), said: "Our work demonstrates that lighter skin colour evolved independently in Europe and East Asia. We also show that this gene was under strong natural selection in East Asia, possibly as adaptation to changes in sunlight levels and ultraviolet radiation."
quote:Originally posted by Doug M: Thats fine and dandy but the point still stands Denisovans aren't human and we know how humans got to Asia. And Denisovans are not a key to human migration to or evolution in Asia, which is implied by this statement. Aboriginal Australians and the Aborigines of the Andamans do not have any Denisovan DNA either and those two groups are be representative of the oldest human populations in Asia. Not to mention the fact that MOST of the mixing between humans and ancient hominids took place in Africa because that is the birthplace of the hominid family tree to begin with.
Actually Australian aborigines do have Denisovan DNA, but the Andamanese have not. Most Denisovan DNA has a people in the Philippines. People from Papua New Guinea also have a high percentage of Denisovan DNA.
Homo sapiens mixed with archaic humans in Africa, we also mixed with neanderthals in the Middle East and Europe and we mixed probably more than one time with Denisovans in different parts of Asia. Perhaps we mixed with three different groups of Denisovans who had slightly genetical differencies from each other.
Also Denisovans and Neanderthals seem to have mixed with each other.
The mixing of humans and hominids isn't special is my point. Again, the hominid family tree originated millions of years ago in Africa and they have been mixing every since. HSS are the last of a long line of species of hominids that emerged from Africa and migrated to other parts of the globe. And as I posted previously, the skin color of HSS already included ancient genetic mutations for light and dark skin from previous hominid ancestors. That didn't come from neanderthal or denisovan mixture. People keep trying to make more of this than it really is as if hominids didn't originate in Africa, including Denisovans and Neanderthals. We know how humans migrated into Asia and Denisovans and Neanderthals are not "key" to understanding that because all those early groups did not mix with them. And honestly at one point Europeans used to call various aboriginal popultions "primitive hominids".
But to the point of this thread, skin color genes for "light" and "dark" skin have always been in humans since the beginning. However, over time different populations have evolved novel mutations to those genes in various circumstances. This is why it is not possible to say there is one single gene responsible for skin color. It is more complex than that.
quote:Originally posted by Archeopteryx: When it concerns if Denisovans were human or not one can only imagine if they would have managed to survive until today. Would we have regarded them as humans or not? They belonged to the same genus as we and they could get fertile offspring with us, so I would regard them as humans.
Then if that is the case then all archaic hominids are humans then, but they aren't. Again, humans are the last of the ancient hominid species to spread from Africa and the most successful. Not Denisovans or Neanderthals.
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Actually the genus Homo is often called humans in the literature, even if they were different species (or possibly subspecies). As i said we could interbreed with both Neanderthals and Denisovans and get fertile offspring, that fact alone justifies calling them humans. Also in other aspect they were human, having good cognitive abilities, making relatively advanced tools, and having behavioral patterns that are considered human. Some of the earlier hominins were maybe not so compatible, and they were also separated in time from us. One can also wonder about species like Homo floresiensis and Homo luzonensis, they seem to have been more unlike us than neanderthals or denisovans. But generally speaking those we mated with are also regarded as humans. As I said if some neanderthals or denisovans would have survived until today we would most probably have considered them human.
Some people also today would probably mated with them and got babies with them. Those people would hardly regard their partners as some kind of alien animals.
One must also remember that not so long time ago not even all members of our own species (modern Homo sapiens) were considered fully human.
About skin color, yes skin color is complex and an interplay between different genes, but it seems we learn more and more about these genes and how they affect skin color.
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quote:Originally posted by Archeopteryx: Actually the genus Homo is often called humans, even if they were different species (or possibly subspecies). As i said we could interbreed with both Neanderthals and Denisovans and get fertile offspring, that fact alone justifies calling them humans. Also in other aspect they were human, having good cognitive abilities, making relatively advanced tools, and having behavioral patterns that are considered human. Some of the earlier hominins were maybe not so compatible, and they were also separated in time from us. One can also wonder about species like Homo floresiensis and Homo luzonensis, they seem to have been more unlike us than neanderthals or denisovans. But generally speaking those we mated with are also regarded as humans. As I said if some neanderthals or denisovans would have survived until today we would most probably have considered them human.
Some people also today would probably mated with them and got babies with them. Those people would hardly regard their partners as some kind of alien animals.
