ABSTRACT
The Younger Dryas (YD) and other cold climatic pulses occur within the Pleistocene/Holocene transition, a period that witnessed the first clear evidence of human occupation in South America. The first humans moving into North America experienced very dramatic climatic instability in Beringia, including cold and warm phases. The chapter discusses the climatic conditions and the existence of a cold signal in high latitudes underscores the importance of dry conditions at the end of the Pleistocene. It also discusses the earliest presence of humans in southern South America. The duration of late Pleistocene cold pulses, be it the YD, the Huelmo-Mascardi, or the Antarctic Cold Reversal (ACR), is too short to expect any specific biological adaptation of animals or humans. Any adaptation to cold climates observed in animals is probably related to previous, longer glacial periods. The extinction of the Pleistocene megafauna is a process that occurred during the end of the late Pleistocene across South America.
