The Palaeobiology Thread:

[James Kerman]

Recent evidence here in Australia has also pushed back time estimates of occupation at least 10,000 years.
 

Quote

• Dating of artefacts and fossils from Warratyi indicates human settlement between 49,000 and 46,000 years ago
• Timing shows people moved through central Australia and used key technologies such as stone axes and ochre much earlier than previously thought
• Archaeological evidence also shows humans lived alongside, and hunted megafauna

http://www.nature.com/articles/s41559-017-0436-8?WT.feed_name=subjects_archaeology

http://www.abc.net.au/news/science/2016-11-03/rock-shelter-shows-early-aboriginal-settlement-in-arid-australia/7983864

[Scotius]

This shows very well how non-linear and random was human emigration from Africa. I mean - who in their right mind would cross richer and more welcoming lands in  South Asia (and further north and east), and decided to settle in friggin' Australia of all places?

[Green Baron]

Yep, and the Arabian desert is in between, if they took the southern route. I don't know about the climatic and environmental conditions there, but the Sahara went through changes in the late Pleistocene, making it inhabitable from time to time. So maybe the Arabian desert too ? Some land masses might have been connected through sea level low stands, or at least in sight from shore to shore, nevertheless it is a long way from Africa into Australia, and it apparently took humans >150ky for the journey.

Until we know of older occurrences, of course. It can only get older :-)

 

The evolutionary path from archaic forms to the likes of us is not linear. Several lines on different evolutionary stages went side by side and all except one ended up sorted out, making the puzzle not easier.

Edited January 28, 2018 by Green Baron

[James Kerman]

1 hour ago, Scotius said:

I mean - who in their right mind would cross richer and more welcoming lands in  South Asia

Now I'm not sure about route, but it appears from the research that the original inhabitants of my country were desert adapted from the start.

[Green Baron]

20 minutes ago, James Kerman said:

Now I'm not sure about route, but it appears from the research that the original inhabitants of my country were desert adapted from the start.

This is extremely interesting ! I haven't been following this, but somebody i knew spent a lot of time trying to argue in favour of the southern route (pm me if you want to know):

https://www.nature.com/news/2011/110126/full/news.2011.55.html

Edit: oops wrong paper:

http://science.sciencemag.org/content/331/6016/453

 

Edited January 28, 2018 by Green Baron

[Scotius]

2 hours ago, James Kerman said:

Now I'm not sure about route, but it appears from the research that the original inhabitants of my country were desert adapted from the start.

I've been thinking about this for a bit, and something occured to me. Deserts can be harsh, that's for sure. Temperature differences between day and night, lack of water, scarcity of food, poisonous snakes, scorpions etc. everywhere. But... desert areas also lack in other things. Namely, diseases. No malaria, yellow fever, dengue and other nasties that probably took a heavy toll on our savanna-bred ancestors when they left their arid homeland in Eastern Africa. They already knew, and had tools to deal with similiar environment. But they didn't have any way to deal with illnesses breeding in mosquito-filled jungles of equatorial Asia. Maybe that was the reason initial waves of migration branched out so fast north and south - to drier and colder climates.

[PB666]

4 hours ago, Scotius said:

This shows very well how non-linear and random was human emigration from Africa. I mean - who in their right mind would cross richer and more welcoming lands in  South Asia (and further north and east), and decided to settle in friggin' Australia of all places?

Australia once had big juicy megafauna with zero experience dealing with humans.

 

[PB666]

First I need to introduce a problem. And let me state from the start there is no problem with the way the genes or the genome evolves, and this appears to be pretty consistent over time but there are problems with the way that scientist have addressed the problem. So to see this I need to start with a completely uninteresting problem, the branching of the great apes. Overtime collections of bones have appeared in the fossil record and as paleontologist do, the tend to say 'Its a this, or its a that'. Evolution of the apes has been pretty consistent, its been a bit slower than other mammals in general but it has sped up a bit in the chimpanzee lineages. The reason it sped up in the chimpanzee lineages is that chimpanzees engage in sperm-selection, and the problem with this is about 75% of the SNP evolution occurs in the sperm in such situations, so it revs up the evolutionary rate. If we lay out a no apriori argument of some long stretch of a chromosome and follow it over time and overlay that with what paleontologist have put forth, they don't match, and some of the branch points are off by millions of years, up to 4 million in some cases. So the problem here is  . . . 

To capsulize the argument Genetic [(Some effective breeding population) ------> Representations (Variants) ][Set 1]=====over time =======> [Set 2]

As branches split over time you get branch points. [Set 1]=====over time =======> [Set 2],[Set 3]
AS I stated don't get me started on the problem with strictly using paleontology to do this. I am going to break this up.

First example, research claims to have found the missing link.

[Set 0] - - - - - -> [Set 1, missing link] - - - - - ->[Set 2]  Evolution is not a ladder, if you here a missing link argument, 99% of the time its wrong, it infers you captured a given subpopulation that rapidly evolving from a parent population to a new population (we are talking about populations within a 200 ky span). So in a general failing in the popular literature its either everything is a missing link, and in the critical literature nothing is a missing link.

What can Set 1 be (examples of each have been identified
[Set 0] - - - - - ->[Set 1a, Set 1b 'missing link]  - - - - - - >[Set 1a-> Set2], [Set 1b - - - -> Extinct]  Missing link was on other branch.
[Set 0, pseudo Set 1 'missing link']                                                         Missing link was just a trait variant and not statistically important in the evolution (ebb and flow of traits over time).
[Set pre-0] - - -  ->[Set 0], [Set 1] - - - - - -  -> [Set 0's, Set 2]                    Missing link was on an entirely different (lower) branch anchored in a different ancestor.

Frequently in these cases when the questioned is asked, was the comparative anatomy done objectively, its found often that it wasn't, but the historic opinion persists over time, often for decades.

So that often, before you can do decent genetic analysis you have to fix a historic problem.

 

 

Edited January 28, 2018 by PB666

[PB666]

The issue regarding African Evolution and the resolutions of the plums in the pudding revolves around a key problem, what is the chronological context. In the genetic analysis we take the paleontological evidences as informers but not directors.
So for example when someone says this is AMH, from a genetic point of view is more about trait evolution and tracing trait evolution, because as I will present later reticulations do occur in the population. A physical equivalent of a reticulation would be convergent evolution, two independently evolving similar traits because selective forces are similar. A good example of this is Neanderthal and Human cranial capacity, the volumes are the same, but if we look carefully the Neanderthals has more occipital lobe development and humans appear to have more prefrontal lobe development, this could be trivial or it could have implications regarding the genes and specific function. The argument is that more processing capacity was needed, the Neanderthals  put more of it into processing for the eyes whereas humans put more of into all the varied things the prefrontal lobe does. Or it may just be chance, we got the gene that enhanced X,Y,Z and they got the gene that enhanced Q,P.

