Expansion of modern humans out of Africa and within Africa. Mellars (2006).
When we discuss the origins of modern humans, the term ‘Out of Africa’ is a bit misleading. Our common ancestors came not from Africa as a whole but from a relatively small area somewhere in East Africa. Beginning around 80,000 years ago, this area was the scene of several population expansions that culminated in a ‘big bang’ c. 60,000 BP (Watson et al., 1997). This was a sustained expansion that pushed out of Africa and into Europe, Asia, Oceania, and the Americas.
These modern humans spread at the expense of more archaic ‘hominins’: Neanderthals in Europe and West Asia, and other poorly known groups elsewhere. But the latter were not totally replaced, as seen in the 1 to 4% Neanderthal admixture of present-day Europeans, East Asians, and Papuans. This has led some people to quip that only Africans are pure Homo sapiens:
Well, no. Sub-Saharan Africans actually have more archaic admixture. The difference is that it came not from Neanderthals but from archaic groups within Africa. About 13% of the sub-Saharan gene pool comes from an earlier expansion of pre-modern hominins that occurred c. 111,000 years ago and seems to correspond to the entry of Skhul-Qafzeh hominins into the Middle East (Watson et al., 1997). This higher level of admixture may have come about because archaic Africans were behaviorally and physically closer to modern humans than the Neanderthals were.
Nonetheless, these ‘Paleoafricans’ were clearly archaic. They lacked something that modern humans had. What was this disadvantage that ultimately removed them from the struggle for existence? The answer is much debated, but most authors posit a limited capacity for symbolic thinking and social organization:
Thus, when we discuss human origins, the real split was not between Africans and non-Africans but rather between two groups of Africans: archaics and moderns. Dienekes (2005) uses the terms ‘Paleoafricans’ and ‘Afrasians’:
All of this leads to an intriguing conclusion. Since present-day sub-Saharan Africans were used as a benchmark to estimate Neanderthal admixture in present-day Eurasians, and since Paleoafrican gene sequences should be less ‘derived’ and more similar to Neanderthal gene sequences, Neanderthal admixture in present-day Eurasians is probably a bit higher than the estimated 1 to 4%.
References
Atkinson, Q.D., R.D. Gray, and A.J. Drummond. (2009). Bayesian coalescent inference of major human mitochondrial DNA haplogroup expansions in Africa, Proceedings of the Royal Society B, 276, 367–373
Camphausen, R.C. (2010). Evidence for interbreeding with Neanderthals, only Africans pure, Digital Journal, May 10, 2010,
http://www.digitaljournal.com/article/291798
Dienekes. (2005). The mitochondrial time depth of humanity, Dienekes’ Anthropology Blog, May 14, 2005.
http://dienekes.blogspot.com/2005/05/mitochondrial-time-depth-of-humanity.html
Mellars, P. (2006). Why did modern human populations disperse from Africa ca. 60,000 years ago? A new model, Proceedings of the National Academy of Sciences (USA), 103, 9381-9386.
http://www.pnas.org/content/103/25/9381.abstract
Watson, E., P. Forster, M. Richards, and H-J. Bandelt. (1997). Mitochondrial footprints of human expansions in Africa, American Journal of Human Genetics, 61, 691-704.
When we discuss the origins of modern humans, the term ‘Out of Africa’ is a bit misleading. Our common ancestors came not from Africa as a whole but from a relatively small area somewhere in East Africa. Beginning around 80,000 years ago, this area was the scene of several population expansions that culminated in a ‘big bang’ c. 60,000 BP (Watson et al., 1997). This was a sustained expansion that pushed out of Africa and into Europe, Asia, Oceania, and the Americas.
These modern humans spread at the expense of more archaic ‘hominins’: Neanderthals in Europe and West Asia, and other poorly known groups elsewhere. But the latter were not totally replaced, as seen in the 1 to 4% Neanderthal admixture of present-day Europeans, East Asians, and Papuans. This has led some people to quip that only Africans are pure Homo sapiens:
Better yet, and a blow to Caucasian and Asian racists, the comparison of the human and Neanderthal genome makes it clear that it is only Africans who are 100 percent Homo sapiens, while in European (including American and Australian settlers) and Asian populations one can find up to 4 percent DNA stemming from the archaic and often maligned Neanderthal species - a hominid that went extinct more than 20,000 years ago. (Camphausen, 2010)
Well, no. Sub-Saharan Africans actually have more archaic admixture. The difference is that it came not from Neanderthals but from archaic groups within Africa. About 13% of the sub-Saharan gene pool comes from an earlier expansion of pre-modern hominins that occurred c. 111,000 years ago and seems to correspond to the entry of Skhul-Qafzeh hominins into the Middle East (Watson et al., 1997). This higher level of admixture may have come about because archaic Africans were behaviorally and physically closer to modern humans than the Neanderthals were.
