Biodiversity on Earth is generated through the formation of new species. This project seeks to understand the role of differences in chromosomal gene arrangements in facilitating the formation of new species and allowing them to persist once formed. Recent theoretical work and experimental data suggest that chromosomal rearrangements can facilitate species persistence because genes cannot easily cross between hybridizing species in rearranged parts of the genome but can cross in collinear regions. Two sets of experiments are proposed to test this hypothesis. The first set compares the genetics of hybrid sterility in Drosophila pseudoobscura and D. persimilis in populations that coexist and populations that are geographically separated. The second set will evaluate if DNA sequences differ more between species in rearranged parts of the genome than collinear regions in two other species groups.
Modern evolutionary biologists have an impressive understanding of how genes evolve within populations, but a poorer understanding of how one species splits into two. This research will illuminate mechanisms of speciation, providing insights into the fundamental evolutionary processes that regulate biodiversity on Earth. It will also offer insight into genetic attributes that allow different species to persist together, which has become increasingly important when human activities threaten the extinction of many species.
