Publisher's Synopsis
An understanding of evolution, by which is meant the gradual development of complex organisms from the primeval beginnings, has been gradually advancing. This book attempts to contribute a more complete theory by combining molecular, genetical and evolutionary data and reconsidering the evolutionary significance of genetic variation. Accordingly, this book does not stress unity of process, but evolutionary differences as expressed in the various living phyla and classes.;In this study, alterations in gene structure that lead to adaptive changes are discussed at three taxonomic levels: sub-specific, involving the acquisition of genetic resistance to inhibitors and the breeding of plants and animals; the specific level, where alterations in the timing and placement of gene action are important; and at the ordinary level, which involves the genetic generation of novel structures or functions. Possible reasons are advanced for the slowing or cessation of major evolution in many groups.