Nonetheless, these ‘Paleoafricans’ were clearly archaic. They lacked something that modern humans had. What was this disadvantage that ultimately removed them from the struggle for existence? The answer is much debated, but most authors posit a limited capacity for symbolic thinking and social organization:
[…] the African exodus was predated by a cultural revolution involving new stone blade technologies, skin working tools, ornaments and imported red ochre […] More advanced symbolic systems in language and religious beliefs could have provided a competitive advantage to a group by promoting coordination and cohesion. (Atkinson et al., 2009)
Thus, when we discuss human origins, the real split was not between Africans and non-Africans but rather between two groups of Africans: archaics and moderns. Dienekes (2005) uses the terms ‘Paleoafricans’ and ‘Afrasians’:
It is common to distinguish between Africans and non-Africans, with the former being much more genetically diverse than the latter. But, the real "gap" in human origins seems to be between the really old Africans ("Paleoafricans") and the rest ("Afrasians").
The Paleoafrican element is entirely confined to Africa, while the Afrasian one is found in both Africa and Eurasia. Indeed, modern humans can be entirely split into two groups: (i) a group of "pure" Afrasians which includes all non-Africans, and (ii) a group of Afrasian-Paleoafricans which includes all non-Caucasoid Africans. Human groups of entirely Paleoafrican origin, unhybridized with the younger Afrasians are no longer in existence.
All of this leads to an intriguing conclusion. Since present-day sub-Saharan Africans were used as a benchmark to estimate Neanderthal admixture in present-day Eurasians, and since Paleoafrican gene sequences should be less ‘derived’ and more similar to Neanderthal gene sequences, Neanderthal admixture in present-day Eurasians is probably a bit higher than the estimated 1 to 4%.
References
Atkinson, Q.D., R.D. Gray, and A.J. Drummond. (2009). Bayesian coalescent inference of major human mitochondrial DNA haplogroup expansions in Africa, Proceedings of the Royal Society B, 276, 367–373
Camphausen, R.C. (2010). Evidence for interbreeding with Neanderthals, only Africans pure, Digital Journal, May 10, 2010,
http://www.digitaljournal.com/article/291798
Dienekes. (2005). The mitochondrial time depth of humanity, Dienekes’ Anthropology Blog, May 14, 2005.
http://dienekes.blogspot.com/2005/05/mitochondrial-time-depth-of-humanity.html
Mellars, P. (2006). Why did modern human populations disperse from Africa ca. 60,000 years ago? A new model, Proceedings of the National Academy of Sciences (USA), 103, 9381-9386.
http://www.pnas.org/content/103/25/9381.abstract
Watson, E., P. Forster, M. Richards, and H-J. Bandelt. (1997). Mitochondrial footprints of human expansions in Africa, American Journal of Human Genetics, 61, 691-704.
35 comments:
More advanced symbolic systems in language and religious beliefs could have provided a competitive advantage to a group by promoting coordination and cohesion.
Isn't that group selection?
Promoting coordination and cohesion within a group also has the effect of putting up barriers to those outside the group, hence all other things being equal modern humans would hybridise less.
I don't think Neanderthals were predators on humans with a penchant for woman stealing like Vendramini says, I bet that's how humans thought of them though (people believed things like that about the great apes for a long time). The religious beliefs of early man would have mobilised humans against Neanderthals and led to their demise.
So, the admixture occured when archaic hominids very close to neanderthal hybridized with archaic-africans (who themselves, apparently, would deserve to be included in a different h. sapiens subspecies). Those hybridized archaic hominids/archaic-africans later hybridized again with modern east africans and the resulting hybrids archaic hominids/archaic africans/modern east-africans finally expendend to Eurasia to give rise to eurasian populations, while only the archaic africains/modern africans hybrids stayed in Africa.
