"humans are 70% water, the sea was our habitat once,"
That's doesn't prove evolution no more than the fact that whales are also 70% water, instead of 100% water since their fish. The fact is we are all(meaning humans and animals) water-based beings who coincidently need water for survival. We and animals breathe oxygen, put a butterfly in a jar with no air holes it will die. This account for probably 90% of living things. The other 10% that does no need oxygen are bacteria, virus, but I think they made need it, too. lol