The Great Mental Models, Volume 2: Physics, Chemistry and Biology

by Shane Parrish

The competitive exclusion principle, also known as Gause’s Law, states that perfect competition between two species requiring the same resources to survive in the same niche is impossible. Georgii Frantsevich Gause first identified the principle in 1934 when he found that two species of bacteria requiring the same resources could not coexist in a petri dish. One species will find its own niche by becoming increasingly specialized to require different resources from the other. This is known as resource partitioning. If it doesn’t, the second species’ slight advantages will become significant enough to wipe out the first. For instance, if there are two carnivores in the same area that hunt the same prey animals, one species will always have some meaningful advantage, like greater speed or camouflage. This will enable it to outpace its competitor, which will have to find another food source or face extinction.