If this is correct, then I have two questions.
1) Neanderthal himself has nothing to with this admixture anymore, it just happened that the african archaic hominids who hybridized with archaic africans were closer to neanderthal than modern africans. Correct and if so, is it a sure thing ?
2) Where do modern africans come from exactly ? unhybridized archaic-africans or directly from yet another african archaic hominid ?
Perhaps Neanderthals had become distinct enough that the human/Neanderthal hybrids had high levels of sterility. Could this not also explain the low percentage of admixture? Maybe this was one of the reasons for Neanderthals dying out. Their hybrid offspring had low reproduction rates and those that were fertile were eventually absorbed into the homo sapien gene pool.
Tod,
It sounds like group selection, but I'm not sure. Usually, group selection is invoked for traits that are advantageous to the group as a whole, but not to each individual taken separately. This, in turn, leads to the problem of 'free riders.' In contrast, language is useful at both levels and doesn't seem to lead to the quandary of free riders.
Ben10,
First, I'm throwing out different explanations in the hope of getting feedback. The more I think about this puzzle, the more I favor explanation #4 of my previous post. Eurasia was probably home to different archaic groups that were more closely related to each other than they were to modern humans. So 'Neanderthal admixture' actually means archaic admixture. I also think that Europeans and East Asians descend from a recent (c. 20,000 BP) ancestral population, so they would necessarily have the same Neanderthal admixture.
But to answer your questions:
1. I think much if not most Neanderthal admixture entered modern humans indirectly, via intermediary 'almost-modern' humans (like the Skhul-Qafzeh hominins of the Middle East).
2. Modern Africans are modern humans like yourself (I'm assuming you're a European from France). The genetic differences between Modern Europeans and Modern Africans are twofold:
a) The archaic admixture is different. Modern Europeans admixed with Neanderthals and Modern Africans with Paleoafricans.
b) Modern Europeans and Modern Africans have followed different evolutionary paths for the past c. 50,000 years.
Sagat,
There may have been reduced fertility, but I suspect the main barriers were behavioral and cultural. An infant skeleton from Spain (c. 24,500 BP) looks like a hybrid. (Proc. Natl. Acad. Sci, 96, 7604-7609, 1999)
"Sub-Saharan Africans actually have more archaic admixture. The difference is that it came not from Neanderthals but from archaic groups within Africa. About 13% of the sub-Saharan gene pool comes from an earlier expansion of pre-modern hominins that occurred c. 111,000 years ago and seems to correspond to the entry of Skhul-Qafzeh hominins into the Middle East (Watson et al., 1997)."
Do you base this off anything other than this 1997 study?
"Nonetheless, these ‘Paleoafricans’ were clearly archaic. They lacked something that modern humans had. What was this disadvantage that ultimately removed them from the struggle for existence? The answer is much debated, but most authors posit a limited capacity for symbolic thinking and social organization:"
I don't think many people still hold onto this idea behavioral modernity any more: http://en.wikipedia.org/wiki/Behavioral_modernity#Continuity_hypothesis
"Thus, when we discuss human origins, the real split was not between Africans and non-Africans but rather between two groups of Africans: archaics and moderns. Dienekes (2005) uses the terms ‘Paleoafricans’ and ‘Afrasians’:"
How old are these paleo-africans? Were they h. erectus?
Re behavioral modernity - Robin Dunbar on What Makes us Human?
Collective solutions to the problems of survival required living in larger groups this led to the evolution of key areas of the brain which allowed "higher orders of intentionality that are crucial in the development of fully fledged religion as we know it,'". Religion is proposed to be a solution to the free rider problem.
Ok, but that doesn't have much to do with the original point, being that Frost might be subscribing to an idea of behavioral modernity that's lost alot of popularity, in that it didn't arise only several tens of thousands of years ago but has been around for a very long time.
There's not much reason to assume neanderthals were any less sapient than us, either: http://www3.interscience.wiley.com/journal/113440973/abstract
I believe we also diverged from them awhile before the bare minimum frame of speciation for primates of a complexity such as ourselves, that being around 1 million years.
