Data from: Phenotypic variation and covariation indicate high evolvability of acoustic communication in crickets

Studying the genetic architecture of sexual traits provides insight into the rate and direction at which traits can respond to selection. Traits associated with few loci and limited genetic and phenotypic constraints tend to evolve at high rates typically observed for secondary sexual characters. Here, we examined the genetic architecture of song traits and female song preferences in the field crickets Gryllus rubens and G. texensis. Song and preference data were collected from both species and interspecific F1 and F2 hybrids. We first analysed phenotypic variation to examine interspecific differentiation and trait distributions in parental and hybrid generations. Then, the relative contribution of additive and additive-dominance variation was estimated. Finally, phenotypic variance-covariance (P) matrices were estimated to evaluate the multivariate phenotype available for selection. Song traits and preferences had unimodal trait distributions and hybrid offspring were intermediate with respect to the parents. We uncovered additive and dominance variation in song traits and preferences. For two song traits we found evidence for X-linked inheritance. On one hand, the observed genetic architecture does not suggest rapid divergence, although sex-linkage may have allowed for somewhat higher evolutionary rates. On the other hand, P matrices revealed that multivariate variation in song traits aligned with major dimensions in song preferences, suggesting a strong selection response. We also found strong covariance between the main traits that are sexually selected and traits that are not directly selected by females, providing an explanation for the striking multivariate divergence in male calling songs despite limited divergence in female preferences.探究性性状的遗传结构（genetic architecture），能够揭示性状响应选择的速率与方向。受少数基因座调控、且遗传与表型约束有限的性状，往往以较高速率演化——这类特征常见于第二性征（secondary sexual characters）。本研究以田野蟋蟀（field crickets）Gryllus rubens与G. texensis为对象，分析其鸣唱性状与雌性鸣唱偏好的遗传结构。我们从两个亲本物种以及种间F1、F2杂交后代中采集了鸣唱性状与偏好数据。首先通过表型变异分析，考察亲本与杂交世代的种间分化程度与性状分布模式；随后估算加性与加性-显性变异（additive and additive-dominance variation）的相对贡献；最后构建表型方差-协方差（P）矩阵，以评估可供选择作用的多变量表型。鸣唱性状与偏好均呈单峰分布，杂交后代的表型介于双亲之间。本研究检测到鸣唱性状与偏好存在加性与显性变异，其中两项鸣唱性状呈现X连锁遗传（X-linked inheritance）的证据。一方面，尽管性连锁（sex-linkage）可能一定程度上提升了演化速率，但观测到的遗传结构并未提示存在快速分化。另一方面，P矩阵分析显示，鸣唱性状的多变量变异与雌性偏好的核心维度高度契合，表明存在较强的选择响应。此外，我们还发现受性选择的核心性状与未受雌性直接选择的性状间存在强协方差，这为"尽管雌性偏好的分化程度有限，但雄性鸣唱歌却呈现出显著的多变量分化"这一现象提供了合理解释。