Deep-time convergent evolution in animal communication presented by shared adaptations for coping with noise in lizards and other animals

Convergence in communication appears rare compared to other forms of adaptation. This is puzzling, given communication is acutely dependent on the environment and expected to converge in form when animals communicate in similar habitats. We uncover deep-time convergence in territorial communication between two groups of tropical lizards separated by over 140 million years of evolution: the Southeast Asian Draco and Caribbean Anolis. These groups have repeatedly converged in multiple aspects of display along common environmental gradients. Robot playbacks to free-ranging lizards confirmed the most prominent convergence in display is adaptive, as it improves signal detection. We then provide evidence from a sample of the literature to further show convergent adaptation among highly divergent animal groups is almost certainly widespread in nature. Signal evolution is therefore curbed towards the same set of adaptive solutions, especially when animals are challenged with the problem of communicating effectively in noisy environments.

Methods
See main paper and associated online supporting information for details on methods.

与其他适应形式相比，通讯趋同现象似乎较为罕见。这一点令人费解，因为通讯高度依赖于环境，且当动物在相似生境中进行通讯时，其通讯形式本应趋于一致。我们揭示了两个演化上相隔逾1.4亿年的热带蜥蜴类群——东南亚飞龙蜥属（Draco）与加勒比安乐蜥属（Anolis）——在领地通讯上存在深层演化趋同。这两个类群沿着共同的环境梯度，在展示行为的多个维度上反复发生趋同演化。针对自由活动野生蜥蜴的机器人回放实验证实，展示行为中最显著的趋同特征具有适应性，因为它提升了信号检测效果。随后我们通过文献样本分析进一步证明，高度分化的动物类群间的趋同适应，在自然界中几乎必然广泛存在。因此，信号演化会被约束于同一套适应性解决方案的范畴内，尤其是当动物面临在嘈杂环境中实现有效通讯的难题时。
方法
详细方法请参见主论文及配套在线补充材料。