Understanding the role of eco-evolutionary feedbacks in host-parasite coevolution

Area of Science:

• Ecology
• Evolutionary Biology
• Theoretical Biology

Background:

• Eco-evolutionary feedbacks are crucial for understanding evolution but often omitted in host-parasite coevolution models for simplicity.
• Constant population size assumptions in models may limit the understanding of evolutionary robustness when eco-evolutionary feedbacks are considered.

Purpose of the Study:

• To develop a simple method for assessing the qualitative impact of eco-evolutionary feedbacks on host-parasite coevolutionary outcomes.
• To determine if omitting eco-evolutionary feedbacks leads to qualitatively different evolutionary predictions.

Main Methods:

• Modified existing host-parasite coevolution models by allowing interspecific encounter probabilities to depend on population densities.
• Applied the framework to established genetic and quantitative trait models from the literature.
• Tested the direct effect of eco-evolutionary feedbacks on evolutionary dynamics without altering model structure.

Main Results:

• Eco-evolutionary feedbacks can qualitatively alter coevolutionary outcomes, contrary to predictions from models that omit them.
• The inclusion of eco-evolutionary feedbacks can shift dynamics between stable states (monomorphism/polymorphism) and cyclical patterns.
• The nature of evolutionary cycles can also be significantly changed by incorporating eco-evolutionary feedbacks.

Conclusions:

• Eco-evolutionary feedbacks are not just quantitative but can fundamentally change the qualitative nature of host-parasite coevolutionary outcomes.
• The developed method provides a straightforward approach to test the significance of eco-evolutionary feedbacks in various coevolution models.
• Future coevolutionary models should consider incorporating eco-evolutionary feedbacks to ensure accurate predictions of evolutionary trajectories.