European Prehistory Is Rewritten By Ancient DNA
Stunning diversity within ice age cultures is revealed by genes.
Europe had vast steppes with herds of grazing mammoth and other megafauna thirty thousand years ago, as well as what we consisted a startlingly homogeneous human society. The people who lived there, known as the Gravettians by archaeologists, either lived in caves or structures made of mammoth bones. They left their distinctive material culture in the form of art and artifacts from Spain to western Russia. They fashioned palm-sized sculptures from mammoth tusk, portraying mammoths, cave lions, and stylized female figurines with ornate headdresses and exaggerated breasts and buttocks. There is evidence to support the claim that the Gravettian was the first pan-European culture.
Yet, the Gravettians were not a singular group of people, despite appearances. The Gravettians of France and Spain were genetically unique from those who lived in what is now the Czech Republic and Italy, according to new DNA findings published in Nature. In reality, two separate groups make up what we once believed to be one homogeneous item in Europe 30,000 years ago. The Gravettian findings are a small piece of a bigger collection of ancient European DNA that indicates remarkable genetic variation within seemingly cohesive prehistoric cultures.
The comprehensive study examined 116 recently sequenced genomes and hundreds of previously published ones. The genomes' dates ranged from 6,000 B.C.E. to around 45,000 years ago and from the Iberian Peninsula to the western steppes of present-day Russia. Several of the samples were in bad shape, and some originated from unexpected locations, such as the Doggerland, a now-submerged region between the British Isles and the Netherlands. Researchers were able to extract information from severely deteriorated bones and teeth, including some that had just 1% of their original genetic content, thanks to new analytical techniques and increasingly potent DNA sequencing instruments.
The genetic data indicates that, period after period, inferences made regarding tools, hunting techniques, and burial customs should be reassessed. These cultural entities, which archaeologists considered to be coherent populations, fail the criteria. See, the DNA data sheds light on the Gravettians' subtle regional variances in tool types and subsistence practices, which have baffled archaeologists for decades. Although archaeologists have made a few small cultural observations, it was unclear until recently whether these related to the same or separate groups.
For instance, mammoth bone shelters were only made by inhabitants in Eastern and Central Europe. Even the female miniatures are constructed differently from different materials, placed in varied environments, and discovered in different scenarios as you enlarge the image slightly. They now appear to have been created by many populations.
The DNA also gives information on what transpired to these prehistoric Europeans during the last glacial maximum, a period of 25,000 to 19,000 years ago when the environment deteriorated and much of Northern and Central Europe was covered in ice that was more than one kilometer thick. Archaeologists previously believed that people, including the Gravettians, began to retreat into ice-free regions of southern Europe some 26,000 years ago, and then gradually made their way back up north as the glaciers melted thousands of years later.
On the Iberian Peninsula and the southern part of France, it seems that this scenario is accurate: Humans who lived there before the ice reached its height remain there during the coldest part of the period and subsequently swarm back north and east as the continent warms.
Yet, the Italian Peninsula, which was previously believed to be a comparatively secure sanctuary, demonstrated otherwise. DNA analysis shows that the refuge was a dead end despite what appeared to archaeologists to be evidence of continued habitation during and after the glacial maximum.
It is a major surprise because one anticipates Italy to be a climate refugium, yet there has been a sudden and total change. The entire Gravettian people vanishes. Instead, following the glacial maximum, individuals in Italy exhibit genetic affinities with the Near East, indicating the arrival of a fresh population from the Balkans.
Archaeologists saw cultural changes around 14,000 years ago, when temperatures on the continent suddenly increased over a short period of time. However, they believed that the adjustments were due to the existing population learning to hunt in hotter, denser forested areas. In contrast, DNA reveals a nearly total population replacement: the Magdalenians, who survived the glacial maximum, virtually disappear, and are replaced by populations migrating north from postglacial Italy.
The study also looked at the last 10,000 years of hunter-gatherers in Europe, when the wide steppes was changing into dense woodlands and a rich wetland due to global warming. The genes again revealed an unexpected wrinkle in this situation: while having largely comparable hunting and gathering lifestyles, people in Western Europe continue to be genetically distinct from those living east of the Baltic Sea.
They even had distinct appearances: According to genetic evidence, hunter-gatherers in Western Europe had dark complexion and bright eyes until farmers began to settle in northern Europe around 6000 B.C.E. In contrast, people in Eastern Europe and Russia had fair complexion and dark eyes. Most surprisingly, despite their being no physical obstacles separating modern-day Germany and Russia, the two populations did not interact for thousands of years. They do not mix at all between 14,000 years ago and 8,000 years ago.
But, the team's samples don't completely cover the continent, and there are no samples in the likely interaction areas, such as Poland and Belarus, according to the authors. Further genetic information from such regions may reveal local population mixing between the two. We are reevaluating long-held beliefs, it is believed that archaeologists will welcome the new DNA facts. This genomic information demonstrates that our understanding of population interaction has been oversimplified and offers far more subtlety than archaeological evidence alone.
Posth, C., Yu, H., Ghalichi, A. et al. Palaeogenomics of Upper Palaeolithic to Neolithic European hunter-gatherers. Nature 615, 117–126 (2023). https://doi.org/10.1038/s41586-023-05726-0