"Crows and domesticated dogs can be markedly better than chimpanzees in some skills while being genetically much more remote from us. To put it another way, you could say that ... reveal[s] the extent to which human beings can all too easily project their own mentality onto other species: something I would call hyper-mentalizing and something that I would also claim is the core and essence of insanity". Here
I'm not sure what you're arguing for. The sort of behavioral modernity I'm showing argues that it arose quite some time ago, and took awhile to fully propser due to certain social dynamics.
In regards to neanderthals:
http://news.bbc.co.uk/2/hi/science/nature/5098748.stm
http://science.niuz.biz/worlds-t97868.html?s=32dcfe67413f7f6eccd8e2b88125c3ae&
Peter, you're correct about my ancestry but you said:
"...The archaic admixture is different. Modern Europeans admixed with Neanderthals ..."
You just said before they did not, unless you mean 'european ancestors, while still in the middle east, admixed with early african nenderthals'.
So, once again, European Neanderthals have nothing to do with this admixture or do they ?
Beside the point, but in scientific american there is this article who describe a, hairy but not furry, neanderthal with some sort of necklace made of seashell.
Anon,
1. There have been a number of articles on archaic admixture in modern Africans (Dienekes has them listed under 'Paleoafricans' on his blog).
The most recent article is one by Wall, Lohmueller, and Plagnol (2009) "Detecting ancient admixture and estimating demographic parameters in multiple human populations." They too found that the signal of ancient admixture was stronger in their West African sample than in their European and East Asian samples.
2. "I don't think many people still hold onto this idea behavioral modernity any more"
I'm sorry but you're wrong. Most anthropologists accept that a major behavioral shift occurred c. 80,000 BP. Yes, there were incremental improvements previously, but they were much more modest.
Only 40,000 years before this 'great leap forward', the Skhul-Qafzeh hominins spread out of Africa and into the Middle East. They were largly modern anatomically, yet their technology was indistinguishable from that of the Neanderthals. Something major happened after 120,000 BP.
3. The 'paleoafricans' may have survived until 20,000 years ago in parts of Africa. Were they Homo erectus? The question is semantic. 'Homo sapiens' and Homo erectus' are terms that we impose on a continuum of anatomical and behavioral development. It might be nice to situate the boundary between the two at the 'great leap forward' 80,000 years ago. But this is not a point I would argue.
On the other hand, if you think Homo sapiens arose 1 million years ago, I would have to strongly -- strongly -- disagree.
Ben10,
There are several hypotheses. In my opinion, the two leading ones are:
1. Modern humans received Neanderthal admixture as they began to spread out of Africa. This would explain the similar level of admixture in Europeans, East Asians, and Papuans.
2. 'Neanderthal admixture' is a proxy for admixture with any of the different archaic groups in Eurasia, i.e., these other archaics were genetically similar to Neanderthals.
Frost,
If you believe behavioral modernity didn't arise until so recently, then does that mean people wern't fully sapient until then? How can we all be considered human beings if we have varying degrees of ancestry from non-human hominids who were also non-sapient?
And again, just how old were these paleo-africans? How old do you think "humanity" is?
"If you believe behavioral modernity didn't arise until so recently, then does that mean people wern't fully sapient until then?"
Again, we're looking at a continuum of physical and behavioral changes that has continued up to the present. Nobody is fully anything. Evolution is an ongoing process. The term 'sapiens' is a discontinuous construct that we impose on a continuous reality, presumably to make reality more understandable.
"How can we all be considered human beings if we have varying degrees of ancestry from non-human hominids who were also non-sapient?"
We all have 100% ancestry from non-humans if you go back far enough. It might be better to ask whether archaic admixture is evolutionarily meaningful. If a human population has 20% admixture, is it more backward than one that has 10% admixture?
My answer: probably not. If natural selection is allowed to operate, it will gradually replace less useful "archaic" alleles with more useful "modern" ones. So this is not a subject to feel emotionally distressed over.
Archaic admixture becomes interesting if it contributes alleles that are more useful. This is the big debate over Neanderthal admixture in modern Eurasians. Did it contribute anything useful? I'm frankly skeptical, but I could be wrong.
"Again, we're looking at a continuum of physical and behavioral changes that has continued up to the present. Nobody is fully anything. Evolution is an ongoing process. The term 'sapiens' is a discontinuous construct that we impose on a continuous reality, presumably to make reality more understandable."
