J P Ricker

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Morphological correlates of male mating success were assessed in natural populations of three Drosophila species. Mating males in D. simulans were larger than single males but were characterized by reduced developmental stability as indicated by fluctuating asymmetry. Mating male D. pseudoobscura were no larger than single males but exhibited significantly(More)
Among Drosophila melanogaster, divergently selected for geotaxis intermittently over 600 generations (28 years), about 80,000 animals have been analyzed behavior-genetically. Each major chromosome pair from two lines was isogenized on an unselected isogenic background. Measurement of their behavioral effects revealed the relative magnitudes II greater than(More)
Drosophila melanogaster and its sibling species D.simulans were hybridized in the laboratory to test the hypothesis that developmental homeostasis in hybrids between two species having no prior gene flow would be significantly reduced. Developmental stability was assessed by measuring fluctuating asymmetry for three bilateral traits: sternopleural chaetae,(More)
Long-term divergent selection for geotaxis in lines of Drosophila melanogaster (the fruit fly) is described. After 26 years (600+ generations) of intermittent selection, the mean geotactic scores now remain stable upon relaxed selection, a result suggesting that evolutionary changes have occurred in these lines. Because the stability is not due to genetic(More)
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