there is a woman anthropologist, I believe from England or Wales, who had a popular book out about 20 years ago with the theory that humans actually evolved from aquatic mammals, not from apes, that we actually have more in common with other large mammals which are, or were, at one time, aquatic, hippos, elephants, whales, manatees etc. even the pig. I guess the theory is when the glaciers melted after one of the ice ages and oceans covered a large part of the earth, we and all these other mammals were aquatic, spending most of the time swimming but coming on shore to mate and give birth, like seals. I don’t recall if she said we had gills, like that Kevin Costner movie Waterworld. So evolving in this direction would actually be moving backward.