Relationship between heterozygosity for enzyme loci and variation of morphological characters in natural populations.

Abstract

THERE is little consensus among evolutionary biologists on the roles of morphological and protein variation within populations, and little consideration is given to their covariation. Morphological variation is known to be influenced by both the genetics of individuals and the environments in which they develop. Crosses between domesticated strains of plants and animals suggest that highly heterozygous individuals have enhanced developmental homeostasis1, but the implications of this phenomenon for natural populations have not been extensively explored. Reported here is an examination of the relationship between genetic heterozygosity of proteins and morphological variation in natural populations of the killifish, Fundulus heteroclitus. Results indicate that individuals heterozygous for an enzyme locus are likely to be less morphologically variable than individuals homozygous for that locus.