13.1 kya. The Clovis culture lasts less than half a millennium. But it coincides with a major change in the North and South American fauna: specifically with a wave of extinctions of large animals. We’ve seen something like this before with the human settlement of Australia. There’s still controversy about the causes, but it seems likely that humans played a major role in both extinctions, even if climate change also mattered.
The mass extinctions caused by humans differ significantly from the five generally recognized earlier mass extinctions, which mostly seem to have resulted from physical disasters, like asteroid strikes and poisonous gases. A better analogy for human mass extinctions might be found all the way back at the beginning of the Cambrian period, 540 million years ago. Then, a relatively low-key, more-or-less predator-free fauna (the Ediacaran fauna) faced a devastating challenge from newly evolved, mobile, visually guided predators. The Human Revolution may come to rival the Cambrian Revolution in its biotic consequences.