Tuning environmental timescales to evolve and maintain generalists

Area of Science:

• Evolutionary biology
• Population genetics
• Immunology

Background:

• Natural environments pose challenges, favoring specialized genotypes.
• Generalist genotypes, fit across multiple environments, are difficult to evolve.
• B cell affinity maturation involves selecting broadly neutralizing antibodies.

Purpose of the Study:

• To investigate how environmental dynamics influence the evolution of generalist genotypes.
• To determine optimal environmental change timescales for evolving generalists.
• To explore the impact of complex dynamic environments on evolutionary outcomes.

Main Methods:

• Simulating evolutionary dynamics under varying environmental change rates.
• Comparing evolutionary outcomes in static versus dynamic environments.
• Analyzing the rate of generalist evolution from specialist populations.

Main Results:

• Intermediate-timescale environmental changes significantly enhance the evolution of generalists.
• Faster or slower environmental changes are less effective in evolving generalists.
• Complex dynamic environments, like frequency chirps, further increase generalist yield.
• The reverse process (specialist evolution from generalists) is not enhanced.

Conclusions:

• Environmental change on timescales comparable to evolutionary transients is key for evolving generalists.
• Dynamic fitness landscapes can guide populations toward previously unobtainable genotypes.
• This provides design principles for manipulating evolutionary trajectories.