hybrid (hĪˈbrĭd) [key], term applied by plant and animal breeders to the offspring of a cross between two different subspecies or species, and by geneticists to the offspring of parents differing in any genetic characteristic (see genetics). The mule, the hybrid steer, and hybrid corn are examples of hybrids produced by breeders, but some animal species may cross-breed in the wild, as the gray wolf and coyote sometimes do. Hybridization between cultivars or varieties is often used in agriculture to obtain greater vigor or growth (heterosis). Hybrid vigor is achieved by crossing two inbred strains (see breeding). The first generation shows greatly increased vigor and a better yield primarily because many genes for recessive, often deleterious, traits from one parent are masked by corresponding dominant genes in the other parent.