Mutation predicts 40 million years of fly wing evolution

Area of Science:

• Evolutionary Biology
• Genetics
• Developmental Biology

Background:

• The role of mutation in shaping adaptation is debated.
• Evolutionary hypotheses suggest mutation supply constrains adaptation, but empirical evidence is limited.
• Understanding mutation's impact on phenotypic divergence is crucial.

Purpose of the Study:

• To quantify the relationship between mutation, genetic variation, and evolutionary rates.
• To test evolutionary hypotheses regarding mutation supply as a constraint on adaptation.
• To investigate the influence of mutation on phenotypic divergence in Drosophilid flies.

Main Methods:

• Analysis of precise morphometric data from over 50,000 Drosophilid fly wings.
• Quantification of mutational variation, standing genetic variation, and rates of phenotypic evolution.
• Comparison of empirical data with evolutionary models and constraint hypotheses.

Main Results:

• Demonstrated unexpectedly strong positive relationships between mutation, standing genetic variation, and evolutionary rates.
• Observed evolutionary rates significantly lower than predicted by mutational and standing variation.
• Found evidence inconsistent with simple constraint hypotheses, challenging existing models of mutation in evolution.

Conclusions:

• Mutation and standing genetic variation are strongly linked to the rate of evolution.
• Evolutionary rates appear constrained, not by mutation supply, but by other factors.
• Existing models of mutation's role in evolution require re-evaluation.