Peter Chesson classified mechanisms for creating this situation as either dependent or independent of spatial variation, with the storage effect exemplifying a dependent mechanism. David Tilman postulated that this situation can occur if each participant has a locally minimum value for a quantity denoted R-star. This situation is represented on a phase plane by a stable equilibrium point that is the intersection of two zero-growth isoclines. The unusually large number of different (*) phytoplankton species that are in this situation together is called the “paradox of the plankton.” According to Gregory Gause's law of competitive exclusion, (-5[1])this situation cannot occur for two species competing for the same niche. For 10 points, (10[1])name this situation in which multiple species survive in the same environment. ■END■ (10[2])