Discover more from Grey Goose Chronicles
Monthly Archaeology Round-Up: October
A Palaeolithic Special: Neanderthals, Gravettians, Magdalenians
Welcome to another monthly round-up of all the best archaeological news from October. This time there is a theme, a Palaeolithic special, since so many crucial new papers came out about early prehistory. We have exciting news from Neanderthal genetics, the origins of the mysterious Gravettians and more information about the cannibalistic Magdalenians. So grab a coffee, and let’s go back to the Ice Age…
Since 2012 the public has been aware of a fairly shocking fact, that modern humans and Neanderthals intermixed at some point in our past. It might seem unremarkable today, but for many decades it was orthodoxy to regard such intermixing as almost heresy. One reason for this was the insistence that all humans everywhere were genetically identical, save for the basic evolutionary facts of isolation and drift. We now know of course that not only do modern humans possess small amounts of Neanderthal DNA, but that this level differs depending on your ancestry. Modern Europeans have about 1-2%, Africans a trace amount and East Asians the most, with about 20% than Europeans. We know that this has come down to us from the paternal line of Neanderthals, and that it represents likely one or two singular events, rather than a long period of mixing.
This month we add to this knowledge with another quite shocking revelation. It seems that, not only did Neanderthals donate some DNA to modern humans, but at some even earlier point, humans donated some DNA to Neanderthals. A paper from the University of Pennsylvania, Philadelphia, along with some collaborators in Africa, has set out a compelling case for this early mixing event. Broken down it looks something like this:
A very early human population, prior to any diversification, interbred with some Neanderthals, leaving them with some Homo sapien DNA.
A split in the human population resulted in a small number leaving Africa, the remainder staying behind.
This small number intermixed with Neanderthals, acquiring some DNA. This spread of modern humans eventually resulted in Neanderthals disappearing.
Ancient Neanderthal DNA possesses human DNA sections found in all humans. Modern human DNA possesses Neanderthal sections found only in some humans.
Keen eyed observers might be thinking, “sure, but didn’t Neanderthals evolve in Eurasia? How would humans donate DNA to Neanderthals if humans evolved in Africa and Neanderthals did not?”
A good question. To resolve this we need to look at a few boundaries. Firstly we have genetic evidence to show that the ancestral Khoisan and Central African Pygmies diverged from the rest of humanity between 150-285,000 years ago. Secondly we have some archaeology to support very early Homo sapien intrusions into Eurasia between 180-210,000 years ago. To quote from my article about the origin of humans in Europe:
Dating the entrance of Homo sapiens into Europe has always been a topic of great interest amongst archaeologists, especially since examples dating back around 180,000 years have been found at Misliya Cave in Israel. Debates continue to be had over the identity of a pair of skulls found at Apidima Cave in Greece, one of which has been suggested to be an early Homo sapien, but could equally be Homo erectus with early Neanderthal features. Given that these date back around 210,000 years, we are looking at potentially multiple waves of modern humans either within Europe or on her borders.
Adding this to the knowledge that a group of non-diversified humans donated DNA to some Neanderthals outside of Africa, and we are left with the following conclusion - that an early pre-Khoisan-split group of Homo sapiens left Africa and encountered Neanderthals somewhere between the Mediterranean and central Asia. This is what the authors conclude in their discussion:
The AMH [anatomically modern humans] -to-Neanderthal introgression event inferred to be ∼250 kya, which gave rise to AMHIR [anatomically modern human introgressed regions], requires the coexistence in Eurasia of Neanderthals and an early group of AMHs that diverged from modern AMH ancestors prior to the diversification of all extant human lineages. This event took place prior to most estimates of the deepest divergences between modern human groups (those differentiating the Khoesan and Central African hunter-gather populations from all other human lineages,28,29 which occurred between 150 and 285 kya) and more than 100 ky prior to the out-of-Africa expansion of AMHs.3,4,5,27 The presence of this early diverged group of AMHs is consistent with archeological evidence of AMHs in modern day Israel and Greece from ∼170 to 210 kya.23,24
To help solidify this interpretation, the authors of the paper took DNA samples from a variety of African peoples, many of which are rarely used in genetic modelling. The researchers were able to show that sub-Saharan groups whose ancestors never left Africa, such as the Hadza and Khoisan, possessed the DNA sections found in Neanderthals. But they didn’t show any donated DNA from Neanderthals back into humans. Whereas groups like the Amhara and Fulani, who have some Levantine ancestry, showed markers for Neanderthal DNA.
This kind of deep prehistorical DNA work quickly gets confusing, and these interpretations are models which best fit the current data and will certainly change in the future. But right now we can be reasonably certain that some very ancient humans mixed with Neanderthals many tens of millennia ago, and left their mark.
The Origins of the Gravettians
The Gravettians rank as one of the most unique human cultures in my opinion, the first and last modern humans to unite Europe from the Urals to the Atlantic in a common culture, what I call the Pax Gravettia. Their reign ran from about 33 - 21,000 years ago, and they produced some of the most fascinating artwork, burials and material culture in the Upper Palaeolithic record, including the famous Venus of Willendorf and the spectacular child burials at Sunghir. One of the enduring mysteries about them is how, when and where they originated. Since identifying cultures before genetics rested on the typology of lithics and differences in material culture, there has always been a debate about whether the Gravettians were an intrusion or just a development of the previous Aurignacian peoples.