I don't know if I really agree. There was definitely a point in time where humans wern't fully sapient, so why shouldn't there be a sort of division?
Where do you stand on the issue of behavioral modernity then?
"We all have 100% ancestry from non-humans if you go back far enough. It might be better to ask whether archaic admixture is evolutionarily meaningful. If a human population has 20% admixture, is it more backward than one that has 10% admixture?"
The question is whether or not this archaic admixture can be considered human. What do you think?
Anonymous, I am not an expert anthropologue but regarding sapience, I'll argue that we cannot regard the higher primates as completely deprived of it. Chimpanzee can hunt in group, they use stone tool, although they don't make it, and they surely exchange elementary communication signs. They know the concepts of 'I' and 'you'. I am not sure that Australopithecus was much better than that. Well, I tought it was not even certain that Australopithecus made their stone tools. Was even Homo erectus much smarter than a chimp ?
I wonder what these hominids needed their big brain for, as it seems that with a little bit of training, a chimp or a gorilla with a 500 cc brain can do as well as an erectus with a 800 cc, or more, brain.
I guess it is another example of unintelligent design. Hominids had variants with bigger brains with no use, maybe (that's my pet hypothesis) as a result for constant sexual selection for neotenic traits which could have fuelled an encephalisation trend in the homo genus.
There are also some modern cases of growth retardation with microcephaly and the affected individuals can still speak despite a very small brain. So the idea that sapience is an all-or-nothing mental state restricted in our species is hard to support.
If Neanderthal was able to make decorative tools (like in the latest issue of Scientific American) then i can't see how we could be sure he was more stupid than a modern hunter gatherer with an IQ of 70.
This said, I don't agree with this fear to classify modern humans in different subspecies of h. sapiens sapiens. Neanderthal was put in a different subspecies based on anatomical differences but in fact, I believe that anatomic similarities, the capacity to interbreed and a common african origin have no legitimacy anymore to classify modern humans in a single species.
Everything has happened in the brain at a far higher speed than previously in Evolution. If the cultural shift 80 000 years ago is a proven thing, it indicates a shift in brain hardwired which should be enough to remove the older h. sapiens from their status of modern humans.
Thanks for your input, but a couple of things regarding sapiency:
"Well, I tought it was not even certain that Australopithecus made their stone tools. Was even Homo erectus much smarter than a chimp ?
I wonder what these hominids needed their big brain for, as it seems that with a little bit of training, a chimp or a gorilla with a 500 cc brain can do as well as an erectus with a 800 cc, or more, brain.
I guess it is another example of unintelligent design. Hominids had variants with bigger brains with no use, maybe (that's my pet hypothesis) as a result for constant sexual selection for neotenic traits which could have fuelled an encephalisation trend in the homo genus."
I don't know if this is really true at all- there's good evidence indicating the correlation between IQ and brain size follows very similarly throughout the primate order: http://www.timesonline.co.uk/tol/news/uk/article1654998.ece
"He also found that the single most important factor in deciding a species’ intelligence was simply the size of its brain: “The correlation of brain size with mental ability found in humans appears to extend throughout the primate order.”"
I don't know if it's a perfectly linear correlation, but I once read part of the study and found it a very similar correlation between tests of primate intelligence and normal IQ tests in humans between brain size.
"There are also some modern cases of growth retardation with microcephaly and the affected individuals can still speak despite a very small brain. So the idea that sapience is an all-or-nothing mental state restricted in our species is hard to support."
People with mental retardation can speak too. There's more going on than just brain size.
"If the cultural shift 80 000 years ago is a proven thing, it indicates a shift in brain hardwired which should be enough to remove the older h. sapiens from their status of modern humans."
I don't know about that- genetic similarity is a prime factor here.
I'm confused as to where you all stand on behavioral modernity- did it arise relatively recently, or much longer ago?
One other thing- it seems as though correcting for brain size and age between humans and chimpanzees, there's still distinct cognitive differences between the two. It holds true for virtually any higher primates, whether it be gorillas and orangutans as well.
Many retarded children probably overlap the higher primate brain size average, yet all of them do indeed have capacities far different from them.
What probably sets humans apart is some sort of distinct internal structural traits and wiring that works independently of brain size. And what I'm wondering is when this truly arose.
