The Palaeobiology Thread:

[Green Baron]

I don't argue with you over opinions that can't be proven or disproven. Genetics have failed us more than once, they are only one tiny tool, more important is the finding and its interpretation, in this case the bones, cave sediments, stone tool ensembles and dating by different methods and a wide range of comparisons and related work. Your mouthing over the colleagues that have contributed several decades of research and discussion to Anthropology feels somewhat strange ... i am not always content with everything but these guys are no idiots. And i do not know who you are.

If you don't accept it no problem. But don't demand that others must share your opinion. If you can't distinguish between a modern human and a neandertal, no problem, I can. I maybe a bit out of practice, but like any serious man or woman, before i go out and make a fool out of myself i discuss the finding with colleagues, share opinions, have several specialist look over it, etc. The case is not taken out of the air, you know.

 

But you already said that Nature magazine and its peer review is bunk. Maybe science mag is the same ?

Edited January 26, 2018 by Green Baron

[Green Baron]

1 hour ago, PB666 said:

Chris falls into a camp that focuses on two populations Hss and Hn or He,

This is plain nonsense a false claim !

https://www.nature.com/articles/546212a

http://rstb.royalsocietypublishing.org/content/371/1698/20150237

Edit: it is an absolute common place that humans as hunters and gatherers, whatever species or subspecies they belonged to, were always on the move in out of where they were. Again, "out of Africa" is no single event. The simple thing here is to find evidences of when who was where. And who in this case is one with all traits a modern one and none of neandertals (go through them if you like) and it is determined to be 60.000 years earlier than before. That's all. No need to cast any fog.

Edited January 26, 2018 by Green Baron

[PB666]

25 minutes ago, Green Baron said:

This is plain nonsense a false claim !

https://www.nature.com/articles/546212a

http://rstb.royalsocietypublishing.org/content/371/1698/20150237

Then his views have changed, which leads one to wonder why he would hype up the claim, 20 years ago he was decidedly OoA. He's now touting claims that me and others were pointing at 10 to 15 years ago and saying hey, guys why are you ignoring these. There is nothing in these links that I disagree with, it is unfortunate that the conclusions are so late in coming. These view I have held for more than a decade. If these teeth were found 500 miles to the SW, it would hardly raise an eyebrow.

My point is that apomorphies can move into adjacent populations. And also I feel very uncomfortable about calling something a human apomorphy in the sense that we assume that the gene flow was from human and dates in the 170ky range, simply because it could be a trait that flowed from the N.African population into SSA population and not vice versa. But when we talk about homo sapiens in the North African context we are talking about Archaics, that means they have a spectrum of plesiomorphic and apomorphic traits. As such we can talk about apomorphies in SW Eurasia, at times as being trans Saharan gene flow, not necessarily human or Netherlander in their origin.

There is something else that needs to be stated, since I studied 6p21.3 (about 3 mnts) that along with scant evidence for admixture in the gene population, when the human population is polled for extreme examples of evolution (the most variant or deepest branches) the pocketed variation (see manifold definition) did not appear in Eurasia, but was pocketed in W/Central Africa . . . .very close to the deepest branch of the Y chromosome and proximal to one of the latest appearance of multiple plesiomorphic traits in Africa. Taken together it does hold for some sort of complex model of Hss evolution. The idea of AMH (anatomically modern human) is a simply a purest idea its a fantasy to believe that all humans became AMH at once. In if thats true, then its more true for adjacent populations. 

But also, based on genetics, neither is it evident that these Archaics evolved into to something else, in fact the genetic evidence shows the opposite, that if they contributed they would have needed in totality to have moved south admixed into SSA and then reexpanded as something else. I find this highly unlikely. In my mind the original suggestion that these were African Neandertals is partially true and that they were also homo sapiens is also true, both are true, but the problem is we don't know how stable the population was AND that any stability it might have had might be attributed to evolving Hss and Hn. Likewise as humans expanded (L1 tangenika, L2 central and west Africa) really 100 to 140 kya time range, that the stability of this 'trans'species might have been in jeopardy. Once Humans appear in Europe then its stability is in great jeopardy.

