Changes to allometry, or the relative proportions of organs and tissues within organisms, is a common means for adaptive character change in evolution. However, little is understood about how relative size is specified during development and shaped during evolution. Here, through a phylogenomic analysis of genome-wide variation in 35 species of flying fishes and relatives, we identify genetic signatures in both coding and regulatory regions underlying the convergent evolution of increased paired fin size and aerial gliding behaviors. To refine our analysis, we intersected convergent phylogenomic signatures with mutants with altered fin size identified in distantly related zebrafish. Through these paired approaches, we identify a surprising role for an L-type amino acid transporter, lat4a, and the potassium channel, kcnh2a, in the regulation of fin proportion. We show that interaction between these genetic loci in zebrafish closely phenocopies the observed fin proportions of flying fishes. The congruence of experimental and phylogenomic findings point to conserved, non-canonical signaling integrating bioelectric cues and amino acid transport in the establishment of relative size in development and evolution.

异速生长，或生物体内器官和组织的相对比例的变化，是进化中适应性特征变化的常见手段。然而，人们对相对大小在发育过程中是如何指定以及在进化过程中如何形成的了解甚少。在这里，通过对 35 种飞鱼及其亲属的全基因组变异进行系统发育分析，我们确定了编码区和调控区的遗传特征，这些遗传特征是成对鳍尺寸增加和空中滑翔行为趋同进化的基础。为了完善我们的分析，我们将趋同的系统发育特征与在远亲斑马鱼中发现的鳍尺寸改变的突变体进行了交叉分析。通过这些配对方法，我们发现了 L 型氨基酸转运蛋白 lat4a和钾通道kcnh2a在调节鳍比例中的惊人作用。我们表明，斑马鱼中这些遗传位点之间的相互作用与观察到的飞鱼的鳍比例密切相关。实验和系统发育学研究结果的一致性表明，在发育和进化中建立相对大小时，存在保守的、非规范的信号传导，整合了生物电信号和氨基酸运输。