posted
Page last updated at 17:32 GMT, Thursday, 24 April 2008 18:32 UK
Human line 'nearly split in two'
By Paul Rincon Science reporter, BBC News
Humans diverged into separate populations for 100,000 years
Ancient humans started down the path of evolving into two separate species before merging back into a single population, a genetic study suggests.
The genetic split in Africa resulted in distinct populations that lived in isolation for as much as 100,000 years, the scientists say.
This could have been caused by arid conditions driving a wedge between humans in eastern and southern Africa.
Details have been published in the American Journal of Human Genetics.
It would be the longest period for which modern human populations have been isolated from one another.
But other scientists said it was still too early to reconstruct a meaningful picture of humankind's early history in Africa. They argue that other scenarios could also account for the data.
At the time of the split - some 150,000 years ago - our species, Homo sapiens, was still confined to the African continent.
We don't know how long it takes for hominids to fission off into separate species, but clearly they were separated for a very long time
Dr Spencer Wells, Genographic Project
The results have come from the Genographic Project, a major effort to track human migrations through DNA.
The latest conclusions are based on analysis of mitochondrial DNA in present-day African populations. This type of DNA is the genetic material stored in mitochondria - the "powerhouses" of cells.
It is passed down from a mother to her offspring, providing a unique record of maternal inheritance.
"We don't know how long it takes for hominids to fission off into separate species, but clearly they were separated for a very long time," said Dr Spencer Wells, director of the Genographic Project.
"They came back together again during the Late Stone Age - driven by population expansion."
Family tree
Although present-day people carry a signature of the ancient split in their DNA, today's Africans are part of a single population.
The researchers compiled a "family tree" of different mitochondrial DNA groupings found in Africa.
A major split occurred near the root of the tree as early as 150,000 years ago.
On one side of this divide are the mitochondrial lineages now found predominantly in East and West Africa, and all maternal lineages found outside Africa.
On the other side of the divide are lineages predominantly found in the Khoi and San (Khoisan) hunter-gatherer people of southern Africa.
Many African populations today harbour a mixture of both.
Although there is very deep divergence in the mitochondrial lineages, that can be different from inferring when the populations diverged from one another
Dr Sarah Tishkoff, University of Pennsylvania
The scientists say the most likely scenario is that two populations went their separate ways early in our evolutionary history.
This gave rise to separate human communities localised to eastern and southern Africa that evolved in isolation for between 50,000 and 100,000 years.
This divergence could have been related to climate change: recent studies of ancient climate data suggest that eastern Africa went through a series of massive droughts between 135,000-90,000 years ago.
Lead author Doron Behar, from the Rambam Medical Center in Israel commented: "It is possible the harsh environment and changing climate made populations migrate to other places in order to have a better chance of survival.
"Some of them found places where they could and - perhaps - some didn't. More than that we cannot say."
Back together
Dr Wells told BBC News: "Once this population reached southern Africa, it was cut off from the eastern African population by these drought events which were on the route between them."
Modern humans are often presumed to have originated in East Africa and then spread out to populate other areas. But the data could equally support an origin in southern Africa followed by a migration to East and West Africa.
The genetic data show that populations came back together as a single, pan-African population about 40,000 years ago.
This renewed contact appears to coincide with the development of more advanced stone tool technology and may have been helped by more favourable environmental conditions.
"[The mixing] was two-way to a certain extent, but the majority of mitochondrial lineages seem to have come from north-eastern Africa down to the south," said Spencer Wells.
But other scientists said different scenarios could explain the data.
Dr Sarah Tishkoff, an expert on African population genetics from the University of Pennsylvania, said the Khoisan might once have carried many more of the presumed "East African" lineages but that these could have been lost over time.
"Although there is very deep divergence in the mitochondrial lineages, that can be different from inferring when the populations diverged from one another and there can be many demographic scenarios to account for it," she told BBC News.
She added: "As a general rule of thumb, when mitochondrial genetic lineages split, it will usually precede the population split. It can often be difficult to infer from one to the other."
