| Mendel proposed and proved the dominant / recessive gene business. People knew before him that fast horses bred fast foals, smart dogs bred smart puppies and that a black person who married a white one would have children the color of coffee with a lot of cream in it, but no one was sure why.
He codified the 'rules' he observed. Some genes, like eye color, have dominant / recessive traits. Some, like skin color in humans, do not.
I don't think anyone preceeded him. I'm not an expert; you could ask again in Biology. |