About skin color, yes skin color is complex and an interplay between different genes, but it seems we learn more and more about these genes and how they affect skin color.
The discovery of ancient hominids at Jebel Irhoud going back 300,000 years ago shows that archaic hominids of all types have existed in Africa for millions of years. There is nothing "special" about Neanderthals and Denisovans as they are simply a branches of the hominid family tree. What is at issue here is the scientific classification of ancient skeletal remains and if you look at the history of such, you will see many theories. At the end of the day there is no complete skull of a Denisovan and everything about them is based purely on theoretical DNA evidence. Neanderthals are much more well established as a species of homo erectus. But again, in Africa if you actually look at the skulls being found going back over 100,000 years you will see many variations, this is how you get Homo Naledi in South Africa. So really hominids of all types have been roaming around in Africa for millions of years and mixing, but this is something that only has come to the forefront relatively recently. Most of the history of the scientific classification of hominid species has been focused on Eurasia and at one time there was an out of Asia theory as well. This really isn't the thread for it though and I don't want to sidetrack it on a tangent discussion.
quote: Any model consistent with our data requires a more dynamic scenario and a more complex population structure than the one implied by the classic Out-of-Africa model. Our findings on neurocranial shape diversity are consistent with the assumption that intra-African population expansions (21, 22) produced temporarily subdivided and isolated groups (8, 26). In such a metapopulation model, transient populations are connected by migration, subject to extinction and rebirth by colonization, as well as to fluctuation in local size (7, 27). This view is in agreement with recent genetic results (28) suggesting divergence of some recent human populations from the rest of the human mtDNA pool 90–150,000 years ago, and isolation times between 50 and 100,000 years. Separated demes (population subdivisions) might have partly merged again, whereas others left Africa at different times and maybe using different routes, and still others probably also remigrated to Africa.
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Seemingly ancient contributions to the modern human gene pool (36) have been explained by admixture with archaic forms of Homo, e.g., Neanderthals. Although we cannot rule out such admixture (37), the clear morphological distinction between AMH and archaic forms of Homo in the light of the proposed ancestral population structure of early AMH to us suggests another underestimated possibility: the genetic exchange between subdivided populations of early AMH as a potential source for “ancient” contributions to the modern human gene pool (9, 36).
Although more data are needed to corroborate our inferences, we could clearly demonstrate the pronounced variability of early AMH and their morphological relationship to modern humans. It is crucial for any analysis, genetic or phenetic, of modern human origins to take into account this Late Pleistocene African diversity that predates the range expansions into Eurasia. The molecular and fossil evidence of the African continent deserves more attention in the modern human origins debate.
Suffice to say this is a tangent discussion but again, the genes for skin color variation have always been in Africa and various populations in Africa have different complexions due to that. This issue with North African skin color is primarily derived from a question of when Eurasians entered into North Africa and affected the morphology of the populations there.
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Humans in some form have existed outside Africa for nearly two million years, and new species have now and then left Africa and replaced and/or mixed with the older ones.
Neanderthals and denisovans are not so special, the only thing is maybe that the neanderthals have been known longer time than many other archaic humans, and they are maybe the ones that are most researched (which is not so strange since the first neanderthal remains were found in Europe and at that time it was mostly Europeans who conducted that kind of research). But gradually more and more other ancient human species have been discovered and researched. Probably there are still different species to be found. Now and then new variants pops up, like H. floresiensis and H. luzonesis in Asia. Actually we seem to find some new fossils nearly every year. All these species have their origins in Homo erectus but have adapted to different environments.
We know DNA from Denisovans, we have some bones, including a half lower jaw, some teeth, and we maybe we have parts of a couple of skulls, if they can be shown to be Denisovans. Some of the African archaic humans that introgressed into Homo sapiens are also very little known, they exist as a kind of shadow DNA in modern humans.
Still there are many discoveries to be make, and often we also get news from researchers like Svante Pääbo who even got a nobel prize for his research about neanderthals and denisovans and their introgressions into Homo sapiens.
Still 50 000 years from now there were still maybe fem or six, or even more speparate species of humans, before modern Homo sapiens in the end became the only version of humans left on earth.
Here is a couple of more recent articles about the interplay between archaic humans and Homo sapiens
quote:Originally posted by Archeopteryx: Hopefully better techniques to retrieve and analyze DNA from human remains will help to also see how those ancient people looked like. Already now they start to try to assess phenotype from DNA out of just fragments of skeletons, and soon perhaps also from eDNA.
