Ancient Bison DNA Reveals How Clovis People Reach America

A team of researchers led by Peter Heintzman and Beth Saphiro of University of California, Santa Cruz has discovered that a bison population was present in the land between two melting glaciers, making it possible for clovis people to travel along the 900-mile ice-free corridor connecting Alaska and the Americas.

Their findings, published in the journal Proceedings of the National Academy of Sciences, were based on the mitochondrial DNA of an ancient bison. The researchers believe that ancient bison population in Alaska and North America were separated when the glaciers merged 23,000 years ago, making them to evolve minor variations in their DNA. To find out if the bison in Alaska had traveled south to North America through the ice-free corridor, or the North American bison traveling north to Alaska, researchers collected ancient bison bones from both ends of the corridor.

The researchers found out that the ice-free corridor as "fully opened" for bison traffic about 13,000 years ago. This make it possible for the clovis people to travel along the corridor because bison served as the major prey for these humans.

However, another study published in the journal Nature suggests that the clovis people were unlikely to travel along the corridor going through Americas because they have reached Americas before the corridor is teeming with life.

Their findings showed that steppe vegetation, bison and mammoth did not appear in the corridor until 12,600 years ago. About 11,500 years ago open forest, elk and moose appeared in the corridor, followed by boreal forest about 10,000 years ago.

Clovis people are believed to arrive in America about 13,000 years ago, making it impossible for them to pass through the ice-free corridor that was not viable for life until 12,600 years ago.

Both team of researchers believe that early people living in America, including pre-clovis, may have avoided the glacier and traveled through the waters. The researchers are now determined to find evidence of such coastal voyage to better understand how early humans arrived in America.