Lorioux-Chevalier Ugo, Tuanama Valles Mario, Gallusser Stephanie, Mori Pezo Ronald, Chouteau Mathieu
LEEISA, UAR 3456, Université de Guyane, CNRS, IFREMER, Cayenne, France.
Instituto de Investigación Biológica de las Cordilleras Orientales, Tarapoto, Peru.
R Soc Open Sci. 2023 Jun 7;10(6):230354. doi: 10.1098/rsos.230354. eCollection 2023 Jun.
Predation is expected to promote uniformity in the warning coloration of defended prey, but also mimicry convergence between aposematic species. Despite selection constraining both colour-pattern and population divergence, many aposematic animals display numerous geographically structured populations with distinct warning signal. Here, we explore the extent of phenotypic variation of sympatric species of poison frogs and test for theoretical expectations on variation and convergence in mimetic signals. We demonstrate that both warning signal and mimetic convergence are highly variable and are negatively correlated: some localities display high variability and no mimicry while in others the phenotype is fixed and mimicry is perfect. Moreover, variation in warning signals is always present within localities, and in many cases this variation overlaps between populations, such that variation is continuous. Finally, we show that coloration is consistently the least variable element and is likely of greater importance for predator avoidance compared to patterning. We discuss the implications of our results in the context of warning signal diversification and suggest that, like many other locally adapted traits, a combination of standing genetic variation and founding effect might be sufficient to enable divergence in colour pattern.
捕食行为预计会促使具有防御能力的猎物的警戒色趋于一致，同时也会推动拟态物种之间的拟态趋同。尽管选择作用限制了颜色模式和种群分化，但许多具有警戒色的动物都呈现出众多具有不同警戒信号的地理结构化种群。在此，我们探究了箭毒蛙同域物种的表型变异程度，并检验了关于拟态信号变异和趋同的理论预期。我们证明，警戒信号和拟态趋同都具有高度变异性且呈负相关：一些地区表现出高变异性且不存在拟态，而在其他地区，表型是固定的且拟态十分完美。此外，警戒信号的变异在各地区内始终存在，并且在许多情况下，这种变异在种群之间存在重叠，从而使得变异是连续的。最后，我们表明颜色始终是变异性最小的元素，并且与图案相比，对于躲避捕食者可能更为重要。我们在警戒信号多样化的背景下讨论了我们研究结果的意义，并提出，与许多其他局部适应性状一样，现存遗传变异和奠基者效应的结合可能足以导致颜色模式的分化。
