There are more and more races as time goes on

These genes are the gene pool.The 20 different genes are like cards in a deck that keep getting reshuffled with each new generation. Sex is simply a reshuffling
of the genetic deck. The cards are reshuffled and passed to the next generation; the deck remains the same, 50 percent red. The genes are reshuffled and passed to the next generation; the gene pool remains the same, 50 percent red. Even though the population may grow in size over time, he frequency should stay at about 50 percent.