So what has to be done (see above) is to create a reference set of points that everyone can agree upon.
With humans this has proven to be spectacularly hard, and not just at one point but many points. The anchor point that everyone wants to use is the chimp-human last common ancestor. The problem is that ancestor is not anchored. The timing, even by some well respected paleontologist has ranged from 4 million years to 8 million years before present. And admixture may have occurred until 2.5 million years ago. I personally use the timing proposed by White and place it around 6 to 7 million years, at around 7.5 million years that timing stresses the entire framework of Ape evolution and it becomes appreciably hard to justify it based on concordance with the fossil record. It is plausible to place that MRCA later in time, but the essential problem is that you need some evolution change (the homonid line for instance undergo late maturation longer generation times, etc).  The confidence interval is not good, and so for some genes you have to clock over branch points that are even harder to pin-point in time, the Gorilla-(CH), the orangutan-(G-(C/H)). For genomic genes you can do this back to the lessor apes, but clocking into the old-world monkeys and using their branch points compounds another issue, which is evolution rate.

For mitochondrial and Y-chromosomal evolution there is another alternative, you can use an internal clock.

I want to phrase this carefully because there is an implicit and explicit point to be made. The problem in deciphering African chronological evolution is that there is uncertainty over what is plum and what is pudding. And so because of the ambiguity one should have to take a more strict definition of what AMH than most do. Given the problems in past paleontology analysis it is best to be cautious. This is not to say, when did the first bonafida AMH arise . . . . . .if the apomorphies are present there is a chance local to the place where the multiple of all apomorphic frequencies are highest that AMH appears and then disappears in a single generation, this could have been 300 kya. And this is exactly consistent with observations of trait variation in the fossil record of Africa. What happens over time is these AMH appear more frequently and begin to persist for generations, over a much longer periods, it is clear on the other hand that AMH morphology was not 'fixed' in Africa until recently, which means we don't have AMH evolution occurring 300 to 200 kya, its occurring over a much wider chronology. This is a fact and its not true in one place but not others, its roughly true everywhere. We have to be carefully about deducing apomorphies and plesiomorphies . . . . .apomorphies belong to humans and plesiomorphies belong to Neanderthals or archaics. This is not true, Neanderthals, particularly classic Neanderthals had their own apomorphies. There are apomorphies in Africa that appeared and then were excluded from the population. The brow ridges of Bodo for instance, may have been an apomorphy that did not persist. These are all apart of the paleoanthropology of Pleistocene Africa. For this we need to be cautious because something that we believe completes AMH may simply not persist. What is AMH is that which persisted in Africa or spread also out of Africa and can be largely defined by what expands from the constrict in Africa. This last part I have not defined yet because this argument lack adequate sensors (I have yet to dig these out).  And to be fair, it also includes cromagnon traits that may also have not persisted, but  . . . . .

But the humans that migrate out of Africa, in general, appear to have the fixed trait (the original group of persistent migrants appear to have been small in number upon exit, 100 to 1000 individuals, those whose descendant colonized India and Indonesia). This then informs us that, in fact, we do have an internal anchor point, but its not in Africa. And so the link I gave can create a probability manifold, and that manifold basically describes when first Anatomically modern humans existed in Asia over time. The reason we have to create a manifold is that we need a place, a construct, to throw a sensor . . .and then after throwing in the sensor we can make educated guesses about evolution in Africa. So a cautious definition of AMH is what is shared apomorphies exist between those in Africa and traits obvious in those who left (given some admixture and some non-african apomorphies).

 

[Green Baron]

That is why we need fossils. Hardware rocks. And has physical parameters for measurement and classification. But of course, it is nice if genetics contribute their part.

[PB666]

3 hours ago, Green Baron said:

That is why we need fossils. Hardware rocks. And has physical parameters for measurement and classification. But of course, it is nice if genetics contribute their part.

You don't absolutely need internal fossils, but they keep your external clock honest. And the reason you need honesty (by as many points a possible) is that the paleontology is often subjectively interpreted. You assume also that some of your internal clocking points are also subjective and so that manifold that you create needs an associated fuzziness on the boundaries just like a quantum molecular orbital has fuzziness.

But the more important point is this, African Paleontology is, according to OoA, a unitary model its a model of what happened in SSA as inferred by the genetics. Its like a quantum singularity, you look at a black hole from the outside you see one thing, from the inside its completely different. What makes it a black hole is the constriction event. So the question is what was in the black hole, and the answer is without being able to be inside of it, you can't know.

One way we have to be inside the constriction is aDNA, the problem is that the aDNA in the tropics does not last that long. aDNA is effectively bringing a piece of that individuals forward in time, so that we can inspect them. What about culture, to use culture you have to apply a discriminator, for example this array element here that has associated culture is more relevant to the next. But the problem is that we cannot spatially define the array, the best you can do is create a manifold, and in Africa that is a challenge, because people in Africa, for whatever reason, isolate on times scales much longer than people in the rest of the world, and this creates artificial and permanent boundaries to gene flow but not necessarily cultural flow. This creates the species and subspecies arguements that paleonotology trips over. I have heard all kinds of argument, you can't have more than one speciation event per 10,000 years, etc.

Rigid speciation is like a hohmann transfer, you (ot they) have to make a change, then you (or they) have to make another change and you get two orbits. If a majority of members of either subpopulations have 2 of these special changes relative to the next then you can have a species. Members of either species may not know and in may not be under selection. If its not underselection, then the only way to fix it is via a population constriction. So for example classic Neandertals went under a rather intense selection whereas Levantine neadertals may have been peripheral, and so Neandertals could say interbreed with Levantine Neandertals and then this could intbreed with humans. The fact the second in between the two provides a speciation slowing element, but not the extremes. Lets say that average speciation times in australopith/homo is 3 million years, then the probability that only two events occur in 10 million years is 10%, but by the same token in one million years you could randomly have two loosely interbreeding populations undergo speciation. The problem with this diagnostic looking at splits, because mostly in the fossil records if you have radiations, the other radials mostly go extinct, and many splits also leave only one produce. So if I have many isolates, some a few thousand years diverged, some 100,000 years, some 500,000 years . . .and I start testing these over time what I am going to see. Some of these will remain rigid through the course of testing, but some, because they had the minimal change, will leak via reverse mutations, and others, because they had not fixed sufficiently will leak, and finally others will simply blend seamlessly in. The plum pudding model it just a testing device, it does not hold that each plum is a species, the plums are space holders in which we can put something into it and then ask the question what fits this.

