Rapid evolution of larval life history, adult immune function and flight muscles in a poleward moving damselfly

Although a growing number of studies have documented the evolution of adult dispersal-related traits at the range edge of poleward-expanding species, we know little about evolutionary changes in immune function or traits expressed by nondispersing larvae. We investigated differentiation in larval (growth and development) and adult traits (immune function and flight-related traits) between replicated core and edge populations of the poleward-moving damselfly Coenagrion scitulum. These traits were measured on individuals reared in a common garden experiment at two different food levels, as allocation trade-offs may be easier to detect under energy shortage. Edge individuals had a faster larval life history (growth and development rates), a higher adult immune function and a nearly significant higher relative flight muscle mass. Most of the differentiation between core and edge populations remained and edge populations had a higher relative flight muscle mass when corrected for latitude-sp...尽管已有越来越多的研究记录了向极地扩张的物种分布范围边缘处成体扩散相关性状的演化过程，但学界对其免疫功能的演化变化，抑或是不扩散幼虫所表达的性状仍所知有限。本研究以正向极地扩散的豆娘物种Coenagrion scitulum的重复设置核心种群与边缘种群为研究对象，探究了其幼虫（生长与发育）及成体性状（免疫功能与飞行相关性状）的分化情况。研究人员通过同质园实验，在两种不同食物水平下饲养实验个体并测定上述性状——这是因为在能量短缺条件下，资源分配权衡效应更易被检测到。结果显示，边缘种群个体展现出更快的幼虫生活史速率（生长与发育速率）、更高的成体免疫功能，以及接近统计学显著水平的相对飞行肌质量。核心种群与边缘种群间的多数分化仍得以保留，且在对纬度相关因素（原文表述未完整）进行校正后，边缘种群仍具备更高的相对飞行肌质量。