Minimum Viable Population

minimum viable population (MVP), ecological threshold that specifies the smallest number of individuals in a species or population capable of persisting at a specific statistical probability level for a predetermined amount of time. Ecologists seek to understand how large populations must be in order to establish population-size benchmarks that help to keep species from going extinct. These benchmarks can vary according to species and according to measures set by the ecologist performing the study, but one that is commonly used in ecological investigations involves establishing greater than 95 percent probability of survival for more than 100 years. Since different species have different life spans, however, a time benchmark of 40 generations also may be used, especially when making comparisons between species.