The First Americans, Part 1

For several decades, archaeologists thought the first Americans were the Clovis people, said to have reached the New World 13,000 years ago from northern Asia by following Mammoths and other large prey across the Beringia Bridge. Supposedly, they journeyed rapidly overland from the Yukon to Alberta, leaving behind their distinctive stone tools across what is now the lower 48 states. But it has now been established that humans reached the Americas thousands of years earlier. The evidence comes not only from archaeological finds, but also from genetics and geology.

For instance, from a Texas creek bank, excavators discovered more than 19,000 artifacts, some no larger than a thumbnail. One such artifact was once part of an all-purpose cutting tool, like an ice age equivalent of a box cutter. Artifacts like these are pushing the history of humans in the New World back beyond the Clovis people, since these tools were dated to 15,500 years ago.

In southern Chile, archaeologists found traces of early Americans who slept in hide-covered tents and ate seafood and wild potatoes 14,600 years ago. That was long before the Clovis people appeared in North America. in Paisley Five Mile Point Caves in Oregon, another team found 14,400-year-old human feces containing seeds of desert parsley and other plants.

Over the past decade, geneticists have been finding new clues where the first Americans came from and when they left home by studying the DNA of indigenous peoples. This information strongly indicates the first Americans' ancestors came from southern Siberia. Although this confirmed the suspected homeland, it also indicated that the New World colonists left their homeland between 25,000 and 25,000 years ago. This would have been a difficult time to migrate, for huge glaciers capped the mountain valleys of Asia, and massive ice sheets mantled most of Canada, New England and several northern states. But that didn't necessarily stop the colonists.

The ice sheets had lowered sea level by more than 100 meters, exposing continental shelves. The newly revealed land of northeastern Asia and Alaska, plus adjacent regions in Siberia, Alaska and northern Canada, formed a landmass joining the Old World to the New known as Beringia.

The air that swept over Beringia were dry and brought little snow to the area, thus preventing the growth of ice sheets. It was an arid tundra grassland inhabited by woolly mammoths, giant ground sloths, steppe bison, musk ox and caribou. Genetic studies suggest that sea lions likely inhabited the rocky islands that studded Beringia's south shore. So human migrants had their pick of hunting terrestrial mammals or seafaring ones.

The major genetic lineages of Natives Americans suggests that the earliest Americans paused somewhere and evolved in isolation for thousands of years before continuing on. Some 19,000 years ago, North America's ice sheets began shrinking, creating 2 passable routes to the south. Several studies of the geographical distribution of genetic diversity in indigenous Americans indicate the earliest colonists arrived between 18,000 and 15,000 years ago, which places them a pre-Clovis.

 

https://www.scientificamerican.com/article/the-first-americans/#:~:text=For%20decades%20archaeologists%20thought%20the,thousands%20of%20years%20before%20that.