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View Full Version : DNA shows that Homo sapiens and Neanderthals first admixed over 100,000 years ago



Maciamo
18-02-16, 08:39
The Guardian (https://www.theguardian.com/science/2016/feb/17/oldest-known-case-of-neanderthal-human-sex-revealed-by-dna-test) is relaying this morning the publication of a new paper (Kuhlwilm et al. 2016) (http://www.nature.com/nature/journal/vaop/ncurrent/full/nature16544.html) which established that a population that diverged early from other modern humans in Africa contributed genetically to the ancestors of Neanderthals from the Altai Mountains roughly 100,000 years ago.

This finding will have important repercussions on palaeontologists' understanding of early Homo sapiens dispersal out of Africa, as it means that at least one migration of H. sapiens had left Africa for Asia 40,000 years earlier than what current theories held.

I had explained two years ago in my article What were really Neanderthals like and how much did we inherit from them? (http://www.eupedia.com/europe/neanderthal_facts_and_myths.shtml) that 'the first migration of Homo sapiens into Europe could have started as early as 100,000 years ago, albeit in such small numbers that no archeological trace of it could be found to date.' It looks like I was right, although I was referring to small migrations to Europe via the Middle East and the Gibraltar Strait. But obviously once they reach Ukraine or Russia what is to prevent them from going all the way to the Altai and Mongolia ? They were nomadic hunter-gatherers after all, following the herds of large animals like mammoths.

bicicleur
18-02-16, 10:02
the paper is behind a paywall

we allready knew modern humans were in the Persian Gulf area 125 ka and in the Levant 110 ka, and even in SW China > 80 ka
these are extinct though, as they were outcompeted by the modern humans of the 55-45 ka expansion

when the 110 ka modern humans arrived in the Levant, the Neanderthals seemed to have dissapeared from the Levant for some 30-40.000 years
now some of these Neanderthals pop up in the Altaï ? it is becoming even more complicated

I don't think any modern humans were in Europe prior to 50 ka, and if they were I'd guess they crossed via Gibraltar (there were modern humans in the Atlas Mts 160 ka with the same skull type as the 110 ka modern humans in the Levant)

for those who speak Spanish :

http://terraeantiqvae.com/profiles/blogs/tuvimos-hijos-con-los-neandertales-ya-hace-mas-de-100-000-anos#.VsWL7vLhDs1

7627

Greying Wanderer
19-02-16, 16:08
Fascinating stuff - I've always wondered if the official OoA narrative was burying some critical Neanderthal element.

Angela
19-02-16, 16:51
Ed. Gronau, a co-author of the paper, has posted on the Dienekes blog.

http://www.dienekes.blogspot.com/2016/02/ancestors-of-eastern-neandertals.htm

"
http://img2.blogblog.com/img/b16-rounded.gif (https://www.blogger.com/profile/13887524618272491088)
Ilan Gronau (https://www.blogger.com/profile/13887524618272491088) said... I'm not sure I would say that this completely re-writes the current view of human migration out of Africa. Let me try to clarify the hypothesis we are trying to put forward:

~100 ka a group of early modern humans interbred with Neanderthals (could have been earlier, but not much later than 100 ka). This population diverged from the ancestors of present-day humans much earlier (~ 200 - 300 ka). If you want to place the divergence event geographically, then it likely happened in Africa, unlike the interbreeding, which likely took place in the Near East. So sometime in between, there was migration of humans out of Africa. Now, according to the genetic evidence, this population of early modern humans does not have any descendants in present-day humans. So they likely stayed very isolated in the Near East and never spread much in Eurasia. This is why we were trying to point out the Skhul and Qafzeh humans as a possible link.

I would say that this actually complements archaeological evidence of the presence of early modern humans out of Africa around and before 100 ka by providing the first genetic evidence of such populations."

Dienekes' response:

"If you want to place the divergence event geographically, then it likely happened in Africa, unlike the interbreeding, which likely took place in the Near East.

