Indian Site of Attirampakkam Pushes Middle Palaeolithic of India Back to 385 Kya

Great Googlymoogly!  Fresh on the heels of the discovery of the Misliya site (upcoming BioLogos post) that the Middle Palaeolithic Levallois technology was present in Israel as early as 194 thousand years ago, we now have news from India that places the emergence of the same technology as early as 385 thousand years ago.  From Malcolm Ritter at the site PhysOrg:

Homo sapiens arose in Africa at least 300,000 years ago and left to colonize the globe. Scientists think there were several dispersals from Africa, not all equally successful. Last week's report of a human jaw showed some members of our species had reached Israel by 177,000 to 194,000 years ago.

Now comes a discovery in India of stone tools, showing a style that has been associated elsewhere with our species. They were fashioned from 385,000 years ago to 172,000 years ago, showing evidence of continuity and development over that time. That starting point is a lot earlier than scientists generally think Homo sapiens left Africa.

This tool style has also been attributed to Neanderthals and possibly other species. So it's impossible to say whether the tools were made by Homo sapiens or some evolutionary cousin, say researchers who reported the finding Wednesday in the journal Nature.

Nowhere is there any indication that modern humans are associated with the tools at Attirampakkam (ATM). In fact, there are no hominin remains whatsoever at ATM. The Indian subcontinent has always had a paucity of human remains, the most notable of which is the Narmada Homo erectus cranium.  In Europe, the Levallois technology, which also shows up at ATM, is almost exclusively associated with Neandertals and in the Levant, at the Skhul, Qafzeh, Tabun and Amud sites in the Mt. Carmel region, it is used by both Neandertals and early moderns. Consequently, while someone was using early Middle Palaeolithic tools at ATM, we don't know who.

What is incredibly striking about the ATM site is that, from 385 ky down to 172 ky, there is continuous technological evolution, beginning with what the describers call the “terminal Acheulean,” through a punch flake industry with points, to knives.  Another point made by the authors is that this Middle Palaeolithic industry appears and flourishes during a time where other sites in India are still using Acheulean technology.  This suggests “that spatial variability among Palaeolithic cultural sequences is larger than previously thought.”  From the Nature article¹:

The behavioural transformations that mark the advent of the Indian Middle Palaeolithic at ATM are summarized by the following diagnostic features: the obsolescence of Acheulian large-flake reduction sequences, with a directional shift towards smaller tool components; the adoption and continuance of Levallois recurrent and preferential strategies; a gradual intensification of blade reduction; and an increased use of finer grained quartzite during phase II than during A gradual discontinuation of biface use—which becomes definite at ATM after approximately 172 ± 41 ka—has been reported at other Middle Palaeolithic and Middle Stone Age sites worldwide (see Supplementary Information and references therein).

This is an astounding find for so many reasons. It establishes the appearance of the Levallois technology, one we know originated in Africa, outside Africa over 150 thousand years earlier than we thought. This is a technology that was considered to have originated some 400 thousand years ago. We may now have to revise this date further into the past.

It shows a clear progression of human cultural evolution, from the late Acheulean hand axes, through Middle Palaeolithic Levallois technology to a more blade-oriented technology.  Sadly, it appears as though the site began to fall into disuse and the sequence stops cold around 74 kya.  This is not surprising since it coincides with the Toba supervolcano eruption in Indonesia.  Nonetheless, as the authors point out, it suggests multiple migrations out of Africa of first archaic Homo sapiens, then modern Homo sapiens, such as those in Misliya and that these groups interacted with the Archaic hominins they encountered along the way.

¹Akhilesh, K., Pappu, S., Rajapara, H. M., Gunnell, Y., Shukla, A. D., & Singhvi, A. K. (2018). Early Middle Palaeolithic culture in India around 385–172 ka reframes Out of Africa models. Nature, 554, 97. https://doi.org/10.1038/nature25444

Anatomically Modern Humans in the Levant at 55,000 BP

Nature News (the story appears in other outlets, as well) is reporting a new discovery of an anatomically modern skull cap in Israel, at Manot Cave.  The skull was found on a shelf and the associated deposits have been securely dated by uranium/thorium.  The skull is unquestionably modern, with the characteristic “house” shape. The maximum cranial breadth is high on the parietals and overall shape is rounded, rather than flattened, as in Neandertals.  Further, the rear of the vault is lacking the occipital bun present in Neandertals and the cranium is much shorter, having the length of a modern human.  Further compound the issue is that the Neandertals in the region from the sites of Amud and Kebara are, based on the best estimates, coeval in time with the Manot Cave specimen. 

