Cyclic dominance

Definition

Cyclic dominance refers to a situation in a game where three or more strategies can each defeat one another in a circular manner, creating a non-transitive relationship among them. This concept is essential in understanding the dynamics of evolutionary stable strategies, as it illustrates how different strategies can coexist and influence population behavior over time. In biological contexts, cyclic dominance helps explain how certain traits or behaviors can persist within populations despite competitive pressures.

5 Must Know Facts For Your Next Test

1. Cyclic dominance creates a balance of strategies in populations, allowing for diversity and adaptability in changing environments.
2. This phenomenon can be observed in various biological systems, including species interactions like predator-prey dynamics and mating behaviors.
3. Cyclic dominance often leads to fluctuating population sizes, as each strategy periodically gains an advantage over others.
4. In evolutionary game theory, cyclic dominance serves as a foundation for understanding how multiple traits can coexist without one completely overtaking the others.
5. Real-world examples include certain species of fish that exhibit traits that are beneficial against some competitors but less effective against others, creating a dynamic equilibrium.

Review Questions

• How does cyclic dominance contribute to the stability of multiple strategies within a population?
  • Cyclic dominance contributes to stability by allowing different strategies to periodically gain an advantage over one another. This creates a balance where no single strategy can completely dominate the others, leading to coexistence within the population. As a result, diverse traits are maintained over time, which can enhance the overall adaptability of the population to environmental changes.
• Discuss the implications of cyclic dominance in predator-prey relationships and its effects on population dynamics.
  • In predator-prey relationships, cyclic dominance illustrates how various strategies employed by predators and prey can create a dynamic equilibrium. For instance, if certain prey species develop defenses against specific predators, these predators may then shift their hunting strategies to target other prey. This back-and-forth interaction leads to fluctuations in population sizes and contributes to the resilience of ecosystems by promoting diversity in traits and behaviors.
• Evaluate how cyclic dominance can influence the evolutionary trajectory of species over time and its relevance in ecological research.
  • Cyclic dominance influences evolutionary trajectories by fostering genetic diversity among populations. As different strategies succeed at different times due to their cyclic interactions, it encourages the persistence of various traits rather than leading to uniformity. This concept is crucial in ecological research as it helps scientists understand the mechanisms driving biodiversity and how species adapt to changing environments through complex interactions.

Related terms

Evolutionary Stable Strategy (ESS): A strategy that, if adopted by a population, cannot be invaded by any alternative strategy that is initially rare, ensuring its persistence within the population.

Non-transitive Relationships: Relationships where the usual rule of transitivity does not hold, meaning if A beats B and B beats C, it does not necessarily follow that A beats C.

Rock-Paper-Scissors: A simple game illustrating cyclic dominance where rock crushes scissors, scissors cut paper, and paper covers rock, demonstrating how no single strategy is superior.