Population growth makes waves in the distribution of pairwise genetic differences.
Population growth makes waves in the distribution of pairwise genetic differences.
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DOI：
10.1093/oxfordjournals.molbev.a040727
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发表时间：
1992-05
影响因子：
10.7
通讯作者：
A. Rogers;H. Harpending
中科院分区：
文献类型：
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作者：
A. Rogers;H. Harpending
种群增长和下降的周期在成对个体之间的核苷酸（或限制性酶切）位点差异的分布中留下了特征性的签名。这些特征出现在直方图中，显示了存在i个位点差异的成对个体的相对频率，其中i = 0，1，..。在这个分布中，一段生长产生一个向右传播的波，每1/2u代穿过水平轴的一个单位，其中u是突变率。初始粒子数越小，波的前沿面就越陡。人口规模的增加越大，分布的垂直截距就越小。持续指数增长的影响与突然爆发的人口增长的影响是无法区分的。人口规模的瓶颈也会产生类似于突然扩张所产生的波动，但具有升高的上尾概率。人口规模的减少最初会产生具有高身份概率的L形分布，但这些分布会迅速收敛到一个新的平衡点。在平衡种群中，理论曲线没有波动。然而，计算机模拟这些人口产生的经验分布与许多峰值和理论几乎没有相似之处。另一方面，协议是更好的瞬态（非平衡）的情况下，模拟经验分布通常表现出非常相似的波理论预测。因此，经验分布中的波可能富含关于种群动力学历史的信息。
Episodes of population growth and decline leave characteristic signatures in the distribution of nucleotide (or restriction) site differences between pairs of individuals. These signatures appear in histograms showing the relative frequencies of pairs of individuals who differ by i sites, where i = 0, 1, .... In this distribution an episode of growth generates a wave that travels to the right, traversing 1 unit of the horizontal axis in each 1/2u generations, where u is the mutation rate. The smaller the initial population, the steeper will be the leading face of the wave. The larger the increase in population size, the smaller will be the distribution's vertical intercept. The implications of continued exponential growth are indistinguishable from those of a sudden burst of population growth Bottlenecks in population size also generate waves similar to those produced by a sudden expansion, but with elevated uppertail probabilities. Reductions in population size initially generate L-shaped distributions with high probability of identity, but these converge rapidly to a new equilibrium. In equilibrium populations the theoretical curves are free of waves. However, computer simulations of such populations generate empirical distributions with many peaks and little resemblance to the theory. On the other hand, agreement is better in the transient (nonequilibrium) case, where simulated empirical distributions typically exhibit waves very similar to those predicted by theory. Thus, waves in empirical distributions may be rich in information about the history of population dynamics.