Looking for the optimal rate of recombination for evolutionary dynamics

Area of Science:

• Evolutionary biology
• Population genetics
• Theoretical biology

Background:

• Understanding the interplay between mutation, recombination, and selection is fundamental in evolutionary dynamics.
• Previous models often assume monotonic relationships between recombination rates and population fitness.

Purpose of the Study:

• To investigate conditions where recombination nonmonotonically affects mean population fitness.
• To identify specific fitness landscapes that support an optimal recombination rate.

Main Methods:

• Analysis of many-site mutation-recombination models with selection.
• Examination of evolutionary dynamics in finite populations on rugged fitness landscapes.
• Modeling horizontal gene transfer with asymmetric mutations.

Main Results:

• Two fitness landscapes were identified that exhibit nonmonotonic mean fitness with respect to recombination rate.
• One landscape involves evolution near an error threshold on a neutral-network-like fitness landscape.
• A more realistic scenario involves rugged fitness landscapes with random fitness contributions.

Conclusions:

• Recombination's effect on mean fitness is not always monotonic and can be optimized.
• Rugged fitness landscapes are key to observing nonmonotonic behavior in finite populations.
• Specially designed (ideal) fitness landscapes are required for nonmonotonicity in both mutation and recombination.