Here are some examples.

At time A (say 150 kya - throw the date away after the example is finished) A gives rise to a variant B, that just happens to be an expanding feature of an otherwise static population so that at time say 120 kya, B should be 1500 miles on average away from A. But B's salient is surrounded by C, a self-isolating population. So later on as time progresses C completely dies out or at least its diagnostic elements disappear, so only residuals of B are apparent and C is not. But say at the onset of B's incursion into the area its 10% and C is 90%. So that if you are sampling you are more likely to detect C's presence in the fossil record than B's present. If the fossil we find looks markedly different from A do we conclude that Bs ancestors evolved during the move?  Put the fossils in  a place holder an test them. If there is uncertainty however you cant really use a potential C to test the rate of evolution of B from A. That likewise applies to molecular evolution. Thus you must have certainty at what you are looking at. If you had absolute knowledge of what B was and aDNA you could create a molecular clock of B's DNA, and if you don't then you will either give up or work from inferences. So what we want is such stark differences between B and C that we immediately know, if we find C its then not B. And thats a problem in Africa.

An extension of this is that B continues to expands such that eventually if fills in a wide space over time (b', B", B'''), it creates a temperospatial manifold. And at some time later you detect B and you can coordinates its genetics to the current population. So then you begin to look at branch points between and infer a ancestral group B, then you have something but you don't know where B formed or where it radiated. So that although you have a manifold a somepoint in time that manifold becomes very fuzzy as it goes back in time, so once again you don't know were B is and C is, you might deduce the size of B, but at the same time not know where it was. From your point of view B could have been anywhere from inside of A to the other side of C.

Lets take B', we put B' on a boat and we carry off an place it in a new place, one with a far less competitive human population. B' then has a rapidly expanding population, it grows from 10 individuals to 10,000 individuals in say 1000 years. B' will produce a spectacular number of derivatives D and if it does that then we have a founder effect we can follow over time. Founder greatly increase the amount of molecular clocking data you have, so that you can absolutely say at some point D moved from fuzzy point B' during this time framework. Once you do that you have effectively clocked B' and everything between A if you can find  a suitable anchor for A (again this is an issue).  This assumes that D so rapidly increases its population that fossils and culture attributed to D quickly appear, if for some reason they dont (acid soils, they all lived below current sea level) etc then you are going to be working from an underdating hypothesis. In human evolution this is almost always the case, and historically PA and MA have been unable to correct this issue. The review I linked you will see this many of the areas they talk about, humans traveled over land, not around the coast, but the areas they are all looking at and the times they are considering,. . . .the times were all low stands and we are at a high stand. At a high stand its extremely difficult to gather fossil records of people who travel at a low stand. In the South China sea, the horizontal distances between high and low stands are 100s of miles. Your say we only found human finds 40 km from shore, at a low stand thats 140 km so whats the meaningful difference between 100 and 140 km from shore. So this gets subjective.

If I say they must have traveled over high land, then the fossils I find and date are going to date D, but if I argue they spread along the coast and then moved inland, the the fossils I find are D migration date plus some expansion factor (t), which I am going to applied -t to the dates of may fossils to get D. Again since we are blind to either we have to assume that probabilitic time manifolds will explain this. There is another way, you find D' is modal where your fossils were found and other D are found closer to the coast, then you estimate the difference, you would need dozens of these to estimate the genetic distance (average) between D and various descendant Ds.

The second thing is that we can use proxies, as you stipulated the graded evolution over time, but the problem is that the evolution was not a continuous grade. By my previous post if we had 'god' mode view of Africa we see the first AMH appear and then wait two or three generations than another one appears . . . . 100 generations AMHs appear continously in some tribe (say 50 people) then that the spreads to other places (the population can grow just not much) . But the Ne was 10,000, with newer information effectively larger, maybe 13,000 individuals, that (using a 2:1 total to Ne ratio) is 450 tribes. If you are relying on that information to spread quickly, then its replacement by demic diffusion and slowly simply by diffusion, young adults leave the tribe of their birth and join adjacent tribes. So that this process is very difficult to see when fossils are distributed say 1 per 300,000 sq km per 100,000 years. People also shift, as enviroment changes rivers change courses, etc they move to optimize there advantage.

[PB666]

So that the framework describes a means of delving into the problem of migration. The paper I referenced gives equivocal evidence of early human occupation of Asia, to 125 kya, most of the evidence is rather disputed.
If we apply our manifold, humans completely cover East and South Asia now, and the populations are so large that older mtDNA are only excluded slowly. I we take our manifold back in time we find humans for example in Siberia, in the Southermost and most isolated Ryukyu island by ~30 kya years ago, and also at the Mungo Lake in Australia. So at least by 30,000 years ago the population cannot be considered in a constricted state. The manifold starts to get fuzzy around 42 kya, there is alot of stone age artifacts that are attributed to human, but not so much remains. There are dentate from china and indonesia that questionably date to 100+ kya. So by this early date the manifold is very faint and fuzzy. There is almost no convincing archeological evidence from India for the period although there are few very ancient stone age sites, these could be attributed to Neandertals of the desanovan or narmada types. The one sort of pesky outlier LM3 according to thornes dating could be 62.5 kya, but he has fairly wide distributions and these overlap with Bowlers in the 50 to 55 kya range. More importantly the mtDNA while poor carried the M type pattern in it. The evidence is suggestive that humans might have arrived in South and East Asia before 60kya.

Of all of these finds LM3 may be the most important, for several reasons. First its an intact skeleton, its not homo erectus, which was common to the region of Indonesia, the cultural context of the burial was one recognized by the local population, which anatomically modern homo sapiens in every sense. it was first chronologically characterized by Bowler and dated by charcoal dating to 30kya, but C14 dating isn't really great for things, particularly on a lakeside, of more than 25,000 years. It was later characterized by Thorne and eventually an mtDNA sequence was derived for the hypervariable region. Again there were dates of 30, 62.5 and later 42 kya assigned. Its seems that 42 is in general agreement now. The sequence is an M type derivative and when I looked it also bears 2 to 4 potential sites that are known to exist in Haplogroup M derivatives. This makes LM3 younger, by a few thousand years at least, relative to the center of haplogroup M diversity.

