Data from: The evolution of colour pattern complexity: selection for conspicuousness favours contrasting within-body colour combinations in lizards

Many animals display complex colour patterns that comprise several adjacent, often contrasting colour patches. Combining patches of complementary colours increases the overall conspicuousness of the complex pattern, enhancing signal detection. Therefore, selection for conspicuousness may act not only on the design of single colour patches, but also on their combination. Contrasting long- and short-wavelength colour patches are located on the ventral and lateral surfaces of many lacertid lizards. As the combination of long- and short-wavelength-based colours generates local chromatic contrast, we hypothesized that selection may favour the co-occurrence of lateral and ventral contrasting patches, resulting in complex colour patterns that maximize the overall conspicuousness of the signal. To test this hypothesis, we performed a comparative phylogenetic study using a categorical colour classification based on spectral data and descriptive information on lacertid coloration collected from the literature. Our results demonstrate that conspicuous ventral (long-wavelength-based) and lateral (short-wavelength-based) colour patches co-occur throughout the lacertid phylogeny more often than expected by chance, especially in the subfamily Lacertini. These results suggest that selection promotes the evolution of the complex pattern rather than the acquisition of a single conspicuous colour patch, possibly due to the increased conspicuousness caused by the combination of colours with contrasting spectral properties.

诸多动物展现出由多个相邻且常呈对比色的色块构成的复杂体色图案。将互补色的色块进行组合，可提升该复杂体色图案的整体显眼度，强化信号探测效果。因此，针对显眼度的选择压力，不仅会作用于单个色块的设计，还会影响其组合方式。诸多正蜥科（Lacertidae）蜥蜴的腹面与体侧分布着长波长与短波长的对比色色块。由于基于长波长与短波长的色彩组合会产生局部色对比，我们据此提出假说：选择压力或会青睐体侧与腹面对比色色块的共存，最终形成可最大化信号整体显眼度的复杂体色图案。为验证该假说，我们开展了一项比较系统发育研究：采用基于光谱数据的分类体色分类法，并整合了从文献中收集的正蜥科体色描述信息。研究结果显示，在正蜥科的系统发育关系中，显眼的腹面色块（基于长波长）与体侧色块（基于短波长）的共存频率显著高于随机概率，尤其在正蜥亚科（Lacertini）中这一现象更为突出。上述结果表明，选择压力推动的是复杂体色图案的演化，而非单个显眼色块的独立获得，这可能是因为具有对比光谱特性的色彩组合，能够提升整体的显眼度。