Viral plasticity facilitates host diversity in challenging environments.

Area of Science:

• Ecology
• Evolutionary Biology
• Microbiology

Background:

• Antagonistic coevolution between microbes and viruses is a key driver of microbial community diversity.
• Interactions between environmental variables and defense-counterdefense strategies remain poorly understood.
• Observed microbial diversity declines in nutrient-rich conditions and at high latitudes, contrary to expectations.

Purpose of the Study:

• To introduce an eco-evolutionary model for bacteria-virus antagonistic coevolution.
• To explain previously unexplained patterns in microbial and viral diversity.
• To identify key drivers of microbial diversity across varying environmental conditions.

Main Methods:

• Development of an eco-evolutionary model for microbe-virus interactions.
• Analysis of theoretical predictions regarding community composition and diversity.
• Integration of environmental variables into the coevolutionary framework.

Main Results:

• The model harmonizes observations of microbial diversity across different growth conditions.
• Negative density dependence and viral plasticity are identified as crucial factors.
• Environmental conditions favoring slow host growth limit viral performance, promoting host diversity.

Conclusions:

• Eco-evolutionary dynamics, driven by negative density dependence and viral plasticity, explain microbial diversity patterns.
• Host diversity supports viral portfolio effects and bet-hedging, sustaining viral diversity.
• Understanding these interactions is critical for fields ranging from marine ecology to phage therapy.