Rapid prey evolution can alter the structure of predator-prey communities

Area of Science:

• Ecology
• Evolutionary Biology
• Microbial Ecology

Background:

• Microevolution's role in pairwise interactions is known, but its impact on complex communities is understudied.
• Predator-prey dynamics are crucial in structuring ecological communities.
• Understanding rapid evolution in microbial communities is key to ecological insights.

Purpose of the Study:

• To investigate how rapid evolution influences the structure of predator-prey communities.
• To examine the effects of microevolution in a multi-species microbial system.
• To assess the impact of prey evolution on community composition and stability.

Main Methods:

• Utilized two Pseudomonas fluorescens prey strains (SBW25, F113) and a Tetrahymena thermophila protist predator.
• Conducted a 24-day experimental evolution study.
• Analyzed community structure changes under predation pressure and inter-bacterial competition.

Main Results:

• Initially, both bacterial strains coexisted without predation.
• In the presence of predator and SBW25, F113 was competitively excluded.
• SBW25 evolved enhanced anti-predatory defenses with lower growth cost, explaining F113's exclusion.

Conclusions:

• Rapid prey evolution significantly alters predator-prey community structure.
• Evolutionary outcomes depend on the initial community composition and competitive interactions.
• Biocontrol bacteria effectiveness may be reduced in competitive, high-predation environments.