Department of Biological Statistics and Computational Biology, Cornell University, Ithaca, NY 14853, USA.
Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14853, USA.
Trends Genet. 2016 Jul;32(7):408-418. doi: 10.1016/j.tig.2016.04.005. Epub 2016 May 13.
Population genetics largely rests on a 'standard model' in which random genetic drift is the dominant force, selective sweeps occur infrequently, and deleterious mutations are purged from the population by purifying selection. Studies of phenotypic evolution in nature reveal a very different picture, with strong selection and rapid heritable trait changes being common. The time-rate scaling of phenotypic evolution suggests that selection on phenotypes is often fluctuating in direction, allowing phenotypes to respond rapidly to environmental fluctuations while remaining within relatively constant bounds over longer periods. Whether such rapid phenotypic evolution undermines the standard model will depend on how many genomic loci typically contribute to strongly selected traits and how phenotypic evolution impacts the dynamics of genetic variation in a population. Population-level sequencing will allow us to dissect the genetic basis of phenotypic evolution and study the evolutionary dynamics of genetic variation through direct measurement of polymorphism trajectories over time.
群体遗传学在很大程度上依赖于一个“标准模型”，其中随机遗传漂变是主导力量，选择清除很少发生，有害突变通过净化选择从种群中清除。对自然中表型进化的研究揭示了一幅截然不同的图景，其中强烈的选择和快速的可遗传性状变化很常见。表型进化的时间率标度表明，表型选择通常在方向上波动，使表型能够快速响应环境波动，同时在较长时间内保持相对稳定的范围。这种快速的表型进化是否会破坏标准模型将取决于通常有多少个基因组位点对强烈选择的性状有贡献，以及表型进化如何影响种群中遗传变异的动态。群体水平测序将使我们能够剖析表型进化的遗传基础，并通过直接测量随时间变化的多态性轨迹来研究遗传变异的进化动态。
