Do Evolutionists believe sea men could be real?

According to evolutionists, several kinds of mammals have adapted to living in an aquatic environment. They claim that sea otters, pinnipeds, and the deer-like water chevrotain are examples of this. Obviously, evolutionists believe men might decide to evolve and become semi-aquatic and then we would have sea men! I hope this never happens because I'd be afraid to go swimming if there was a lot of sea men floating around in the water.