My Master's thesis is all about life-history strategies. r/K theory has fallen somewhat out of favor in the last 30 or so years. The first reason is that a general trend in ecology has been away from basic natural history, and more focused on gl... read more
I would say the r/K selection theory is pretty commonly used in ecology. It provides a simple explanation for the majority of life strategies used by animals so it is easily applied to practical work with animals. As far as I know, it is only really used by animal ecologists. The CSR triangle mentioned by Gideon is typically only used in plant ecology. read more
Although r/K selection theory became widely used during the 1970s, it also began to attract more critical attention. In particular, a review by the ecologist Stephen C. Stearns drew attention to gaps in the theory, and to ambiguities in the interpretation of empirical data for testing it. read more