I attended an interesting lecture at SunWatch today entitled “Early Humans in the Americas: When Did They Arrive and Where Did They Come From?”
The lecture was presented by Steven and Kathleen Holen, a husband-and-wife team from the Center for American Paleolithic Research in Hot Springs, South Dakota. Here’s a video that describes the work they do (and have done in the past):
https://www.youtube.com/watch?v=mWgtf6v3L8M
The earliest theories had humans entering the Americas across the Bering land bridge 4000-6000 years ago. Subsequent discoveries at the Folsom / Wild Horse Arroyo Site in New Mexico (1927) and Dent Mammoth Site in Colorado pushed that estimate back to 8000-9000 and 11,000-13,000 years, respectively.
Now, discoveries and interpretations by the Holens have pushed that estimate back much further, to the 22,000-70,000 year range.
Their studies include examination of spiral and negative cone bone breakage in animal remains at the La Sena and Lovewell II sites. (Negative cone breakage occurs when bone is struck by an object like a hammer stone vs. the pressure fractures resulting from carnivore chewing.) They have conducted experimental archaeological bone breakage studies to compare the effects of human technology with carnivore ravaging on bone damage, with resulting quantitative information.
Other study sites include Villa Grove in Colorado, the Burnham Site in Oklahoma, and the Miami Mastodon Site in Missouri (where dating was done by stimulated luminescence).
The Holens have posited a theory of a Mammoth Steppe biome which resulted in a sparse population of treeless-grassland-adapted humans extending into the Americas. Specifically, they believe that humans may have entered the Americas during the middle of the Wisconsin Glacial Episode.
As an interesting aside, Mr. Holen mentioned that horse bones were found at the Burnham Site. I thought that horses were brought to the Americas by Europeans much later, so I raised this question. Mr. Holen explained that earlier species of horses existed in the Americas much earlier, but became extinct around 11,000 years ago. They were then reintroduced by the Spanish.
It was an engaging presentation by a couple of very knowledgeable people, interspersed by amusing husband-and-wife banter. It’s quite interesting to imagine this early human presence.