Research Project
Full description Understanding how levels of genetic diversity levels are maintained in natural populations and their relationship to species abundance is central to many conservation problems. We address this question in ecologically important crown-of-thorns sea stars to advance our understanding about the determinants of genetic diversity in species undergoing extreme population size fluctuations or outbreaks. In this work, we report the first germline mutation rate estimate for a marine invertebrate using whole-genome sequencing of parent-offspring trios. Our results reveal that unexpectedly high mutational contributions and reduced effective population size (stronger genetic drift than predicted by abundance) shape genetic diversity in this species, despite outbreaking populations sizes exceeding 20-90 million individuals. Our results are consistent with theory on mutation rate evolution, whereby elevated mutation rates evolve in response to reduced effective population size or generation time length. Our findings highlight the potential importance of high mutation rates in maintaining extreme deleterious mutational loads observed in marine invertebrate taxa and moderate genetic diversity levels despite population declines. Such fundamental knowledge advances our understanding about the determinants of genetic diversity in large marine populations and is valuable for testing future hypotheses on mutation rates evolution across diverse animal phyla.