The thrill of the chase

摘要

Whales evolved from cat-sized terrestrial hoofed mammals, evolutionary biologists tell us. How could a tiny, deer-like creature morph into such a radically different leviathan? The notion has often provoked gleeful ridicule from creationists, especially because, until the 1990s, so few intermediate fossils had been discovered. Little more than a decade later, spectacular finds had bridged that gap so convincingly that whales now stand as one of the best-documented fossil transitions - literally a textbook case of evolution in action. Much of that change is thanks to Hans Thewissen, a palaeontologist at Northeast Ohio Medical University in Rootstown, who has made many of the key discoveries. The Walking Whales is his account of his research.