Hara Yuichiro
Phyloinformatics Unit, RIKEN Center for Life Science Technologies.
Genes Genet Syst. 2015;90(3):123-31. doi: 10.1266/ggs.90.123.
Mutations that have occurred in human genomes provide insight into various aspects of evolutionary history such as speciation events and degrees of natural selection. Comparing genome sequences between human and great apes or among humans is a feasible approach for inferring human evolutionary history. Recent advances in high-throughput or so-called 'next-generation' DNA sequencing technologies have enabled the sequencing of thousands of individual human genomes, as well as a variety of reference genomes of hominids, many of which are publicly available. These sequence data can help to unveil the detailed demographic history of the lineage leading to humans as well as the explosion of modern human population size in the last several thousand years. In addition, high-throughput sequencing illustrates the tempo and mode of de novo mutations, which are producing human genetic variation at this moment. Pedigree-based human genome sequencing has shown that mutation rates vary significantly across the human genome. These studies have also provided an improved timescale of human evolution, because the mutation rate estimated from pedigree analysis is half that estimated from traditional analyses based on molecular phylogeny. Because of the dramatic reduction in sequencing cost, sequencing on-demand samples designed for specific studies is now also becoming popular. To produce data of sufficient quality to meet the requirements of the study, it is necessary to set an explicit sequencing plan that includes the choice of sample collection methods, sequencing platforms, and number of sequence reads.
人类基因组中发生的突变有助于深入了解进化历史的各个方面,如物种形成事件和自然选择程度。比较人类与大猩猩或人类之间的基因组序列是推断人类进化历史的可行方法。高通量或所谓的“下一代”DNA测序技术的最新进展使得数千个人类个体基因组以及多种原始人类参考基因组得以测序,其中许多都是公开可用的。这些序列数据有助于揭示人类谱系的详细人口历史以及过去几千年来现代人类人口规模的激增。此外,高通量测序还展示了新突变的速度和模式,这些新突变正在产生当下的人类遗传变异。基于家系的人类基因组测序表明,突变率在整个人类基因组中差异显著。这些研究还提供了一个改进后的人类进化时间尺度,因为从家系分析估计的突变率是基于分子系统发育的传统分析估计值的一半。由于测序成本大幅降低,为特定研究设计的按需测序样本现在也越来越普遍。为了生成足够高质量的数据以满足研究要求,有必要制定一个明确的测序计划,包括样本采集方法、测序平台和测序读数数量的选择。