One of the most important open problems in ecosystem modeling is explaining the origin of biodiversity in competitive ecosystems: these are most commonly described mathematically using MacArthur's consumer-resource model, leading to the ‘‘competitive exclusion principle’’ which limits the number of coexisting competing species to the number of available resources. Nevertheless, several empirical evidences - like the ‘‘paradox of the plankton’’, but also bacterial community culture experiments - show that this principle is violated in real ecosystems. Another experimental evidence that cannot be explained in this framework is the existence of diauxic (or polyauxic) shifts in microbial growth curves: bacteria consume resources sequentially, using first the one that ensures the highest growth rate and then, after a lag phase, they start growing using the second one. By introducing adaptive metabolic strategies whose dynamics tends to maximize species' relative fitness, we are able to explain both these empirical evidences, thus setting the paradigm for adaptive consumer-resource models.