Interesting is that they tried to make some kind of reconstructions from the autosomal DNA from three of the Abusir specimens.
Even the phenotype of the Denisovans has been predicted by DNA analysis
quote: Now, in an impressive feat, Gokhman and his colleagues have mapped out a proposed Denisovan skeleton using information for 32 skeletal features encoded in DNA that was extracted from a pinky bone. The research, published today in the journal Cell, doesn’t give exact values for Denisovan proportions, but it does offer a comparative look at how this mysterious kind of hominin measured up against Homo sapiens and Neanderthals.
This is a good example of the bias in pigment predictors. I looked at the raw data behind the Denisovan and they had a darker pigment gene profile than the Africans. According to their genes, they should be Dinka dark. Likewise the Abu Sir 3 probably should have been darker too. If Bob Marley is the standard I remember one of them having darker pigment genes than a mixed Jamaican, one was very close to the mixed Jamaican and the other was lighter. All three of them look lighter than Marley in the prediction.
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Its the same source from my old Black Neanderthal video. Its in the description. Denisovans pigment genes were compared to a bunch of people and they had darker pigment genes than the all the homosapiens.
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Here is one study which discusses eventual variability in Neanderthal skin color and how different genes for phenotype also can have affected modern humans through introgressions.
Since Neanderthals inhabited several environments, some on relatively high latitudes during a longer time than modern Homo sapiens it would not be surprising if their phenotypes can have varied just like modern humans.
And regarding Denisovans we have not DNA from very many places (actually we have aDNA from one location) so maybe we have not caught the variation that can have occurred among them.
quote: Assessing the genetic contribution of Neanderthals to non-disease phenotypes in modern humans has been difficult because of the absence of large cohorts for which common phenotype information is available. Using baseline phenotypes collected for 112,000 individuals by the UK Biobank, we can now elaborate on previous findings that identified associations between signatures of positive selection on Neanderthal DNA and various modern human traits but not any specific phenotypic consequences. Here, we show that Neanderthal DNA affects skin tone and hair color, height, sleeping patterns, mood, and smoking status in present-day Europeans. Interestingly, multiple Neanderthal alleles at different loci contribute to skin and hair color in present-day Europeans, and these Neanderthal alleles contribute to both lighter and darker skin tones and hair color, suggesting that Neanderthals themselves were most likely variable in these traits.
Dannemann, M., & Kelso, J. (2017). The Contribution of Neanderthals to Phenotypic Variation in Modern Humans.` The American Journal of Human Genetics, 101(4), 578–589.
According to this map we have light sin alleles in Europeans about 22 000 to 28 000 years ago, and alleles for blonde hair around 18 000 years ago.
Seems that alleles for light skin arose also among Asians at that time or maybe earlier.
Natural selection affects humans too with different adaptations in different environments, so it would be a bit strange if Neanderthals and Denisovans all looked alike regarding skin color, hair color and other traits.
The National Geographic article about Denisovan traits did not mention skin color, it concentrated on skeletal elements. The picture is an artistic reconstruction which wants to catch the shape of the Denisovans head based on such elements.
Skin and hair are more artistic license.
But there is also this model which does not show skin color, even if it shows hair.
A 3D-printed reconstruction of a female Denisovan. Photo by Maayan Harel
There is also a somewhat darker version of the drawing
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About bias in facial reconstructions, and even more in works of art, they probably can contain some bias, depending on who has made them. Maybe we all have a wish to identify with these ancient humans so we want them to have some resemblance to us. So black artists maybe tend to make somewhat darker reconstructions and white artists will make somewhat lighter reconstructions.
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quote:Originally posted by Archeopteryx: About bias in facial reconstructions, and even more in works of art, they probably can contain some bias, depending on who has made them. Maybe we all have a wish to identify with these ancient humans so we want them to have some resemblance to us. So black artists maybe tend to make somewhat darker reconstructions and white artists will make somewhat lighter reconstructions.
An important difference being that white(and pretty much any other non-Black person) reconstructionists are accorded an automatic presumption of competence and objectivity in their reconstructions that black reconstructionists are not given no matter their rigor or qualifications.
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quote:Originally posted by Archeopteryx: Humans in some form have existed outside Africa for nearly two million years, and new species have now and then left Africa and replaced and/or mixed with the older ones.
