Do we descend from Neanderthal ?

[Tecibbar]

Can we choose our ancestor by a poll?

 

[innonimatu]

I don't buy the "pure 'human'", out-of-Africa dogma.

The basic problem is that the evidence is simply appaling. A few, sparsely scattered skeletons scattered over the entire length of the planet and separated by thousands of years each. They're trying to reconstruct the city of London from the damaged base of a Fulham letterbox.

A smaller problem is that it flies in the face of our knowledge of human beings. The idea that every primitive humanoid was totally wiped out everywhere is plainly nonsense. Virtually all the human evolution that we can document is cultural, not genetic. If humans kill rival groups, they don't tend to kill fertile women...at least, there is a strong tendency not to in all the cultures surveyed by anthropologists. T

Also, don't they have to explain why human habitation of Australasia appears to significantly predate the African exodus. Maybe the "Africans" did get to Australia before the modern era, but they clearly mixed with the indigenous inhabitants.

http://home.twmi.rr.com/canovan/kowswamp/kowswamp.htm

My problem is that I'm really not an expert. Yet people tell me all these things, and "scientists" appear to be very bad historians. The Out-of-Africa theory is nothing more than a suggestion in the face of almost total ignorance...and it'll change once they start to dig up more skeletons, as it always has.

Well, we now have another piece to add to this puzzle, strongly backing your reservations about that "out of Africa" theory:

Siberian Fossils Were Neanderthals’ Eastern Cousins, DNA Reveals

An international team of scientists has identified a previously shadowy human group known as the Denisovans as cousins to Neanderthals who lived in Asia from roughly 400,000 to 50,000 years ago and interbred with the ancestors of today’s inhabitants of New Guinea.

All the Denisovans have left behind are a broken finger bone and a wisdom tooth in a Siberian cave. But the scientists have succeeded in extracting the entire genome of the Denisovans from these scant remains. An analysis of this ancient DNA, published on Wednesday in Nature, reveals that the genomes of people from New Guinea contain 4.8 percent Denisovan DNA.

An earlier, incomplete analysis of Denisovan DNA had placed the group as more distant from both Neanderthals and humans. On the basis of the new findings, the scientists propose that the ancestors of Neanderthals and Denisovans emerged from Africa half a million years ago. The Neanderthals spread westward, settling in the Near East and Europe. The Denisovans headed east. Some 50,000 years ago, they interbred with humans expanding from Africa along the coast of South Asia, bequeathing some of their DNA to them.

“It’s an incredibly exciting finding,” said Carlos Bustamante, a Stanford University geneticist who was not involved in the research.

The research was led by Svante Paabo, a geneticist at the Max Planck Institute for Evolutionary Anthropology in Liepzig, Germany. Dr. Paabo and his colleagues have pioneered methods for rescuing fragments of ancient DNA from fossils and stitching them together. In May, for example, they published a complete Neanderthal genome.
[...]

And the paper in Nature.

Looking at the pool results so far, this turn of events should also serve as a warning for people who are too ready to accept "scientific consensus" as the absolute truth.

 

[civ_king]

This is why I've maintained my "I'm willing to entertain the idea" comment on the "Out of Africa" Theory which obnoxiously gets met with "That's racist"

 

[Cynovolans]

There needs to be a "all Eurasians are 1-4% (genetically) Neandertal" option now.

 

[CELTICEMPIRE]

if I told you what I thought we would get into a big argument which belongs in another thread

 

[Arakhor]

So don't bring it up at all, Celtic Empire.

 

[B-29 Bomber]

But the genetic evidence does support the out of Africa theory - humans are a very undiverse species - a single tribe of a couple dozen chimpanzess has more genetic diversity than the entire human race. If early humans did mix with other hominids, you would expect there to be a lot more genetic diversity. Now, I expect that early humans did TRY to mix with other hominids - but it is entirely possible that homo sapiens just couldn't have fertile children with other hominids.

Sure I'll bite. The lack of biodiversity was due to the Tambora super-eruption in Indonesia some 60,000-100,000 years ago. It killed off most of Humanity to the point where there was only about 30 fertile females in Africa(though I can't quite remember. I got it from a show about the Yellowstone Super-volcano and it was a while since I saw it). So based off of that it was the Tambora Event that caused the lack of Biodiversity in humanity. If you study Super-volcanoes you'll understand why the majority of Humanity was killed by the Tambora Event. The conditions in the aftermath would be Hell.

