Data from: Parallel genomic architecture underlies repeated sexual signal divergence in Hawaiian Laupala crickets

When the same phenotype evolves repeatedly, we can explore the
predictability of genetic changes underlying phenotypic evolution. Theory
suggests that genetic parallelism is less likely when phenotypic changes
are governed by many small-effect loci compared to few of major effect,
because different combinations of genetic changes can result in the same
quantitative outcome. However, some genetic trajectories might be favoured
over others, making a shared genetic basis to repeated polygenic evolution
more likely. To examine this, we studied the genetics of parallel male
mating song evolution in the Hawaiian cricket Laupala. We compared
quantitative trait loci (QTL) underlying song divergence in three species
pairs varying in phenotypic distance. We tested whether replicated song
divergence between species involves the same QTL and the likelihood that
sharing QTL is related to phenotypic effect sizes. Contrary to theoretical
predictions, we find substantial parallelism in polygenic genetic
architectures underlying repeated song divergence. QTL overlapped more
than expected based on simulated QTL analyses. Interestingly, QTL effect
size did not predict QTL sharing, but did correlate with magnitude of
phenotypic divergence. We highlight potential mechanisms driving these
constraints on cricket song evolution and discuss a scenario that
consolidates empirical quantitative genetic observations with
micro-mutational theory.