16.1 Early Theories of Inheritance

Thousands of years before Mendel, many societies carried out practical plant and animal breeding. The ancient practices were based on experience rather than on a full understanding of the rules of genetic transmission, but they were nevertheless highly successful. In Mesoamerica, for example, Native Americans chose corn (maize) plants for cultivation that had the biggest ears and softest kernels. Over many generations, their cultivated corn came to have less and less physical resemblance to its wild ancestral species. Similarly, people in the Eurasian steppes selected their horses for a docile temperament suitable for riding or for hitching to carts or sleds. Practical breeding of this kind provided the crops and livestock from which most of our modern domesticated animals and plants derive.