At once a spirited defense of Darwinian explanations of biology and an elegant primer on evolution for the general reader, What Evolution Is poses the questions at the heart of evolutionary theory and considers how our improved understanding of evolution has affected the viewpoints and values of modern man. Science Masters Series Ernst Mayr was the leading evolutionary biologist of the 20th century. He was Professor Emeritus at the Zoology Department of Harvard University and for twenty-three years served as Curator at the American Museum of Natural History in New York. He died in February 2005 in Massachusetts.