遗传多样性上限假说所揭示的进化历程

摘要

As two major popular theories to explain evolutionary facts, the neutral theory and Neo-Darwinism, despite their proven virtues in certain areas, still fail to offer comprehensive explanations to such fundamental evolutionary phenomena as the genetic equidistance result, abundant overlap sites, increase in complexity over time, incomplete understanding of genetic diversity, and inconsistencies with fossil and archaeological records. Maximum genetic diversity hypothesis (MGD), however, constructs a more complete evolutionary genetics theory that incorporates all of the proven virtues of existing theories and adds to them the novel concept of a maximum or optimum limit on genetic distance or diversity. It has yet to meet a contradiction and explained for the first time the half-century old Genetic Equidistance phenomenon as well as most other major evolutionary facts. It provides practical and quantitative ways of studying complexity. Molecular interpretation using MGD-based methods reveal novel insights on the origins of humans and other primates that are consis-rntent with fossil evidence and common sense, and reestablished the important role of China in the evolution of humans. MGD theory has also uncovered an important genetic mechanism in the construction of complex traits and the pathogenesis of complex diseases. We here made a series of sequence comparisons among yeasts, fishes and primates to illustrate the concept of limit on genetic distance. The idea of limit or optimum is in line with the yin-yang paradigm in the traditional Chinese view of the universal creative law in nature.%作为生物进化的两个主流理论,中性学说和现代达尔文进化理论相对系统地揭示了进化机理和历程,但 也都有缺陷,比如对某些重大进化现象如遗传等距离和重叠位点(Overlap sites)的忽视,对复杂性的视而不见,对遗传多样性的片面解读,以及与化石证据相悖等.遗传多样性上限假说(Maximum genetic diversity hypothesis,MGD)通过对遗传等距离现象的重新解读,给出了复杂性的量化定义和可操作研究手段,提出了重叠特征和遗 传多样性具有上限等结论.它对人猿分类关系和现代人多地区起源的分子解读结论,与独立的化石证据契合度 较高,重新肯定了中国在人类发展中的关键作用,点出了流行分子结论的荒谬在于误用了极限距离.该理论同 时对复杂性状和复杂疾病的遗传机制研究具有指导意义.文章对多种酵母、鱼类、灵长类的细胞色素c 进行序 列比对,独立验证了MGD 假说的部分论断,并解释了重叠位点在遗传距离计算上的重要意义.MGD 假说中的 上限或最佳平衡概念,与传统国学和中医阴阳中庸思想对宇宙基本规律的描述是一脉相承的.