Dawkins
"If species A evolves into a later species B ... there must come a point when a mother belongs to the old species A and her child belongs to the new species B. Members of different species cannot interbreed with one another. ... a child could hardly be so different from its parents that it could not interbreed with their kind. So, isn't this a fatal flaw in the theory of evolution?
But it is we that choose to divide animals up into discontinuous species. On the evolutionary view of life there must have been intermediates, even though, conveniently for our naming rituals, they are usually extinct:
The lawyer, with his trained discontinuous mind, insists on placing individuals firmly in this species or that. He does not allow for the possibility that an individual might lie half-way between two species, or a tenth of the way from species A to species B. 'Human', to the discontinuous mind, is an absolute concept. There can be no half measures. And from this flows much evil.
The word 'apes' usually means chimpanzees, gorillas, orang-utans, gibbons and siamangs. We admit that we are like apes, but we seldom realise that we are apes. Our common ancestor with the chimpanzees and gorillas is much more recent than their common ancestor with the Asian apes — the gibbons and orang-utans. There is no natural category that includes chimpanzees, gorillas and orang-utans but excludes humans."
The 'questions' of Anonymous remind me of someone.
Tod,
Your quote hit the nail on the head!
Ben10,
Any definition of Homo sapiens will be open to debate. For one thing, the genetic differences between the Neanderthals and early Homo sapiens are less than the differences between the latter and present-day Homo sapiens.
John Hawks made this point a few weeks ago on his blog (May 6, 2010):
"In our earlier work, we inferred a recent acceleration of human evolution from living human populations. That is a measure of the number of new selected mutations that have arisen very recently, within the last 40,000 years. And most of those happened within the past 10,000 years.
[...] Our recent evolution, after the dispersal of human populations across the world, was much faster than the evolution of Late Pleistocene populations. In adaptive terms, it is really true -- we're more different from early "modern" humans today, than they were from Neandertals. Possibly many times more different."
Anon,
"The question is whether or not this archaic admixture can be considered human. What do you think?"
All humans have archaic admixture, be it Neanderthal, Paleoafrican, or whatever. But that doesn't make us less human. There are even genes of viral origin in our genome. Does that make you feel icky? I hope not. We are what we are.
"I'm sorry but you're wrong. Most anthropologists accept that a major behavioral shift occurred c. 80,000 BP. Yes, there were incremental improvements previously, but they were much more modest."
I posted what you replied to awhile ago. How is it wrong when what I cited suggests behavioral modernity occured long ago?
Has anyone seen this: http://erectuswalksamongst.us/
This article is very interesting and seems to disagree with orthodoxy: http://rafonda.com/origin_of_humans.html
"About 13% of the sub-Saharan gene pool comes from an earlier expansion of pre-modern hominins that occurred c. 111,000 years ago"
What about the remaining 87%?
"About 13% of the sub-Saharan gene pool comes from an earlier expansion of pre-modern hominins that occurred c. 111,000 years ago"
What about the remaining 87%.
Never ceases to amaze me how liberal zealot college types ignore reality & logic, and look for any tiny piece of evidence to support their 'politically correct' theories. Why does a logically & practical thinking person who disagrees with these rac & evolutionary theories have to be a racist? All your theories are just that...but my thought is based on historical fact. First off, it doean't hurt my 'racist' feelings to know Europeans are not 'pure homo sapiens'...that is simply a word..the facts are pure Africans (homo sapiens) are further back in evolutionary time...you even state that,,,thus, they are physical stronger (closer to apes in time), while pure Europeans (your hybreds) are more intelligent, as they do not need to be physically stronger to adapt...they use technology,,,i.e. intelligence. Nothing complicated here. Early Egyptian civilation was advanced because the upper class were decendents of meditterranean types, Romans were expotentially more advanced than any African culture. Europeans had gun powder, ocean going ships, castles, etc...while the most advance African cultures were basically still in straw hut with spears...and this was well before colonialization. To negate one of your examples,,,Greeks fought among each other, so they had to develope technoilogies is a ridiculous theory, as certainly Africans fought more violently against each other ...and still do within their own nation.Call me what you want..you 'sugar coating the reality'...while I am presenting logic with no bias.
Superb. I know it well -- negroes are not human.
