In doing so, he could observe the differences in fitness over successive generations between males that received the “male-centric” set of genes and those that were the product of normal chromosome segregation. To test his hypothesis, Chippendale and his team developed a system that linked male-specific genes in Drosophila into one large Y-chromosome.

He explained that conflict over which of these alleles will reside at which locus can be fierce. Chippendale employed the term “sexually antagonistic gene” to describe a gene that is helpful in males but unwanted in females. That is, the phenotypes characteristic of low-fitness males represent adaptations that actually make females more fit, and vice versa. The root of this sexual conflict is readily observable: traits that may be desirable in one sex are often directly opposed to traits that lead to success in the other. He determined that sexual conflict explained much of the variation: cycles of antagonistic evolution between males and females result in less-than-ideal fitness levels for both sexes. This week, Adam Chippendale, Associate Professor of Biology at Queen’s University in Ontario, gave a lecture entitled, “Sexual Conflict: Evolutionary Arms Race or Tug-of-War?” His discussion focused on how sexual conflict helps explain the variability in fitness among Drosophila melanogaster populations.Ĭhippendale’s research question stemmed from his observation that even after hundreds of generations, male Drosophila varied considerably in fitness despite ample time to adapt to their conditions. Share on Twitter Share on Facebook Share on Email

Evolutionary arms race sexual conflict