The causes and consequences of venom evolution in cone snails (Family, Conidae)
The ability to produce venom has evolved multiple times throughout the animal kingdom and consist of complex mixtures of toxic proteins. The causes and consequences of venom evolution frequently remain unclear, potentially due to the difficulty of obtaining comprehensive data on venom composition across multiple species. Here, I present an in-depth analysis of the factors governing venom evolution, and the impact of venom evolution on speciation rates. Chapter 1 focuses on the impact of diet on venom evolution. Using RNAseq data to characterize the venom cocktails of 12 Conidae species, I recovered a positive correlation between venom complexity and dietary breadth, suggesting that species with more generalist diets express a greater number of venom proteins. Chapter 2 investigates the impact of genetics on venom evolution. Using a novel targeted sequencing approach, I describe how positive selection, gene duplication, and expression regulation all contribute to the diversification of venom. Finally, in Chapter 3, I investigate the impact of venom evolution on speciation rates. Using a targeted sequencing approach, I characterize the venom repertoire of over 300 cone snail species and find no relationship between venom evolution and speciation rates. My results suggest that venom is not the rate-limiting factor in determining speciation events and that other factors, such as ecological opportunity or traits regulating dispersal are more critical in governing diversification patterns.