We are the children of Sea-Monkeys

From the BBC:

The hypothesis proposes that the physical characteristics that distinguish us from our nearest cousin apes - standing and moving bipedally, being naked and sweaty, our swimming and diving abilities, fat babies, big brains and language - all of these and others are best explained as adaptations to a prolonged period of our evolutionary history being spent in and around the seashore and lake margins, not on the hot dry savannah or in the forest with the other apes.