Data from: A population genomic scan in Chorthippus grasshoppers unveils previously unknown phenotypic divergence

Understanding the genetics of speciation and the processes that drive it
is a central goal of evolutionary biology. Grasshoppers of the Chorthippus
species group differ strongly in calling song (and corresponding female
preferences) but are exceedingly similar in other characteristics such as
morphology. Here, we performed a population genomic scan on three
Chorthippus species (Chorthippus biguttulus, C. mollis and C. brunneus) to
gain insight into the genes and processes involved in divergence and
speciation in this group. Using an RNA-seq approach, we examined
functional variation between the species by calling SNPs for each of the
three species pairs and using FST-based approaches to identify outliers.
We found approximately 1% of SNPs in each comparison to be outliers.
Between 37% and 40% of these outliers were nonsynonymous SNPs (as opposed
to a global level of 17%) indicating that we recovered loci under
selection. Among the outliers were several genes that may be involved in
song production and hearing as well as genes involved in other traits such
as food preferences and metabolism. Differences in food preferences
between species were confirmed with a behavioural experiment. This
indicates that multiple phenotypic differences implicating multiple
evolutionary processes (sexual selection and natural selection) are
present between the species.