Physiological and Demographic Variation Associated With Allozyme Variation

Abstract

A corpus of empirical data, extending back more than a half century, documents the related phenomena of heterosis and inbreeding depression (Wright, 1977; Frankel, 1983). Because the majority of this experimental work has been with domesticated species of plants and animals, the observations and the controversy concerning the underlying mechanism(s) have had little impact upon the study of natural populations. Yet recent studies of enzyme polymorphisms suggest that the same continuum of inbreeding depression and heterosis occurs in natural populations. Further analyses of genetic variation and components of fitness in natural populations will not only reveal more about the dynamics of selection within populations, but they will also produce new insights into the mechanisms causing inbreeding depression and heterosis.