Isolation by distance in a quantitative trait.
Isolation by distance in a quantitative trait.
复制标题
数量性状中的距离隔离。
DOI：
10.1093/genetics/128.2.443
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发表时间：
1991
期刊：
影响因子：
3.3
通讯作者：
Lande,R
中科院分区：
文献类型：
--
作者：
Lande,R
定量特征中的随机遗传漂变是针对在一维或二维的无限栖息地中具有连续空间分布的种群进行建模的。该分析将赖特的邻域大小概念扩展到不同位置预期表型的空间自相关采样变化。假设弱稳定选择在每个地方都朝着相同的最佳表型运作，并且从亲本到后代的扩散距离的分布是一个（径向）对称函数。预期局部表型的地理变异的平衡模式取决于邻域大小、邻域内的遗传方差和选择强度，但几乎独立于扩散函数的形式。在其他条件相同的情况下，二维栖息地中的地理方差比一维栖息地中的地理方差要小，并且预期局部表型之间的协方差随着二维栖息地之间的距离的增加而减小得比一维中的要快。平衡地理方差小于地点内的表型方差，除非邻域规模很小且选择极弱，尤其是在二维情况下。然而，随机遗传漂变造成的地理差异的分散是维持当地人群遗传差异的重要机制。对于高斯分散函数，研究表明，即使邻域规模较小，二维栖息地中的种群也可以在邻域内维持无限恐慌种群中出现的大部分遗传方差。
Random genetic drift in a quantitative character is modeled for a population with a continuous spatial distribution in an infinite habitat of one or two dimensions. The analysis extends Wright's concept of neighborhood size to spatially autocorrelated sampling variation in the expected phenotype at different locations. Weak stabilizing selection is assumed to operate toward the same optimum phenotype in every locality, and the distribution of dispersal distances from parent to offspring is a (radially) symmetric function. The equilibrium pattern of geographic variation in the expected local phenotype depends on the neighborhood size, the genetic variance within neighborhoods, and the strength of selection, but is nearly independent of the form of the dispersal function. With all else equal, geographic variance is smaller in a two-dimensional habitat than in one dimension, and the covariance between expected local phenotypes decreases more rapidly with the distance separating them in two dimensions than in one. The equilibrium geographic variance is less than the phenotypic variance within localities, unless the neighborhood size is small and selection is extremely weak, especially in two dimensions. Nevertheless, dispersal of geographic variance created by random genetic drift is an important mechanism maintaining genetic variance within local populations. For a Gaussian dispersal function it is shown that, even with a small neighborhood size, a population in a two-dimensional habitat can maintain within neighborhoods most of the genetic variance that would occur in an infinite panmictic population.