Fluted stone tools known as Clovis points have been found in several sites around the Americas, and analysis of these tools generally suggested that humans began colonizing the land mass around 15,000 years ago, after they had migrated across the Bering Land Bridge from Asia after the retreat of the Arctic ice sheets. But more recent findings have pushed back the date of the migrations several thousand years, and raised questions about how the first settlers colonized the Americas so quickly.
Clovis Culture
Various sites around the Americas bear the hallmarks of what is known as Clovis culture, defined by a particular style of stone tool, chipped in a distinctive way. The many examples of these artifacts date from between 12,800 to 13,100 years ago, and seemed to suggest that settlers arrived no earlier than 15,000 years ago.
Pre-Clovis Stone Tools
But other stone tools — similar to but not identical to the distinctive Clovis tool style — have been found in parts of Texas, Wisconsin, Pennsylvania, Oregon, and even at a site as far south as Monte Verde, Chile. Analysis of the artifacts using optically stimulated luminescence suggested that these tools were far older than 15,000 years. In fact, the Texas site, situated northwest of Austin in Buttermilk Creek, was likely continuously occupied from at least 15,500 years ago, which pushed the arrival of the first Americans to a significantly earlier date.
Asian Origin
Though few stone tools from northeastern Asia have been found, the few examples studied show a few similarities with the early tools found in the Americas, particularly the bifacial tools known as bladelets. While there is nothing to suggest that the earliest Americans didn't migrate from Asia, and genetic evidence supports this hypothesis, researchers stress that more information will be needed before stone tool technology between the cultures can be definitively established.
Rapid Southern Migration
The pre-Clovis stone tools found at the site in Chile are particularly interesting; they are more than 14,000 years old and suggest that the first Americans had come much farther south much earlier than previously realized. While it's possible that the settlers traveled down the west coast from the Bering Land Bridge in a relatively rapid few thousand years, experts are puzzled as to why no settlements have yet been discovered in other desirable sites along the way, such as the San Francisco Bay.
Source:
- Harmon, Katherine. "People Were Chipping Stone Tools in Texas More Than 15,000 Years Ago." Scientific American. 24 Mar. 2011. Web. 12 Apr. 2011. scientificamerican.com.
Jenny Ashford - Jenny Ashford is a writer and graphic artist from central Florida. Her main area of interest in her Suite 101 articles is science, with a ...
Join the Conversation