Evolution of realized niche breadth diversity driven by community dynamics.

Area of Science:

• Evolutionary biology
• Ecological modeling
• Population dynamics

Background:

• Herbivorous insects often specialize on host plants, even when those plants aren't optimal for larval growth.
• The evolutionary drivers of this host plant specialization remain a significant question in biology.

Purpose of the Study:

• To develop a novel model explaining host plant preference evolution in herbivorous insects.
• To integrate evolutionary frameworks with modern coexistence theory, considering demographic dynamics.

Main Methods:

• A mathematical model was developed to simulate host plant preference evolution for two insect species.
• The model incorporated negative and positive frequency-dependent community dynamics.
• Eco-evolutionary equilibria were analyzed.

Main Results:

• Insect species can evolve into specialists and generalists under combined negative and positive frequency dependence.
• Multiple eco-evolutionary equilibria (up to nine) were identified.
• Positive frequency dependence allows specialization even in suboptimal habitats, decoupling preference from performance.

Conclusions:

• The model explains counterintuitive empirical observations in insect-plant interactions.
• It provides mechanistic insights into niche breadth evolution.
• Evolved habitat preferences are influenced by community dynamics, not solely by resource quality.