The Nested Sets Hypothesis posits that localities with less diversity will exhibit morphology that is "nested" within localities of higher diversity . The Periphery Addition Hypothesis asserts that as morphological diversity increases, additional species will be more likely (than random) to add to the periphery of a morphological space expressed by a lower diversity region . The Decrease of Variance Hypothesis, posits that as species richness increases, the variance within species will decrease (e.g. relatively less polymorphism) . The Lumpy Architecture Hypothesis posits that the discontinuous nature of terrestrial habitats should create discontinuous size distributions of animals .