Kiwi bird extreme example of parental investment single egg inside of the bird. Dispersal is the movement of organisms or propagules from their birthplace. Each bar shows the length of time that one species persisted in the fossil record. On average, species with nonplanktonic larvae persisted 2. 2 million years whereas species with planktonic larvae persisted 4. 4 millions years. Often organisms as they go through development end up in different environment with different pressures. If something can swallow you it will . Larger size a lot less predation on you early stages are more vulnerable then larger stages. Once the larvae have accuulated sufficient mass, they metamorphose into adult butterflies, moths and beetles whos main function is often to disperse find a mate and reproduce. Small disperse easily floating in current advantage in exploring new environments. Protection small stages grow extreme spines or structures that save them.