People in Eurasia today have genetic material linked to Neanderthals from the Altai mountains in modern-day Siberia, according to a new study.
That’s noteworthy because past studies have shown that Neanderthals connected to a different, distant location—the Vindija Cave in modern-day Croatia—have also contributed DNA to modern-day Eurasian populations.
The results reinforce the concept that Neanderthal DNA has been woven into the modern human genome on multiple occasions as our ancestors met Neanderthals time and again in different parts of the world.
“The story of human evolution is not so much like a tree with branches that just grow in different directions. It turns out that the branches have all these connections between them.”
“It’s not a single introgression of genetic material from Neanderthals,” says lead researcher Omer Gokcumen, associate professor of biological sciences at the University at Buffalo. “It’s just this spider web of interactions that happen over and over again, where different ancient hominins are interacting with each other, and our paper is adding to this picture.
“This project will now add to an emerging chorus—we’ve been looking into this phenomenon for a couple of years, and there are a couple of papers that came out recently that deal with similar concepts.”
“The picture in my mind now is we have all these archaic hominin populations in Europe, in Asia, in Siberia, in Africa. For one reason or another, the ancestors of modern humans in Africa start expanding in population, and as they expand their range, they meet with these other hominins and absorb their DNA, if you will,” Gokcumen says. “We probably met different Neanderthal populations at different times in our expansion into other parts of the globe.”
To complete the project, scientists analyzed the DNA of hundreds of people of Eurasian ancestry. The goal was to hunt for fragments of genetic material they may have inherited from Neanderthals.
The research found that the Eurasian populations studied could trace some genetic material back to two different Neanderthal lineages: one from a Neanderthal whose remains were discovered in the Vindija cave in Croatia, and another from a Neanderthal whose remains were discovered in the Altai mountains in Russia.
Scientists also discovered that the modern-day populations they studied also share genetic deletions—areas of missing DNA—with both the Vindija and Altai Neanderthal lineages.
Different research teams have previously sequenced the DNA of the Vindija and Altai Neanderthals, along with the modern human populations studied.
“It seems like the story of human evolution is not so much like a tree with branches that just grow in different directions. It turns out that the branches have all these connections between them,” Gokcumen says.
“We are figuring out these connections, which is really exciting. The story is not as neat as it was before. Every single ancient genome that is sequenced seems to create a completely new perspective in our understanding of human evolution, and every new genome that’s sequenced in the future may completely change the story again.”
The paper appears in the journal Genetics. Additional coauthors are from the University of Chicago, the Foundation for Research and Technology in Greece, and the University at Buffalo.
Source: University at Buffalo