Diet-Related Molecular Evolution Differs between Vertivores, Invertivores, and Combined Carnivores
Mammals have repeatedly evolved specialized diets, including a variety of predatory diets targeting different prey animals. Prior research has found differences in positive selection, gene family evolution and gene functional loss linked with diet, but has focused primarily on trophic level classifications of herbivory, carnivory, and omnivory. Here we divide "carnivores" into vertivores and invertivores, due to the differences in nutrient composition of those food sources. We find significant differences in evolutionary conservation of multiple genes and GO categories between vertivores and invertivores. Conservation relative to herbivores differs among vertivores, invertivores, and the combination of all carnivores. Lineages with predatory diets have increased conservation in lipid and amino acid metabolism relative to herbivores. Notably, we find that results in the combined carnivore-herbivore comparison are much more similar to those of the invertivore-herbivore comparison than the vertivore-herbivore comparison, which suggests that prior studies on carnivory may have been detecting signatures of selection related to invertivory.