The University of Pennsylvania researcher stressed it was not possible to pinpoint where in Africa the populations had once lived - complicating the process of reconstructing scenarios from genetic data.
The Genographic Project's findings are also consistent with the idea - held for some years now - that modern humans had a close brush with extinction in the evolutionary past.
The number of early humans may have shrunk as low as 2,000 before numbers began to expand again in the Late Stone Age.
Some of the stuff I read indicates that man's origin was more South Africa rather than East Africa. Essentially because Than San people are the oldest and they are found primarily in South Africa.
-------------------- Without data you are just another person with an opinion - Deming Posts: 12143 | From: When you have eliminated the impossible, whatever remains, however improbable | Registered: Jun 2007
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posted
Anyone ever notice how these people try and act like there was no African migration to North Africa? I'll bet alot of dullards never notice it.
Posts: 3085 | Registered: Jan 2008
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posted
^lol this guy is funny, but he's a bastard at the same time. Reminds me of 50 Cent . Shall we all call him 25 Pence from now on? .
Posts: 3423 | From: the jungle - when y'all stop playing games, call me. | Registered: Jul 2006
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quote:Originally posted by Tigerlily: Page last updated at 17:32 GMT, Thursday, 24 April 2008 18:32 UK
Human line 'nearly split in two'
By Paul Rincon Science reporter, BBC News
Humans diverged into separate populations for 100,000 years
Ancient humans started down the path of evolving into two separate species before merging back into a single population, a genetic study suggests.
The genetic split in Africa resulted in distinct populations that lived in isolation for as much as 100,000 years, the scientists say.
This could have been caused by arid conditions driving a wedge between humans in eastern and southern Africa.
Details have been published in the American Journal of Human Genetics.
It would be the longest period for which modern human populations have been isolated from one another.
But other scientists said it was still too early to reconstruct a meaningful picture of humankind's early history in Africa. They argue that other scenarios could also account for the data.
At the time of the split - some 150,000 years ago - our species, Homo sapiens, was still confined to the African continent.
We don't know how long it takes for hominids to fission off into separate species, but clearly they were separated for a very long time
Dr Spencer Wells, Genographic Project
The results have come from the Genographic Project, a major effort to track human migrations through DNA.
The latest conclusions are based on analysis of mitochondrial DNA in present-day African populations. This type of DNA is the genetic material stored in mitochondria - the "powerhouses" of cells.
It is passed down from a mother to her offspring, providing a unique record of maternal inheritance.
"We don't know how long it takes for hominids to fission off into separate species, but clearly they were separated for a very long time," said Dr Spencer Wells, director of the Genographic Project.
"They came back together again during the Late Stone Age - driven by population expansion."
Family tree
Although present-day people carry a signature of the ancient split in their DNA, today's Africans are part of a single population.
The researchers compiled a "family tree" of different mitochondrial DNA groupings found in Africa.
A major split occurred near the root of the tree as early as 150,000 years ago.
On one side of this divide are the mitochondrial lineages now found predominantly in East and West Africa, and all maternal lineages found outside Africa.
On the other side of the divide are lineages predominantly found in the Khoi and San (Khoisan) hunter-gatherer people of southern Africa.
Many African populations today harbour a mixture of both.
Although there is very deep divergence in the mitochondrial lineages, that can be different from inferring when the populations diverged from one another
Dr Sarah Tishkoff, University of Pennsylvania
The scientists say the most likely scenario is that two populations went their separate ways early in our evolutionary history.
This gave rise to separate human communities localised to eastern and southern Africa that evolved in isolation for between 50,000 and 100,000 years.
This divergence could have been related to climate change: recent studies of ancient climate data suggest that eastern Africa went through a series of massive droughts between 135,000-90,000 years ago.
Lead author Doron Behar, from the Rambam Medical Center in Israel commented: "It is possible the harsh environment and changing climate made populations migrate to other places in order to have a better chance of survival.
"Some of them found places where they could and - perhaps - some didn't. More than that we cannot say."
