Before revision:  In this Letter , we draw on recent theoretical progress in random matrix theory and statistical physics to fundamentally extend and reinterpret May's theorem. We confirm that a wide range of ecological models become unstable at the point predicted by May , even when the models do not strictly follow his assumptions.
After revision:  In this Letter , we draw on recent theoretical progress in random matrix theory and statistical physics to fundamentally extend and reinterpret May's approach to generalized consumer-resource models. We show that in diverse ecosystems adding even modest amounts of noise to consumer preferences results in a transition to "typicality" where macroscopic ecological properties of communities are indistinguishable from those of random ecosystems , even when the models do not strictly follow his assumptions.