Breeding of strawberries variety "Old Black", which is of uncertain origin. This variety was created by pollination, not direct manipulation of the plant's genes. Molecular breeding is the application of molecular biology tools in a breeding program. Genetic engineering is typically defined as the introduction of non-native genes into an organism. An excellent example of transgenic modification is in the case of cold resistant strawberries. In one particular variety genes from the arctic flounder, a fish that lives in very cold water, were used to give plants resistance to cold. This modification works because of the genetics of the arctic flounder. It lives
Selective breeding in contrast to the notion of breed purity. However, on the other hand, indiscriminate breeding of crossbred or hybrid animals may also result in degradation of quality. Studies in evolutionary physiology, behavioral genetics, and other areas of organismal biology have also made use of deliberate selective breeding, though longer generation times and greater difficulty in breeding can make such projects challenging in vertebrates. Plant breeding has been used for thousands of years, and began with the domestication of wild plants into uniform and predictable agricultural cultigens. High-yielding varieties have been particularly important in agriculture. Selective plant breeding is also used