As the article mentions, the molecular studies are much less quiet on the Issue. A basal Eurasian mtDNA haplogroup M diversified in South Asia, there can be little doubt about this, this was a major founder affect in India which signifies that sometime between 50 and 70 kya there was a major expansion of the human population into India the last time I counted there were something like 20 basal M derivatives in India most of them have a number of derivative substitutions and that is with a very tiny sample of the Indian population, of course there are M derivatives in other places. What can we say about M, basically you can talk about M evolution and talk until you reach the tip of South America, because that is the furthest extent of there derivation process (haplogroup D). And its pretty much present in most populations in between India and South America. The extent of the founder event therefore characterizes a large proportion of the genetic heritability of the East Asian and Native American populations.

So what is M, M is a direct ancestor of East African L3. In fact derivative of M are also found in East Africa. What this means is that M is from the horn of East Africa and was a part of a population that founded Hss in India, where L3 also diversified into other sequences in the region. In this one step we have anchored L3 evolution using the process as it occurred to a few 1000 years, it certainly did not take 100,000 years or 50,000 years. For technical reasons it was unlikely direct (because the HN sequences would be more dilute) but the motion was relatively rapid compared to the weighted motion of alleles in Africa. Thus its really hard to argue for an L3 older than 100,000 years.

So that the demographics of Africa are starting to find an container and basically the constriction inflection point can basically be pointed to L2 evolution. The L2 evolution appears to have moved the OoA population northward and opened up the Sahel, subsequently, after a couple of handful of mutations basically L3 evolved from L2. So something about the pudding has changed, people who were rather static are now moving. So when did this constriction end, again conservatively, 75,000 years ago more relaxed scenarios allow 125,000 years ago. Beyond this early date its stressing the internal and external calibration points backwards in time where they unseat from their anchors. Since humans were in an expansion mode potentially 125 kya then we can tolerate motions to SW Asia and other parts of Africa. L2 diversification, unlike M occurred over a longer period of time, the population did not grow extremely quickly but it did grow steadily. The constriction could also be older than 125 kya, in fact various dates for entry have been given of 195, 205 etc, it could be as old as 215 to 250 kya. There is no early limit for entry intrinsic to the statistics, but there could be exterior problems, for example the contribution of Neanderthal genes around the same time as these start dates.

The other major contributor appears to be haplogroup N, some have suggested that N arrived before M, or came in through a different route. The resolution is not so great, N and M evolved at the same time, pretty much.

So with the container we have a way for AMH to evolve, but whats going on and where. Critical to the evolution of humans are the lakes within the rift valley. The L1 evolution seems to favor the lake Tangenika region and this would be 10,000s of years before the expansion. L2 is an L1 derivative, so the we have a vector from the middle of the rift lake extend roughly pointing in the direction of central Africa republic and somewhere along there L3 branches off and moves eastward to the horn of Africa. Between the first L1 and the tMRCA for the human mtDNA there is alot of time for motion in Africa. Subsequent to L0 branch there was diversification, by and large L0 sequences have favored the peopling of southern Africa.

So in this context we can ask question, how many people where in this population. The earlier the constriction is pushed in time, the larger the population, somewhat. The population could have been 20,000 to 30,000 individuals with a fractional number of effective breeders.

What other groups were in Africa, if any, that is a question that is hard, if not impossible to answer with DNA, aDNA simply does not survive long periods in either hot or wet climates. We can look to see if some populations got a unique injection of DNA, that appears to be the case for a small group of individuals is central Africa, but other than that its been more or less suggested by the discovery of late primitive fossils and good luck.

Without looking at the cultural anthropology of Africa, its seems almost certain that humans continued to evolve toward modernicity during the constriction. Close to the end we see Blombos cave and other sites in southern Africa indicating of more artistic and abstract things, but also we see certain derived mtDNA starting to move away from those SE centers of diversity doubling the area of Africa covered densely enough to persist over time, and they moved into Eurasia and spread rather rapidly given the rather sudden and extreme isolation that these groups were placed.

The final question is how flexible is the model to other events. The contribution of Neanderthal sequence more recently appears largely to be the result of backflow, largely historic backflow from Iberia on the North and Arabia on the East. The process has not been one way, there has been substantive gene flow since the exodus of M and N dwellers. In particular that are notable migrations from West and NW Africa into Iberia and other parts of pre-Neolithic Europe. The most isolated groups in W. Europe tend to have the highest compliment, and the immune genes appear to have an unusually high influence. There also appears to have been recent, prehistoric, migrations into S.Asia . . .in Kerala part of india and into Pakistan. More recently migration into parts of Arabia. So by no means should we consider Africa a static element after the initial migrations, it continued to feed genes into Asia. So much so that the original compliment of Neandethal genes in Eurasians was 4 to 6  percent, still evident in Koreans and Japanese, but diluted to about 2% in Iberians. This indicates at least residual selective preference of Hss of HN genes in a global context. But another intepretation of this is that Africa was a really good place to live during an Ice Age (particularly one the covered much of the land in the Northern Hemisphere with Ice). Studies have shown the mammals in particular evolve faster in the tropics than in temperate regions, but speciation occurs faster in temperate regions than in the tropics. There is still room despite the very good work done on Africa, that other introgression events might have occurred, but it will require more detailed studies.

 

 

 

Edited January 29, 2018 by PB666

[Green Baron]

Pop science articles interpreting the Jebel Faya i linked above, which is about modern humans out of Africa on the southern route between ois 6 and 5, probably at the end of 6 around 125,000 years bp.

Here's something: https://www.livescience.com/11651-ancient-arabian-artifacts-rewrite-oout-africao-story.html

Jebel Faya has a Wikipedia page i see. Wikipedia, *sigh* :-)

https://news.nationalgeographic.com/news/2011/01/110127-out-of-africa-earlier-early-humans-left-science-climate-stone-tools/

https://www.scientificamerican.com/article/middle-eastern-stone-age-tools/

 

Edited January 29, 2018 by Green Baron

[James Kerman]

Very interesting articles.  It seems these migrations were aided by falling sea levels.

