I study gene flow and rapid evolution in natural populations by integrating data on animal behavior, mating signals and genetics.
Mating signals and the complex behaviors that animals use to locate and choose mates greatly influence reproduction and patterns of genetic exchange between populations and species. By combining data on the social interactions of groups of organisms, genomic data, and network analyses, my research examines the causes and consequences of gene flow and selection in the wild.
Rapid evolution of song & wings in Pacific field crickets
The Pacific field cricket (Teleogryllus oceanicus) island-hopped across the Pacific aboard the outriggers of human Polynesian settlers. In Hawaiian populations, the crickets now encounter an introduced parasitoid fly (Ormia ochracea) that eavesdrops on the male crickets' song, depositing their larvae that subsequently consume the cricket host from the inside out. The cricket's song is therefore exposed to opposing natural and sexual selection; the males must sing to attract mates, but in doing so expose themselves to a fatal parasite. In response to these complex selective pressures, several novel cricket morphs have arisen on the Hawaiian islands in just the last 20 years.
By combining laboratory-based social network trials, field-based mesocosm studies, and whole genome sequencing of different cricket morphs, my research aims to quantify the relative selective pressures exerted by conspecifics and eavesdropping natural enemies.
Assortative behavior & reproductive isolation in a quail hybrid zone
Behavior can strongly influence the degree of hybridization and gene flow between animal populations. For my dissertation, I used social network analyses to test the influence of phenotypic and genotypic differences on both social structure and mating outcomes in a hybrid zone between the California and Gambel’s quail.
By integrating detailed data on behavioral associations (captured via RFID tags), phenotype (plumage and body size), and genetics (captured via ddRAD sequencing) in an area of sympatry, I showed the complex ways that traits and behavior structure the social environment and genetic exchange between these closely related species.
Genomics of hybridization across an abrupt ecological transition
The California and Gambel's quail differ in their ecological niches: Gambel's quail occupy arid ecosystems of the Sonoran and Mojave Deserts, while California quail are found in the semi-arid scrub and chaparral habitats of the Baja Peninsula, California, and the Pacific Northwest. Using the same ddRAD genomic data used to assess paternity and ancestry within populations (see above), I am analyzing how genomic regions and specific loci transition across the stark ecological transition seen within the hybrid zone. Are there signatures of selection or local adaptation on loci across the hybrid zone? Could introgression be involved in the observed movement of California quail into the historical range of Gambel's quail?
Other projects & collaborations
In addition to work in the California/Gambel's quail hybrid zone, I have also worked on:
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Synthesis of empirical and theoretical data on assortative mating in animals
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Network analysis of the social behavior of reintroduced populations of endangered California Condors
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Review and framework for studying social feedback on animal signaling traits
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Geolocator study of migratory behavior between two barn swallow subspecies in Western China
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Methods development of proximity logging tags for high-resolution interaction data in small birds