Life Histories and Natural Selection

Free Response

Why is long-term parental care not associated with having many offspring during a reproductive episode?


Parental care is not feasible for organisms having many offspring because they do not have the energy available to take care of offspring. Most of their energy budget is used in the formation of seeds or offspring, so there is little left for parental care. Also, the sheer number of offspring would make individual parental care impossible.

Describe the difference in evolutionary pressures experienced by an animal that begins reproducing early and an animal that reproduces late in its lifecycle.


A species that reproduces early in its life cycle is under evolutionary pressure to reach sexual maturity as soon as possible. Animals that mature earliest will be able to reproduce the most times, and therefore more of the next generation will carry their early maturation genes.

A species that reproduces late in its life cycle will only generate offspring from parents that were able to survive in their habitats. This increases the likelihood that the next generation will be well-adapted to its environment.