Ancient and Modern DNA Tells the Story of the First Humans in the Americas

Tracing back the history of humans has long been a challenge for researchers. When and where did humans migrate? What happened after they arrived at a location? Now, researchers have used DNA to tell the story of how ancient humans first came to the Americas and what happened to them when they were there.

Actually understanding this story, though, required a bit of physical evidence. The researchers actually took samples from modern humans in order to trace back lineages to the ancient past. More specifically, they looked at changes in the mitochondrial genome, which children inherit only from their mothers. In addition, the scientists analyzed changes in the Y chromosome.

"The best opportunity to infer the evolutionary history of Native Americans and to assess the effects of European colonization is to analyze genomes of ancient Native Americans and those of their living descendants," said Ripan Malhi, one of the researchers, in a news release. "I think what makes my lab unique is that we focus not only on the initial peopling of the Americas but also what happened after the initial peopling. How did these groups move to new environments and adapt to their local settings over 15,000 years?"

The scientists actually found a direct ancestral link between ancient humans remains in the Prince Rupert Island area and the native peoples living there today.  They also found that along the northwest coast and California, communities in the ancient past were complex hunter-gatherer societies. That's in stark contrast to Mexico and Guatemala, where communities transitioned to farming and then experienced the effects of European civilization.

The findings help fill in the blanks on studies that seek to tell the story of life in the Americas before and after European colonization. More specifically, the genomic studies reveal hard evidence of human migration-something that's difficult to achieve through other sources.

The findings will be presented at the Royal Society in London on Nov. 18 and 19.