Book excerpt: This volume considers the genetic variability of human populations, particularly in the tropics: its origins and maintenance, and its contribution to the phenotypic variability of complex characters. The first section deals with the ways of analysing genetic variation and provides a valuable review of relevant developments in molecular biology. The origin and maintenance of genetic diversity is considered in the second section with data presented for Pacific, African, Asian and Central American populations. The final section concerns characters in which the genetic contribution to variability is complex and shows how such characters may be used to elucidate biological problems of affinity and differentiation, of adaptation and survival. Published as part of the Decade of the Tropics research programme of the International Union of Biological Sciences, this volume will be of particular interest to human geneticists, physical and biological anthropologists.