Jonny Wilkinson (for those of you among you who don't know who he is, he's a national hero pointscoring rugby uber-man) went to my college, and so whenever we get the old "try hard" assembly, we always here how Jonny's brother Mark was far more talented, but didn't want it as hard as Jonny. As a result, Jonny trained and trained and trained until he was better that big bro. I don't know how much is true, but its the story that is always peddled.
Talent is genetic. Many (including me) believe genetics determine the peak you could reach, however, they don't mean you are there to begin with (although you may have a head start). One then has to work to achieve one's potential, however, you can never conquer you genetic deficiencies. You can only be as good at something as your genes let you.