1 hour ago, Green Baron said:

they are only one tiny too

When genetic approaches are properly applied, when they are fully statistically condition it is one of the most most powerful tools that paleoanthropology has, when it is misapplied, when it represents a huge selection bias, or when statistics are not used to condition the arguments, then like any other technique it can be bunk. For example most of the Y studies before 2000 are bunk.

But in terms what has been more misinterpreted, the physical versus the genetic. . . .the first studies by V. Sarich in 1975 are largely validated as with the first studies by Brown in 1980 and Vigilant there after. And of course no single person in the study of physical paleoanthropology approaches the quality and breadth of work that Sarah Tishkoff has done.

[PB666]

1 hour ago, Green Baron said:

If you don't accept it no problem.

The point is that I am skeptical. I used to follow MREH, but then I looked at the genetic studies and i realized that Paleontology was very good at dressing up lies, packaging them into expensive books and selling them. As a scientist nothing ever taught me to be so much of skeptic as the historical study of paleoanthropology. And more importantly to basically defend MREH one has to take the devil's advocacy. . . . prove what you are saying true. And eventually it was proven, but not by the physical paleoanthropologist, almost all (not stringer he has 97% correct) of their conclusions were wrong, it was the molecular evolution that eventually (after much beating and critique) proved the point , 10 fold less.

When I see something like humans were in Israel 170kya and knowing about all the consistencies in the molecular genetics and the plotting of human fossils and MDTs around the Earth, it raises the eyebrow very high.

As I pointed out that inside of a bubble 235 to 170 kya (which can really be extended as a slowly opening funnel to about 120 kya) you have a container, and then outside the container things are going on. The container does not contain all human apomorphies it only excludes certain molecular traits (that is to say plesiomorphies of certain types were excluded, observed with X-chromosome, mtDNA and Y chromosome). Nor does it restrict the engagement of external apomorphies with the human population, it simply argues that if those traits enter the Hss population they should be highly selective to fix in humans by the time that they expand. There is nothing that limits admixture of traits before the expansion other than violations of the 2N rule. That is to say that if a male contributes an apomorphy, and his offspring or offsprings offspring are all female, we can not trace Y flow with the apomorphy even if the apomorphy is selective.

What it means is that novel claims create uncertainties in several directions and we should not be fast to throw these under the rug simply because a popular author offers a conclusion.

[Green Baron]

53 minutes ago, PB666 said:

 If these teeth were found 500 miles to the SW, it would hardly raise an eyebrow.

And that is point ! To survive in the Levant humans needed a different package, like clothing and portable fire to survive a frosty night. Not so in Sudan. And yes, that's an old hat. But here's the bone, maybe not a smoking gun, but a loaded one.

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My point is that apomorphies can move into adjacent populations.

We know that. If i were you i'd attack the stone tool ensemble ...

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And also I feel very uncomfortable about calling something a human apomorphy

*shrug* There is a stack of studies, including simple morphology. Suggested search terms: "neandertal modern human teeth morphologic identification". If you dare include German and French publications, as there sit a lot of specialists.

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There is something else that needs to be stated, since I studied 6p21.3 (about 3 mnts) that along with scant evidence for admixture in the gene population, when the human population is polled for extreme examples of evolution (the most variant or deepest branches) the pocketed variation (see manifold definition) did not appear in Eurasia, but was pocketed in W/Central Africa . . . .very close to the deepest branch of the Y chromosome and proximal to one of the latest appearance of multiple plesiomorphic traits in Africa. Taken together it does hold for some sort of complex model of Hss evolution.

A link would be nice, Wikipedia not accepted. But it leaves the sense and meaning of the paper above, which is about modern humans outside of their origin earlier than before.

