Redpath Museum, McGill University, 859 Sherbrooke St. West, Montréal, QC, Canada.
J Evol Biol. 2011 Jan;24(1):23-35. doi: 10.1111/j.1420-9101.2010.02155.x. Epub 2010 Nov 19.
Different environments should select for different aspects of organismal performance, which should lead to correlated divergence in morphological traits that influence performance. The result should be genetic divergence in aspects of performance, morphology and associations ('maps') between morphology and performance. Testing this hypothesis requires quantifying performance and morphology in multiple populations after controlling for environmental differences, but this is rarely attempted. We used a common-garden experiment to examine morphology and several aspects of swimming performance within and between the lake and inlet populations of threespine stickleback (Gasterosteus aculeatus) from the Misty system, Vancouver Island, Canada. Controlling for body size, lake stickleback had shallower bodies, larger caudal fins and smaller pelvic girdles. With or without morphological covariates, lake stickleback showed greater performance in both sustained and burst swimming. In contrast, inlet stickleback showed greater manoeuverability than did lake stickleback in some analyses. Morphology-performance relationships were decoupled when considering variation within vs. between populations. Moreover, morphology-performance mapping differed between the two populations. Based on these observations, we advance a hypothesis for why populations adapting to different environments should show adaptive genetic divergence in morphology-performance mapping.
不同的环境应该选择不同的生物体表现方面，这应该导致影响表现的形态特征的相关分歧。其结果应该是在性能、形态以及形态与性能之间的关联（“图谱”）方面存在遗传分歧。要验证这一假设，需要在控制环境差异的情况下，在多个种群中量化性能和形态，但这种尝试很少。我们使用一个共同的花园实验，在加拿大温哥华岛 Misty 系统的三种棘鱼（Gasterosteus aculeatus）的湖泊和入口种群中，检查了形态和游泳性能的几个方面。在控制体型大小的情况下，湖泊中的棘鱼的身体较浅，尾鳍较大，骨盆带较小。无论是否有形态学协变量，湖泊中的棘鱼在持续和爆发游泳中都表现出更好的性能。相比之下，在某些分析中，入口中的棘鱼比湖泊中的棘鱼具有更好的机动性。当考虑种群内部和种群之间的变异时，形态-性能关系被解耦。此外，这两个种群的形态-性能映射也存在差异。基于这些观察，我们提出了一个假设，即为什么适应不同环境的种群应该在形态-性能映射方面表现出适应性遗传分歧。
