New York: Columbia University Press, 1937. - 364 p.The present book is devoted to a discussion of the mechanisms of species formation in terms of the known facts and theories of genetics. Some writers have contended that evolution involves more than species formation, that macro- and microevolutional changes may be distinguished. This may or not be true; such a duality of the evolutionary process is by no means established. in any case, a geneticist has no choice but to confine himself to the micro-evolutionary phenomena that lie whithin reach of these method, and to see how much of evolution in general can be adequately understood on this basis.Contents
Organic diversity
Gene mutation
Mutation as the basis for radial and specific differences
Chromosomal changes
Variation in natural populations
Selection
Polyploidy
Isolating mechanisms
Hybrid sterility
Species as natural units
