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Published on: August 18, 2023
Self-optimization, community stability, and fluctuations in two individual-based models of biological coevolution
1School of Computational Science, Center for Materials Research and Technology, National High Magnetic Field Laboratory, and Department of Physics, Florida State University, Tallahassee, FL 32306-4120, USA. rikvold@scs.fsu.edu
Journal of Mathematical Biology
|May 31, 2007
Summary
This study compares two models of biological coevolution, finding that both self-optimize community potential. Mutualistic communities arise from positive interactions, while predator-prey models require external resources and show different species lifetime dynamics.
Area of Science:
- Theoretical Ecology
- Mathematical Biology
- Evolutionary Dynamics
Background:
- Biological communities exhibit complex dynamics driven by species interactions and evolution.
- Individual-based models (IBMs) offer a powerful framework for simulating these dynamics from the ground up.
- Understanding long-term evolutionary trajectories and community stability remains a key challenge.
Purpose of the Study:
- To compare and contrast the long-time dynamical properties of two distinct individual-based models of biological coevolution.
- To investigate how different interaction structures (mutualistic vs. predator-prey) influence community assembly and stability.
- To analyze emergent properties such as 1/f noise and power-law distributions in community and species lifetimes.
Main Methods:
- Exact linear stability analysis applied to both IBMs.
- Large-scale kinetic Monte Carlo simulations to validate analytical predictions.
- Examination of population size as a function of average interspecies interaction strength.
- Analysis of time series data for community diversity and population size.
Main Results:
- Both models demonstrate self-optimization towards maximizing a community potential function via mutation and selection.
- Randomly distributed positive interactions lead to self-sustaining mutualistic communities.
- Antisymmetric interactions in predator-prey models necessitate external resources for sustained populations.
- Approximate 1/f noise and power-law distributions observed in community and species lifetimes for both models.
Conclusions:
- The exponent of lifetime distributions differs between mutualistic and predator-prey models, suggesting varying resilience to mass extinctions.
- Predator-prey models, forming food-web-like communities, may exhibit greater resilience.
- These findings highlight the crucial role of interaction structure in shaping coevolutionary dynamics and community stability.
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