Did people settle the Americas once or many times?
Corey Watts
It’s a question archaeologists yearn to answer and some think new genetic evidence from Peru wraps up the debate.
(Photo by Corey Watts)
Now, the prestigious British scientific journal Nature reports new research from Peru suggesting the continent was settled in one great wave of migration, with people colonizing the full length of the Americas in mere centuries.
Scientists generally agree that, in the depth of the last Ice Age, when the seas were lower, the First Americans crossed an ancient bridge of land between Siberia to Alaska—about 17,000 years ago.
The crossing to America marks the last great prehistoric migration of human beings and one of the least understood. They still argue about whether there was one migration or many.
In an effort to settle the question, a team of scientists led by Lars Fehren-Schmitz from the University of California, Santa Cruz, has been working with Peru’s National Museum of Archaeology, Anthropology, and History in Lima.
Ancient Peruvians can still speak
In the 1950s and 1960s, Peruvian archaeologist Augusto Cardich discovered human remains in a rock shelter perched high in the Andes.
Together, the scientists sampled and analysed DNA from the five ancient people who lived there as far back as 9,000 years ago.
This makes the group, which includes a woman and 2-year-old child, amongst the first people to live at high altitude anywhere on the planet.
Though they passed away long ago their remains still whisper their stories to the scientists.
By looking for markers in their genetic make-up the researchers hope to find out if they were kin to those first migrants in the Arctic or not. If no, then it would mean there was at least one other migration.
Previously, telltale features on the bones of the ancient Peruvians’ spoke of multiple migrations, but this new genetic evidence suggests there was only ever the one until Columbus.
It seems they were indeed descended from those people living around the Bering Strait generations ago.
Even so, not all scientists are convinced, with some saying the research is inconclusive and, besides, there is more work to be done. Perhaps, they say, we should look not just at the genetic lines of humans but also of their crops, like maize and potato.
After all, it’s just one cave in one part of South America.
The quest to understand the rich prehistory of the Americas continues.