Species that arose through hybridization provide a unique opportunity to examine the origins of biotic diversity, because the genomes of hybrid species contain evidence of past evolutionary processes. This project will examine the process of hybrid speciation in four distinct evolutionary lineages of a well-studied butterfly. Comparison of the genomes of the lineages will be used to identify portions of the genome that are under natural selection and assess the extent to which the selective processes underlying speciation are homogeneous and repeatable or varied. The genomic data will be linked with detailed ecological information to increase the biological interpretation of the results.
This project will result in the most comprehensive examination to date of the genomic outcomes of hybridization. Broadly applicable statistical methods for genome-level DNA sequence analysis will be developed and implemented in freely available software. The project will provide training for undergraduate, graduate, and postdoctoral scholars, outreach programs for K-12 students and educators, training in natural history for interested community groups, and contributions to public education about evolution and genetics.
Species can arise when populations evolve differences from ancestors and contemporary relatives that prevent them from successful interbreeding and that allow independent evolution. Hybridization, or breeding between distantly related organisms, results in novel genetic combinations, which can be the basis for the evolution of novel species. We have been investigating how hybridization can lead to new species in butterflies in the western United States (butterflies in the genus Lycaeides, see photo). We have characterized the genetics of individuals from many populations and sequenced genomes of butterflies that we have inferred are likely ancestral species and those that probably originated through hybridization. We are continuing to analyze data as some parts of the collaborative research grant are on-going. We already know that hybridization leads to more diverse outcomes and is likely to have led to novel species in more instances than we knew about before this research. A final objective in our work is to learn about the predominance of idiosyncratic or deterministic forces in the evolution of new species. Evidence for more determinism would suggest greater potential to learn enough to be able to make predictions about the evolution of new species, whereas a predominance of idiosyncrasy would make that goal much more difficult to achieve.
