DISSERTATION RESEARCH: Evolvability and diversification: testing macroevolutionary predictions in cone snails.

点击翻译按钮获取中文摘要

Understanding why some groups of organisms are more diverse than others is a central goal in evolutionary biology. Evolvability, or the intrinsic capacity of a lineage for evolutionary change, is thought to influence disparities in diversity across the tree of life. Over long evolutionary time scales, groups of organisms that have higher evolvability should (a) have higher species richness and (b) display greater morphological diversity. Carnivorous species within the cone snail genus Conus offer a unique opportunity to test the hypothesis of evolvability because they use prey-specific venom to capture prey and exhibit extensive diversity in radular morphology. Using the diversity of venom genes and differences in radular morphology, this research will document how evolvability may shape biodiversity in the genus. One graduate student will be trained and results from the research will be broadly disseminated through the 'Exploring Your Universe' public science event at UCLA. International research infrastructure with the Republic of Indonesia will also be enhanced through collaboration with the Indonesian Biodiversity Research Center in Bali. In addition, data generated from this research project will also lead to the rapid discovery of novel venom proteins, greatly increasing the number of these natural products that could be developed for the treatment of chronic pain, epilepsy and other neurological diseases. Venom diversity in cone snails is extensive, with much of this diversity having arisen through gene duplication. Theory predicts that higher gene diversity confers a greater potential to generate novel traits for specialization and adaptation. Therefore, if venom gene diversity in Conus gives rise to varying levels of evolvability, then evolvability will be positively correlated with (a) speciation rates, (b) structural diversity of venom proteins, and (c) evolutionary rates of radular morphology. Researchers will use next-generation sequencing to generate data that will be used to reconstruct a molecular phylogeny of Conus, in addition to species-level data on venom gene diversity within the lineage. The researchers will also quantify radular morphology using images generated from scanning electron microscopy. With these data, the researchers will use comparative phylogenetic methods to test the influence of evolvability on long-term diversification within cone snails.