[Dimensio]

Why would a successful fish crawl up onto land? Why would a successful monkey leave the trees that make up his home?

Alterations in an environment can make traits that previously inhibited survival into essential functions of the organism.

[ShadowAce]

Alterations in an environment can make traits that previously inhibited survival into essential functions of the organism.

Those same alterations would kill any who did not evolve, then. But we still have fish, and monkeys still live in trees.