A few decades back, someone apparently came up with the idea of man as the “aquatic ape”
as a means of explaining why we have subcutaneous fat and little body hair, looking so different from our closest relatives, the gorilla and chimpanzee. I thought that was a brilliant idea. That would explain a lot and is eminently feasible, that man’s adaptation to water was interrupted, but man still carries vestiges of that era. Certainly we’re not still hanging around the African ‘hood’, and there’s no shortage of water in the Great Rift Valley, for that matter, if the adaptation occurred early in man’s evolution. There’s no shortage of precedent from other sea mammals, whose closest relatives tend to be their land-based relatives, not each other. It’s a good career move. Life in water is relatively easy. Hell, I’ve thought about it myself. There’s only one problem. There’s no evidence that any such activities ever took place. Logic is cheap; evidence is expensive. Furthermore, there is another explanation that has a better record in the history of evolution: neoteny, the retention of juvenile or even larval characteristics into older age, and sexual maturity at an early age. Lose the hair and gain the fat; sound like anybody you know? Our close relative, gorillas give birth at a similar term and have a life expectancy in captivity similar to an African’s life expectancy, yet reaches sexual maturity at seven years. Why? It works. They’re lousy at math anyway. That would explain baby fat and adult diaper rash in humans. It might also explain some extremely juvenile behavior in adults, but that would be cultural neoteny, I suppose. It sounds better than cultural pedomorphism, at least.