<P> In ecology, r / K selection theory relates to the selection of combinations of traits in an organism that trade off between quantity and quality of offspring . The focus upon either increased quantity of offspring at the expense of individual parental investment of r - strategists, or reduced quantity of offspring with a corresponding increased parental investment of K - strategists, varies widely, seemingly to promote success in particular environments . </P> <P> The terminology of r / K - selection was coined by the ecologists Robert MacArthur and E.O. Wilson in 1970 based on their work on island biogeography; although the concept of the evolution of life history strategies has a longer history (see e.g. plant strategies). </P>

What is the difference between r and k species