I've never cared much for the theory; it feels too post hoc, and too much like retrofitting human anatomy to a hypothetical lifestyle rather than observing the way people actually live. Besides, if it were true, I'd expect us to be much more water-adapted than we are. My questions are:

1.) why don't we have webbed fingers and toes?
2.) Why aren't our legs extra long for more kick through the water?
3.) Why are we only mediocre at holding our breath?
4.) Why don't we have polarizing membranes across our corneas (like some shore birds) that can allow us to see through water reflections?
5.) For that matter, why are our eyes useless underwater?

I could go on.

__________________
"I must find if I too if I possess this special skill. Remember, do not stop until I give you the signal or dramatically throw you to the ground and request a towel."

--Kung Pow!