Manphin, reading your post led me to consider an alternate, but similar, hypothesis:

Perhaps humans evolved from apes, as presumed, but evolution did not end there. Rather, dolphins evolved from humans! This would explain how humans have so many ape-like and dolphin-like traits, and many intermediate traits (quantity of body hair, brain size and structure, etc.).

The implication of all this is that dolphins are more evolutionarily advanced than humans, and Manphin, as the missing between human and cetacean, is a kind of superior human.