Bapteste Eric, Walsh David A
Canadian Institute for Advanced Research Program in Evolutionary Biology, Department of Biochemistry and Molecular Biology, Dalhousie University, 5850 College Street, Halifax, Nova Scotia, B3H 1X5, Canada.
Trends Microbiol. 2005 Jun;13(6):256-61. doi: 10.1016/j.tim.2005.03.012.
In a recent stimulating paper, Rivera and Lake applied a new phylogenetic method to study the evolution of genomes, which challenges the classical representation of the Tree of Life. Acknowledging the evolutionary importance of lateral gene transfer, they used the conditioned genome approach to reconstruct the Tree of Life, and in the end proposed a Ring of Life. They explained that the Ring of Life structure is a result of a single fusion event between two prokaryotic genomes at the base of the eukaryotic tree, probably between the ancestors of a photosynthetic bacterium and an archaeon. Because this constitutes an important conclusion with regards to the evolutionary process and origin of the eukaryotic cell, their work deserves further attention before these conclusions can be accepted. Here we question the reconstruction and the meaning of the Ring of Life. In addition to general problems associated with gene-content-based phylogenetic analyses, we discuss some implicit premises and potential weaknesses of the conditioned genome method and conclude that, although Rivera and Lake's conclusions might be right, they have not been established by their current approach.
在最近一篇引人深思的论文中，里维拉和莱克应用了一种新的系统发育方法来研究基因组的进化，这对生命之树的传统表示提出了挑战。他们认识到横向基因转移在进化中的重要性，采用条件基因组方法来重建生命之树，最终提出了生命环。他们解释说，生命环结构是真核生物树基部两个原核基因组之间一次单一融合事件的结果，可能发生在光合细菌和古菌的祖先之间。由于这一结论对于真核细胞的进化过程和起源具有重要意义，在这些结论被接受之前，他们的工作值得进一步关注。在此，我们对生命环的重建及其意义提出质疑。除了与基于基因含量的系统发育分析相关的一般问题外，我们还讨论了条件基因组方法的一些隐含前提和潜在弱点，并得出结论，尽管里维拉和莱克的结论可能是正确的，但他们目前的方法尚未证实这些结论。
