Not to do with tides, specifically, but the watery evolution of man. There is a theory that at some point water dwelling hominids branched off from other ape-id...which accounts for the fact that alone of the primates human babies naturally hold their breath under water, also for the layer of fat, like sea mammals, that humans have, unlike other primates. and our lack of body hair (babies didn't need it to grip on to mothers as they were swung thru the trees)...