Parasite transmission among relatives halts Red Queen dynamics

Area of Science:

• Evolutionary Biology
• Ecology
• Genetics

Background:

• The Red Queen hypothesis suggests coevolving hosts and parasites create fluctuating selective environments, driving evolutionary dynamics.
• Empirical evidence for Red Queen dynamics, crucial for understanding sex evolution and genetic variation, remains limited.
• Existing models often assume random encounters between hosts and parasites.

Purpose of the Study:

• To investigate how familial parasite transmission affects coevolutionary dynamics.
• To determine if non-random encounters, specifically within family groups, disrupt Red Queen dynamics.

Main Methods:

• Developed a theoretical model incorporating familial parasite transmission.
• Analyzed the impact of related hosts encountering parasites from genetically similar individuals.

Main Results:

• Even slight degrees of familial parasite transmission are sufficient to halt coevolutionary fluctuations.
• Coevolutionary cycling is predicted to be less evident in systems with familial aggregation.
• Random host-parasite mixing is more likely to yield observable Red Queen dynamics.

Conclusions:

• Familial aggregation presents a significant challenge to the Red Queen hypothesis and related evolutionary theories.
• Future empirical studies should consider host-parasite contact patterns when seeking evidence for coevolutionary cycling.
• The findings necessitate a re-evaluation of assumptions in coevolutionary models.