We investigated the effects of genotypic frequencies on egg-to-adult viabilities in pairwise combinations of four strains of Drosophila melanogaster. The experiments involved mixture of a total of 42,000 eggs in varying proportions under controlled densities and observation of surviving adults. Viabilities were found to depend on frequencies in several genotypic combinations. In the most extreme case, the absolute viability of cn; bw females increased monotonically from 54% when common to 70% when rare. The results illustrate several statistical and methodological problems that might explain why some experiments have failed to detect frequency-dependent viabilities. These problems include heterogeneity between replications, sex differences in susceptibility to competition, and strong dependence of the experimental outcome on the choice of competitor genotypes.
|Original language||English (US)|
|Number of pages||5|
|Journal||Journal of Heredity|
|State||Published - Mar 1991|
Bibliographical noteFunding Information:
From the Department of Ecology, Evolution, and Behavior, University of Minnesota, Minneapolis, and the Department of Genetics and Cell Biology, University of Minnesota, St. Paul. The authors thank Drs. Larry Mueller and Therese Markow for comments. Research is supported by grants from the National Institutes of Health (KO4 HD 00638 and RO1 HD 20776) to Dr. Curt-singer. Address reprint requests to J. W. Curtsinger, Department of Ecology, Evolution, and Behavior, University of Minnesota, 318 Church St SE, Minneapolis, MN 55455.