Ecological and biogeographic processes drive the proteome evolution of snake venom

The emergence of venom is an evolutionary innovation that favored the
diversification and survival of snakes. The composition of snake venoms is
known in detail from venom gland proteomic data. However, there is still a
gap of knowledge about the forces that lead to the expression of different
toxins in different proportions in the venom cocktail across space and
time. LOCATION World. TIME PERIOD Modern. MAJOR TAXA STUDIED Elapidae and
Viperidae. We integrated proteomic data with phylogenetic comparative
methods to understand how ecological and biogeographical processes drive
the evolution of snake venom. We observed that more productive
environments favor a more complex venom, which presents a higher diversity
and similarity on the toxin proportions in its composition. We found that
the taxa that live in islands, where there is lower variability of
resources, tended to present  less complex venom dominated by few
toxins. In this case, the island's isolation seems to be a relevant
element for a faster fixation of specific venom compositions. We show that
ecological and biogeographic processes, which can act differentially over
time and space, affect the gene expression of toxins in snake venoms.