Back together
Dr Wells told BBC News: "Once this population reached southern Africa, it was cut off from the eastern African population by these drought events which were on the route between them."
Modern humans are often presumed to have originated in East Africa and then spread out to populate other areas. But the data could equally support an origin in southern Africa followed by a migration to East and West Africa.
The genetic data show that populations came back together as a single, pan-African population about 40,000 years ago.
This renewed contact appears to coincide with the development of more advanced stone tool technology and may have been helped by more favourable environmental conditions.
"[The mixing] was two-way to a certain extent, but the majority of mitochondrial lineages seem to have come from north-eastern Africa down to the south," said Spencer Wells.
But other scientists said different scenarios could explain the data.
Dr Sarah Tishkoff, an expert on African population genetics from the University of Pennsylvania, said the Khoisan might once have carried many more of the presumed "East African" lineages but that these could have been lost over time.
"Although there is very deep divergence in the mitochondrial lineages, that can be different from inferring when the populations diverged from one another and there can be many demographic scenarios to account for it," she told BBC News.
She added: "As a general rule of thumb, when mitochondrial genetic lineages split, it will usually precede the population split. It can often be difficult to infer from one to the other."
The University of Pennsylvania researcher stressed it was not possible to pinpoint where in Africa the populations had once lived - complicating the process of reconstructing scenarios from genetic data.
The Genographic Project's findings are also consistent with the idea - held for some years now - that modern humans had a close brush with extinction in the evolutionary past.
The number of early humans may have shrunk as low as 2,000 before numbers began to expand again in the Late Stone Age.
] UH OH watch out. This kind of study will get you called a TROLL on Egyptsearch because it deviates from the RELIGION of Afro-NAzism and the fact that there MIGHT be such a thing as RACES Posts: 343 | Registered: Feb 2008
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Tigerlily isn't a troll, check the posting numbers AND her PPG (percentage of posts that are garbage): she's an Egyptsearch ALLSTAR.
Race - in the biological sense (subspecies as a dichotomy in humans) simply doesn't exist scientifically.
Or at least, the evidence isn't there biologically.
And the majority of the forum that DO ADHERE to your Santa-Claus like concept ARE AFROCENTRISTS, you moron!
Now you, can procede whining about the fact that we don't believe in your Santa Claus ideology or you can substantiate a basis for such a dichotomy in humans.
'We' tend instead to lean on the hard facts of biology, and are otherwise scientific in our scholarly pursuits.
Oh, and, FYI, the study does not even hint that "there MIGHT be such a thing as races".
quote:Originally posted by Alive-(What Box): Dude.. what theF UCK R u talkin bout?
Tigerlily isn't a troll, check the posting numbers AND her PPG (percentage of posts that are garbage): she's an Egyptsearch ALLSTAR.
Race - in the biological sense (subspecies as a dichotomy in humans) simply doesn't exist scientifically.
Or at least, the evidence isn't there biologically.
And the majority of the forum that DO ADHERE to your Santa-Claus like concept ARE AFROCENTRISTS, you moron!
Now you, can procede whining about the fact that we don't believe in your Santa Claus ideology or you can substantiate a basis for such a dichotomy in humans.
'We' tend instead to lean on the hard facts of biology, and are otherwise scientific in our scholarly pursuits.
Oh, and, FYI, the study does not even hint that "there MIGHT be such a thing as races".
Hope I helped.
You obviously didn't read it you big toothed gay mulatto read it again freak! And watch your god damn mouth talking to me boy you are still a kid have some respect for you elders what the hell is wrong with you?!?! Posts: 343 | Registered: Feb 2008
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I simply posted an article on this forum and didn't mean to ruffle any feathers.
A high five to Alive, thanks for trying to clarify!! Posts: 30135 | From: The owner of this website killed ES....... | Registered: Feb 2004
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posted
Alive-(What Box) wrote: Oh, and, FYI, the study does not even hint that "there MIGHT be such a thing as races".
While that is true: It is also true, that the study ONLY deals with Blacks in Africa. No mention is made of the Whites and Mongols who will later evolve in the Eurasian Plains.