 

[Fugitive Sisyphus]

Sure I'll bite. The lack of biodiversity was due to the Tambora super-eruption in Indonesia some 60,000-100,000 years ago. It killed off most of Humanity to the point where there was only about 30 fertile females in Africa(though I can't quite remember. I got it from a show about the Yellowstone Super-volcano and it was a while since I saw it). So based off of that it was the Tambora Event that caused the lack of Biodiversity in humanity. If you study Super-volcanoes you'll understand why the majority of Humanity was killed by the Tambora Event. The conditions in the aftermath would be Hell.

I don't really have an opinion but I'll bite as well.

If this were the case, why would the other modern primate species not be similarly lacking in genetic diversity? I don't see why, for example, Chimpanzees would fair better in a super-eruption.

 

[Lord Baal]

I don't really have an opinion but I'll bite as well.

If this were the case, why would the other modern primate species not be similarly lacking in genetic diversity? I don't see why, for example, Chimpanzees would fair better in a super-eruption.

Stole my argument. Not to mention various non-primate species not suffering the same problems.

A very interesting thread on a topic I find interesting. Great find innonimatu.

 

[Gustave5436]

This is why I've maintained my "I'm willing to entertain the idea" comment on the "Out of Africa" Theory which obnoxiously gets met with "That's racist"

Usually, fringe theories which reject the overwhelming scientific consensus on dubious grounds have ulterior motives. In this case, the notion that H. sapiens evolved independently in multiple different locations with different initial genetic stock makes it much easier to assert that there are separate "races" of humans than the widely accepted out of Africa theory.

The idea is not inherently racist, but there's an awful lot of overlap between them.

 

[civ_king]

Usually, fringe theories which reject the overwhelming scientific consensus on dubious grounds have ulterior motives. In this case, the notion that H. sapiens evolved independently in multiple different locations with different initial genetic stock makes it much easier to assert that there are separate "races" of humans than the widely accepted out of Africa theory.

The idea is not inherently racist, but there's an awful lot of overlap between them.

I'm not saying it's wrong, I'm just maintaining the possibility it could hypothetically be wrong

 

[Plotinus]

The multi-regional hypothesis always strikes me as intrinsically highly unlikely given that, as far as I know, no other species are supposed to have evolved in this way. As I understand it, speciation typically happens when populations become isolated or face new environments, and that seems to make the probability of a single species evolving in different locations at the same time highly unlikely. Why would H. sapiens evolve in a way quite different from any other species?

 

[Cynovolans]

The multi-regional hypothesis always strikes me as intrinsically highly unlikely given that, as far as I know, no other species are supposed to have evolved in this way. As I understand it, speciation typically happens when populations become isolated or face new environments, and that seems to make the probability of a single species evolving in different locations at the same time highly unlikely. Why would H. sapiens evolve in a way quite different from any other species?

I don't think the evolution of other species has been studied so much as compared to human evolution. Particularly the other great apes, they have a very poor fossil record and multi-regional theory requires fossil evidence so a multi-regional theory for a species that does not have a fossil record would have no evidence.

 

[GinandTonic]

The multi-regional hypothesis always strikes me as intrinsically highly unlikely given that, as far as I know, no other species are supposed to have evolved in this way. As I understand it, speciation typically happens when populations become isolated or face new environments, and that seems to make the probability of a single species evolving in different locations at the same time highly unlikely. Why would H. sapiens evolve in a way quite different from any other species?

Agree with you about H. Sapiens, but the pedant in me has to point out the Larus Gulls.

 

[civ_king]

The multi-regional hypothesis always strikes me as intrinsically highly unlikely given that, as far as I know, no other species are supposed to have evolved in this way. As I understand it, speciation typically happens when populations become isolated or face new environments, and that seems to make the probability of a single species evolving in different locations at the same time highly unlikely. Why would H. sapiens evolve in a way quite different from any other species?

While no one is claiming that Homo sapiens evolved in multiple regions what has been postulated is that species close enough to Homo sapiens interbred with it, think ring species

 

[innonimatu]

Yes, the fossil records leave no doubt that these different groups of humans existed and overlapped in time, the only uncertainty was whether they mingled and combined to produce present day humans.

And I don't see how this is racist. If they've mingled, clearly there is only one race. In any case that consideration is not relevant at all for this research.