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The idea of AMH (anatomically modern human) is a simply a purest idea its a fantasy to believe that all humans became AMH at once. In if thats true, then its more true for adjacent populations. 

That sounds like a creation event and makes me shiver.

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...  were African Neandertals ...

???

Your beloved genetics in honour, but they are only one tool of many. A mysterious group that may or may not have contributed must yet be found. I mean by bones and stone tools, the classic style, or they don't exist ;-)

 

Be it as it may, modern humans in the Levant 180.000bp. Yay.

 

Edited January 26, 2018 by Green Baron

[PB666]

20 minutes ago, Green Baron said:

And that is point ! To survive in the Levant humans needed a different package, like clothing and portable fire to survive a frosty night. Not so in Sudan. And yes, that's an old hat. But here's the bone, maybe not a smoking gun, but a loaded one.

In the context of 500 miles in Africa and the distribution of fossils during that period 500 miles is a few foot steps. You don't know, those hominims might have been in Levant during the summer and back in Sudan by the fall. Remember, pre-neolithic peoples were unsettled. Even worse, they could have traveled from Blombos cave region all the way to the Red Sea by dugout.

 

24 minutes ago, Green Baron said:

shrug* There is a stack of studies, including simple morphology. Suggested search terms: "neandertal modern human teeth morphologic identification". If you dare include German and French publications, as there sit a lot of specialists.

40 kya, 80 kya even 100 kya, no problem. 170 kya its dubious.  If you ever have studied gene flow in a population or even collection of subpopulations 70 ky is a very long time.  

 

29 minutes ago, Green Baron said:

A link would be nice, Wikipedia not accepted. But it leaves the sense and meaning of the paper above, which is about modern humans outside of their origin earlier than before.

http://haplogroup-a.com/Ancient-Root-AJHG2013.pdf

http://www.bbc.com/news/science-environment-14947363

What it leaves is that until rather recently Africa was more like a plum pudding with pocketed variation persisting in spots, isolated as the human population largely underwent speciation. S. and E. Africa was the core, on the peripheral of the core other interesting things were going on. Some of these things were captured by the human population, some of them were not. The things that were not captured we have no further evidence of or where they roamed. The genetic anomalies in the West/Central African population we spotted 20 years ago, and supported by physical anthropology 7 years ago. Likewise the genetics spotted admixture, probably between Homo neandertalensis narmada/desinova that occurred in Indonesia with no, I repeat, no evidence of Neanderthals being in Indonesia. If you can't see what I am getting at you are not thinking abstractly enough. The physical typology of paleoanthropology is pretty much a fail without the genetics (aDNA and molecular evolution), even with genetics its pretty incomplete.  The plums in the pudding (like florensiensis) were more frequent than anyone can imagine, and tracking the plums over time is not a trivial issue. There is one other abstract issue, we can detect admixture if an only if we have a sensor, otherwise its just evolution. Yes, there have been studies in humans to detect ancient outgroups without aDNA, but the result is more like classical physics trying to replicate QM on the small scale. What you need are sensors . . . .but I have to say there are elements in the human population that neither fit Hss or Neandertal and they are spatially localized which means there are phantom plums.

In terms of archaeology I can point you to the fact that one site (unknowingly mesolithic) was characterized as having Neandertal stone tools (and in all fairness they really looked homologous to Neanderthal stone tools at a different site) until it was precisely dated and later found to be mesolithic tools. Tools reflect what people are doing, not their genes per say, but how they live, if you have a clever tool that makes what I am doing easier, I will strive to make it. The differences between N.African Archaics and humans of the same period, cognitively, were trivial. 

 

 

 

[Green Baron]

8 minutes ago, PB666 said:

40 kya, 80 kya even 100 kya, no problem. 170 kya its dubious.

If you say so. I need evidence. And the presented one is quite conclusive. And surely not the last word.