Posts: 22721 | Registered: Oct 2005
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posted
^ Because the study isn't about race. For me the study is fine, and not particularly interesting in that it relates nothing that was not already implied by anthropology and genetics.
- Humans evolved in East Africa 150 thousand years ago.
Humans reached the southern tip of Africa at least 80 thousand years ago, and prior to outmigration of non Africans.
Some of the earliest evidences of human culture are from south Africa at this time.
East Africa has the oldest lineages in the world.
In term of mtdna - this means L1, from which L2 and L3 derive [all 3 originate in East Africa].
The most interesting genetic fact about South Africans is that they also have high amounts of underived E3b. [but little or no derived E3b]
Now E3b originates in East Africa about 25 to 30 thousand years ago. About 15 thousand years ago, this lineage began splitting to - E3b1, E3b2, E3b3, etc.
So if South Africans have underived E3b then their ancestry includes East African migrants from 15 to 25 thousand years ago.
It is also possible that there have been major migrations of south Africans to the north.
It should be understood that L1 L2 and L3 [the 3 base lineages whose progeny makes up the ENTIRE human genome] are found all over Africa.
The existence of the three lineages by definition implies bottlenecks, or population separation. And the existence of all these lineages in virtually all African populations implies by definition that they are all related, and from very ancient times.
Posts: 15202 | Registered: Jun 2004
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posted
^ It should also be understood that all 3 of the basal African lineages, L1, L2 and L3 are found in modern Egypt.
Likewise the earliest human remains found in the NileValley exhibits and obvious African phenotype, which is disputed for whether it more closely resembles modern 'nubian', or 'modern' khoisan.
One of the reasons the concept of race based on phenotype isolate has come to be rejected by informed scientists is that the anthropological record contradicts the theory of race.
Race theory divides humans into descrete phenotypes which at some point of time should exist in a clearly descerned [racially pure] form.
^ This is what the theory of race predicts. [although most laymen who believe in race, beleive out of laziness and not critical analysis]
Where these types are transgressed the cause *should be* recent 'mixture'.
The proof of this *should be* found in the fact, that you can go back to point of time 'x' preceding said 'mixture' and find your pure races.
In fact as you go back in time you find even more variation in phenotype than there is today, which is what makes it so difficult to place said remains in stereotyped 'race' catagories.
This suggests that the reason that human beings cannot be divided into phenotypical races -today-, is not beause the original race archtypes later mixed', but rather because said 'races' never existed to begin with.
Posts: 15202 | Registered: Jun 2004
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quote:Originally posted by rasol: It should be understood that L1 L2 and L3 [the 3 base lineages whose progeny makes up the ENTIRE human genome] are found all over Africa.
The existence of the three lineages by definition implies bottlenecks, or population separation. And the existence of all these lineages in virtually all African populations implies by definition that they are all related, and from very ancient times.
^Right.
Now as for E or even E3 is concerned it was confusing as heck at first but it seems like the Sahara really did work like an accelerator of African trans-continental migrations.
quote:One of the reasons the concept of race based on phenotype isolate has come to be rejected by informed scientists is that the anthropological record contradicts the theory of race.
Race theory divides humans into descrete phenotypes which at some point of time should exist in a clearly descerned [racially pure] form.
^ This is what the theory of race predicts. [although most laymen who believe in race, beleive out of laziness and not critical analysis]
Where these types are transgressed the cause *should be* recent 'mixture'.
The proof of this *should be* found in the fact, that you can go back to point of time 'x' preceding said 'mixture' and find your pure races.
In fact as you go back in time you find even more variation in phenotype than there is today, which is what makes it so difficult to place said remains in stereotyped 'race' catagories.
This suggests that the reason that human beings cannot be divided into phenotypical races -today-, is not beause the original race archtypes later mixed', but rather because said 'races' never existed to begin with.
Laid out clearly.
quote:Originally posted by a biiatch with the alias "wolofi":
I know in your deluded state you may intend for your raves to hurt someone, but hos need help too so I'll asist you: those ramblings that read as if they were typed by a whore whose face was dick-ridden don't do shi'ite.
