The role of environmental variation in mediating fitness trade‐offs for an amphibian polyphenism
The role of environmental variation in mediating fitness trade‐offs for an amphibian polyphenism
复制标题
环境变化在调节两栖动物多态性适应性权衡中的作用
DOI：
10.1111/1365-2656.13974
复制
发表时间：
2023
影响因子：
4.8
通讯作者：
Whiteman, Howard H.
中科院分区：
文献类型：
--
作者：
Kirk, Mark A.;Reider, Kelsey E.;Lackey, Alycia C. R.;Thomas, Scott A.;Whiteman, Howard H.
适合度权衡是生态学和进化论的基础，因为适合度权衡可以解释生活史变异、表型可塑性和多物性的存在。使用来自高海拔、多物性种群的1093只成年亚利桑那州虎火蜥蜴(Ambystoma Mavortium Nebulosum)32年的标记重新捕获数据集。我们评估了两种生活史形态(水生足形与陆生变态)在繁殖和身体状况方面表现出与环境变化(例如气候)和基于内部状态的变量(例如年龄)的适合性权衡的程度。这两种形态在春季降水较多的年份对较高的繁殖概率表现出相似的反应(即不表明特定形态的适合度权衡)。这两种生活史形态在繁殖状态上很可能没有气候诱导的适合度权衡，因为降水和水的可用性对两栖动物的繁殖至关重要。身体条件对两种形态的反应截然不同，这表明了气候诱导的适宜性权衡。虽然变质作用与夏季积雪条件呈正相关，但足形物不受影响。夏季积雪带来的健康权衡可能是由于临时池塘中延长的水期，变态动物在夏季生长季通过利用拟态动物无法获得的资源来获得健康优势。然而，足形动物似乎具有越冬的健康优势，因为在夏季生长季开始时，它们的身体状况一直高于变态动物。我们的结果表明，气候和栖息地类型(以陆生为主的变态动物，完全水生的脚形动物)相互作用，为每种形态赋予不同的优势。这些结果通过整合基于气候的机制，促进了我们目前对这种研究很好的多酚两栖动物的适应性权衡的理解。我们的结论促使未来的研究探索气候变化如何维持多物性和促进生活史多样性，以及气候变化对多物性的影响。
Fitness trade‐offs are a foundation of ecological and evolutionary theory because trade‐offs can explain life history variation, phenotypic plasticity, and the existence of polyphenisms.Using a 32‐year mark‐recapture dataset on lifetime fitness for 1093 adult Arizona tiger salamanders (Ambystoma mavortium nebulosum) from a high elevation, polyphenic population, we evaluated the extent to which two life history morphs (aquatic paedomorphs vs. terrestrial metamorphs) exhibited fitness trade‐offs in breeding and body condition with respect to environmental variation (e.g. climate) and internal state‐based variables (e.g. age).Both morphs displayed a similar response to higher probabilities of breeding during years of high spring precipitation (i.e. not indicative of a morph‐specific fitness trade‐off). There were likely no climate‐induced fitness trade‐offs on breeding state for the two life history morphs because precipitation and water availability are vital to amphibian reproduction.Body condition displayed a contrasting response for the two morphs that was indicative of a climate‐induced fitness trade‐off. While metamorphs exhibited a positive relationship with summer snowpack conditions, paedomorphs were unaffected. Fitness trade‐offs from summer snowpack are likely due to extended hydroperiods in temporary ponds, where metamorphs gain a fitness advantage during the summer growing season by exploiting resources that are unavailable to paeodomorphs. However, paedomorphs appear to have the overwintering fitness advantage because they consistently had higher body condition than metamorphs at the start of the summer growing season.Our results reveal that climate and habitat type (metamorphs as predominately terrestrial, paedomorphs as fully aquatic) interact to confer different advantages for each morph. These results advance our current understanding of fitness trade‐offs in this well‐studied polyphenic amphibian by integrating climate‐based mechanisms. Our conclusions prompt future studies to explore how climatic variation can maintain polyphenisms and promote life history diversity, as well as the implications of climate change for polyphenisms.