Science a GoGo's Home Page Forums General Discussion General Science Discussion Forum Did the Neanderthals die before we got to Europe?

phys.org:New study suggests Neanderthals died out earlier, did not coexist with modern humans

I have my doubts about this study. It seems to me that there have been quite a few datings of Neanderthal fossils that fall in the presumed 42,000 to 27,000 year time frame when both Neanderthals and modern humans were in Europe. There is also the question of Neanderthal/modern human interbreeding revealed in genetic studies. This was discussed in pretty good detail in the NOVA report I discussed a couple of weeks ago.

Bill Gill

Here's a bit more about it.

http://www.laboratoryequipment.com/news/...ns?et_cid=30749

40-50 thousand years ago brings the date close to that often suggested for Mungo Man, and he is not neanderthal. I thought that there had been evidence recently of neanderthal DNA in some modern humans. Is this so?

I did mention in my first post that there is genetic evidence for interbreeding between Homo Sapiens and Neanderthals. So there must have been overlap between HS and HN. As far as Mungo is concerned this is one of those things that some people are still kind of concerned about. The HN genetic material is found in all humans except those from Africa, so it happened before we spread all around the world. There is evidence for an HS presence in the mid east around 100k years ago, although they were using the same types of tools as their HN neighbors, rather than the more sophisticated tool used by the Cro-Mmagnons, the first HS in Europe. In the NOVA show I reported on a while back they said that the greatest evidence for interbreeding in in Europe, and may have happened quite a bit later than 100k years. The evidence suggests to me that the earliest interbreeding may have taken place in the mid east as HS was starting to work its way out of Africa. So Mungo would have already had HN genes when he made it on through to Australia.

As far as I can see Mungo seems to indicate that HS made it all the way to Australia before Cro-Magnon made it to Europe. There are some interesting questions as to how that happened. Possibly we were waiting for our skills to be developed enough to make a full assault on the colder European weather. That of course is my idea, not necessarily a good one. For one thing HN had been living in Europe for 200,000 years right through some extensive glacial episodes and I would think we could learn from them.

Anyway there is quite a bit of evidence for HN and HS sharing Europe for a long time, over 10,000 years, so I tend to question their new dates. Of course they did just date some sites in Spain, there could be different dates for elsewhere.

Bill Gill

But this is unlikely to have occurred in Europe, as all humans, aside from black Africans, have neanderthal DNA*. So it is well possible that neanderthals were extinct from Europe before modern humans got there, assuming the mixing occurred in the middle east.

*I put a star, as it remains controversial as there is an alternative explanation for the shared genes - inheritance from a common ancestor:
http://www.sciencedaily.com/releases/2012/08/120813155521.htm

Bryan

Welcome back, Bryan; I thought we had lost you.

What we need now is your old sparring partner, Kallog to return so I can get back to having fun with infinity.

glad to be back. The whole life/job thing got in the way of my internet playing...hopefully I can be somewhat regular.

Bryan

You have some good points there Bryan. In fact I don't know that anything is set in concrete either way. There is some evidence that HS and HN shared space in modern Israel for some time. They found HS fossils in a cave just a short distance from a cave where they found HN fossils at around 100K years. Apparently both species were in the area at around the same time. And they were both showing the same kind of lifestyle. There was little or no difference in the stone tools that they used. So that is one point where there could have been a sharing of genes. But the report on NOVA a while back seemed to indicate that the greatest sharing occurred in Northern Italy. Which could only have happened after HS had swept through Europe. So there are a lot of questions.

Bill Gill

IMO, it is more likely that we mixed with neanderthals than the common descent option, for a few reasons:
1) Those genes thought to be neanderthal-derived are the same across non-African populations. It would be an amazing coincidence for that exact pattern of inheritance to occur during divergent evolution from heidelbergensis to neanderthals and non-African HS. In contrast, it is exactly what you'd expect with admixture.

2) Skeletons that appear to be hybrids have been found.

3) Dating the timing some of the supposedly-neanderthal genes entered modern humans puts the entry of those genes into the modern human lineage at ~40KYA; again, consistent with influx from another population rather than inheritance from a more distant ancestor.


Israel seems a likely place for the first admixture; that would account for the finding of neanderthal DNA in all modern humans except for black African populations. But that doesn't preclude additional mixing, which quite possibly happened in Italy and elsewhere. It has been a while since I read the papers, but if I recall some groups of Italians have the largest portion of neanderthal DNA; consistent with additional admixture &/or preferential inheritance of the neanderthal DNA.

Bryan

Bryan, the only point you make that I have some question about is 2). The hybrid skeletons are in question by many paleoanthropologists. At the same time there must have been some hybrids around at one time or another so that is one that will take a while to be answered. If they could get some DNA from one of the skeletons that is considered a hybrid they might be able to get some good answers.

If you are interested John Hawks has a web log. He is an anthropologist who has been studying bones and genes for a long time. He talks about a number of different things, but does report on developments in genetic research of our origins.

Bill Gill

I agree that the hybrids are controversial; I'm not sure if they have recoverable DNA, but even if they do and they are hybrids, it still isn't proof that our (modern humans) DNA came from neanderthals.

IMO, at this juncture the evidence is strongly in favour of admixture between sapiens and neanderthal in non-African populations. I only pointed out the controversy as it is important to remember that this isn't settled science.

As an example, in the first paper suggesting neandertal-sapiens intermixing, it was proposed that autism was a trait inherited from neanderthals in the form of 2 genes. Turns out that was dead-wrong, for 3 reasons:
1) both of the purported genes are fixed in modern humans (meaning, in the populations that carry them, everyone has the neanderthal version),
2) one of the genes has since been shown to not be involved in autism, and
3) the second causes autism through a unique mechanism (chromosomal translational) that is irrelevant to inheritance

Admixture is a neat and emerging scientific field, but right now what we know is far less than what remains to be discovered.

Bryan