Come to think of it...
It actually did produce a small chuckle.
Posts: 5555 | From: Tha 5th Dimension. | Registered: Apr 2006
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quote:Originally posted by Wolofi: UH OH watch out. This kind of study will get you called a TROLL on Egyptsearch because it deviates from the RELIGION of Afro-NAzism and the fact that there MIGHT be such a thing as RACES
Believing in race goes against Afro-Nazism? I don't know which is more moronic, this or AMR1's statement that Egypt is the center of the Earth. Racial thinking is in fact one of the core tenets of the Nazi ideology, so anyone who doesn't believe in race probably can't be called an Nazi, Afro- or otherwise.
Posts: 7083 | From: Fallbrook, CA | Registered: Mar 2004
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quote:Originally posted by Tyrann0saurus: Racial thinking is in fact one of the core tenets of the Nazi ideology, so anyone who doesn't believe in race probably can't be called an Nazi, Afro- or otherwise.
Nothing that psuedo-wolof ever says makes sense, unless you know its true agenda .
quote:Originally posted by Alive-(What Box): And the majority of the forum that DO ADHERE to your Santa-Claus like concept ARE AFROCENTRISTS, you moron!
A note (I just had to clarify on this): before the current influx of trolls, most of the time the majority of peeps who believed in the concept were indeed Euro- and Medicentric.
Posts: 5555 | From: Tha 5th Dimension. | Registered: Apr 2006
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posted
I agree with Rasol that what Tigerlily posted is a very interesting scientific finding that unfortunately been hijacked by idiocy.
quote:Originally posted by Tyrann0saurus: Believing in race goes against Afro-Nazism? I don't know which is more moronic, this or AMR1's statement that Egypt is the center of the Earth. Racial thinking is in fact one of the core tenets of the Nazi ideology, so anyone who doesn't believe in race probably can't be called an Nazi, Afro- or otherwise.
Actually to believe in 'race' is to believe in a lie that is actually nonsensical when you think about all the internal contradictions that take place. Note how racialist nutcases who post here like White Nord or Sshaun run around in circles with thier cirular logic.
quote:Originally posted by HORUS^*^: ^lol this guy (argyle) is funny, but he's a bastard at the same time. Reminds me of 50 Cent . Shall we all call him 25 Pence from now on? .
LMAO I think you just insulted 50 cent! Gargoyle is not worth even a nickel!
Posts: 26285 | From: Atlanta, Georgia, USA | Registered: Feb 2005
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quote:Originally posted by Tigerlily: Page last updated at 17:32 GMT, Thursday, 24 April 2008 18:32 UK
Human line 'nearly split in two'
By Paul Rincon Science reporter, BBC News
Humans diverged into separate populations for 100,000 years
Ancient humans started down the path of evolving into two separate species before merging back into a single population, a genetic study suggests.
The genetic split in Africa resulted in distinct populations that lived in isolation for as much as 100,000 years, the scientists say.
This could have been caused by arid conditions driving a wedge between humans in eastern and southern Africa.
Details have been published in the American Journal of Human Genetics.
It would be the longest period for which modern human populations have been isolated from one another.
But other scientists said it was still too early to reconstruct a meaningful picture of humankind's early history in Africa. They argue that other scenarios could also account for the data.
At the time of the split - some 150,000 years ago - our species, Homo sapiens, was still confined to the African continent.
We don't know how long it takes for hominids to fission off into separate species, but clearly they were separated for a very long time
Dr Spencer Wells, Genographic Project
The results have come from the Genographic Project, a major effort to track human migrations through DNA.
The latest conclusions are based on analysis of mitochondrial DNA in present-day African populations. This type of DNA is the genetic material stored in mitochondria - the "powerhouses" of cells.
It is passed down from a mother to her offspring, providing a unique record of maternal inheritance.
"We don't know how long it takes for hominids to fission off into separate species, but clearly they were separated for a very long time," said Dr Spencer Wells, director of the Genographic Project.
