Paleoindian groups* occupied North America throughout the Younger Dryas interval, which saw a rapid return to glacial conditions approximately 11,000 years ago. Until now, it has been assumed that cooling temperatures and their impact on communities posed significant adaptive challenges to those groups. David Meltzer from the Southern Methodist University in Dallas, USA, and Vance Holliday from the University of Arizona in Tucson, USA, suggest otherwise in their review of climatic and environmental records from this time period in continental North America, published in Springers Journal of World Prehistory.
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, who during this interval, successfully dispersed across the diverse habitats of Late Glacial North America.