It looks to me like this "Southern Group" was moving from wetter conditions to a more arid climate, possibly avoiding or quickly moving through true desert regions (as at Jebel Faya - i.e. lack of archeological evidence during intense dry times) while the "Northern Group" stuck to more temperate conditions.

I've often read that the DNA evidence pointed towards a small original group moving out of Africa, followed much later by other excursions but I'm starting to think that there might have been many concurrent migrations, with the routes being dictated by cultural adaptation to different conditions.

[Green Baron]

25 minutes ago, James Kerman said:

I've often read that the DNA evidence pointed towards a small original group moving out of Africa, followed much later by other excursions but I'm starting to think that there might have been many concurrent migrations, with the routes being dictated by cultural adaptation to different conditions.

I think it'll become more and more difficult to keep that single group argument if more places are found.

It is difficult to define specific adaptations >45,000 before now because the tools and technologies are rather homogeneous, only with few exceptions. A great variety (in Europe) shows up all at once with the moving in of modern humans (blade technology of the Aurignacien, bone tools dedicated to clothing, composite tools). The latter two where known to the Neandertals in Europe as well at least since late ois 5 (find site Königsaue), probably much earlier.

https://www.sciencedirect.com/science/article/pii/S0305440312000969

But i know almost nothing about the conditions in Australia. It is absolutely ok to expect that early modern humans were able to survive in adverse conditions. I can say from experience that dry and heat is challenging, people should watch each other or the inexperienced drink too little, overheat and start to talk and do nonsense :-)

[James Kerman]

As far as I know there are no known Neanderthal remains found in Australia however the Denisovans were in Asia and the origional Australians have a high percentage of Denisovan genes (4% to 6%).

There is a controversy over two finds here (with various theories proposed):
Mungo Man and Woman - 2 skeletons that were unearthed in the late 60's/early 70's, are gracile and date to at least 42,000 years ago.
The Kow Swamp People - 40 skeletons that date between 10,000 and 22,000 years ago but have features more like homo erectus.

Interestingly, Mungo Man (Mungo Woman was cremated) and the Kow swamp People seemed to share similar burial ceremonies (Ochre, shells and other artifacts included in the graves).

[PB666]

10 hours ago, James Kerman said:

Very interesting articles.  It seems these migrations were aided by falling sea levels.

It looks to me like this "Southern Group" was moving from wetter conditions to a more arid climate, possibly avoiding or quickly moving through true desert regions (as at Jebel Faya - i.e. lack of archeological evidence during intense dry times) while the "Northern Group" stuck to more temperate conditions.

I've often read that the DNA evidence pointed towards a small original group moving out of Africa, followed much later by other excursions but I'm starting to think that there might have been many concurrent migrations, with the routes being dictated by cultural adaptation to different conditions.

" no human fossils have been found at Jebel Faya, Armitage and others have argued that the Assemblage C artifacts, dated to 125,000 years BP, were produced by anatomically modern humans (AMH) "  I shutter when I see this kind of logic.
[Denisovan] Neandertals were fully capable, in fact Neanderthals probably made it as far east as Papua New Guinea if we take stock in the aDNA studies and molecular genetics. They probably also made shell implements . . . .Secondarily while I scoff at claims that SSA humans from traveling willy-nilly about the middle east, the distinction between N. African and Levantine group is not clear to me (infact from bodo, idaltu, Jebel Irhoud, . . . . the distinction is not so clear in a chronological context), neither were there boundaries, and the population was not likely large (a few 1000). They probably migrated over large areas, and advancing SS Africans may have learned from these individuals when they intermixed how to get to the eastward and northern boundaries of SW Asia.

The point is that N.African middle eastern hominds, we should just assume they can produce AMH artifacts, no need for SS Africans to make these or exodus from Africa, The blended nature of the group is suggestive on N/S geneflow which means 80, 125 or 200 kya, it does not matter, archaics were already on the move in the area, and they were likely the recipient of cultural flow from both Asia and SS Africa. We should look at the Levant as a place that hominims moved back and forth through during the late Ionian and early Tarantian.

 

10 hours ago, Green Baron said:

I think it'll become more and more difficult to keep that single group argument if more places are found.

It is difficult to define specific adaptations >45,000 before now because the tools and technologies are rather homogeneous, only with few exceptions. A great variety (in Europe) shows up all at once with the moving in of modern humans (blade technology of the Aurignacien, bone tools dedicated to clothing, composite tools). The latter two where known to the Neandertals in Europe as well at least since late ois 5 (find site Königsaue), probably much earlier.

https://www.sciencedirect.com/science/article/pii/S0305440312000969

But i know almost nothing about the conditions in Australia. It is absolutely ok to expect that early modern humans were able to survive in adverse conditions. I can say from experience that dry and heat is challenging, people should watch each other or the inexperienced drink too little, overheat and start to talk and do nonsense :-)

Given the rather high likelihood that homo sapiens (late,fully modern) and "archaic" homo sapiens mixed in Africa we have the issue of what is going on in the core versus the peripheral of the core. The core is defined, its that which was in Subsaharan Africa before humans migrated out of Africa, and I don't think any of the major players contest this. There was obviously a North African context, but it is uncertain how long in persisted. But the problem is there is no detectable center of diversity in N. Africa now, it may have moved south 30 kya and blended into the human population (and if so by the time the two merged the population was tiny) or it may have left N. Africa all together. Since we have no aDNA its lost to us. Certainly the Sahel + Sahara suffice to have more than enough space and resources for more than one group of archaics.(the term is being used a chronospecific identifier not to say that these hominids were more primative, but with the respect to human apomorphies they carried plesiomorphies - previously noted).

The distinction culturally between pre L2 and post L2 humans in terms of their migratory ability is notable. The time frames are realistically between 70 to 125 kya which then places some type of cultural shift also at the time. The problem of cultural mapping of humans is that the migratory prowess is probably tied to cultural flexibility, certainly we are see this strongly by 30 kya. There is not doubt that by 30 kya humans were extremely flexible both in their culture and how they moved. One of the big eye-openers for me was to see the cultural artifacts discovered in Japan from the incipient Jomon period (the period that produced that produced the first pottery, ~17 kya) was just the broad range cultural artifacts is notable. This is pretty much the edge of the world just about as far as you can get away from Africa. In that context the presence of LM3 or even early finds to 60 kya in  Australia are not outstanding, people moved the culture they needed and adapted quickly. In Australia the story telling appears to be as important as the tools they hunted with, so important that the stories were maintained for 10s of 1000s of years.  Story telling wont get you to the next Island over the horizon and adapting to those new lands when you arrive requires flexibility.