Btw. your beloved but in my eyes not all encompassing genetics allow for a much older occurrence, depending on where you place the separation (370-520ky bp). But again, one brick in the wall, and i still don't see a problem.

8 minutes ago, PB666 said:

  If you ever have studied gene flow in a population or even collection of subpopulations 70 ky is a very long time.  

I had to attend a course. I hated it. Illogical.

8 minutes ago, PB666 said:

 more like a plum pudding with pocketed variation persisting in spots,

Yeuch.

8 minutes ago, PB666 said:

isolated as the human population largely underwent speciation. S. and E. Africa was the core, on the peripheral of the core other interesting things were going on. Some of these things were captured by the human population, some of them were not.

I can't say no, i can't say yes. So i say maybe.

8 minutes ago, PB666 said:

The things that were not captured we have no further evidence of or where they roamed. The genetic anomalies in the West/Central African population we spotted 20 years ago, and supported by physical anthropology 7 years ago. Likewise the genetics spotted admixture, probably between Homo neandertalensis narmada/desinova that occurred in Indonesia with no, I repeat, no evidence of Neanderthals being in Indonesia. If you can't see what I am getting at you are not thinking abstractly enough.

This is not about neandertals in Indonesia. It is about modern humans in the Levant. Yes, i totally lack your abstraction here :-)

8 minutes ago, PB666 said:

The physical typology of paleoanthropology is pretty much a fail without the genetics

Outch. A lot of people would cold bloodedly kill you for that. I not. I am peaceful. Mostly. And i don't have a knife @hand.

8 minutes ago, PB666 said:

 The plums in the pudding (like florensiensis) were more frequent than anyone can imagine,

How do you get that link now ? Remember, we are talking about modern humans in the Levant 180ky earlier than now.

8 minutes ago, PB666 said:

and tracking the plums over time is not a trivial issue.

They rot so quickly, don't they ?

8 minutes ago, PB666 said:

there are elements in the human population that neither fit Hss or Neandertal and they are spatially localized which means there are phantom plums.

Yes. But what if the sample is clearly a neandertal, or a modern guy (or girl) ?

8 minutes ago, PB666 said:

In terms of archaeology I can point you to the fact that one site (unknowingly mesolithic) was characterized as having Neandertal stone tools (and in all fairness they really looked homologous to Neanderthal stone tools at a different site) until it was precisely dated and later found to be mesolithic tools.

Which one ? I don't exclude that categorically, but you have a chance here to surprise me ?

8 minutes ago, PB666 said:

Tools reflect what people are doing, not their genes per say, but how they live,

Yes, sir ! Think about this again and again, and then about our division of the stone ages, local specialties and differences, development over time and ecology. Hullo ! Everybody reading this, that's definitely worth citing ! No joke.

8 minutes ago, PB666 said:

The differences between N.African Archaics and humans of the same period, cognitively, were trivial. 

I don't know whom you mean with archaics, but if that's about differences between neandertals and modern guys, then i agree. I wouldn't say "trivial" because it takes some time and effort to work it out, maybe "gradual" ?

[PB666]

46 minutes ago, Green Baron said:

allow for a much older occurrence, depending on where you place the separation (370-520ky bp)

In Africa the paleontology allows for older occurrence, that is because modern evolution was stochastic. Specific trait evolution (apomorphies) attributed top AMH were variants until rather recently. I should point out that its not by my definition, hominims with certain level of plesiomorphies are called Archaic homo sapiens, but an earlier name Homo rhodesiensis (c.1921), by a recent name homo heidelbergensis. Again, I am not going to mince the terminology, but I should point out that there was also apomorphic gene flow from Europe into Africa  (ergo the name African Neandertals) and from SSA and there is no reason to believe that genes flowed one direction and not the other. So N. African hominids are a mixed bag and the best name for a mixed bag is archaic homo sapiens. IN species we call this a gradient. You start with Classic (stage 4) Neanderthals, you have Levantine Neandertals, you Have North Africa archaics, then . . .  homo sapiens. But that by definition is a recent thing, before that plesiomorphies and apomorphies in Africa appears stocastically intermixed with exceptions. And the exceptions lack statistical weight to mean anything. But the genetics shows waves of motions, first before 500 kya then around 200-250 kya and finally recent introgression, this informs us why there is stochasm. Genes don't flow like waves, they move in pulses the same way small groups migrate.

