Ice Age Europeans had some serious drama going on, according to their genomes - The Was... - 0 views
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before researchers could start analyzing that genetic material, they had to get it. DNA degrades over time, so extracting it from ancient human remains is difficult and costly.
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In the end, they had data from 51 individuals — a tenfold increase over the measly four that once gave researchers their only glimpses into this period.
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"Trying to represent this vast period of European history with just four samples is like trying to summarize a movie with four still images," Reich said. "With 51 samples, everything changes; we can follow the narrative arc; we get a vivid sense of the dynamic changes over time.
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One of the oldest genomes studied came from a thigh bone discovered in Goyet Cave in Belgium and given the unwieldy name GoyetQ116-1. Radiocarbon dating pegs the Goyet individual at some 35,000 years old,
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Around 1,000 years after the Goyet individual was found, a new culture swept through Europe: the Gravettians. Analysis of genetic material from the time shows that art and artifacts weren't the only things changing. The Gravettians' DNA was significantly different from their Aurignacian predecessors, suggesting that they were a completely separate lineage.
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Goyet guy's descendants retreated to the Iberian Peninsula (modern day Spain and Portugal) and waited for their time to come again.
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It did, some 15,000 years later. Probably spurred by climate changes as glaciers began to recede, this dormant lineage expanded back into the rest of Europe, bearing a new culture known as Magdalenian.
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Not long after that, their genomes started to look like those of people from the Middle East and the Caucasus, suggesting that new arrivals from the southeast were mingling with — and in some cases supplanting — the existing population.
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This was a surprise, because researchers used to think that transition happened much later, when Turkish farmers introduced agriculture to Europe some 8,500 years ago.
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The genetic analysis allowed researchers to trace the inexorable decline of Neanderthal DNA, which was two to three times more prominent in early human genomes than it is in modern-day ones. This supports theories that early humans interbred with Neanderthals, but that their DNA was toxic to us and gradually weeded out by natural selection over the course of millennia.