Center for Molecular Medicine and Genetics and Department of Anatomy and Cell Biology, Wayne State University School of Medicine, Detroit, MI 48201, USA.
Proc Natl Acad Sci U S A. 2010 May 11;107 Suppl 2(Suppl 2):8918-23. doi: 10.1073/pnas.0914626107. Epub 2010 May 5.
In Charles Darwin's tree model for life's evolution, natural selection adaptively modifies newly arisen species as they branch apart from their common ancestor. In accord with this Darwinian concept, the phylogenomic approach to elucidating adaptive evolution in genes and genomes in the ancestry of modern humans requires a well supported and well sampled phylogeny that accurately places humans and other primates and mammals with respect to one another. For more than a century, first from the comparative immunological work of Nuttall on blood sera and now from comparative genomic studies, molecular findings have demonstrated the close kinship of humans to chimpanzees. The close genetic correspondence of chimpanzees to humans and the relative shortness of our evolutionary separation suggest that most distinctive features of the modern human phenotype had already evolved during our ancestry with chimpanzees. Thus, a phylogenomic assessment of being human should examine earlier stages of human ancestry as well as later stages. In addition, with the availability of a number of mammalian genomes, similarities in phenotype between distantly related taxa should be explored for evidence of convergent or parallel adaptive evolution. As an example, recent phylogenomic evidence has shown that adaptive evolution of aerobic energy metabolism genes may have helped shape such distinctive modern human features as long life spans and enlarged brains in the ancestries of both humans and elephants.
在查尔斯·达尔文的生命进化树模型中，自然选择会适应性地改变新出现的物种，因为它们与共同祖先分支开来。根据这个达尔文概念，阐明现代人类祖先中基因和基因组适应性进化的系统基因组学方法需要一个有充分支持和充分采样的系统发育树，该树能够准确地将人类与其他灵长类动物和哺乳动物相互之间进行定位。一个多世纪以来，首先是从纳托尔（Nuttall）关于血液血清的比较免疫学工作，现在是从比较基因组学研究，分子发现都证明了人类与黑猩猩的密切亲缘关系。黑猩猩与人类的遗传密切对应，以及我们进化分离的相对短暂性表明，现代人类表型的大多数独特特征在我们与黑猩猩的祖先中就已经进化了。因此，对人类身份的系统基因组学评估应该既检查人类祖先的早期阶段，也检查后期阶段。此外，随着许多哺乳动物基因组的出现，应该探索远缘分类群之间表型的相似性，以寻找趋同或平行适应性进化的证据。例如，最近的系统基因组学证据表明，有氧能量代谢基因的适应性进化可能有助于塑造人类和大象的祖先中长寿命和大脑增大等独特的现代人类特征。