Want to provide any scientific study or source stating such a thing? Because the oldest HSS remains are about 300,000 years old and only found in Africa. Archaic hominids are not humans and humans evolved exclusively in Africa for hundreds of thousands of years before leaving the continent and they coexisted with remnants of other hominids that existed in Africa for millions of years. That happened in no other place.
quote:Originally posted by Archeopteryx: Neanderthals and denisovans are not so special, the only thing is maybe that the neanderthals have been known longer time than many other archaic humans, and they are maybe the ones that are most researched (which is not so strange since the first neanderthal remains were found in Europe and at that time it was mostly Europeans who conducted that kind of research). But gradually more and more other ancient human species have been discovered and researched. Probably there are still different species to be found. Now and then new variants pops up, like H. floresiensis and H. luzonesis in Asia. Actually we seem to find some new fossils nearly every year. All these species have their origins in Homo erectus but have adapted to different environments.
Humans as in homo sapien sapiens only evolved in Africa and nowhere else. Ancient hominids like homo erectus are not humans but they too originated in Africa.
quote:Originally posted by Archeopteryx: We know DNA from Denisovans, we have some bones, including a half lower jaw, some teeth, and we maybe we have parts of a couple of skulls, if they can be shown to be Denisovans. Some of the African archaic humans that introgressed into Homo sapiens are also very little known, they exist as a kind of shadow DNA in modern humans.
Still there are many discoveries to be make, and often we also get news from researchers like Svante Pääbo who even got a nobel prize for his research about neanderthals and denisovans and their introgressions into Homo sapiens.
Still 50 000 years from now there were still maybe fem or six, or even more speparate species of humans, before modern Homo sapiens in the end became the only version of humans left on earth.
Here is a couple of more recent articles about the interplay between archaic humans and Homo sapiens
Again archaic humans outside of Africa have nothing to do with the origin of the skin color genes in homo sapiens sapiens. I already provided you a source stating this clearly, yet you persist in trying to act like archaics outside of Africa have something to do with it. Humans have been in North Africa for 300,000 years. And for most of that time they were darker skinned but that still included variation with some on the lighter end of the scale without any Eurasian input.
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quote:Originally posted by Punos_Rey: An important difference being that white(and pretty much any other non-Black person) reconstructionists are accorded an automatic presumption of competence and objectivity in their reconstructions that black reconstructionists are not given no matter their rigor or qualifications.
^^ That is one factor. But probably some other factors do also matter in how your reconstruction will be perceived: For example are you connected to, or have made reconstructions for a major institution (like a university or museum) or magazine? Do you work alone or together with scientists? Have you access to for example casts of skulls, or 3D- visual data in a computer? So also among whites a person without formal attachment to academia (or major magazines) will probably not be taken as seriously as one who is backed by such entities. But admittedly are these issues connected since fewer Black (and other non whites) are working for these major institutions.
Thus one can for example see a difference in "status" (at least in the academic world) between Oscar Nilsson who often works for major institutions, and Ancestral Whispers who works from photos and who mostly works online, and who are more or less anonymous.
But admittedly things like race or ethnicity also plays a role, since fewer Blacks (or other non Whites) are connected to major institutions or magazines.
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quote: Posted by Doug M Want to provide any scientific study or source stating such a thing? Because the oldest HSS remains are about 300,000 years old and only found in Africa. Archaic hominids are not humans and humans evolved exclusively in Africa for hundreds of thousands of years before leaving the continent and they coexisted with remnants of other hominids that existed in Africa for millions of years. That happened in no other place.
When I talked about humans I meant in a broader sense, not only Homo sapiens. For example remains of Homo are found in Georgia which are around 1,8 million years old.
quote:Posted by Doug M Again archaic humans outside of Africa have nothing to do with the origin of the skin color genes in homo sapiens sapiens. I already provided you a source stating this clearly, yet you persist in trying to act like archaics outside of Africa have something to do with it. Humans have been in North Africa for 300,000 years. And for most of that time they were darker skinned but that still included variation with some on the lighter end of the scale without any Eurasian input.
Did I not just post a study that shows that archaic genes can have a role in the phenotype of Homo sapiens outside Africa?
quote:Here, we show that Neanderthal DNA affects skin tone and hair color, height, sleeping patterns, mood, and smoking status in present-day Europeans. Interestingly, multiple Neanderthal alleles at different loci contribute to skin and hair color in present-day Europeans, and these Neanderthal alleles contribute to both lighter and darker skin tones and hair color, suggesting that Neanderthals themselves were most likely variable in these traits.
