all beings and all desires rose up toward it Therefore at its rise and at its every return, shouts and hurrahs and all beings and all desires rise up toward it — Chandogya Upanishad, ca 800 BCE What makes an egg an egg? Of the two reproductive cells, it’s the larger, less mobile one It receives the sperm cell, accommodates the joining of the two gene sets, and then divides and differentiates into the embryonic organism It also provides food for at least the initial stages of this growth This is why eggs are so nutritious: Like milk and like plant seeds, they are actually designed to be foods, to support new creatures until they are able to fend for themselves Improving the Package The first animal eggs were released into the equable oceans, where their outer membrane could be simple and their food supply minimal Some 300 million years ago, the earliest fully landdwelling animals, the reptiles, developed a selfcontained egg with a leathery skin that slowed fatal water loss, and with enough food to support prolonged embryonic development into a fully formed animal The eggs of birds, animals that arose some 100 million years later, are a refined version of the primitive reptile egg Their hard, mineralized shell is impermeable enough that the embryo can develop in the driest habitats; and they contain an array of antimicrobial defenses These developments made the bird egg into an ideal human food It contains a sizeable and balanced portion of animal nutrients; and it’s so well packaged that it keeps for weeks with little or no care The Chicken, from Jungle to Barnyard Eggs, then, are nearly a billion years older than the oldest birds The genus Gallus, to ... develop in the driest habitats; and they contain an array of antimicrobial defenses These developments made the bird egg into an ideal human food It contains a sizeable and balanced portion of animal nutrients; and it’s...animals, the reptiles, developed a selfcontained egg with a leathery skin that slowed fatal water loss, and with enough food to support prolonged embryonic development into a fully formed animal The eggs of birds,... into a fully formed animal The eggs of birds, animals that arose some 100 million years later, are a refined version of the primitive reptile egg Their hard, mineralized shell is impermeable enough that the embryo can