The dentate you seem to so strongly support as a human determinant,  . . . nor do we know when or where it evolved in Africa.

[Green Baron]

18 minutes ago, PB666 said:

The dentate you seem to so strongly support as a human determinant,  . . .

It's modern human. You don't accept it without actually discussing the description from the paper. Which is conclusive (the paper). That's all of the problem.

People can tell between a Mercedes and Hyundai (i can't). Others between a modern human and a neandertal. By the teeth and a maxilla fragment. And a lot of comparison.

I'd have problems with a rib fragment. But even a shaft fragment from a long bone could in ideal cases be identified. Some can, others can't.

:-)

Edited January 26, 2018 by Green Baron

[tater]

I had a friend (she died recently) who was a paleoanthropologist. She was also blind. She could not only tell species by touch, she’d ID which tooth (upper right second molar, etc). My other friend, a prosthodontist, quizzed her once with piles of teeth he had (writing a textbook, had many organized in drawers). Didn’t miss any.

[Green Baron]

Impressive. And more so if she did that with an incisor :-)

Molars can be identified by the cusps, flanks and ridges, which by no means belittles her performance ! Just telling ...

 

Edit: and my sympathy for the loss of a friend.

Edited January 26, 2018 by Green Baron

[PB666]

46 minutes ago, Green Baron said:

It's modern human. You don't accept it without actually discussing the description from the paper. Which is conclusive (the paper). That's all of the problem.

People can tell between a Mercedes and Hyundai (i can't). Others between a modern human and a neandertal. By the teeth and a maxilla fragment. And a lot of comparison.

I'd have problems with a rib fragment. But even a shaft fragment from a long bone could in ideal cases be identified. Some can, others can't.

:-)

170 kya is not modern human, this is pre AMH, homo sapiens idulatu is defined as the delineation point between Anatomically Modern and Premodern dates to 160 kya. Some people hold that anatomically modern human evolved between 200 to 300 kya, but I should point out that the definition maybe inclusive of more than just preOoA humans. Again, the pointers to mtDNA which forced back as far back as the dating can be force requires an initiation no earlier than 250 kya and a procession of at least 50,000 years within a N_e population of 10,000 individuals. When you are talking about entry into the constriction almost by definition you are talking about premodern and the holoarchaeology of sub-saharan africa does not support a designation of fully modern. 

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has features that show resemblances to more primitive African fossils, such as huge and robust skulls, yet have a globular shape of the brain-case and the facial features typical of H. sapiens  . . . . . . . . . . comparative craniometric analysis of the Herto Homo idaltu skull with ancient and recent crania from other parts of Africa found that the specimen was morphologically closest to the Pleistocene Rabat fossil and Early Holocene Kef Oum Touiza skeleton. see wiki link for idaltu 

Rabat is the Jebel Irhoud samples and Kef Oum Touiza is in Algeria. This can mean one of two things, its too early for anatomically modern humans or that the affinities are the result of flux in the north African archaic population.

By definition you are talking about the evolution of Apomorphies not immigration of moderns.

 

[tater]

She could ID all of them.

[Green Baron]

9 hours ago, PB666 said:

 homo sapiens idulatu 

idaltu is the name. And yes , its an early sapiens.

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Some people hold that anatomically modern human evolved between 200 to 300 kya,

Most. Your personal notion is not above the generally accepted opinion.

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Rabat is the Jebel Irhoud samples and Kef Oum Touiza is in Algeria. This can mean one of two things, its too early for anatomically modern humans or that the affinities are the result of flux in the north African archaic population.

