Humans have always needed to eat, but the ways in which we satisfy our nutritional needs are subject to change.  I doubt that the pace of change in food has ever been swifter than in our lifetimes, due to the striking internationalization of our diets and to the industrialization of the restaurant industry via the proliferation of fast food outlets. I grew up in an era where tacos were exotic, Thai food unheard of, and the concept of a fusion Korean/Mexican fusion taco truck unthinkable.

Cows are the domesticated form of a now-extinct critter called the "aurochs," from which we derive the term "ox." The aurochs was larger and more aggressive than the present-day cow, with large, lyre-shaped horns on both males and females.  With a huge, shaggy mane covering its enormous shoulders, it was an impressive beast. The aurochs' naturally ranged throughout Eurasia and south into the Near East. It was killed off by humans - through hunting, loss of habitat, and, ironically, the disease that spread from domesticated herds. The last aurochs died in the 1600's.

By 8,000 years ago, humans in the Near East, or "Fertile Crescent" as it became known, had developed fields of high quality wheat and allied grains. They had domesticated sheep and goats, which were a good source of milk, meat, leather and muscle power. The aurochs were probably attracted to the grain fields, and humans started to see them as potentially better sources of milk, meat, leather and muscle power than sheep and goats.  They were probably captured and the most aggressive animals were quickly killed and eaten. The more docile individuals were allowed to breed. Their offspring were even more docile and the process of domestication began.