Studies of Enzyme Polymorphisms in the Kamuela Population of D. MERCATORUM. I. Estimation of the Level of Polymorphism

A Kamuela, Hawaii, population of Drosophila mercatorum was surveyed for enzyme variability. The mean heterozygosity and the proportion of polymorphic loci were estimated as 0.1255 and 0.37, respectively. Neither deviates more than one standard error from their respective means for 43 Drosophila species (Nevo 1978). Heterozygosity was distributed across enzyme categories in much the same manner as observed in other species (Gillespie and Kojima 1968; Johnson 1974), and enzymes associated with glycolysis were about as variable as other enzymes of central metabolism.--The levels of heterozygosity and polymorphism in this population do not seem to have been affected by a low-level capacity for parthenogenesis. The observed parthenogenetic reproduction is not strongly associated with particular allelic variants among viable parthenogenetic adults; however, the capacity to establish a self-sustaining parthenogenetic clone is strongly associated with the phenotype with the most frequent allele at every locus studied. We interpret these results to mean that isozyme variants do not strongly influence viability under total homozygosity (the genetic condition imposed by parthenogenesis), but they do have an impact upon the reproductive biology of parthenogenetic adults.