 This led to an artificial selection process, producing ever-prettier (to humans) flowers.This is thought to have occurred for the entire history of agriculture, perhaps even slightly earlier, when people tended to favor naturally occurring food-gathering spots.This may also explain why many flowers function as companion plants to more useful agricultural plants; they had evolved that symbiotic relationship with the food plants before either was domesticated, and therefore was found in the same area, convenient to be selected as an attractive plant.