A mix of dissimilar resources will tend to support specialists, whereas a mix of similar resources will favor generalists or specialists. Why? 

 

A mix of dissimilar resources will tend to support specialists, whereas a mix of similar resources will favor generalists or specialists. Why

Generalist consumers commonly coexist in many ecosystems. Yet, eco-evolutionary theory poses a problem with this observation: generalist consumers (usually) cannot coexist stably. consumers can ecologically coexist through tradeoffs in resource encounter rates; however, this coexistence is evolutionary unstable. Thus we find that nutritional interactions between resources and the shape of acquisition tradeoffs produce very similar evolutionary outcomes in isolation. Specifically, they produce evolutionarily stable communities composed either of two specialists (concave acquisition tradeoff or antagonistic nutrition) or a single generalist (convex acquisition tradeoff or complementary nutrition). Thus, the generalist coexistence problem remains. the combination of nonlinear resource acquisition tradeoffs with nonlinear resource nutritional relationships creates selection forces that can push and pull against each other.

Ecological specialization has been suggested as a major constraint impeding the response of species to environmental changes

natural selection creates an important problem for this resource-based, ecological explanation for coexistence of generalists.