Dannemann, M., & Kelso, J. (2017). The Contribution of Neanderthals to Phenotypic Variation in Modern Humans.` The American Journal of Human Genetics, 101(4), 578–589. https://tinyurl.com/yv32hbd9
You can of course deny that, or criticize those authors, it is up to you.
If archaic humans are humans is of course a matter of definition, but many sources actually define them as human.
quote: Posted by Doug M Want to provide any scientific study or source stating such a thing? Because the oldest HSS remains are about 300,000 years old and only found in Africa. Archaic hominids are not humans and humans evolved exclusively in Africa for hundreds of thousands of years before leaving the continent and they coexisted with remnants of other hominids that existed in Africa for millions of years. That happened in no other place.
When I talked about humans I meant in a broader sense, not only Homo sapiens. For example remains of Homo are found in Georgia which are around 1,8 million years old.
quote:Posted by Doug M Again archaic humans outside of Africa have nothing to do with the origin of the skin color genes in homo sapiens sapiens. I already provided you a source stating this clearly, yet you persist in trying to act like archaics outside of Africa have something to do with it. Humans have been in North Africa for 300,000 years. And for most of that time they were darker skinned but that still included variation with some on the lighter end of the scale without any Eurasian input.
Did I not just post a study that shows that archaic genes can have a role in the phenotype of Homo sapiens outside Africa?
quote:Here, we show that Neanderthal DNA affects skin tone and hair color, height, sleeping patterns, mood, and smoking status in present-day Europeans. Interestingly, multiple Neanderthal alleles at different loci contribute to skin and hair color in present-day Europeans, and these Neanderthal alleles contribute to both lighter and darker skin tones and hair color, suggesting that Neanderthals themselves were most likely variable in these traits.
Dannemann, M., & Kelso, J. (2017). The Contribution of Neanderthals to Phenotypic Variation in Modern Humans.` The American Journal of Human Genetics, 101(4), 578–589. https://tinyurl.com/yv32hbd9
You can of course deny that, or criticize those authors, it is up to you.
I posted this earlier and you just keep ignoring it in the context that AMH or Homo Sapien Sapiens got their genetics for light skin before even leaving Africa as inherited from archaic hominid ancestors in Africa. The idea that this only happened as a result of neanderthal mixture is silly. Again, like I said before, the point is that "lighter skin" has always existed to some degree in parts of Africa and does not require Eurasian mixture to explain it. Human diversity originates in Africa not Eurasia.
quote:
While many have turned to science to falsely support the notion of a biological construct of race, modern research has demonstrated genetics has little to do with it. Now, as Ed Yong at The Atlantic reports, a large-scale study of skin pigmentation demonstrates that humans with both light and dark skin pigmentation have co-existed for hundreds of thousands of years.
A long-standing assumption about the evolution skin color was that Homo sapiens started out in Africa with darkly pigmented skin, full of melanin to protect from the intense ultraviolet radiation from the sun. As humans migrated out of Africa, it was believed that mutations led to lighter skin that can supposedly regulate vitamin D production in lower sunlight levels. But the new study, published in the journal Science, shows that the evolution of skin color is much more complex.
A team of researchers led by Sarah Tishkoff at the University of Pennsylvania and her postdoctoral fellow Nicholas Crawford measured the skin pigmentation of over 2,000 genetically and ethnically diverse people across Tanzania, Ethiopia and Botswana. They analyzed the genome of nearly 1,600 of those people, which allowed them to identify eight key areas in the DNA associated with skin pigmentation.
[bAs Colin Barras at New Scientist reports, each of these sites had genetic variants associated with paler skin and ones associated with darker skin. Seven genetic variants associated with lighter skin developed at least 270,000 years ago and four more than 900,000 years ago. Considering our species, Homo sapiens, did not evolve until around 200,00 to 300,000 years ago, the discovery suggests that the genes responsible for lighter skin tones were present into the genetic material of our hominin ancestors—hundreds of thousands of years before the first humans walked the Earth.[/b]
In order for this neanderthal or denisovan mixture model to even make sense, there would have to have been sex breeding camps right on the route where Africans left Africa. And every group of Africans leaving would have had to have mated with the Neanderthals at this camp in order to guarantee that every surviving future Eurasian passed on these neanderthal or denisovan genes. Otherwise it is impossible for such a thing to have happened because we know there was more than one wave of migration out of Africa and they all didn't follow the same routes making it extremely difficult to see how this mixture would be passed on to all Eurasian OOA descendants.
