Tradeoffs

"Natural selection favours those individuals who most abundantly transmit copies of their genes to future generations. This task demands appropriate allocation of limited resources between the conflicting requirements of reproduction and survival, in an environment which is at best capricious and at worst predictably hostile. The result of this allocation is the life history, which is defined by a schedule of fecundity and survival that may show changes with age, environment, individual condition, and social setting. Depending on the time-scale of environmental change, adaptive adjustments of life history may be behavioural, physiological, developmental, or genetic."

-- Horn and Rubenstein 1984, p. 279

A Case Study Example:

Ache Women