Abstract：
Selection experiments play an increasingly important role in comparative and evolutionary physiology. However, selection experiments can be limited by relatively low statistical power, in part because replicate line is the experimental unit for analyses of direct or correlated responses (rather than number of individuals measured). One way to increase the ability to detect correlated responses is through a meta-analysis of studies for a given trait across multiple generations. To demonstrate this, we applied meta-analytic techniques to two traits (body mass and heart ventricle mass, with body mass as a covariate) from a long-term artificial selection experiment for high voluntary wheel-running behavior. In this experiment, all four replicate High Runner (HR) lines reached apparent selection limits around generations 17-27, running approximately 2.5- to 3-fold more revolutions per day than the four non-selected Control (C) lines. Although both traits would also be expected to change in HR lines (relative heart size expected to increase, expected direction for body mass is less clear), their statistical significance has varied, despite repeated measurements. We compiled information from 33 unique studies and calculated a measure of effect size (Pearson\'s R). Our results indicate that, despite a lack of statistical significance in most generations, HR mice have evolved larger hearts and smaller bodies relative to controls. Moreover, plateaus in effect sizes for both traits coincide with the generational range during which the selection limit for wheel-running behavior was reached. Finally, since reaching the selection limit, absolute effect sizes for body mass and heart ventricle mass have become smaller (i.e. closer to 0).
摘要：
选择实验在比较和进化生理学中起着越来越重要的作用。然而,选择实验可能受到相对较低的统计能力的限制，部分原因是重复线是分析直接或相关反应的实验单位（而不是测量的个体数量）。提高检测相关反应能力的一种方法是通过对多个世代的给定性状进行研究的荟萃分析。为了证明这一点，我们将荟萃分析技术应用于两个特征(体重和心室质量，以体重为协变量）来自长期的人工选择实验，用于高自愿性车轮行驶行为。在这个实验中,所有4个重复的HighRunner(HR)品系在第17-27代左右达到表观选择极限,比4个未选择的对照(C)品系运行约2.5-3倍的转/天多。虽然这两个特征也会在HR线中发生变化（相对心脏大小预计会增加，体重的预期方向不太清楚)，统计意义各不相同，尽管重复测量。我们从33个独特的研究中收集了信息，并计算了效应大小的度量（Pearson'sR）。我们的研究结果表明,尽管大多数世代都缺乏统计意义，相对于对照,HR小鼠已经进化出更大的心脏和更小的身体。此外，这两个特征的效果大小的平台与达到车轮运行行为选择极限的世代范围一致。最后,由于选择限制，体重和心室质量的绝对效应大小变得更小(即，接近0）。
