Of all the foods that we obtain from animals and plants, meat has always been the most highly prized. The sources of that prestige lie deep in human nature. Our primate ancestors lived almost exclusively on plant foods until 2 million years ago, when the changing African climate and diminishing vegetation led them to scavenge animal carcasses. Animal flesh and fatty bone marrow are more concentrated sources of food energy and tissue-building protein than nearly any plant food. They helped feed the physical enlargement of the brain that marked the evolution of early hominids into humans. Later, meat was the food that made it possible for humans to migrate from Africa and thrive in cold regions of Europe and Asia, where plant foods were seasonally scarce or even absent. Humans became active hunters around 100,000 years ago, and it’s vividly clear from cave paintings of wild cattle and horses that they saw their prey as embodiments of strength and vitality. These same qualities came to be attributed to meat as well, and a successful hunt has long been the occasion for pride, gratitude, and celebratory feasting. Though we no longer depend on the hunt for meat, or on meat for survival, animal flesh remains the centerpiece of meals throughout much of the world.