We’ll never know exactly why chickens were domesticated, but they may well have been valued more for their prolific egg production than for their meat. Some birds will lay only a set number of eggs at a time, no matter what happens to the eggs. Others, including the chicken, will lay until they accumulate a certain number in the nest. If an egg is taken by a predator, the hen will lay another to replace it—and may do so indefinitely. Over a lifetime, these “indeterminate layers” will produce many more eggs than the “determinate” layers. Wild Indian jungle fowl lay clutches of about twelve glossy, brown eggs a few times each year. In industrial production—the ecological equivalent of unlimited food resources combined with unrelenting predation—their domesticated cousins will lay an egg a day for a year or more.