By definition you are talking about the evolution of Apomorphies not immigration of moderns.

This is pointless. It means nothing. There is a modern human maxilla outside of Africa 60.000years earlier than before. An outgrown individual died there. You are only casting meaningless fog to belittle other people's work.

 

 

And you still owe me a proof for your claim the somebody mixed up mesolithic and middle palaeolithic stone tools. What's holding you back ?

 

Edited January 27, 2018 by Green Baron

[Xemina]

On 1/25/2018 at 4:29 AM, CatastrophicFailure said:

Actually... 

...there’s a theory that T-Rex was primarily a scavenger, incapable of real hunting and mostly harmless... 

Good theory, I like that one! There's only a slight problem though; Tyrannosaurus had very strong jaws and very big teeth, which you wouldn't evolve if you scavenged, the theory was based on the fact T. rex had small arms.

Question, has anyone watched the video on  What the T.rex Really Sounded Like? (Must use headphones for sound)

https://www.youtube.com/watch?v=cpipaUfcnmM

[Green Baron]

The some Hadrosaurids might have had quite a nice snorting organ, derived from air chambers in the skull.

Of course, that's hypothetical.

Example: http://www.ucmp.berkeley.edu/diapsids/ornithischia/hadrosauria.html

Edited January 27, 2018 by Green Baron

[PB666]

2 hours ago, Green Baron said:

Most. Your personal notion is not above the generally accepted opinion.

 I wouldn't say most. And BTW I don't know when people started believing this because up to a few years ago it was only 100ky or so.

There are a ton of problems with the early definition that can be shown as flawed. Since you don't comprehend the genetics I will end the discussion now.

Note: I just saw your request for reference on the N/ML request, just to make point, I generally don't keep track of hype any more than I take stock in what Nature publishes.

 

 

[Green Baron]

57 minutes ago, PB666 said:

 I wouldn't say most. And BTW I don't know when people started believing this because up to a few years ago it was only 100ky or so.

Now. 250ky is in discussion since decades. Examples for early and transitional forms: Bodo, Ndutu Lake, Kabwe, Salé, Eyasi, Florisbad, Eliye Springs, Laetoli, and the ones you already mentioned. I am sure there is more but don't remember them all.

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There are a ton of problems with the early definition that can be shown as flawed.

You haven't done so. Edit: 160.000 is only the lower limit.

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Note: I just saw your request for reference on the N/ML request, just to make point, I generally don't keep track of hype any more than I take stock in what Nature publishes.

Then just admit that your claim was false and everything is fine.

 

Edit: this estimates the genetic divergence to 260-350ky bp and it has nice and long reference list. The picture is almost complete, isn't it ?

http://science.sciencemag.org/content/early/2017/09/27/science.aao6266.full

 

Edited January 27, 2018 by Green Baron

[PB666]

3 hours ago, Green Baron said:

Now. 250ky is in discussion since decades. Examples for early and transitional forms: Bodo, Ndutu Lake, Kabwe, Salé, Eyasi, Florisbad, Eliye Springs, Laetoli, and the ones you already mentioned. I am sure there is more but don't remember them all.

[snip] Here is a human skull.

Note the brow and thin-ness of the bones in the skull.

Bodo is NOT AMH, kabwe  (Broken hill 1) is the rhodesiensis type specimen and was called a Neanderthal by its founder. I have never heard anyone support these as Modern [snip]. Secondarily you can't use Kabwe 1 to date AMH because . . .[drum roll] it was never dated, the skull was posted on a stake and miners took pot shots at it. Bad Archaeology, worst use of fossils for dating AMH that I've yet to see.

Ndutu

Note the pronounced brow ridges and thickness of the skull (400kya) {classified as homo erectus or homo rhodesiensis) Also lacking dentate.

