The “overkill hypothesis” proposes that the rapid expansion of Clovis hunters — arriving in territories whose large animals had no evolutionary experience of human predators and thus no appropriate fear responses — resulted in the rapid hunting to extinction of the most vulnerable megafauna species.

The overkill hypothesis remains controversial, with ongoing debate about the relative contributions of climate change and human hunting to the megafauna extinctions.

But the kill-site evidence for Clovis megafauna hunting is genuine, and the temporal coincidence between the Clovis expansion and the rapid extinction of multiple megafauna species across the Americas is a real pattern that requires explanation.

How the Anzick Child’s Genome Was Sequenced

The greatest scientific contribution of the Anzick site came not from the initial discovery in 1968 but from work carried out more than four decades later, when advances in ancient DNA technology made it possible to extract and sequence the genome of the Anzick child.