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quote:Originally posted by Archeopteryx: Well, seems like different researchers came to somewhat different conclusions. We just have to wait and see what future studies lead to.
They may have come to different conclusions of mixture sure but the skeletal evidence from Africa shows clearly multiple archaic types coexisted there as well with HSS. The problem is the lack lack of widespread coverage for all regions of Africa in terms of skeletal remains.
quote: In order to establish the affinities of the Hofmeyr fossil, team member Katerina Harvati of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, used 3-dimensional measurements of the skull known to differentiate recent human populations according to their geographic distributions and genetic relationships. She compared the Hofmeyr skull with contemporaneous Upper Paleolithic skulls from Europe and with the skulls of living humans from Eurasia and sub-Saharan Africa, including the Khoe-San (Bushmen). Because the Khoe-San are represented in the recent archeological record of South Africa, they were expected to have close resemblances to the South African fossil. Instead, the Hofmeyr skull is quite distinct from recent sub-Saharan Africans, including the Khoe-San, and has a very close affinity with the European Upper Paleolithic specimens.
And the Khoe San are an example of lighter skin among Africans not necessarily tied to Eurasian mixture.
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quote:Originally posted by Doug M: They may have come to different conclusions of mixture sure but the skeletal evidence from Africa shows clearly multiple archaic types coexisted there as well with HSS. The problem is the lack lack of widespread coverage for all regions of Africa in terms of skeletal remains.
I think that no one denies that there have been multiple archaic types in Africa. After all humans (in a wide meaning) have existed there the longest time.
Outside Africa humans (including archaic humans) have existed maybe two million years. And now and then new skeletons pop up (like Homo floresiensis and Homo luzonensis) But since humans been in Africa longer time we can expect more archaic humans there and a longer time of coexistence. It is a field open for more research.
And now a new generation of African paleoanthropologists are emerging who can further enhance research in the area.
quote: Generations of scholars from around the world have converged to study human evolution in East Africa. Now a new training program seeks to bring more African students into the field.
quote:Originally posted by Doug M: "lighter skin" has always existed to some degree in parts of Africa and does not require Eurasian mixture to explain it. Human diversity originates in Africa not Eurasia.
where are these parts of Africa?
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quote:Originally posted by Doug M: They may have come to different conclusions of mixture sure but the skeletal evidence from Africa shows clearly multiple archaic types coexisted there as well with HSS. The problem is the lack lack of widespread coverage for all regions of Africa in terms of skeletal remains.
I think that no one denies that there have been multiple archaic types in Africa. After all humans (in a wide meaning) have existed there the longest time.
Outside Africa humans (including archaic humans) have existed maybe two million years. And now and then new skeletons pop up (like Homo floresiensis and Homo luzonensis) But since humans been in Africa longer time we can expect more archaic humans there and a longer time of coexistence. It is a field open for more research.
And now a new generation of African paleoanthropologists are emerging who can further enhance research in the area.
quote: Generations of scholars from around the world have converged to study human evolution in East Africa. Now a new training program seeks to bring more African students into the field.
Hopefully there will also be findings of ancient DNA which will further clarify ancestry and relatedness and similar issues.
A lot of these issues simply boils down to trying to make definitive statements about ancient times with little data, especially in Africa. This happpens all the time though mostly because of overconfidence in statistical models which invariably get shown to be wrong as new data is uncovered.
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Math tutor can also provide valuable feedback on assignments and tests. They can help identify areas where a student is counting pennies worksheet and offer suggestions on how to improve. This feedback can be especially helpful when preparing for exams. A tutor can review past tests with a student and help them understand where they went wrong and how to avoid similar mistakes in the future.
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White people did not introduce light skin into North Africa, or Africa generally.
Light skin has always been in Africa because the pigmentation center is SLC24A5. The ancestral gene for light skin rs1426L54 is “predominante” among sub-Saharan African (SSA) populations (Canfield et al., 2014). The derived allele from this coding polymerphism for light skin is A111T alleles (Canfield et al., 2014).
Presence of these genes make it clear that light skin Blacks would have always been found in Africa, since light skin is common among Black people.
quote:Originally posted by Archeopteryx: Hopefully better techniques to retrieve and analyze DNA from human remains will help to also see how those ancient people looked like. Already now they start to try to assess phenotype from DNA out of just fragments of skeletons, and soon perhaps also from eDNA.