This month we get a little closer to the answer, with the publication of new genetic sequences from Crimea. The rock shelter of Buran-Kaya III on the peninsula has delivered an extended sequence of materials and human remains, from Neanderthals to the Middle Ages. One such sequence was a series of ‘Gravettian’ stone tools and fragments of skulls and human teeth. Two human genomes were able to be recovered and sequenced from this debris: BuKa3A and BuKa3C. Given that this site has been identified previously as ‘proto Gravettian’, with 5 thousand years between here and the earliest Gravettians in central Europe, these genetic sequences are the perfect way to test any connections.
The results were complicated for the non-expert, but they can be summarised as follows:
The two genomes show high levels of relatedness to later Gravettian clusters (Vestonice, Fournol)
They show more Aurignacian admixture than previously expected
When mapped onto the Gravettian genetic landscape it reveals both an east-west and north-south gradient for admixture with the Aurignacians previously inhabiting Europe
Unexpectedly the two genomes show high levels of similarity to later Central Hunter-Gatherers (CHGs) from the Caucasus
Aurignacian genetic legacy survived both through mixing with incoming Gravettians, and contributing to the CHGs of the Holocene period.
We can be more confident now that a proto-Gravettian culture developed between the Crimea and Caucasus (where the earliest similar tools have been found), around 37,000 years ago. These people then expanded into Europe through the Danube corridor, sometimes mixing with the already existing people, but ultimately replacing their way of life. Those Gravettians who lived more southerly and to the west of Europe had more Aurignacian ancestry than to the east and north, probably reflecting initial contact and mixing. This Aurignacian-Gravettian genetic legacy was also preserved in the Caucasus in the CHG population, although how that worked is unclear.
Our final paper carries on the narrative from the Gravettians, looking at the next phase of Upper Palaeolithic Europe. As the glaciers began to retreat after about 20,000 years ago, two genetically distinct human cultures occupied Europe - the Epigravettians (no relationship to the Gravettians) and the Magdalenians (Gravettian descendants) who lived roughly between 19 - 10,000 years ago. Even being able to genetically distinguish these people is a huge advance from a decade ago, and now that the dust is beginning to settle on this explosion of genetic data, researchers are beginning to fit the traditional archaeological data back into the equations.
One such interesting piece of data is that the Magdalenians and Epigravettians appear to have buried their dead in very different ways. The latter preferred to bury people directly in the ground, often with shells and ochre and grave goods. The Magdalenians by contrast present with confusing burial rites, sometimes with scattered bones, displaying marks of having been butchered. More darkly, a few Magdalenian sites have revealed the careful transformation of human heads into ‘skull cups’ (Gough’s Cave, UK)
Now that we have the genetic data to identify the difference between the groups, it is possible to start grouping types of burials by ancestry. Magdalenian ancestry is largely defined by a cluster called GoyetQ2, which emerged from Franco-Iberia as the descendants of the western Gravettians were forced into isolation by the glaciers. The Epigravettians, confusingly have no Gravettian ancestry, and instead arose from a group of hunter-gatherers with Near East connections who came through the Balkans into Italy as the climate became more favourable. Genetically they are defined by the Villabruna cluster.
When the authors of this new paper decided to survey all known Magdalenian burials, they found the following:
Twenty five percent (25%) of all Magdalenian sites reviewed (or 60% of the Magdalenian sites for which the funerary behaviour is known) show evidence of cannibalism, a relatively high frequency compared to the occurrence of cannibalism among other cultural groups. At least six Magdalenian sites (40% of the cannibalistic sites) show evidence of post-mortem manipulation of the cranial vaults associated with the manufacture of skull-cups and at two sites unusual incisions on the human remains have been interpreted as possible artistic engraving. We thus propose that cannibalism was practiced as a form of funerary behaviour by Magdalenian human groups.
This is interesting enough on its own, but when they combined these with known genetic data from some of these burials, the results were unambiguous.
Aside from El Miròn, which was already known to be an outlier, the genetic data matched against the burial type is one of the clearest results I’ve ever seen in such a publication. Funerary cannibalism was a Magdalenian cultural trait, and as the Epigravettians spread out into Europe and replaced them, the burials switched to directly putting people in the ground.
Funerary cannibalism is well known in the ethnographic record, from the Amazon to New Guinea. Typically this ‘endocannibalism’ is exclusive with ‘exocannibalism’, where people from outside the group are eaten. Funerary cannibalism can be part of belief system where the spirit of the dead person needs to be consumed, or released by eating the body. The fact that the Epigravettians did not conduct such rites might indicate an intentional group differentiation.
It is however undeniable, that the frequency of cannibalistic cases among Magdalenian sites exceeds any incidence of this behaviour among earlier or later hominin groups (Bello et al., 2015), and suggests that mortuary cannibalism was a method Magdalenian people used to dispose of their deceased. One of the strongest arguments for cannibalism as a funerary practice comes from its recurrent appearance within a historical context, as a widespread activity over time and an established custom for the group involved.
This kind of joint archaeological-genetic research is the future of the field, combining the ability to distinguish ancestry with the material culture and burial record. So even for scarcely evidenced periods such as the Palaeolithic, we get incredibly clear-cut answers and a glimpse at how radically different these ways of life were from one another and to ourselves.