Alternative life histories and genetic conservation

Abstract

A number of salmonid species contain coexisting phenotypes which differ in life history, habitat use, and morphology. Population genetic studies of these species typically show that there is less genetic differentiation between coexisting life-history types than between the same life-history type sampled from geographically separate localities. The life-history polymorphisms appear to be one way by which salmonid populations adapt to heterogeneous environments. Anthropogenic activities that lead to the loss of genetic variation within and between populations should be discouraged. Such activities should be evaluated with respect to their effect on the life history polymorphism itself, even though this aspect is less well understood. -from Author