 Selective breeding. Selective breeding also called artificial selection is the process by which humans use animal breeding and plant breeding to selectively develop particular phenotypic traits characteristics by choosing which typically animal or plant males and females will sexually reproduce and have offspring together. Domesticated animals aren't known as breeds, normally bred by a professional breeder, while domesticated plants aren't known as varieties, cultichens or cultivars. To purebred animals of different breeds produce a crossbreed, and crossbred plants are called hybrids. Flowers, vegetables and fruit trees may be bred by amateurs and commercial or non-commercial professionals. Major crops are usually the provenance of the professionals. In animal breeding, techniques such as in breeding, blind breeding and out crossing are utilized. In plant breeding, similar methods are used. Charles Darwin discussed how selective breeding had been successful in producing change over time in his 1859 book, On the Origin of Species. Its first chapter discusses selective breeding and domestication of such animals as pigeons, cats, cattle and dogs. Darwin used artificial selection as a springboard to introduce and support the theory of natural selection. The deliberate exploitation of selective breeding to produce desired results has become very common in agriculture and experimental biology. Selective breeding can be unintentional, e.g., resulting from the process of human cultivation, and it may also produce unintended, desirable or undesirable results. For example, in some grains, an increase in seed size may have resulted from certain plowing practices rather than from the intentional selection of larger seeds. Most likely, there has been an interdependence between natural and artificial factors that have resulted in plant domestication.