Experimental evolution and the dynamics of genomic mutation rate modifiers.

Area of Science:

• Evolutionary Biology
• Population Genetics
• Molecular Biology

Background:

• Genes influencing mutation rates are themselves subject to mutation.
• The population genetics of mutation rate modifiers has been studied theoretically for decades.
• Experimental evidence is crucial for understanding mutation rate dynamics.

Purpose of the Study:

• To review experimental contributions to understanding mutation rate modifier dynamics.
• To explore how mutator hitchhiking is suppressed or reversed in natural populations.
• To identify areas for future experimental investigation.

Main Methods:

• Review of numerous evolution experiments.
• Analysis of genetic hitchhiking in microbial populations.
• Theoretical considerations of natural selection and evolutionary forces.

Main Results:

• Mutator alleles readily increase in frequency via genetic hitchhiking in non-recombining microbial populations.
• These findings offer a framework for understanding high mutation rates in pathogens and cancer.
• Most natural populations exhibit very low mutation rates, contrasting with mutator dynamics.

Conclusions:

• Experimental evolution experiments demonstrate the potential for mutator alleles to increase mutation rates.
• The suppression or reversal of mutator hitchhiking in natural populations remains poorly understood.
• Further experimental research is needed to address the low mutation rates observed in most natural populations.