Evolution and the Emergent Self

Evolution and the Emergent Self: The Rise of Complexity

 and Behavioral Versatility in Nature 

http://en.wikipedia.org/wiki/R/K_selection_theory

In this context, r-selection makes a species prone to numerous reproduction at low cost per an individual offspring, while K-selected species expend high cost in reproduction for a low number of more difficult to produce offspring. Neither mode of propagation is intrinsically superior, and in fact they can coexist in the same habitat, as in rodents and elephants.