Over the last decade the biological and physical sciences have been losing their earthly bearings and with such distinguished minds as Rostand, Koestler, and Teilhard de Chardin, a dry vocabulary has taken on the airs of visionary speculation. So it is nice that this modest little book restricts itself to a homey, informative discussion of the basic evolutionary issues, with succinct summaries of all the important post-Darwinian findings, theories, and allied data, as well as dipping into anthropological and paleontological evidence. The style of composition is refreshingly within the grasp of any interested layman and there are simplified definitions of such matters as population, race, subspecies, species, genus, the DNA molecules, genetic combinations, speciation, and so forth. The larger questions or controversies concerning heredity and environment, racial variation and adaptability, the mechanism of evolution, and the fallacy of the ""pure"" race, are all treated in straightforward fashion, including the use of ornithological illustrations, especially that of the Song Sparrow. Carleton Coon's unpopular Congoids-lag theory receives a rather deferential rebuke; and the taxonomy of the differing races has moments of unwitting humor: the Hottentots, we are told, have fat buttocks.