The evolution of recombination in a heterogeneous environment

Area of Science:

• Evolutionary Biology
• Population Genetics

Background:

• Traditional models of recombination evolution assume homogeneous environments.
• Recombination evolution is typically driven by epistasis or genetic drift in single populations.
• Previous models suggest recombination is favored under specific conditions of weak negative epistasis and tight linkage.

Purpose of the Study:

• To investigate the combined effects of spatial selection heterogeneity and epistasis on recombination evolution.
• To determine how environmental variation influences the conditions favoring recombination.

Main Methods:

• A two-patch model with differing selection regimes was developed.
• The model considered mutation-selection balance, migration-selection balance, and the spread of beneficial alleles.
• The study analyzed the impact of epistasis and spatial heterogeneity on recombination modifier evolution.

Main Results:

• Spatial heterogeneity broadens the range of epistasis (including positive epistasis) under which recombination can be favored.
• Recombination can evolve even in the absence of epistasis when spatial selection varies.
• Selection pressure on recombination modifiers is significantly amplified by spatial heterogeneity.

Conclusions:

• Environmental heterogeneity is a crucial factor in the evolution of recombination, interacting with epistasis.
• Predicting the evolution of recombination requires understanding both environmental context and the nature of epistasis.
• Spatial variation can lead to the evolution of recombination even with loosely linked modifiers or free recombination.