The genomics of adaptation in evolutionary radiations


Understanding how species originate and evolve, i.e., why organisms fall into discrete groups generating biodiversity, is a central issue in Evolutionary Biology with still important unsolved questions. This project focuses on species radiations, which have been long recognized as natural replicate experiments of evolution that provide outstanding case studies for assessing the genomic features underlying rapid evolutionary diversification.  The ultimate objective is to delve deeper into the genomic basis of evolutionary radiations. With more than 900 described species, cone snails (Gastropoda: Conidae) are a paradigm of a natural group, which has evolved and diversified through radiation events. They are marine predators that feed mainly on worms, but also on mollusks or on fish. Cone predatory capacity relies on the production of a complex venom formed by a cocktail of hundreds of different peptides called conotoxins. While the great diversity of conotoxins in the cocktails (they vary greatly even among individuals within the same species) seems to be essential for subduing a specific type of prey, little is known on how this diversity is generated and maintained, or even how was it changed during diet shifts. Venom gland transcriptomics is a powerful approach to catalogue the different venom repertoires but the number of catalogued cocktails for comparative studies is still at its minimum compared to the rich species diversity of cones. In addition, the sequencing, assembly, and annotation of a chromosome-level reference genome for the group is mandatory to understand not only the evolutionary processes involved in producing conotoxin diversity but also those responsible for the outstanding diversification rates of the group.  Here, we propose (1) sequencing several genomes at the chromosome level; (2) adding new key genera to the Conidae phylogeny; (3) cataloguing new venom gland transcriptomes from Indo-Pacific cones; (4) performing a low-coverage population genomic comparison on a cone species (with several distinct morphs) endemic to Cabo Verde.