Enzyme Polymorphism and Adaptive Strategy in the Decapod Crustacea

TLDR: Neither population size fluctuations (bottlenecks) nor the random processes and normative selection of mutation-selection balance theory can account for the differential correlation of group I and group II enzymes with the "organismic" and "environmental" group of niche descriptors.

Abstract: Protein polymorphism in 44 species of decapod Crustacea was assayed by electrophoresis. An average of 26 loci per species and 24 individuals per locus were surveyed. Each species (together with an additional seven species for which electrophoretic data were already available) was ranked on each of 10 niche descriptors: adult size, post-larval vagility, trophic level, trophic generalism, number of species per genus, decapod species diversity, latitude, productivity, euryhalinity and littorality; in addition each was ranked on two composite measures, Levinton's "index of opportunism" and a measure of trophic resource instability. Niche descriptors were intercorrelated over species and found to fall into three groups, an "organismic" group, an "environmental" group, and a third consisting of productivity and latitude. Maximum heterozygosities for 10 enzymes were intercorrelated. Though correlations were weak, the enzymes fell into two groups corresponding approximately to the groups I (central metabolic enzy...