 

 

Edited January 29, 2018 by PB666

[Green Baron]

1 hour ago, PB666 said:

" no human fossils have been found at Jebel Faya, Armitage and others have argued that the Assemblage C artifacts, dated to 125,000 years BP, were produced by anatomically modern humans (AMH) "  I shutter when I see this kind of logic.

I don't. Because i have studied it. Stone tools were my specialty. And i have not seen a single well grounded scientific comment doubting the logic. You are alone :-) Which does not mean that it is the last word.

Quote

... in fact Neanderthals probably made it as far east as Papua New Guinea ...

A source would be nice.

 

" As Green Baron notes the ability to produce stone and shell culture is not something unique to OoA crowd. "

I did not say that, though it is trivial. But what i say is that the ensemble presented from the Jebel Faya Team (whom i was a member of for a short time as a student) are typical for African middle stone age and there is absolutely no brain gym necessary to connect it to modern humans until recently. Africa is different than Europe. And the work combines geography, climate reconstruction, classic Archaeology and physical dating.

---------

We will never come to an agreement there. I insist in sticking to the main stream, an encompassing approach that includes fossils, stone tools, sediment samples, palynology, pollen, charcoal, climate, physical dating, landscape reconstruction as far as possible and reasonably applicable. Because these give us a comprehensive and broad approach to the goal of when, who and where. Where there is contradiction it must be described, consensus add to the picture.

--------

Hope that's okay. Now, have the last word, don't get personal, and then lets move on, ok ?

Edited January 29, 2018 by Green Baron

[Diche Bach]

Main problem about paleo- studies of any sort is that some people want to believe too much, and are not happy not being sure enough. Such people are natural headline hogs and they produce far more heat than light. It is the main reason I chose NOT to go down that path and instead focus on living humans (albeit with an evolutionary focus).

At any given time, a non-trivial proportion of what we "think" to be true about the ancient past is likely to be wrong. Even exceptionally "conventional" well-founded, long-standing empirical generalizations can be and have been debunked. Take home being: never be too sure about something you cannot replicate in an experimental context, much less something about which you know based on indirect inferences of things which took place long before your species even existed.

At all times, now and forever, a non-trivial proportion of what we would like to know about the ancient past will be completely unknowable.

If everyone could accept that, paleo- studies of any sort would be a far less disagreeable topic.

[Green Baron]

I like to keep in concrete, focused and on topic.

The publications i and for example @tater and @James Kerman linked are all agreed on, as far as the current state of research permits. There always is room for improvement, naturally, but the working principles and their application to the reality of findings is based on a broad consensus, there is nothing abstruse in it to scoff at.

Peace, brother :-)

Edit: if i may add and to clarify, a work like that on Jebel Faya, which at its time was the earliest find attributed to modern humans outside Africa, is not written by a single person in a candle lit upstairs room. Several institutions in different universities and research institutes work together, giving out bachelor/master/phd theses on climate reconstruction, stone tool analysis and comparison, physical dating methods etc. pp. Of the list of authors, several have their own chair as a professor or are retired meanwhile. These people talk and compare, present and meet on conventions, etc. before they come out.

That's why it takes several years from the find to the culmination in a science or nature paper.

Edited January 29, 2018 by Green Baron

[mikegarrison]

7 hours ago, James Kerman said:

I've often read that the DNA evidence pointed towards a small original group moving out of Africa, followed much later by other excursions but I'm starting to think that there might have been many concurrent migrations, with the routes being dictated by cultural adaptation to different conditions.

Remember that DNA evidence only reveals who left descendants. If a group moved to a place but ultimately didn't leave any descendants, they could still leave artifacts.

[Diche Bach]

44 minutes ago, Green Baron said:

I like to keep in concrete, focused and on topic.

The publications i and for example @tater and @James Kerman linked are all agreed on, as far as the current state of research permits. There always is room for improvement, naturally, but the working principles and their application to the reality of findings is based on a broad consensus, there is nothing abstruse in it to scoff at.

Peace, brother :-)

Edit: if i may add and to clarify, a work like that on Jebel Faya, which at its time was the earliest find attributed to modern humans outside Africa, is not written by a single person in a candle lit upstairs room. Several institutions in different universities and research institutes work together, giving out bachelor/master/phd theses on climate reconstruction, stone tool analysis and comparison, physical dating methods etc. pp. Of the list of authors, several have their own chair as a professor or are retired meanwhile. These people talk and compare, present and meet on conventions, etc. before they come out.

That's why it takes several years from the find to the culmination in a science or nature paper.

Right. In other words, it is careful work.

And even so, in 10 years it might be determined to have been largely false in its conclusions.

It seems to me, in a field were experimentation is largely impossible, this inherent handicap in knowing is critical, and yet few seem willing to acknowledge it. I had a few paleo- and archy profs who made it one of their primary points and some of them were incredibly prolific . . . in small change journals whose contributions were also small and integral to larger syntheses.

The folks who try to make big splashes in the natures and the sciences too often seem to be more concerned with the splash than with the long-term value.

[Green Baron]

44 minutes ago, Diche Bach said:

And even so, in 10 years it might be determined to have been largely false in its conclusions.

"Largely false" most probably not. It is already based on 2 generations of research. I don't want to lecture anybody :-) But the dates may shift farther in the past, most likely not into the future as most dates are already lower limits.

But, of course, a scientist can never categorically exclude a future development :-)

Quote

It seems to me, in a field were experimentation is largely impossible,

Now this depends: the physical part like sediment analyses, physical dating, ... is of course based on experiments and observation. In the case of stone tool ensembles, the techniques and methods themselves are of course experimentally reproducible and reproduced. To combine an ensemble with a specific human type requires a walk around one corner, namely the comparison to other, known findings.

Quote

this inherent handicap in knowing is critical, and yet few seem willing to acknowledge it.

That isn't true. Everybody is aware. If there were serious doubts, we'd discuss them. Doubts may show up in the future, then we discuss them. Be sure i'll post it here as soon as i get knowledge, if the forum is still running, i am still alive and the thread wasn't closed :-)

Quote

The folks who try to make big splashes in the natures and the sciences too often seem to be more concerned with the splash than with the long-term value.

Now that could be understood personal and is not a helpful comment, i hope it wasn't meant so !

