what precisely are we trying to understand? Biological reproduction probabilities?
seems the world has too many people already, and, if anything, we should be teaching people that the survival of the fittest is more about the brain than the penis. Just sayin....
Okay... I think I see where you are coming from now. Larger penises may not have just been useful in wooing a mate, but might have also played a role in general survival, such as fighting off lions in the event spears became scarce.