Local adaptation for enhanced salt tolerance reduces non-adaptive plasticity caused by osmotic stress
Local adaptation for enhanced salt tolerance reduces non-adaptive plasticity caused by osmotic stress
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DOI：
10.1111/evo.13798
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发表时间：
2019-07-18
期刊：
影响因子：
3.3
通讯作者：
McCoy, Michael W.
中科院分区：
文献类型：
--
作者：
Albecker, Molly A.;McCoy, Michael W.
生物体通常通过表型可塑性来响应环境变化，在这种可塑性中，个体根据环境调整其表型。高度可变或变化的环境可以超过生理极限并产生不适应的塑料表型，这被称为非适应可塑性。在某些情况下，选择可能会减少环境压力的负面或破坏性影响，并产生适应当地环境的种群。盐是淡水系统中一种日益普遍的污染物，可以诱导淡水生物如两栖动物的非适应性塑料表型。Hyla cinerea是一种蛙类物种，其种群生活在微咸水的沿海栖息地，因此我们使用这种物种来测试沿海种群是否在当地适应了咸水，方法是确定胚胎和幼虫阶段的盐分暴露如何改变沿海和内陆种群的死亡率以及可塑性发育和变质表型。沿海青蛙的存活率更高，生长速度更快，而且在盐碱地上比内陆青蛙蜕变得更快。沿海青蛙也会变得更小(可能是早期变形的结果)，但保持恒定的大小，而盐度较高的内陆青蛙则会减少变质大小。沿海蛙的进化是为了最大限度地减少咸水对幼虫发育的非适应性和破坏性影响，并加速幼虫时期，以减少在紧张环境中花费的时间。
Organisms often respond to environmental change via phenotypic plasticity, in which an individual modulates its phenotype according to the environment. Highly variable or changing environments can exceed physiological limits and generate maladapted plastic phenotypes, which is termed nonadaptive plasticity. In some cases, selection may reduce the negative or disruptive impacts of environmental stress and produce locally adapted populations. Salt is an increasingly prevalent contaminant of freshwater systems and can induce nonadaptive plastic phenotypes for freshwater organisms like amphibians. Hyla cinerea is a frog species with populations inhabiting brackish, coastal habitats, so we use this species to test whether coastal populations are locally adapted to tolerate saltwater by determining how salt exposure during the embryonic and larval stages alters mortality and plastic developmental and metamorphic phenotypes of coastal and inland populations. Coastal frogs have higher survival, faster growth rates, and metamorphose sooner than inland frogs across salinities. Coastal frogs also metamorphose smaller (likely a consequence of earlier metamorphosis) yet maintain constant size, while higher salinities reduce metamorphic size for inland frogs. Coastal frogs evolved to minimize nonadaptive and disruptive impacts of saltwater during larval development and accelerate the larval period to reduce time spent in a stressful environment.