X Marks the Box

Starred review from October 4, 2010
Beginning with a recently discovered 47-million-year-old primate fossil, Switek effectively and eloquently demonstrates the exponential increase in fossils that have been found since Darwin first published On the Origin of Species. In delightful prose, he blends information about fossil evidence with the scientific debates about how that evidence might be best interpreted. Switek, who writes the Smithsonian's Dinosaur Tracking blog, focuses on evidence for the evolution of major lineages, from reptiles to birds and from fish to tetrapods. He also explains at length how whales, horses, and humans evolved, marshaling compelling fossil evidence and combining it with information from molecular biology; at every step, he makes clear what is still unknown. He underscores that life forms have not "progressed" through evolution to end with Homo sapiens as the highest life form; rather, evolution has produced "a wildly branching tree of life with no predetermined path or endpoint." He superbly shows that "f we can let go of our conceit," we will see the preciousness of life in all its forms. 90 b&w illus.