People have been eating the flesh of bovines since prehistoric times. Cattle were originally identified as three separate species: Bos taurus, the European or "taurine" cattle Bos indicus, the zebu; and the extinct Bos primigenius, the aurochs. The aurochs is ancestral to both zebu and taurine cattle. Recently, these three have increasingly been grouped as one species, with Bos primigenius taurus, Bos primigenius indicus and Bos primigenius primigenius as the subspecies (Cattle). People domesticated cattle around 8000 BC to provide ready access to beef, milk, and leather. Most cattle originated in the Old World, with the exception of bison hybrids. Examples include the WagyÅ« from Japan which refers to several breeds of cattle, the most desired of which is genetically predisposed to intense marbling and to producing a high percentage of oleaginous unsaturated fat. The meat from such wagyu cattle is known for its quality, and demands a high price. In several areas of Japan, wagyu beef is shipped carrying area names, (Wagyu ), Ankole-Watusi from Egypt also known as Ankole longhorn, is a breed of cattle originally native to Africa. Its large, distinctive horns, that can reach up to 8 feet (2.4 m) from tip to tip, are used for defense and cooling by blood vessel honeycombs, (Ankole-Watusi ), and longhorn Zebu from the Indian subcontinent sometimes known as humped cattle or Brahman cattle, are a type of domestic cattle originating in South Asia. They are characterised by a fatty hump on their shoulders, drooping ears and a large dewlap. They are well adapted to withstanding high temperatures, and are farmed throughout the tropical countries (Zebu). It is unknown exactly when people started cooking beef. Cattle were widely used across the Old World as draft animals (oxen), for milk, or specifically for meat. With mechanization of farming, some breeds were specifically bred to increase meat yield or to improve texture. Some breeds have been selected for both meat and milk production; these breeds have been given the name "Hybrid Breeds" (Beef). The idea of Natural Selection is not seemingly new to humans. Natural selection is one of the basic mechanisms of evolution, along with mutation, migration, and genetic drift. Charles Darwin came to understand that any population consists of individuals that are all slightly different from one another. Those individuals having a variation that gives them an advantage in staying alive long enough to successfully reproduce are the ones that pass on their traits more frequently to the next generation. Subsequently, their traits become more common and the population evolves. Darwin called this "descent with modification." The Galapagos finches provide an excellent example of this process. Among the birds that ended up in arid environments, the ones with beaks better suited for eating cactus got more food. As a result, they were in better condition to mate. Similarly, those with beak shapes that were better suited to getting nectar from flowers or eating hard seeds in other environments were at an advantage there. In a very real sense, nature selected the best-adapted varieties to survive and to reproduce. This process has come to be known as natural selection (Early). Charl