Consider one of the standard "laments" or "stories of wonder" in conventional tales of natural history: the mayfly that lives but a single day (a sadness even recorded in the technical name for this biological group - ). Yes, the adult fly may enjoy only a moment in the sun, but we should honor the entire life cycle and recognize that the larvae, or juvenile stages, live and develop for months. Larvae are not mere preparations for a brief adulthood. We might better read the entire life cycle as a division of labor, with larvae as feeding and growing stages, and the adult as a short-lived reproductive machine. In this sense, we could well view the adult fly's day as the larva's clever and transient device for making a new generation of truly fundamental feeders.
Stephen Jay Gould