Yes, it's possible that the divergence event happened in Africa.
It's also possible that it happened in Asia. I see no reason to prefer one or the other.
After all, the main piece of evidence in favor of Out-of-Africa is that Eurasians are nested within African genetic variation.
If this paper is right, this is no longer the case: Africans are nested in Eurasian variation as a whole, inclusive of both modern Eurasians and the mystery population."

Stay tuned. :)

Alan
19-02-16, 17:08
After all, the main piece of evidence in favor of Out-of-Africa is that Eurasians are nested within African genetic variation.
If this paper is right, this is no longer the case: Africans are nested in Eurasian variation as a whole, inclusive of both modern Eurasians and the mystery population."

Stay tuned. :)

I had the same thoughts for quite some time now. What if modern Africans are just a migration from a very early Eurasian group that is nowadays extinct in Eurasia itself and modern Eurasians are merely a little piece of the once bigger Eurasian genetic variation. With other words similar to what happened with EEF in the Near East. It expanded to Europe and was washed out in the Near East itself by a related component. So what if a broad ancient Eurasian population with all it's diversity reached Africa and just after some time when they reached Africa, got almost completely "wiped out" by just one straign of Eurasians.


Another possible scenario is that we are dealing with a "backmigration" from Africa into Eurasia after earlier an "proto Eurasian" population moved into Africa.

Angela
19-02-16, 17:57
Razib's post on it:

http://www.unz.com/gnxp/why-i-still-lean-toward-a-sub-saharan-african-origin-for-modern-humanity/#comments

The comments are worth reading as well.

Angela
21-02-16, 17:52
John Hawks has also chimed in...

http://johnhawks.net/weblog/reviews/neandertals/neandertal_dna/neandertal-early-modern-gene-flow-kuhlwilm-2016.html

Tomenable
21-02-16, 19:17
we allready knew modern humans were in the Persian Gulf area 125 ka and in the Levant 110 ka, and even in SW China > 80 ka

these are extinct though, as they were outcompeted by the modern humans of the 55-45 ka expansionThey were in China 80,000 years ago (as recent finds of AMH teeth show) and in Australia 62,000 years ago (Lake Mungo 3):

Australia (see LM3 individual): http://www.pnas.org/content/98/2/537.full.pdf

China: https://www.washingtonpost.com/news/speaking-of-science/wp/2015/10/15/these-ancient-chinese-teeth-could-rewrite-human-history/

They are not completely extinct, according to Twitter talk between authors of the study and other researchers - quote:

======================
Gronau: "The one thing we can state w high conf is that it's not a classical OOA pop. That's what ED fig 3 shows"
Scally: "by classical you mean closer to present-day non-Africans than others? how sensitive is this to later demography?... e.g. bottleneck strengths. Hard to evaluate I realise."
Gronau: "shouldn't be too sensitive. Later demography (bottleneck & expansion) should make it easier to identify OOA pop"
Scally: "So crucial Q is to what extent can we rule out subsequent gene flow between later non-Africans and this early pop"
Gronau: "not sure we can rule out, but if it happened later (after introg into nean), then it will not affect on our findings"

Gronau: "we actually have a more difficult time detecting signal when using present day Europeans or Asians.... that was our first hint that source pop was not directly ancestral to Eurasians"

Scally: "I'd say the 50 kyr ago single out-of-Africa hypothesis is looking pretty dead now."
Schiffels: "In my view that hypothesis ever only described present day diversity, doesn't preclude earlier dead ends outside of Africa."
Scally: "Are we confident this was a dead end though?"
Siepel: "Not until we've sequenced every human on earth... That's what's known as 'job security'."

Khan: "increase the probability that @maitbb group has discovered some early OoA admixture at low levels in sahulians...."
Metspalu: "Exited! Indeed we think we see them! Need to make the reviewers see them too."

