Today Gregor Mendel is a towering hero of biology, and yet during his own lifetime his ideas about heredity were greeted with deafening silence. In hindsight, it’s easy to blame his obscurity on his peers, and to say that they were simply unable to grasp his discoveries. But that’s not entirely true. Mendel got his ideas about heredity by experimenting on pea plants. If he crossed a plant with wrinkled peas with one with smooth peas, for example, the next generation produced only smooth peas. But when Mendel bred the hybrids, some of the following generation produced wrinkled peas again. Mendel argued that each parent must pass down factors to its offspring which didn’t merge with the factors from the