Flowers changed everything. The angiosperms, as botanists call the plants that form flowers and then encase seeds, appeared during the Cretaceous period and they spread over the earth with stunning rapidity. Now, instead of relying on wind or water to move genes around, a plant could enlist the help of an animal by striking a grand co-evolutionary compact: nutrition in exchange for transportation. By producing sugars and proteins to entice animals to disperse their seed, the angiosperms multiplied the world’s supply of food energy, making possible the rise of large warm-blooded mammals.
Without flowers, the reptiles, which had prospered in a leafy, fruitless world, would probably still rule. Without flowers, we would not be.
– Michael Pollan