Rogers Alan R
Department of Anthropology, University of Utah, Salt Lake City, Utah 84112
Genetics. 2014 Aug;197(4):1329-41. doi: 10.1534/genetics.114.166454. Epub 2014 Jun 6.
The "LD curve" relates the linkage disequilibrium (LD) between pairs of nucleotide sites to the distance that separates them along the chromosome. The shape of this curve reflects natural selection, admixture between populations, and the history of population size. This article derives new results about the last of these effects. When a population expands in size, the LD curve grows steeper, and this effect is especially pronounced following a bottleneck in population size. When a population shrinks, the LD curve rises but remains relatively flat. As LD converges toward a new equilibrium, its time path may not be monotonic. Following an episode of growth, for example, it declines to a low value before rising toward the new equilibrium. These changes happen at different rates for different LD statistics. They are especially slow for estimates of [Formula: see text], which therefore allow inferences about ancient population history. For the human population of Europe, these results suggest a history of population growth.
“连锁不平衡（LD）曲线”将核苷酸位点对之间的连锁不平衡与它们在染色体上的间隔距离联系起来。这条曲线的形状反映了自然选择、种群间的混合以及种群大小的历史。本文得出了关于这些影响中最后一个方面的新结果。当种群规模扩大时，LD曲线变得更陡峭，并且在种群规模经历瓶颈后这种效应尤为明显。当种群缩小时，LD曲线上升但相对平缓。随着LD趋向于一个新的平衡，其时间路径可能不是单调的。例如，在一段增长期之后，它会下降到一个低值，然后再上升到新的平衡。对于不同的LD统计量，这些变化以不同的速率发生。对于[公式：见原文]的估计，变化尤其缓慢，因此可以据此推断古代种群历史。对于欧洲的人类种群，这些结果表明其有过种群增长的历史。