Kabwe (Broken hill 1) Date is uncertain, note the pronouced heavily pnuematized brow (definition of homo rhodesiensis) undated. (c.1975 date 150,000 to 300,000 ya <== not to be trusted)
Eyasi (Mumba Cave) no human remains. Trivial.
https://en.wikipedia.org/wiki/File:Florisbad-Helmei-Homo_heidelbergensis.jpg   dated to 259 kya with ESR, no other dating performed. Classified as homo heidelbergensis
Laetoli - irrelevant fluff
http://humanorigins.si.edu/evidence/human-fossils/fossils/eliye-springs-es11693 Species: Homo heidelbergensis (no dentate)

[snip]
Where are these Anatomically Modern humans running around 200 to 300 kya. Show me at least one clear example?

Here, let me help you, this is the only paper you have https://www.ncbi.nlm.nih.gov/pubmed/28593953. Dated with TL, some other papers also dated with the same technique have been refuted (I.e. LM3). The dentate recovered IIRC are plesiomorphic (Neanderthal like).

 

 

Edited January 27, 2018 by Snark
Redacted by moderator

[Green Baron]

Yes, besides [snip] these are the early and transitional forms that lead to anatomical modernity. The path to modern humans, from 500ky to 250ky before now. Of course they are not full featured modern humans themselves, who said so ? They are the archaic forms you came up with.

[snip] Or do you assume that someone snipped a finger and there were the modern humans ? Then we have a principal problem ! Also, at these times and long afterwards there were more than one human species and subspecies on earth, living side by side. We have to combine the pieces of the puzzle to a picture. That is our work, and the pieces are bones, the find places, the times, dating, sediments etc. blabla and even your genetics (see above).

 

But modernity (Edit in distinguishable characteristic) is there at least 160.000y bp, now we have it 180.000 years ago and outside of Africa. And that is all there was to say. [snip] We can safely place gradual emergence of modernity to 250.000bp, [snip] ? And genetics support that, see the work above.

[snip]

Edited January 27, 2018 by Snark
Redacted by moderator

[Snark]

Thread temporarily locked for maintenance, please stand by.

[Vanamonde]

Thread open again, but only so long as people play nice. 

[tater]

https://www.nature.com/news/oldest-homo-sapiens-fossil-claim-rewrites-our-species-history-1.22114

[PB666]

8 minutes ago, tater said:

https://www.nature.com/news/oldest-homo-sapiens-fossil-claim-rewrites-our-species-history-1.22114

yep, did you catch this one in there " sequenced the genome of a boy who lived in South Africa around 2,000 years ago — only the second ancient genome from sub-Saharan Africa to be sequenced. They determined that his ancestors on the H. sapiens lineage split from those of some other present-day African populations more than 260,000 years ago."

This one is actually not too surprising, and there is another paper that points to ancient contributions to :

https://www.ncbi.nlm.nih.gov/pubmed/26888264

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  Within Africa, fossil evidence suggests that anatomically modern humans (AMH) and various archaic forms coexisted for much of the last 200,000 yr; however, the absence of ancient DNA in Africa has limited our ability to make a direct comparison between archaic and modern human genomes. Here, we use statistical inference based on high coverage whole-genome data (greater than 60×) from contemporary African Pygmy hunter-gatherers as an alternative means to study the evolutionary history of the genus Homo. Using whole-genome simulations that consider demographic histories that include both isolation and gene flow with neighboring farming populations, our inference method rejects the hypothesis that the ancestors of AMH were genetically isolated in Africa, thus providing the first whole genome-level evidence of African archaic admixture. Our inferences also suggest a complex human evolutionary history in Africa, which involves at least a single admixture event from an unknown archaic population into the ancestors of AMH, likely within the last 30,000 yr.

