NBA and MLB: Why is the majority minority?

In case you fine people havent noticed, the majority of the NBA and the MLB is minorities. Why is this? would this ever change in the future? Studies showed that During the olden days, It was not like this. The majority for both the MLB and NBA were all white people. How did this change all of a sudden? Back in the olden days, minorities were not allowed to play these sports or any sports I dont think (I am going to research on that and get back to you). Some key events led to minorities being able to play these sports. For example, for te MLB, a man named Jackie Robinson was one of the first minorities ever to play in the baseball league. He also broke a few records of his own, so its not like he was a "nobody". Events like this made minority races eligible to play in these sports. As of today, Minorities basically took over the NBA and the MLB. If you would ask me would this change again, I really dont know but I honestly doubt it. The reason is because the younger stars that would want to be in the "big leagues" are minorities also, so I dont think it would be changing anytime soon. Im not complaining anyways. Their skills and dedication really makes us enjoy the sport even more!