Quaternary extinction event

The latter half of the Late Pleistocene to the beginning of the Holocene (~50,000-10,000 years Before Present) saw extinctions of numerous predominantly megafaunal species, which resulted in a collapse in faunal density and diversity across the globe. The extinctions during the Late Pleistocene are differentiated from previous extinctions by the widespread absence of ecological succession to replace these extinct megafaunal species, and the regime shift of previously established faunal relationships and habitats as a consequence. The timing and severity of the extinctions varied by region and are thought to have been driven by varying combinations of human and climatic factors. Human impact on megafauna populations is thought to have been driven by hunting ("overkill") as well as possibly environmental alteration. The relative importance of human vs climatic factors in the extinctions has been the subject of long-running controversy. Major extinctions occurred in Australia-New Guinea (Sahul) beginning approximately 50,000 years ago and in the Americas about 13,000 years ago, coinciding in time with the early human migrations into these regions. Extinctions in northern Eurasia were staggered over tens of thousands of years between 50,000 and 10,000 years ago, while extinctions in the Americas were virtually simultaneous, spanning only 3000 years at most. Overall, during Late Pleistocene about 65% of all megafaunal species worldwide became extinct, rising to 72% in North America, 83% in South America and 88% in Australia. The Late Pleistocene saw the extinction of many mammals weighing more than . The proportion of megafauna extinctions is progressively larger the further the human migratory distance from Africa, with the highest extinction rates in Australia, and North and South America. The increased extent of extinction mirrors the migration pattern of modern humans: the further away from Africa, the more recently humans inhabited the area, the less time those environments (including its megafauna) had to become accustomed to humans (and vice versa).