"They came back together again during the Late Stone Age - driven by population expansion."
Family tree
Although present-day people carry a signature of the ancient split in their DNA, today's Africans are part of a single population.
The researchers compiled a "family tree" of different mitochondrial DNA groupings found in Africa.
A major split occurred near the root of the tree as early as 150,000 years ago.
On one side of this divide are the mitochondrial lineages now found predominantly in East and West Africa, and all maternal lineages found outside Africa.
On the other side of the divide are lineages predominantly found in the Khoi and San (Khoisan) hunter-gatherer people of southern Africa.
Many African populations today harbour a mixture of both.
Although there is very deep divergence in the mitochondrial lineages, that can be different from inferring when the populations diverged from one another
Dr Sarah Tishkoff, University of Pennsylvania
The scientists say the most likely scenario is that two populations went their separate ways early in our evolutionary history.
This gave rise to separate human communities localised to eastern and southern Africa that evolved in isolation for between 50,000 and 100,000 years.
This divergence could have been related to climate change: recent studies of ancient climate data suggest that eastern Africa went through a series of massive droughts between 135,000-90,000 years ago.
Lead author Doron Behar, from the Rambam Medical Center in Israel commented: "It is possible the harsh environment and changing climate made populations migrate to other places in order to have a better chance of survival.
"Some of them found places where they could and - perhaps - some didn't. More than that we cannot say."
Back together
Dr Wells told BBC News: "Once this population reached southern Africa, it was cut off from the eastern African population by these drought events which were on the route between them."
Modern humans are often presumed to have originated in East Africa and then spread out to populate other areas. But the data could equally support an origin in southern Africa followed by a migration to East and West Africa.
The genetic data show that populations came back together as a single, pan-African population about 40,000 years ago.
This renewed contact appears to coincide with the development of more advanced stone tool technology and may have been helped by more favourable environmental conditions.
"[The mixing] was two-way to a certain extent, but the majority of mitochondrial lineages seem to have come from north-eastern Africa down to the south," said Spencer Wells.
But other scientists said different scenarios could explain the data.
Dr Sarah Tishkoff, an expert on African population genetics from the University of Pennsylvania, said the Khoisan might once have carried many more of the presumed "East African" lineages but that these could have been lost over time.
"Although there is very deep divergence in the mitochondrial lineages, that can be different from inferring when the populations diverged from one another and there can be many demographic scenarios to account for it," she told BBC News.
She added: "As a general rule of thumb, when mitochondrial genetic lineages split, it will usually precede the population split. It can often be difficult to infer from one to the other."
The University of Pennsylvania researcher stressed it was not possible to pinpoint where in Africa the populations had once lived - complicating the process of reconstructing scenarios from genetic data.
The Genographic Project's findings are also consistent with the idea - held for some years now - that modern humans had a close brush with extinction in the evolutionary past.
The number of early humans may have shrunk as low as 2,000 before numbers began to expand again in the Late Stone Age.
posted
Interesting paper but problematic. One explanation offered is that drought conditions brought on by climate change could have led to the lineage divergence that lasted some 100K years.
But Africa south of the equator has a number of very large lakes and intra-contintental river systems. The Nile, the Limpopo, the Zambezi, the Congo river, etc. would all have helped to prevent massive drought thereby leading to a 100K year separation. In times of drought all that would have been necessary would have been to migrate to the Africa's massive riverine areas.
Further proof is that there is no evidence for the extinction of any of the herbivore species of Africa during that relatively recent period.
Point is that there may have been a split in the lineages but it is doubtful that it would have lasted 100K years given the long migratory history of humans. What I mean is that eeven if there was an initial split and separation, it would not have lasted as long as 100K years.
Also does the MtDNA data correlate with the Y chromosome data?
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this guy is funny, but he's a bastard at the same time. Reminds me of 50 Cent ![[Roll Eyes]](rolleyes.gif)
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and, FYI, the study does not even hint that "there MIGHT be such a thing as races".![[Confused]](confused.gif)
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