Final answer:
The evolution of snake venom was a result of both gene recruitment and natural selection, leading to the diversity of venomous capabilities in snakes.
Step-by-step explanation:
The evolution of snake venom involved both gene recruitment (the co-option of genes from other functions to develop new ones) and natural selection (the differential survival and reproduction of individuals due to differences in phenotype). Gene recruitment allowed for the development of the venom's complex mixtures of proteins and peptides, while natural selection favored those snakes whose venom gave them an advantage in subduing prey, defending against predators, or competing for mates. Over time, these processes resulted in the diverse array of venomous capabilities observed in snakes today.