early human migration

It's complicated: How people first inhabited the Americas

Pre-Columbian archaeolgical burial site at Jiskairumoko, southeast of Puno, Peru.
One of the individuals encountered during excavation at Jiskairumoko, a pre-Columbian archaeological site southeast of Puno, Peru. The human remains have been removed in this image. From the Science Advances study. Photo: Mark Aldenderfer

In the largest examination to date of genetic material from ancient Americans, researchers found some genetic similarity among remains in Montana, Nevada and Brazil — showing there was likely a rapid migration of people from the tip of North America.

Why it matters: Researchers want to better understand how people first migrated, dispersed and settled into the different areas of the Americas. These genetic samplings — including some more than 10,000 years old — bolster some theories of what may have happened, but also bring forth new questions, particularly about new lineages that were discovered.

Native Americans may have arrived in the Americas via several routes

Early excavation site in Beringia with mountains in the background
Excavation of early site in the Beringia area of Alaska. Photo: Ben Potter/University of Alaska Fairbanks

In the long debate over how and when the first Native Americans arrived in the Americas, a group of scientists is arguing that multiple viable possibilities exist, according to a new study in Science Advances Wednesday.

Why it matters: Although there are many circulating theories, research over the past 20 years leans toward the idea that Native Americans arrived via a coastal route around 20,000 years ago. But, this team says they've reviewed enough evidence to indicate another theory is equally or even more strongly true — that they arrived via an inland route. Plus, they say, the earliest they arrived was closer to 16,000 years ago.