Interesting is that they tried to make some kind of reconstructions from the autosomal DNA from three of the Abusir specimens.
Even the phenotype of the Denisovans has been predicted by DNA analysis
quote: Now, in an impressive feat, Gokhman and his colleagues have mapped out a proposed Denisovan skeleton using information for 32 skeletal features encoded in DNA that was extracted from a pinky bone. The research, published today in the journal Cell, doesn’t give exact values for Denisovan proportions, but it does offer a comparative look at how this mysterious kind of hominin measured up against Homo sapiens and Neanderthals.
Many anthropologists have questioned how Egyptian the Abusir individuals really were. Even Egyptologists like Kara Cooney say that Abusir especially in the Late Period from whence these samples come from was settled by foreigners, mostly Asiatics.
As explained earlier in this thread, light skin was introduced to the Maghreb during the Late Neolithic in association with the introduction of Cardial Ware from Europe. Before that, the Early Neolithic peoples of that region as exemplified by IAM remains seem to have had dark that is melanated skin judging by their autosomal genes. Hence the reconstructions below.
Here is Fregel's PCA chart showing population relations via autosomes.
^ Note that IAM is closest to Taforalt and both are intermediate between East African Luxmanda on end and Natufians on the other.
Speaking of which, Natufian autosomal DNA also indicates that melanated skin was also not uncommon and that this complexion was even conserved by some Neolithic individuals (PPB).
So you had dark skin in Northwest Africa in one end and dark skin in the Levant on the other end yet the indigenous people of Northeast Africa/Egypt are somehow light-skinned?
Especially since a German team back in 2005 did a melanin dosage test on mummies:
A-M Mekota1 and M Vermehren2 Skin sections showed particularly good tissue preservation, although cellular outlines were never distinct. Although much of the epidermis had already separated from the dermis, the remaining epidermis often was preserved well (Fig. 1). The basal epithelial cells were packed with melanin as expected for specimens of Negroid origin...
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Skin tones in the Levant seem to have varied over time, the Natufians had probably another skin tone than the chalcolithic people in the Peki’in cave in Israel (who had a higher content of Iranian ancestry). Then the genetic makeup changed again during the Bronze age. We have had some threads about it here on ES.
If one see the reconstructions made of these peoples skin tones, they varied, but not always so enormously. It seems more to have been a gradual scale of tones. Maybe more autosomal ancient samples will give a more comprehensive picture of the human color scale in these regions. Would also be interesting to know more about things like hair structure. As in these reconstructions the Natufian (from Ancestral Whispers) and the Jericho man have straight hair. What do we know about that?
But best not to forget that even if skin color is interesting it was maybe not so important for the peoples of those ancient times. Probably things like family, relations, wealth, power, religion, traditions and culture were considered far more important.
Seems skin color is way more important for us modern people than for the ancients, which for example the heated debate about Netflix Cleopatra has shown.
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Would be interesting to see some facial reconstructions of at least one or two of the Abusir specimens based on actual skulls, not only DNA.
For the pictures above, the Natufian is probably based on photos of a Natufian skull. The Jericho picture is based on an actual skull and the Judaean is based on three skulls.
-------------------- Once an archaeologist, always an archaeologist Posts: 2881 | From: Sweden | Registered: Mar 2020
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Lighter skin has always existed among various African groups as there is no single skin color in Africa and there never has been. So we can safely say that among certain populations in Northern parts of Africa there has always been an indigenous lighter skinned component. However, because coastal areas of Northern Africa are close to Europe and the Levant, then lighter skin from migrations of Europeans and others into these areas have also had an impact.But again, the main area of impact would have been in those coastal areas, while the Sahara, Sahel and Nile Valley always had black populations. And it is only in recent times that the population densities of coastal communities such as Egypt and so forth have risen to the point where those populations with lighter skin are numerically more dominant. That did not exist 5,000 years ago. Case in point, the population of Egypt 2,000 years ago is said to have been between 2 and 4 million people and has risen steadily since due to migration and reproduction, mostly in the northern parts of the country.
As for those reconstructions they are guessing. Because any kind of facial reconstruction depends on databases of features of populations to use as a references for soft facial features. And most of these databases are based on modern European populations.
Posts: 8914 | Registered: May 2005
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