Why the Overkill Hypothesis Collapses When You Count All the Megafauna

The overkill hypothesis - the idea that Palaeolithic hunters drove the megafauna to extinction - has a surface plausibility when applied to mammoths. Humans hunted mammoths. Mammoths disappeared. The logic seems to hold.

It stops holding when you count the full list. Approximately 100 megafaunal species went extinct at the end of the last Ice Age. Randall Carlson runs through the implications directly. Did Palaeolithic hunters also exterminate the cave bears? The dire wolves? The giant camels? The short-faced bears, the American horses, the ground sloths? On and on through a list of apex predators and large herbivores that spanned an entire continent - all of them gone within roughly the same geological window, all of them attributed to the hunting pressure of a relatively small human population spreading across North America for the first time. The arithmetic does not work. Something else was happening at the Younger Dryas boundary, and the overkill hypothesis was never designed to account for all of it.