STUDIES IN EXPERIMENTAL BEHAVIOR GENETICS .V. NEGATIVE GEOTAXIS AND FURTHER CHROMOSOME ANALYSES IN DROSOPHILA MELANOGASTER

Performed an assay using multiple-inversion marker chromosomes to assess effects of selection for negative geotaxis in Drosophila melanogaster after 133 generations of reproductive isolation. Data was collected on 45,247 Ss. Selection made all 3 major chromosomes more negatively geotactic than their unselected homologs. Only additive genetic effects have been measured reliably. Most of this genetic variance was attributable to Chromosomes I and II. A compensatory factor in males seems to make a single dose of Chromosome I approximately equivalent to its double dose in females. Sex differences in response to selection were explained by the greater total contribution to negative geotaxis of the genotype in females. Greater variance of females was the result of genotype-environment interaction peculiar to females. (PsycINFO Database Record (c) 2006 APA, all rights reserved). © 1969 American Psychological Association.