Brush (emeritus history of science, U. of Maryland-University Park) explains how and why British and American biologists, who had shared the skepticism of their continental colleagues about Charles Darwin's theory of evolution, accepted a revised version of it mostly during the 1940s. The modern theory was a synthesis of such disciplines as genetics, zoology, botany, and paleontology, he says, that acknowledged natural selection as a necessary, and perhaps the most crucial, but probably not sufficient cause of evolutionary adaptation. Among his perspectives are mathematical and philosophical biologist Haldane weighs, in, Huxley proclaims a new synthesis, chromosome inversions in Drosophila, the changing views of Dobzhansky and Wright, and whether evolutionary theory is scientific. Annotation 2009 Book News, Inc., Portland, OR (booknews.com)