Edited January 29, 2018 by Green Baron

[PB666]

4 hours ago, Green Baron said:

I don't. Because i have studied it. Stone tools were my specialty. And i have not seen a single well grounded scientific comment doubting the logic. You are alone :-) Which does not mean that it is the last word.

A source would be nice.

 

" As Green Baron notes the ability to produce stone and shell culture is not something unique to OoA crowd. "

 

That sentence I tried to correct, but unfortunately the system did not take my correction, originally that was two sentences, I tried to shorten it to one and goofed, my fault.

AMH is a morphology, not a culture. And so when you say AMH its would be like me saying a that the electron's charge is the cause of gravity. You can say mass correlates with gravity, space-time is the cause of gravity but electrons are only one type of mass and it cant have charge without mass. Humans possess genes that give rise to anatomy and culture. Culture does not give rise to anatomy, its mostly genetic and skeletal anatomy is not the discrepant factor in culture. There is no debate to be had.

I accept that you have a looser definition of AMH than I have, but as a general rule if there are two assertions, one conservative, one not conservative, then its best to use the adjectives and modifiers. "Correlation with AMH" is the correct phraseology.
 

4 hours ago, Green Baron said:

Africa is different than Europe. And the work combines geography, climate reconstruction, classic Archaeology and physical dating.

Thats precisely right, and that is why we have to be especially careful describing things in a different geographic context. Listen, I understand that you include N.African <315 kya as AMH, i get that. And I have already pointed to the fact that these N.African middle eastern things can be considered human in most contexts. But if there is any doubt, (meaning lacking skeletal remains) its best not to guess. I reminescent of the lecture by Ponti, I believe in which he told Steven Hawkings "stop guessing".

The mode of Denisovan contribution to the human population is in Eastern Indonesia, it is difficult to trace, other than modern movements, back to Siberia's. In addition the haplotype studies and runs of homozygosity studies point to introgression of one or few individuals as a potential founding event in the population (the reference I give below suggests one). The most likely explanation is that the archaic fraction already existed proximal eastern Indonesia at that time and humans migrated in smallish numbers (a tribe) into that population. I should point out that while they found slight evidence of pre-Neandertal DNA elements (potentially erectine) in Denisovan no such elements have been found in the contribution of denisovan-like Indonesians to humans. So this is not diffusion of Denisovan-like into extreme SE Asia, this is evidence of a migration of Denisovan DNA carriers into SE Asia.

The papers regarding all of this have been published, the inferences have not. This is why I make the point, in East Asia, like the Levant, you have more than one player, so you have to be extremely careful interpreting culture as evidence of AMH.

To this exact point . . . . . .despite genetic evidence of.
A founder affect and population expansion in India (see the link I provided), the physical anthropology and cultural anthropology are essentially silent, no evidence.
A admixture event between humans and desanovan like neandertals in Indonesia, the physical anthropology and cultural anthropology are essentially silent, no evidence.
The best that they can do in that regard is the hard to interpret remains in Narmada, India and in Siberia.

This is why I am saying to you, you have enough evidence in the conflict between genetic and cultural to warn against liberally interpreting of the cultural.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4306417/

https://www.ncbi.nlm.nih.gov/pubmed/27654910

Quote

Together with evidence from the Western Asian fossil record, and admixture between AMHs and Neanderthals predating the main Eurasian expansion
, our results contribute to the mounting evidence for the presence of AMH out of Africa earlier than 75kya.

I agree with this, should be earlier than 75 kya

Quote

Ancient DNA (aDNA) sequencing studies have found support for admixture between early Eurasians and at least two archaic human lineages
, and suggests modern human reached Eurasia at around 100 kya

I agree, it seems likely that L3 expanded out of Africa at this time, so from two points of view this appears consistent.

Quote

Overall, these findings indicate that the majority of human genetic diversity outside Africa derives from a single dispersal event that was
followed by admixture with archaic humans

Again I have no connection with these authors, have not seen their work but find my conclusion from a decade earlier completely agree. Again the M sequences and expansion of L3 that gives rise to all N and M (the  dominante mtDNA parent group of all Eurasians).

The more important thing here, if humans were in Eastern Arabia >100 kya and we have these massive expansion signatures in India . . .WHERE ARE ALL THE FOSSILS? That 60 ky of evolution and not a trace, how can that be? In addition an M expansion date before 85 kya puts a great  deal of strain on the molecular models, we have to push the C/H LCA back before 10 mya, etc.

But this particular paper makes an outstanding conclusion (Its a Nature paper), it claims that there is another signature in the Papua New Guinea population that causes a refactored divergence with Yoruban of 90kya and with Eurasian of 40kya.
On further examination they found signal of another admixture. BUt first, let me just state this, previous papers have found similar diverengence times with Eurasians between two groups, and given the archaeological evidence could support migrations of 70 to 80 kya. The problem is what the authors describe next is testimony to a replacement model.

Quote

we find in the genomes of Papuans and Philippine Negritos moreshort haplotypes assigned as African than seen in genomes for individuals from other non-African populations (ED7). This pattern remains after correcting for potential confounders such as phasing errors and sampling bias. These shorter shared haplotypes would be consistent with an older population split. Indeed, the Papuan-Yoruban median genetic split time (using MSMC) of 90 kya predates the split of all mainland Eurasian populations from Yorubans at ~75 kya - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5164938/pdf/emss-69788.pdf

Quote

 1) Admixture in Sahul with a potentially un-sampled archaic human population that split from modern humans either before or at the same time as did Denisova and Neanderthal; or 2) Admixture in Sahul with a modern human population (xOoA) that left Africa after the split between modern humans and Neanderthals, but before the main expansion of modern humans in Eurasia (main OoA) -https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5164938/pdf/emss-69788.pdf

Quote

Furthermore, while the observed shift in the African-Papuan MSMC split curve can be qualitatively reproduced when including a 4% genomic component that diverged 120 kya

So here we have an interesting thing and it goes on to describe deep Africa sequences not found in other Eurasians.

https://www.ncbi.nlm.nih.gov/pubmed/28158547

Quote

One interpretation of our results is that ancestors of humans and ancient hominins interbred within Africa. The hypothesis of ancient substructures in Africa with limited gene flow be-tween subpopulations of hominins [] does not contradict this inter-breeding. Neandertals and Denisovans could be more closely related to Africans than to out-of-Africa populations because of more interactions between their ancestors. In this case, since the ancestors of Africans and Neandertals/Denisovans were not clearly separated, this could be considered “admixture” rather than “interbreeding”.

