Figure 6.

Conceptual Model of the Role of Critical Age Classes in Mouth-Form Phenotypic Plasticity

Conceptual life cycle models of monomorphic or dimorphic mouth-form nematodes. In an isolated niche such as a decaying insect carcass, at some point microbial food supplies will run out, leading to a Malthusian catastrophe. Nematodes escape this trap by entering the dauer state and dispersing, and re-starting the cycle. Dimorphic nematodes may sense the impending “catastrophe” earlier by recognizing an abundance of adults in the population, and switching to the Eu morph to exploit new resources and kill competitors. By analogy to economic models, the mouth-form switch is a technological innovation to temporarily escape a Malthusian resource trap.