Data from: Mutation predicts 40 million years of fly wing evolution

Mutation enables evolution, but the idea that adaptation is also shaped by
mutational variation is controversial. Simple evolutionary hypotheses
predict such a relationship if the supply of mutations constrains
evolution, but it is not clear that constraints exist, and, even if they
do, they may be overcome by long-term natural selection. Quantification of
the relationship between mutation and phenotypic divergence among species
will help to resolve these issues. Here we use precise data on over 50,000
Drosophilid fly wings to demonstrate unexpectedly strong positive
relationships between variation produced by mutation, standing genetic
variation, and the rate of evolution over the last 40 million years. Our
results are inconsistent with simple constraint hypotheses because the
rate of evolution is very low relative to what both mutational and
standing variation could allow. In principle, the constraint hypothesis
could be rescued if the vast majority of mutations are so deleterious that
they cannot contribute to evolution, but this also requires the
implausible assumption that deleterious mutations have the same pattern of
effects as potentially advantageous ones. Our evidence for a strong
relationship between mutation and divergence in a slowly evolving
structure challenges the existing models of mutation in evolution.