Evolutionary feedback from the environment shapes mechanisms that generate genome variation

Area of Science:

• Evolutionary biology
• Genetics
• Biochemistry

Background:

• The Modern Synthesis posits random mutations, focusing research on selection rather than variation generation.
• The concept of 'random' mutation is challenged by evidence of non-uniform and adaptive mutation probabilities.
• Genome variation is influenced by biochemical processes and can be regulated by environmental factors.

Purpose of the Study:

• To re-evaluate the role of mutation generation in evolution.
• To explore how biochemical mechanisms and environmental factors influence heritable variation.
• To propose that the ability to evolve itself evolves.

Main Methods:

• Review of existing evolutionary theory and biochemical evidence.
• Analysis of the interplay between selection and mutation generation.
• Conceptual framework integrating environmental influences on variation.

Main Results:

• Mutation probabilities are not uniform across genomes, over time, or independent of adaptive value.
• Biochemical mechanisms have evolved to increase the probability of adaptive mutations.
• Environmental stressors can regulate specific classes of genetic variation.

Conclusions:

• Heritable variation generation is influenced by a feedback loop with selection.
• Understanding the evolution of variation mechanisms is crucial for evolutionary theory.
• Future research should focus on the biochemical basis of variation generation in gametes.