Extermination

An extraordinary number of mammals became extinct during what is called the late Pleistocene era, which includes the time before, during, and immediately after the last ice age. It is difficult to be accurate about exactly when the mass extinctions occurred, but they seem to have been when the glaciers were retreating, about 12,000 years ago. The coincidence in time of the arrival of the first humans and the extinctions of the megafauna forms the basic evidence for an anthropogenic explanation of Pleistocene extinctions. Known as the "Pleistocene overkill hypothesis," the scenario involves rapid colonization by big game-hunting humans with large spears who extirpated the megafauna while spreading throughout the continent. Climate change is an alternative explanation of Pleistocene megafauna extinctions.