All of evolution is survival driven. Traits that do not advance survival are doomed to extinction. The major advantage of human intelligence was the ability to economize efforts. Chasing a herd of bison off a cliff was far more efficient [not to mention safer] than singling out one to pelt with sticks and stones. Erecting a portable shelter was more expedient than competing for local cave space. This is the evolutionary advantage of intelligence - recognizing ways to increase the pay value of survival related tasks. It is an adaptable approach.