Between fifty and ten thousand years ago, most large mammals became extinct everywhere except Africa. Slow-breeding animals also were hard hit, regardless of size. This unusual extinction of large and slow-breeding animals provides some of the strongest support for a human contribution to their extinction and is consistent with various human hunting models, but it is difficult to explain by models relying solely on environmental change. It is an oversimplification, however, to say that a wave of hunting-induced extinctions swept continents immediately after first human contact. Results from recent studies suggest that humans precipitated extinction in many parts of the globe through combined direct (hunting) and perhaps indirect (competition, habitat alteration) impacts, but that the timing and geography of extinction might have been different and the worldwide magnitude less, had not climatic change coincided with human impacts in many places.