Lynch Michael
Department of Biology, Indiana University, Bloomington, IN 47405, USA.
Proc Natl Acad Sci U S A. 2007 May 15;104 Suppl 1(Suppl 1):8597-604. doi: 10.1073/pnas.0702207104. Epub 2007 May 9.
The vast majority of biologists engaged in evolutionary studies interpret virtually every aspect of biodiversity in adaptive terms. This narrow view of evolution has become untenable in light of recent observations from genomic sequencing and population-genetic theory. Numerous aspects of genomic architecture, gene structure, and developmental pathways are difficult to explain without invoking the nonadaptive forces of genetic drift and mutation. In addition, emergent biological features such as complexity, modularity, and evolvability, all of which are current targets of considerable speculation, may be nothing more than indirect by-products of processes operating at lower levels of organization. These issues are examined in the context of the view that the origins of many aspects of biological diversity, from gene-structural embellishments to novelties at the phenotypic level, have roots in nonadaptive processes, with the population-genetic environment imposing strong directionality on the paths that are open to evolutionary exploitation.
绝大多数从事进化研究的生物学家几乎都从适应性角度来解释生物多样性的各个方面。鉴于最近基因组测序和群体遗传学理论的观察结果，这种狭隘的进化观已变得站不住脚。如果不考虑遗传漂变和突变的非适应性力量，基因组结构、基因结构和发育途径的许多方面都难以解释。此外，诸如复杂性、模块化和可进化性等新兴生物学特征，目前都是大量推测的对象，它们可能只不过是在较低组织层次上运行的过程的间接副产品。这些问题是在这样一种观点的背景下进行审视的，即生物多样性的许多方面，从基因结构的修饰到表型水平的新奇事物，其起源都植根于非适应性过程，群体遗传环境对可供进化利用的路径施加了强大的方向性。
