What is the overkill hypothesis for late Pleistocene extinctions?

The overkill hypothesis, proposed by Paul S. Martin in the 1960s, suggests that the mass extinction of large mammals at the end of the Pleistocene was primarily caused by overpredation by human hunters.12

Proponents of this theory point to the coincidence between the timing of these extinctions and the arrival of skilled human hunters from Eurasia, as evidenced by the Clovis complex in North America. The hypothesis posits that these large herbivores had no prior experience with humans as predators and were therefore highly vulnerable to slaughter. Furthermore, the decline of these large prey species would have subsequently caused the extinction of large carnivores that relied on them.1

While the overkill hypothesis remains a significant subject of debate, it is often contrasted with the climatic-change hypothesis, which attributes the extinctions to environmental stress and vegetation shifts during the last glacial-interglacial transition. Many researchers now suggest that both human activity and environmental changes likely played varying roles in these extinctions across different geographic regions.12