Chromosomal inversions and the persistence of species

Duke University, Durham NC

Investigators

Abstract

If individuals of different species mate with each other, the hybridizing species can become more similar and eventually collapse into one species. However, chromosomal rearrangements can allow hybridizing species to persist because large blocks of the genome do not recombine. Previously funded work examined the hybridization process in two Drosophila species. Genes conferring differences between coexisting species were contained within chromosomal rearrangements while genes conferring differences between geographically separated species mapped throughout the genome, thus demonstrating the important of chromosomal rearrangements in prevening hybridization. The work in this project will fine-tune the earlier work by examining the fine details of the genetic architecture of these chromosomal rearrangements. Estimates will be made of whether and how much genetic material passes between these species at points in the genome varying in distance from chromosomal rearrangement breakpoints. This work will thus elucidate of the efficacy of chromosomal rearrangements in maintaining the distinct entities classified as species. With the continued loss of species worldwide from human activities, this work will become increasingly important in identifying the processes that generate and maintain biodiversity on the planet. The work proposed will involve training of undergraduate and graduate students, specifically those from underrepresented groups, and will foster continued collaborations of an empirical lab with others focusing primarily on theory.