I should note that my studies revealed a similar fiindings and were completely independent of these. It also revealed that the alternative centers of diversity outside were likely within Africa or close to Africa.  If you look at the physical anthropology of Africa over the last 400,000 years you can surmise the same thing (see post above). As I said, Africa was a bit of a plum pudding, most groups intermixed during the constriction period, a few intermixed during the expansion. Plesiomorphies and apomorphies appeared to coexist side-by-side sometimes these were variants at other times these were self-isolating populations. Some pops might have been lost. Some of these plesiomorphies still exist, under then skin, in certain African populations.

75% of the human population genetics can be explained by two events (summarized, fully explained you have to look at Tishkoff's genome studies). The first is that mtDNA expanded along a line from East Africa to South Africa, with a strong favoritism along the Southern Rift valley, this is given by Tajima's D value for L5 and slightly higher L1 (these are the most equilibrated and slowly evolving mtDNAs in human, its a measure of stationary populations). The majority of Y chromosomal evolution comes from the A-B branch which is A is localized in Southern Africa and B splits to explain all others. The A00 deep branch dates to 265,000 kya  is likely of N, W African or Arabian origin of the same period as the AB branch.  Those events take a snap shot of where people were once at, but its a low resolution picture. We have to do refined genomic studies to see high resolution. But we have to note that there is not much in here to support a N. African origin of Hss, the N. African population appears to be an intermediate in geneflow more important geneflow of an earlier period, the anecdotes are that maybe a persistent N.African population contributed more recently, but where is the core of this population?

And when we look for centers of diversity in the N or NW African population, not apparent deep centers of diversity although there is gene evidence from Iberia and NW Africa of a prolonged occupation.  In fact the coast population has fractional diversity relative to the SSA population, by many techniques. So that if Jebel Irhoud substantially contributes to the modernization of Africa its contribution has to move southward at least by 215,000 years ago. I suspect that the N.African population contributed to the diversification of Central African populations. What N Africa archaics contributed to H. sapiens would be much, much more apparent if we had  a sensor, aDNA, but unfortunately the temperatures of N. Africa are too high to hope that the DNA would survive.

One might ask the question, why with almost 20 years of a complete human genome that it took so long to find these introgressions into the African population. The answer is that the diploid genome (is capable of) carrying alot of variation, and unless you know the selection coefficients you have to assume that the variants are pass through variants (The HLA loci have something like 10-16 passthrough gene variants for B and DRB1 genes, in comparison mtDNA had 1 invariant passthrough and Y appears now to have 2, but still rather recent TMRCA, HLA RDs TMRCA was estimated at 60 million years). In that context its not easy to often see introgression. HLA is peculiar because it resists exclusion and so its essentially an introgression trap. Africa has 3 fold more variation than the exo-African population. If the signals are weak and the noise is strong, they are difficult to find.

The original HapMap studies were done of the Yoruban, which became a surrogate for Africans. Refined genomic analysis we can get a picture of what longer segments of African genomes look like by looking for long stretches of homozygosity that are unique to certain populations and when you do that you find the 'odd' variants that are in linkage disequilibrium and with that you can identify introgression events. So then you focus that sensor on isolate groups and see what you can find. 

Timing is a problem, and I will, if things stay calm, discuss that another day. Its a big topic and requires some patience to understand, if you want to read the physical side of the argument then. https://www.ncbi.nlm.nih.gov/pubmed/29348642

This is more or less a review, and there is alot of opinion but they seek to show the evidence of MIS 4 (71-60 kya) verus MIS 5 (130-72 kya) migrations into Asia. This will help solve the dilemma of the anchor state and migration manifords (Surface positions over time).

[Green Baron]

Morning,

good to see that we basically agree on the dates of emergence of modern humans. What remains is the morphological "modernity", which is a soft and gradual criterion but a distinguishable one. And, besides the wave 70-50000 years ago, the question when they left Africa. Probably at all times throughout the development.

That find is extraordinary and greatly widens the evolutionary range of modern humans in time and space of origin.

Cheers and piece :-)

Edited January 28, 2018 by Green Baron