Of the two suspected culprits, climate change and human hunting, Ward builds a compelling case for human hunting. Humans arrived in Australia about 40,000 years ago, and the marsupial lions and giant kangaroos vanished soon after; they came to New Zealand 2,000 years ago, and the giant moa was quickly gone; and the American extinction coincides with the spread of the first human populations there.

In order to understand what happened in the Ice Age, Ward takes us on a tour of mass extinctions through earth's history. He presents a compelling account of the great comet crash that killed off the dinosaurs, and describes other extinctions that were even worse. In so doing, he introduces us to a profound paradigm shift now taking place in paleontology: rather than arising from the gradual workings of everyday forces, all mass extinctions are due to unique, catastrophic events. They throw a wild card into the game of evolution and start the contest anew.

Brilliantly written with an irresistible combination of passion and expertise, The Call of Distant Mammoths is an engaging exploration of the history of life and the importance of humanity as an evolutionary force.