Khan: "[email protected] poster really interesting. sahul pops = (early out of africa + later out of africa). second pop sister to east west eurasians"
Metspalu: "thanks! word of caution - the proportion of the early OoA, or the extinct OoA as we call it, in Sahul is tiny (but there!)"

Scally: "Putting it like this makes it all seem rather sordid.. 'Human DNA found in a Neanderthal woman.'"
Saey: "Not sordid. It's the facts of ancient life. This is not 50 Shades of Hominids."
Scally: "I'm sure if they look further they'll find it was a one-night stand and they were both drunk."
Saey: "I prefer to think they were deeply in love and overcame their biological and cultural differences to forge a beautiful life."
======================

So Sahulians (= Aboriginal Australians, Papuans and Melanesians) carry some minor admixture from that Early OoA event.

bicicleur
21-02-16, 20:39
They were in China 80,000 years ago (as recent finds of AMH teeth show) and in Australia 62,000 years ago (Lake Mungo 3):

Australia (see LM3 individual): http://www.pnas.org/content/98/2/537.full.pdf

China: https://www.washingtonpost.com/news/speaking-of-science/wp/2015/10/15/these-ancient-chinese-teeth-could-rewrite-human-history/

They are not completely extinct, according to Twitter talk between authors of the study and other researchers - quote:

======================
Gronau: "The one thing we can state w high conf is that it's not a classical OOA pop. That's what ED fig 3 shows"
Scally: "by classical you mean closer to present-day non-Africans than others? how sensitive is this to later demography?... e.g. bottleneck strengths. Hard to evaluate I realise."
Gronau: "shouldn't be too sensitive. Later demography (bottleneck & expansion) should make it easier to identify OOA pop"
Scally: "So crucial Q is to what extent can we rule out subsequent gene flow between later non-Africans and this early pop"
Gronau: "not sure we can rule out, but if it happened later (after introg into nean), then it will not affect on our findings"

Gronau: "we actually have a more difficult time detecting signal when using present day Europeans or Asians.... that was our first hint that source pop was not directly ancestral to Eurasians"

Scally: "I'd say the 50 kyr ago single out-of-Africa hypothesis is looking pretty dead now."
Schiffels: "In my view that hypothesis ever only described present day diversity, doesn't preclude earlier dead ends outside of Africa."
Scally: "Are we confident this was a dead end though?"
Siepel: "Not until we've sequenced every human on earth... That's what's known as 'job security'."

Khan: "increase the probability that @maitbb group has discovered some early OoA admixture at low levels in sahulians...."
Metspalu: "Exited! Indeed we think we see them! Need to make the reviewers see them too."

Khan: "[email protected] poster really interesting. sahul pops = (early out of africa + later out of africa). second pop sister to east west eurasians"
Metspalu: "thanks! word of caution - the proportion of the early OoA, or the extinct OoA as we call it, in Sahul is tiny (but there!)"

Scally: "Putting it like this makes it all seem rather sordid.. 'Human DNA found in a Neanderthal woman.'"
Saey: "Not sordid. It's the facts of ancient life. This is not 50 Shades of Hominids."
Scally: "I'm sure if they look further they'll find it was a one-night stand and they were both drunk."
Saey: "I prefer to think they were deeply in love and overcame their biological and cultural differences to forge a beautiful life."
======================

So Sahulians (= Aboriginal Australians, Papuans and Melanesians) carry some minor admixture from that Early OoA event.

the 62 ka Mungo dating is very disputed
but yes, probably the first waves that arived in Australia are extinct too - as far as mt- and Y-DNA are concerned

I don't think we'll find many new branches > 50 ka in the mt- or Y-DNA pedigree tough, even if we would sequence every human on earth.
And even if we did, so what? We allready know the main branches.

I'm more interested in the whereabouts of the ancestors of those Altaï Neanderthals.

holderlin
22-02-16, 20:44
Fascinating stuff - I've always wondered if the official OoA narrative was burying some critical Neanderthal element.

Yes, me too. This may have been what got me interested in this subject. There were just too many archaics running around at the same time.