Hutchings Jeffrey A, Swain Douglas P, Rowe Sherrylynn, Eddington James D, Puvanendran Velmurugu, Brown Joseph A
Department of Biology, Dalhousie University, Halifax, Nova Scotia B3H 4J1, Canada.
Proc Biol Sci. 2007 Jul 22;274(1619):1693-9. doi: 10.1098/rspb.2007.0263.
Neither the scale of adaptive variation nor the genetic basis for differential population responses to the environment is known for broadcast-spawning marine fishes. Using a common-garden experimental protocol, we document how larval growth, survival and their norms of reaction differ genetically among four populations of Atlantic cod (Gadus morhua). These traits, and their plastic responses to food and temperature, differed across spatial scales at which microsatellite DNA failed to detect population structure. Divergent survival reaction norms indicate that warm-water populations are more sensitive to changes in food, whereas cold-water populations are more sensitive to changes in temperature. Our results suggest that neither the direction nor the magnitude of demographic responses to environmental change need be the same among populations. Adaptive phenotypic plasticity, previously undocumented in marine fishes, can significantly influence the probability of recovery and persistence of collapsed populations by affecting their ability to respond to natural and anthropogenic environmental change.
对于广盐性产卵的海洋鱼类，人们既不清楚适应性变异的规模，也不了解不同种群对环境做出差异性反应的遗传基础。我们采用了一种共同花园实验方案，记录了大西洋鳕鱼（Gadus morhua）四个种群在幼体生长、存活以及它们的反应规范方面的遗传差异。这些性状以及它们对食物和温度的可塑性反应，在微卫星DNA未能检测到种群结构的空间尺度上存在差异。不同的存活反应规范表明，暖水种群对食物变化更为敏感，而冷水种群对温度变化更为敏感。我们的研究结果表明，不同种群对环境变化的人口统计学反应的方向和幅度不一定相同。适应性表型可塑性此前在海洋鱼类中尚未有记录，它可以通过影响种群对自然和人为环境变化的反应能力，显著影响崩溃种群恢复和持续存在的可能性。
