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

蝾螈Ensatina eschscholtzii是一个模式环物种，因为它形成了一个环周围的加州干旱的中央谷的人口，与生殖隔离的形式重叠在加利福尼亚州南部，但杂交其他人口接触。 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州蝾螈的明亮警告颜色，而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，并限制每个亚种内的交配。 在接触区的蝾螈的颜色模式将研究与光谱放射性测量，记录光波长，以确定如何隐藏的形式在背景上，以及如何警告颜色的形式突出对背景图案。 颜色模式将在模型上进行操作，以评估纯和混合形式的捕食者攻击。本研究主要探讨动物知觉与隐语的基本理论。 它将提供关于生态相互作用如何在长期进化中塑造神秘和警告颜色形式的进化的数据。这些信息对于一般性地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.