How and When People Reached America

Scientists have been fascinated with the origin of Native Americans for decades. Now, molecular genetics is helping scientists put together a detailed story about when people migrated to the New World, how they got here, and even what might have driven their journey.

This is a regular news story, as opposed to a Planet-of-the-Apes column, but it relates to evolution. It ran under Health, which is odd since it’s not a health story. It was originally supposed to run Friday in a longer version with pictures and a map, but factors beyond my control changed things. I'm still trying to track down the map. Here's the story:  

By comparing DNA samples from hundreds of volunteers, a Penn anthropologist and his colleagues have tied Native Americans to a group of people living in a small region of Russia called the Altai, near the borders of Mongolia, China, and Kazakstan.

The results, published in Friday's issue of the American Journal of Human Genetics, add another chapter to the story of the settlement of the Americas. Increasingly efficient DNA technology is helping scientists flesh out the prehistory of the Native Americans and of the human race in general.

Archaeologists have long surmised that Native Americans came from Asia, migrating to Alaska during a time when sea levels were lower and it was possible to walk over the Bering Strait.

But these latest results use the most complete genetic profiling done on the Asian and American sides, offering new insights into the ancestry of Native Americans, the routes they took to the New World, and the timing of the migration.

Artifacts show that humans were living in North America 15,000 years ago; they reached the tip of South America over the next 2,000 years.

Using techniques akin to DNA fingerprinting, scientists have continued to gather evidence that the majority of current native people of North and South America derive their ancestry from Asia.

Read the rest here.

In the early 1800s, serious scholars debated whether all humans were created together and later migrated to other places, or whether separate populations were the product of different creations. Now the evidence is clear we evolved in Africa, but the story is complicated by signs of mixing between anatomically modern humans, Neandertals and another group called Denisovans.  More on this soon.