Alison Pischedda

Alison Pischedda joined the Barnard faculty in 2017. Her research focuses on sexual selection and sexual conflict using the fruit fly model system, Drosophila melanogaster. Her work takes advantage of the promiscuous mating system, high degree of experimental control and extensive genetic tools available in Drosophila to study interactions between males and females using an integrative approach, drawing from the fields of animal behavior, evolutionary biology and population genetics.

Research in the Pischedda Lab spans all levels of sexual interactions, from finding and choosing a mate to producing offspring. Current lines of investigation include:

Male mate choice: Females are often though of as the "choosy" sex, but there is increasing evidence in Drosophila and a number of other species that males can also be choosy if given the chance. This recognition that males also discriminate potential mating partners leads to many unanswered questions about male mate choice: What types of females do males prefer? How do males evaluate female "quality"? What are the evolutionary consequences of these male preferences?

Mating duration: The length of time a pair spends mating is a fundamental way in which the sexes interact, but relatively little is known about the role of this behavior in sexual selection and sexual conflict. Fruit fly mating lasts 15-20 minutes, but sperm transfer is completed within the first ~8 minutes. Longer matings come at the expense of males soliciting other females and females preparing for reproduction. Why, then, do matings last so much longer than is necessary for sperm transfer? Which sex, if any, benefits from such lengthy matings? Is either sex harmed by long matings? 

Sexual conflict and male fitness: One of the consequences of having two sexes is that traits that make an "ideal" male are often different than those that make an "ideal" female. However, each sex is not free to evolve these traits independently, since males and females share largely the same genome. As a result, genetic variation that benefits one sex can actually be costly to the other, a phenomenon known as "intralocus sexual conflict". We study intralocus sexual conflict using hemiclonal analysis, a powerful genetic tool that enables us to experimentally clone haploid genotypes and express them in both sexes. How does this sexual conflict impact male and female fitness? What behaviors/traits that are beneficial to males are costly to females?