I never bought the "consensus" that the neanderthals were an isolated species or an inferior group eliminated by a more recent one. For two reasons: a) there's no evidence of any inter-racial conflict; b) mankind was unable, before historical times, of eliminating many large predators which competed with humans or settling all the planet - how could one "race" of humans then be able to simply eliminate/out-compete another widespread "race" of humans?
The simplest explanation for these two groups to cease showing differences would be a convergence of the two, not the total annihilation of one by the other. And studying bone structure would not reveal this interbreeding because ,as we know from other species, the phenotype of their offspring would not necessarily show physical traits from both parents (already very much alike in this case). There is so little data, so few remains to study, that the "extinction" of the neanderthals may very well have been merely a quick adaptation to a changing world.
In any case there's a lot of speculation in all interpretations of this data, being (ridiculously!) presented as facts during the construction of the "single origin" and the "mixture" hypotheses.

 

[Plotinus]

While no one is claiming that Homo sapiens evolved in multiple regions what has been postulated is that species close enough to Homo sapiens interbred with it, think ring species

No, the multi-regional hypothesis is that Homo sapiens evolved in multiple regions. That's distinct from the hypothesis that other, closely related species interbred with Homo sapiens or its immediate ancestors. The latter seems reasonable to me but the former seems improbable.

Ring species like the gulls are cases where a species is widely distributed and each local group is marginally different from its neighbours, with the result that any two adjacent populations can interbreed, but most distant ones cannot. That's interesting as it tests what we mean by "species" in the first place and can give rise to sorites paradoxes. But it's distinct from a case where a single species evolves in different locations at the same time. After all, a ring species could come about where a species evolves in a single location and then becomes widely distributed, with subsequent evolution in the various populations leading to the "ring" situation. The multi-regional hypothesis is the reverse of this - namely that different populations somehow managed to evolve into one and the same species (presumably as a result of constant inbreeding between geographically scattered populations), with the end result being a single species all of whose populations can interbreed. We're not a ring species today.

 

[civ_king]

No, the multi-regional hypothesis is that Homo sapiens evolved in multiple regions. That's distinct from the hypothesis that other, closely related species interbred with Homo sapiens or its immediate ancestors. The latter seems reasonable to me but the former seems improbable.

Ring species like the gulls are cases where a species is widely distributed and each local group is marginally different from its neighbours, with the result that any two adjacent populations can interbreed, but most distant ones cannot. That's interesting as it tests what we mean by "species" in the first place and can give rise to sorites paradoxes. But it's distinct from a case where a single species evolves in different locations at the same time. After all, a ring species could come about where a species evolves in a single location and then becomes widely distributed, with subsequent evolution in the various populations leading to the "ring" situation. The multi-regional hypothesis is the reverse of this - namely that different populations somehow managed to evolve into one and the same species (presumably as a result of constant inbreeding between geographically scattered populations), with the end result being a single species all of whose populations can interbreed. We're not a ring species today.

I believe the latter. It seems possible that they could have diverged then converged later.

 

[Lord Baal]

I believe the latter. It seems possible that they could have diverged then converged later.

Actually, we know that early hominids diverged then later converged; South African hominids were cut off from East African hominids by desert for quite a while. But they never diverged enough to even qualify as ring species and there's no evidence at all for such a thing happening afterwards, certainly not on the scale you're suggesting.

 

[innonimatu]

It seems that many people are presently disassembling the myths which justified the the out of africa/neanderthal extinction theory. One more:

Neanderthals cooked and ate vegetables

Neanderthals cooked and ate plants and vegetables, a new study of Neanderthal remains reveals. Researchers in the US have found grains of cooked plant material in their teeth.

The study is the first to confirm that the Neanderthal diet was not confined to meat and was more sophisticated than previously thought. The research has been published in the Proceedings of the National Academy of Sciences.

The popular image of Neanderthals as great meat eaters is one that has up until now been backed by some circumstantial evidence. Chemical analysis of their bones suggested they ate little or no vegetables.

This perceived reliance on meat had been put forward by some as one of the reasons these humans become extinct as large animals such as mammoths declined.

But a new analysis of Neanderthal remains from across the world has found direct evidence that contradicts the chemical studies. Researchers found fossilised grains of vegetable material in their teeth and some of it was cooked.

[...]

One question raised by the study is why the chemical studies on Neanderthal bones have been wide of the mark. According to Professor Brooks, the tests were measuring proteins levels, which the researchers assumed came from meat.

"We've tended to assume that if you have a very high value for protein in the diet that must come from meat. But... it's possible that some of the protein in their diet was coming from plants," she said.

This study is the latest to suggest that, far from being brutish savages, Neanderthals were more like us than we previously thought.