Crow Karen D, Wagner Günter P
Department of Ecology and Evolutionary Biology, Yale University, CT, USA.
Mol Biol Evol. 2006 May;23(5):887-92. doi: 10.1093/molbev/msj083. Epub 2005 Dec 20.
Gene and genome duplications provide a source of genetic material for mutation, drift, and selection to act upon, making new evolutionary opportunities possible. As a result, many have argued that genome duplication is a dominant factor in the evolution of complexity and diversity. However, a clear correlation between a genome duplication event and increased complexity and diversity is not apparent, and there are inconsistencies in the patterns of diversity invoked to support this claim. Interestingly, several estimates of genome duplication events in vertebrates are preceded by multiple extinct lineages, resulting in preduplication gaps in extant taxa. Here we argue that gen(om)e duplication could contribute to reduced risk of extinction via functional redundancy, mutational robustness, increased rates of evolution, and adaptation. The timeline for these processes to unfold would not predict immediate increases in species diversity after the duplication event. Rather, reduced probabilities of extinction would predict a latent period between a genome duplication and its effect on species diversity or complexity. In this paper, we will develop the idea that genome duplication could contribute to species diversity through reduced probability of extinction.
基因和基因组复制为突变、漂变和选择作用提供了遗传物质来源，使新的进化机会成为可能。因此，许多人认为基因组复制是复杂性和多样性进化的主导因素。然而，基因组复制事件与增加的复杂性和多样性之间并没有明显的相关性，并且用于支持这一说法的多样性模式存在不一致之处。有趣的是，脊椎动物基因组复制事件的几次估计之前都有多个灭绝谱系，导致现存分类群中存在复制前的空白。在这里，我们认为基因组复制可以通过功能冗余、突变稳健性、进化速率增加和适应性来降低灭绝风险。这些过程展开的时间线并不能预测复制事件后物种多样性会立即增加。相反，灭绝概率的降低预示着基因组复制与其对物种多样性或复杂性的影响之间会有一个潜伏期。在本文中，我们将阐述基因组复制可以通过降低灭绝概率来促进物种多样性的观点。
