In the last three to four years, genetic sampling of ancient and modern individuals has led to some real surprises for the world of prehistory. Many migration events that were dismissed as old hat in the 1990s and 2000s have resurfaced as having an actual basis: the Yamnaya-steppe migrations, the early Neolithic migrations and the Bell Beaker migrations into the British Isles. In the last week, a piece of cutting-edge research has upped the game with a ground-breaking new technique called ASCEND, a simulation program which models the effect of population bottlenecks, introgression and boom-bust cycles on the human genome. The science is still tentative - and the paper has yet to receive a sustained review - but its findings are significant.
Published in PLOS Genetics, Rémi Tournebize and his academic colleagues looked at the sharing of alleles that often happens during 'founder events', or periods where a population contracts and begins to start anew from a bottom floor. The stronger the correlation between alleles in one pair of individuals and another, the closer the period where genetic diversity was low or culturally restricted to a class or group. Two examples of 'recent' founding-events they give are the Ashkenazi Jews, who until the early Modern period were a highly insular and marginalised community in eastern Europe, and the Easter Islanders, whose demographic collapse began a generation or two after European contact.
The real substance of the research comes from its insight into past population movements. Their model confirms that Cuba, about 5,000 BCE, was settled by a tiny group of immigrants from either Mesoamerica or southern Florida, where an Archaic-period maritime economy flourished, becoming the ancestors of all later Taino and mestizo Cubans. A more extreme case is made for the Iberomaurusian culture of Upper Palaeolithic Morocco, where for more than fifteen generations after 17,000 BP the entire population hovered close to 100. The lithics and rock art recovered from this period might well reflect the activities of just two or three family groups who could have known each other.
Another paper by the same authors late last month is even more significant Perhaps the most significant takeaway are two phenomena that happened during the transition to the Neolithic in southwest Asia and Europe. This uses a slightly different program called DATES that compares genomes as a whole rather than correspondences in allele sharing.
The first can be only be described as ancient long-distance travelling between hunter-gatherers of the Balkans and the Iron Gates (i.e., Romania) and early farmers in Anatolia between 10,000 and 8,000 BCE. People were living by the Danube who had grandparents who had been Anatolian farmers and grandmothers who, like them, where eastern European fishers, even at this early a date. Western Hunter Gatherer ancestry has also turned up in samples from early Neolithic Anatolia, suggesting that even hunters from France and Spain travelled to the Near East. They could well have visited the vast array of monumental enclosures in southeast Turkey, such as Gobekli and Karahan Tepe, to feast during auspicious times of the year or to visit relatives. None of this is currently visible in the archaeology, but future discoveries could turn that on its head.
The second is a surprisingly early interaction (circa 10,900 BCE BCE) between farmers in Iran and southern Turkey, with the implication being that the Iranian farmers introduced the practice of agriculture with their introgression, rather than the other way around. Given that Anatolian farmers have traditionally been seen to have been the first to try their hand at it, this seriously shakes up our current understanding of the early Near East. The dates are roughly contemporary with the building of Gobekli Tepe and other sites, so it is tempting to hunt for an ur-Tepe somewhere in the Iranian highlands, in the same way that an ur-Stonehenge was found in the Preseli hills in south Wales. The colourful ceremonies that surely happened there, bustling with animals, shamans and funky costumes, might have been the reason that Iranian, Spanish and eastern European hunters and farmers were attracted to the region.
The DATES and ASCEND simulation programs, when applied to cases across prehistory, bring up a wide array of unexpectedly early results. According to DATES, the first steppe-descended people in Spain actually arrived around 3200 BCE, just after the Yamnaya culture and its Corded Ware cousin can be traced archaeologically in central Europe, which is consistent with the other finding that the Proto-Indo-European ethno-linguistic community coalesced much earlier at around 4,000 BCE (or as early as 4,400 BCE), despite at that point not having adopted chariots or horse-riding on a wide scale.
The latter raises an interesting question: how did people get around before those technologies, enough to develop a common language and lifestyle? One answer might be that mules, onagers, asses or even cattle were ridden to and fro places. Another could be that hide-stretched boats may have formed the primary medium of communication, shuttling up and down the Dnieper, and the tributaries between the Don and Volga where the core steppeland is located. This certainly, as reflected in my piece about it, helped the Finno-Ugric languages to spread, so why not other languages?
All in all, a good deal of exciting conclusions to be made, but ones that need to be tested by a generation of future archaeologists and geneticists.
References:
Chintalapati, M., Patterson, N., & Moorjani, P. (2022). The spatiotemporal patterns of major human admixture events during the European Holocene. eLife, 11, e77625.
Tournebize, R., Chu, G., & Moorjani, P. (2020). Reconstructing the history of founder events using genome-wide patterns of allele sharing across individuals. BioRxiv. Also available at: https://doi.org/10.1371/journal.pgen.1010243
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