This project uses Oceanic swallows, a group of birds native to southeast Asia and the Pacific, to determine how species inhabit and flourish in human environments over long periods of time. As humans reshape the global environment, a critical component of effective conservation strategies is understanding and predicting how plants and animals will respond to human landscape alterations. Plants and animals in urban environments can evolve rapidly, indicating that some species may be able to thrive in close proximity to humans. Small agricultural villages have persisted for over 12,000 years; species that successfully inhabit these environments offer a unique window into the long-term effects of human activity on evolutionary processes. Oceanic swallows build their nests on human structures and forage over agricultural fields. The spread of rural environments has thus created extensive new habitat for these species. This project will rigorously test hypotheses about the role of human landscape modification in shaping the evolutionary history of Oceanic swallows over the last 10,000 years. This novel approach is broadly applicable to other species and will shed new light on how species respond and adapt to human environments. The project is based at a Hispanic-Serving Institution, and will involve extensive research experiences for undergraduate students. It also includes the development of a hands-on, high school- level teaching module on urban evolution.
This project will leverage extensive new geographic sampling, museum specimens, large geospatial datasets, and cutting-edge genomic approaches to examine how swallows have adapted to living in close proximity to humans (human commensalism). As different Oceanic swallow lineages have been commensal for different lengths of time, it is possible to examine the origins and spread of commensalism across multiple temporal scales and within a comparative framework comprised of two commensal and two non-commensal lineages. One lineage of each type has had an extended association with humans, and the others have had more recent association. This project will 1) use species distribution modeling to assess the relative roles of climate variation and post-Neolithic human landscape modification in shaping demographic history, particularly range expansions and population divergence; 2) use high-resolution whole-genome sequence data to determine whether commensal behavior arose via phenotypic plasticity, evolved independently among lineages, or spread via introgression from a single origin; and 3) evaluate evidence for contemporary human-mediated hybridization and erosion of reproductive barriers between previously allopatric groups.
This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
