What is r/K Selection Theory?
R/K selection theory is a popular ecological theory developed by Robert MacArthur and E. O. Wilson from their 1967 work on island biogeography. The term “r/K selection theory” is based after variables in an equation used by MacArthur and Wilson that relates the growth rate of various organisms to the carrying capacity of the environment. Although the theory was introduced in 1967, it didn’t catch on until the 1970s. Although some scientists have pointed out a few holes in the theory, it is still used casually and widely by biologists and zoologists. The key idea of r/K selection theory is that evolutionary pressures tend to drive animals in one of two directions — towards quickly reproducing animals whose specialty is to adopt as many niches as possible using simple strategies, and slowly reproducing animals who are strong competitors in crowded niches and invest substantially in their offspring. These are referred to respectively as r-selected and K-selected species, because the forme
