The Paleoindians who occupied North America throughout the Younger Dryas interval, which saw a rapid return to glacial conditions approximately 11,000 years ago, successfully dispersed across the continent's diverse habitats, according to a new study in the Journal of World Prehistory.  

Experts have generally assumed that cooling temperatures and their impact on communities posed significant adaptive challenges to Paleoindian groups.  But the new review of climatic and environmental records from this time period in continental North America suggests that the Young Dryas age cooling was not as sudden, extensive, or severe, and the notion that these conditions may have taken the Paleoindians by surprise is questionable.

"All things considered, it is likely that across most of North America, south of the retreating ice sheets, Paleoindians were not constantly scrambling to keep up with Younger Dryas age climate changes. After all, adapting to changing climatic and environmental conditions was nothing new to them – it was what they did," the authors write.

From their analysis, they conclude that on the Great Plains and in the Rocky Mountains, conditions were in reality less extreme and therefore may not have measurably added to the challenge routinely faced by Paleoindian groups.

Citation: DJ Meltzer, VT Holliday, 'Would North American Paleoindians Have Noticed Younger Dryas Age Climate Changes?', Journal of World Prehistory, March 2010; doi: 10.1007/s10963-009-9032-4