Roff Derek A
Department of Biology, McGill University, 1205 Docteur Penfield Avenue, Montreal, Quebec, H3A 1B1, Canada.
Evolution. 1996 Aug;50(4):1392-1403. doi: 10.1111/j.1558-5646.1996.tb03913.x.
The genetic correlation is a central parameter of quantitative genetics, providing a measure of the rate at which traits respond to indirect selection (i.e., selection that does not act upon the traits under study, but some other trait with which they have genes in common). In this paper, I review the pattern of variation among four combinations of traits: life history × life history (L × L), morphological × morphological (M × M), life history × morphological (L × M), and behavioral × behavioral (B × B). A few other combinations were investigated, but insufficient data were obtained for separate analysis. A total of 1798 correlations, distributed over 51 different animal and plant species, were analyzed. The analysis was conducted at two levels: first by dividing the data set solely by trait combination, and second by blocking the data by trait combination and species. Because selection will tend to fix alleles that show positive correlations with fitness traits faster than those that are negative and because the latter are expected to arise more frequently by mutation, correlations between life-history traits are predicted to be more often negative than those between morphological traits. This prediction was supported, with the ranking in decreasing proportion of negative correlations being: L × L > L × M > B × B > M × M. The mean magnitude of the genetic correlation shows little variation among morphological and life-history combinations, and the distribution of values is remarkably flat. However, the estimated standard errors and the coefficient of variation (SE/r ) are large, making it difficult to separate biological factors influencing the pattern of dispersion from experimental error. Analysis of the phenotypic and genetic correlations suggest that for the combinations M × M and L × M, but not L × L or B × B, the phenotypic correlation is an adequate estimate of the genetic correlation.
遗传相关性是数量遗传学的核心参数，它衡量了性状对间接选择（即并非作用于所研究的性状，而是作用于与之有共同基因的其他性状）的响应速率。在本文中，我回顾了四种性状组合间的变异模式：生活史×生活史（L×L）、形态学×形态学（M×M）、生活史×形态学（L×M）以及行为×行为（B×B）。还研究了其他一些组合，但因数据不足无法单独分析。共分析了分布于51种不同动植物物种的1798个相关性。分析分两个层次进行：首先仅按性状组合划分数据集，其次按性状组合和物种对数据进行分组。由于选择往往会更快地固定与适应性性状呈正相关的等位基因，而不是那些呈负相关的等位基因，并且因为预计后者通过突变出现的频率更高，所以预计生活史性状之间的相关性比形态学性状之间的相关性更常为负。这一预测得到了支持，负相关性比例从高到低的排序为：L×L > L×M > B×B > M×M。遗传相关性的平均大小在形态学和生活史组合之间变化不大，其值的分布非常平缓。然而，估计的标准误差和变异系数（SE/r）很大，这使得难以将影响离散模式的生物学因素与实验误差区分开来。对表型相关性和遗传相关性的分析表明，对于M×M和L×M组合，而非L×L或B×B组合，表型相关性是遗传相关性的充分估计。