Now they found out an African American man had archaic Y DNA lineage from 338,000 years ago that predates modern homo sapient. What do we make of that? I'm sure more of this will be found in modern humans. I don't like that we get politically correct about science. It does not help anyone and does not help us understand our human journey. According to Cambridge University, Africans were a bunch of different hominids that melted together at times and also mixed with modern homo sapient. It is not true that Africans did not mix with the people of east Africa. Those people went to Eurasia, but also back into Africa never having mixed with Neanderthals. We all have that predominant East African DNA, but then we also have mixed with different hominids.
What we FALSIFY here is the strong out-of-Africa hypothesis
that everyone comes from the same population,” Dr. Paabo
http://www.nytimes.com/2010/05/07/science/07neanderthal.html?_r=0
Unknown Sub-Saharan African hominin
In 2011 Michael Hammer et al. at the University of Arizona studied DNA from two African hunter-gatherer groups, the Biaka Pygmies, the San and the West African agricultural Mandinka people.
They concluded that roughly 2% of the genetic material found in these modern African populations was inserted into the human genome approximately 35,000 years ago. They also concluded these sequences must have come from a now-extinct member of the Homo genus that broke away from the modern human lineage around 700,000 years ago.
In 2012 another study was done by Sarah Tishkoff et al. at the University of Pennsylvania. They tested 3 sub-Saharan African populations - Pygmies from Cameroon and the Hadza and Sandawe, both from Tanzania. The team found signs that the ancestors of the hunter-gatherers bred with different species of hominins, probably more than 40,000 years ago
http://en.wikipedia.org/wiki/Archaic_human_admixture_with_modern_Homo_sapiens#Unknown_Sub-Saharan_African_hominin
It sounds like people are finally starting to care more about science then being politically correct. Yes, African's seem to be the original species on earth, that evolved for millions of years, and are still connected to the primates. Is there much variation or evolution from them though? the evolutionary tree seems "on shaky ground" based on a cave they found with 5 homo erectus skeletons with a lot of variety. Found seperately, they all would have been called different species. If we call all in the homo line homo erectus, other then the big brained Neanderthal (brain size being highly connected to IQ) One might say that any before Neanderthal were homo erectus for millians of years. (Not called humans.) So any homo erectus who didn't interbreed with the Neanderthal, would not make cro magnon, called modern man. Those in the Canary Islands are thought to represent pure cro Magnon stock, and they are an obvious mix of white and black. Thus,it fits that is two species mixing started a very primitive modern man like them, that the Neanderthal would be the original modern man, and like the brain size shows, we have de-evolved by interbreeding. . .it is a deep and controversial theory, but I would love some descussion on it. Check out a very indepth and connected theory on the Neanderthal here, http://passionateproject.blogspot.com/2014/05/all-about-hybrid-neanderthal-named-adam.html and one on the homo erectus here. http://passionateproject.blogspot.com/2014/05/all-about-africans-original-earthly.html
What I have a problem with is the over simplification of African Cultures. Anon only looked at the obvious that Mediterranean culture were more advanced... Except he doesn't include how the cultures took influences from each other for longs period of time, in different geographies to influence cultures so you would obviously have more advance cultures. SS Africans actual did began to trade with neighboring Berbers since the 2nd half of the 1st millennium of B.C.E and eventually took influence from Arabs and built empires. Also for your "straw huts and spears" comment they actually built mud and palm leaf settlements which could be build around above 20 feet high in the case of palaces that they actually planned out as well as farming communities that possibly could have risen from independent metal work (look up Nok, Nigeria). As well (despite it being basic) art like masks, small statues, and engravings still require geometric skill. When you compare Greek and Roman aspects to Africa like their architecture for instance....they didn't build damn columns in a day. Such construction requires ages to develop. And with time and influence you would be surprised at how well Africans can get (Look up Sudano-Sahelian, Yoruba, and Bamileke Architecture). Look, I'm not saying you are a racist based on your policy on using facts, but I am African descent of the populations that this admixture applies to. With my facts and knowledge, I have the right to challenge ignorance on how a society takes actual development and misconceptions on "tribal" populations like Africa. I'm not trying to be a zealot but I respectively ask how much do you really know on cultural history of the world, because if you took it seriously you would've known about SOME of these facts.
The comments totally went to shit after 2010
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