The Nature story expounds thus:

What happened between 90,000 and 45,000 years ago, a period ten times the length of recorded history? Only the fossils can tell us, and they are few. It seems that the earliest modern humans got to the Levant and no farther. Mount Carmel in Israel hosts caves, such as Qafzeh and Skhul, where H. sapiens remains appear in levels older than those occupied by Neanderthals, Homo neanderthalensis. The replacement of our own species by Neanderthals seems to be an affront to our prejudices. So how did humans eventually make it to Europe?

The partial H. sapiens skull from Manot Cave goes some way towards providing an answer, as well as hinting at how complicated our early history might have been. It looks much more modern than skulls from Qafzeh and Skhul. It is also much younger, suggesting that the hominin was closer, genetically and evolutionarily, to the earliest known European representatives of our species. This skull, the simple answer would suggest, represents modern humans poised to expand out of Africa and colonize the rest of the world.

Here comes the ‘but’. Our modern genomes contain Neanderthal DNA. At some point, our ancestors bred with Neanderthals before they became extinct. Does the Manot skull represent that moment? We simply do not know. Welcome, Manot skull, to messy reality.

If so, then these human/Neandertal hybrids would have been the group that colonized Europe and that is why we (some of us, anyway) see archaic traits in the earliest modern humans from Europe that date to between 35 and 25 thousand years ago. These traits are present mostly in the shape and contours of the vault in the Mladeč and Předmosti specimens from central Europe.  As these humans spread west, the archaic traits, which may have been under negative selection, diminished. Arguing against this hypothesis is that the Mladeč and Předmosti specimens are more archaic than the Manot Cave fossil.  Alternatively, the Manot Cave individual may represent the modern end of the spectrum of a population that does represent Neandertal/early modern hybridization and that contained a high degree of morphological variability.  Much is unclear.

The authors seem to think that there was not continuous evolution from the Skhul/Qafzeh humans, which date to around 100k BP, to the population represented by the Manot Cave individual and that the Manot Cave 1 specimen represents a later migration of moderns into the area, although this is based largely on the fact that there aren't fossils that span that time period.  The problem with this argument, of course, is that up until this this year, we didn't have the Manot Cave fossil, either.  Perhaps, the more persuasive argument is that the Skhul/Qafzeh fossils are quite a bit more archaic than Manot Cave 1 and are morphologically closer to late archaic Homo sapiens in the shape plot they provide (this mirrors my own research in this area).  On the other hand, a lot can happen in fifty thousand years and the required evolution could certainly have taken place.

That scenario is simplistic, but may explain some things that have confounded palaeoanthropologists for over fifty years.

After reading the paper, however, I am left with one question: What about the Herto cranium? It is a reasonably complete African cranium dating to around 150k that would provide a fantastic comparison and answer even more questions.

Neandertal/Modern Human Hybridization in North Africa?

That is the focus of a new paper in PLoS ONE by Sanchez and colleagues.  Using 780 thousand single nucleotide polymorphisms of 125 individuals from populations in North Africa, they write:

We found that North African populations have a significant excess of derived alleles shared with Neandertals, when compared to sub-Saharan Africans. This excess is similar to that found in non-African humans, a fact that can be interpreted as a sign of Neandertal admixture. Furthermore, the Neandertal's genetic signal is higher in populations with a local, pre-Neolithic North African ancestry. Therefore, the detected ancient admixture is not due to recent Near Eastern or European migrations. Sub-Saharan populations are the only ones not affected by the admixture event with Neandertals.

Well, raise my rent! When we analyzed the modern human remains in the Near East using canonical variates analysis, we found that they showed more of a similarity with North African archaics than they did Neandertals and that this supported a model of a general northern migration of North Africans into the Levant between 100 and 200 thousand years ago. I will be interested to see the reaction to this from the morphologists.

Ironically, the bulk of the evidence supporting the admixture of modern humans and Neandertals has always been based on the fossil record, while the genetic evidence has traditionally been used to argue for a recent African origin. It is interesting to see all of the genetic studies that have turned the tables. There is not a specific level of admixture at which point you can say "hey, these are the same species," but the studies continue to come out suggesting that admixture was taking place wherever these two groups intermingled and that there do not seem to have been biological imperatives to mate.  They simply decided to do so.  Remember the sage words of J. Lawrence Angel: "When two groups of people meet, they may fight but they willl always mate."