Islands, Isolation, and Genomes: The Evolutionary History of the Galápagos Endemic Lava Gull (Leucophaeus fuliginosus)
Jessica Martin
Department of Biology
Faculty Supervisor: Jaime Chaves
The Galápagos Islands, located 1,000 kilometers off the coast of Ecuador, are renowned for their endemic species, which evolved through founder events, geographic isolation, and the availability of novel ecological niches. One endemic species, the lava gull (Leucophaeus fuliginosus), is the rarest gull species in the world, with an estimated population of only 300 to 600 individuals. Although lava gulls are opportunistic scavengers and predators often drawn to urban areas by human food and waste, their proximity to these environments increases their vulnerability to anthropogenic disturbance. Despite conservation concerns, little genetic research has been conducted on this solitary and sparsely distributed species, limiting our understanding of its population structure, evolutionary history, and conservation status. We assembled a high-quality reference genome from a blood sample from an adult female lava gull sequenced using nanopore technology. We also generated low-coverage whole-genome sequences from 32 individuals across four islands to estimate effective population size, assess population subdivision, and evaluate levels of inbreeding. Preliminary results suggest a historically small effective population size and variable gene flow among islands. High-resolution genomic analyses provide insight into the evolutionary history and conservation status of this imperiled species and offer guidance for management and protection efforts.