POPULATION MIXING AND THE ADAPTIVE DIVERGENCE OF QUANTITATIVE TRAITS IN DISCRETE POPULATIONS: A THEORETICAL FRAMEWORK FOR EMPIRICAL TESTS
POPULATION MIXING AND THE ADAPTIVE DIVERGENCE OF QUANTITATIVE TRAITS IN DISCRETE POPULATIONS: A THEORETICAL FRAMEWORK FOR EMPIRICAL TESTS
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种群混合和离散种群数量性状的自适应发散：实证检验的理论框架
DOI：
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发表时间：
2001
期刊：
影响因子：
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通讯作者：
E. Taylor
中科院分区：
文献类型：
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作者：
A. Hendry;T. Day;E. Taylor
人口混合的重要性，在约束适应性分歧的实证检验还没有很好地在理论上的数量性状在空间离散的人口。我们开发了数量遗传模型来研究两个种群之间的平衡差异，这两个种群正在经历不同的选择制度和交换个体。这些模型表明，适应性分歧是负相关的人口混合率（m，最强烈的是当m低），正相关的表型最佳种群之间的差异，和正相关的加性遗传方差的量（G，最强烈的是当G低）。当遗传力或混合力都不太低（h2 > 0.2或m2> 0.05）时，达到平衡的速度相当快（两个群体不到50代就进化到平衡距离的90%）。该理论可用于辅助经验检验：（1）将观察到的分歧与使用群体混合，加性遗传方差/协方差和选择估计的预测进行比较;（2）检验多个独立群体对之间的群体混合和适应性分歧之间的负相关性;（3）实验性地操纵混合率。应用前两个这些方法的数据，从两个充分研究的自然系统表明，人口混合有约束力的适应性分歧的颜色模式在伊利湖水蛇（Nerodia sipedon），但不是同域对底栖和湖沼棘鱼（Gasterosteus aculeatus）的营养性状。我们概述的理论框架应该提供一个改进的基础，为未来的实证检验人口混合的作用，适应性分歧。
Abstract Empirical tests for the importance of population mixing in constraining adaptive divergence have not been well grounded in theory for quantitative traits in spatially discrete populations. We develop quantitative-genetic models to examine the equilibrium difference between two populations that are experiencing different selective regimes and exchanging individuals. These models demonstrate that adaptive divergence is negatively correlated with the rate of population mixing (m̂, most strongly so when m̂ is low), positively correlated with the difference in phenotypic optima between populations, and positively correlated with the amount of additive genetic variance (G, most strongly so when G is low). The approach to equilibrium is quite rapid (fewer than 50 generations for two populations to evolve 90% of the distance to equilibrium) when either heritability or mixing are not too low (h2 > 0.2 or m̂ > 0.05). The theory can be used to aid empirical tests that: (1) compare observed divergence to that predicted using estimates of population mixing, additive genetic variance/covariance, and selection; (2) test for a negative correlation between population mixing and adaptive divergence across multiple independent population pairs; and (3) experimentally manipulate the rate of mixing. Application of the first two of these approaches to data from two well-studied natural systems suggests that population mixing has constrained adaptive divergence for color patterns in Lake Erie water snakes (Nerodia sipedon), but not for trophic traits in sympatric pairs of benthic and limnetic stickleback (Gasterosteus aculeatus). The theoretical framework we outline should provide an improved basis for future empirical tests of the role of population mixing in adaptive divergence.