This then is the solution to the problem. There was gene flow between mediated by non-constrict Africans. So if this is the case why not have non-constrict Africans, already spread in the Levant basically carrying these Denisovan genes into East Asia >100 kya. You can think of it like a flame, there are parts of the flame that are yellow, parts that are orange, parts that are red, as time proceeds the colors shift in the flame, but they are all characteristic of the flame. This is how genes flow between populations.

So its pretty much to the point the N. African and Levantine populations are key, their influence cannot be ignored when we talk about prewave scenarios. Dressing everything up as AMH (even though no AMH remains are found) does not help the description, in this reality what if the folks that put the artifacts looked like Denisovans? you cannot rule that out, do you consider them AMH? Again I have no relation to these  authors, simply I am noting what they are saying. Many of the things (genentically or archaeolically) are attributed to the OoA population are actually xOoA, they are associated with composite (admixed in Africa and the Levant individuals and mixed with other groups in other directions). This is not just speculation, this is what is creeping out of the genome studies), as the aDNA gets analyzed (clearly not enough as we would like) these complex relationships become apparent.

And you might find it astounding that after proposing a constriction that I would then be arguing admixture, but here is the reason we must accept the possibility, not only that but the likelihood of long distance admixture without necessarily assigning a Morphoological source.

There are explanations and then there are explanations that fulfill the requirements of many areas of study. The original OoA model is not flawed in the sense that it really only defines inside of Africa what >75% of the human population is doing it does not define 99.999%. Of course the genomic studies support more than than 75%, but its not a complete picture of Africa, and the further you go back in time the less complete it is. And this description is entirely consistent with the evolving fossil record in Africa, there is not a single evolving entity, and culture is not exclusive to any group, they are all competitive cultures before the end of the constriction, and that could be as late as 75 kya.

So, lets just peal back the layers a bit and see what the problem is. There was a constrict, this is defined by both mtDNA, X and Y chromosomes. But the constrict is neither static, SSA or all of Africa, it was a manifold that moved around over 50,000 years or so, it was sometimes bigger, smaller. The forces that made the constrict are uninformative, geography is obviously one, competition is another. In the context of the constrict there is allowance that genetic material can flow out, and small amounts can flow in. The frame work of the constriction is less than 250 kya and more than 75 kya, find a 50 ky year slot and fit a constrict into the spot then create a geography and wiggle it around the geography. The onset of the constrict could have been N.Africa, we don't know, but by the end it was SSA, this we can clearly define. The major branches of the human population were isolating in Africa as the constrict was proceeding toward its end. These are the boundaries of the argument, that's it.

So when we look at the motion of what's going on outside of the constrict and before it ended, that's all very plausible stuff. You could have tribes from N.Africa moving all the way across SW Asia, mixing with Denisovans and then ending up in SE Asia, and you can call them AMH, or Johnny moonwalker or fuzzle-mucklovers or putty-toed qzzites or whatever you want, they are not SSA humans, they are not classic Neandertals and they are not Homo erectus.

We know that SSA derived humans could mix with ME Neandertals, Desinovan-like or derived, and therefore they could mix with other African hominids. We not only can infer that, but in Central Africa, that appears to be exactly what happened. There is nothing that stops MSA culture in Africa from being adopted by N. Africans archaics or Levantine Neanderthals. Nothing at all, if SSA derived humans are admixed into the groups over time, its their culture so, no diff, but they are not constrict humans, they are something else. Lets keep that entirely clear once SSA humans admix then they are something else.

Quote

xOoA haplotypes have an estimated MRCA 1.5 times older than the Eurasian haplotypes in Papuan genomes, while the Denisovan haplotypes in Papuans are 4 times older than the Eurasian haplotypes. Adding up the contributions across the genome (Methods) leads to a genome-wide estimate of 1.9% xOoA (95% CI 1.5-3.3) in Papuans, which we view as a lower bound. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5164938/pdf/emss-69788.pdf

1.5 x 75 ky = 112.5 is probably within the constrict timing using the molecular clock that this paper uses to date the Yoruban/PNG split at 75 kya, its likely 10ky before the end of the constrict. Or to put in otherwise using a Yoruban branch time of 75 kya contains the M lineage divergence in India to about <65 kya (usng the  internal clock) and one has to really strain L2 expansion in Africa (stretch the mean divergence time for each of a few mutations that are between L2 and L3. Which generally puts the branchepoints in a relaxed model a few thousand years apart to greater than 30, 000 years apart.  IOW you can change the clock rate, but you have to do it evenly along the branches, you cannot increase the clock rate in India and decrease the clock rate in Africa by 10 fold to make the model fit. Yoruban is representative of L2-L3 timing, therefore its pre L3 and pre-pre M so M timing gets shrunk and so does the timing  L2. This is not a viable choice. Since constrict humans had not expanded within SSA to their northern extent, and we have ample evidence that N. Africa/ME archaics are there, the only way we can get SSA constrict humans to PNG (without a trace in between) without some admixture is to put the tribes on big boats and ship them there. But I should point out that the general hypothesis that PNG/Solomon Islanders branched earlier than the evidence of humans in Oceania has been previously presented.

However it does explain the reason why these Denisovan-like sequences lack any evidence of the Erectine elements, it is because they were closer to Africa and they interbred with generic Africans when those Africans left 100 to 125 kya. They were more like us and less like Homo erectus when this trek across Asia was made. So the discussion of pre-waves is such the second you mention a pre-wave that is older then the first wave by 20ky or more, you are not talking about intraspecific events, but interspecific events. That means Africans in a general sense.

Sorry about the technobabble in the quotes.

EDIT: I need to add to this that Yoruban have something like 5% Eurasian DNA, so that alters the split times somewhat, If you carefully scrape that out you get earlier split times, but this also then applies to the suggested split times (1.5 x 75 kya) of 2% of the genes. So the argument is roughly the same.

 

 

 

Edited January 29, 2018 by PB666

[Green Baron]

But you agree that the Jebel Faya stone tools are typical for modern humans, that these came rather out of Africa then from anywhere else, and the dating of the sediments is credible ? Furthermore you don't accuse the guys of messing things up ?

Edit: tagging @PB666 because my two lines might get lost between the walls of text :-)

Edited January 29, 2018 by Green Baron