Adaptive Color Variation in the Ensatina "Ring Species" Complex: Implications for Ecological Speciation and Mimicry

salamander Ensatina eschscholtzii是一个典型的环形物种，因为它在加利福尼亚州干旱的中央山谷周围形成了一个种群环，在加利福尼亚州南部繁殖隔离的形式重叠，但在其他种群接触的地方杂交。这些蝾螈的颜色模式被认为是为了应对两种相互冲突的生态压力而进化的：选择倾向于模仿剧毒加利福尼亚蝾螈的明亮警告色，选择倾向于融入森林垃圾（伪装）的神秘图案。在这些形式接触的地方，应该有强烈的选择，有利于生殖隔离，限制每个亚种之间的交配。接触区域的蝾螈的颜色模式将通过记录光波长的光谱放射测量来研究，以确定隐藏形式如何在背景上伪装，以及警告色形式如何在背景图案中脱颖而出。颜色图案将在模型上进行操作，以评估捕食者对纯和混合形式的攻击。本研究探讨隐学和动物知觉的基本理论。它将提供关于生态相互作用如何在进化的长期中塑造隐色和警告色形式的进化的数据。这些信息对于一般解释自然种群多样性的演变是很重要的。

The salamander Ensatina eschscholtzii is a model ring species because it forms a ring of populations around the arid Central Valley of California, with reproductively isolated forms overlapping in southern CA but hybridization where other populations contact. Color patterns of these salamanders are thought to have evolved in response to two conflicting ecological pressures: selection favoring bright warning coloration that mimics highly toxic California Newts versus selection favoring cryptic patterns that blend into forest litter (camouflage). Where these forms come into contact there should be strong selection that favors reproductive isolation and that restricts mating within each subspecies. Color patterns of salamanders at contact zones will be studied with spectroradiographic measurements that record light wavelengths to determine how cryptic forms are camouflaged on the background and how warning-colored forms stand out against background patterns. Color patterns will be manipulated on models to assess predator attacks on pure and hybrid forms. This study addresses basic theories of crypsis and animal perception. It will provide data on how ecological interactions shape evolution of cryptic and warning-colored forms in the evolutionary long term. Such information is important in a general explanation of the evolution of diversity in natural populations.