Throughout history, humans and their ancestors have perfected the art of killing big animals. Now, a new study finds that as humans spread around the globe, extinction of large mammals soon followed.
Massive mammals such as wooly mammoths, elephant-sized ground sloths and various saber-toothed cats roamed the Earth between 2.6 million and 12,000 years ago. Now they — and most of the rest of the big ones — are extinct.
Image: (Photo: Bill Neibergall, the Des Moines Register)
