Département de Biochimie, Centre Robert-Cedergren pour la Bioinformatique, Université de Montréal, Québec H3T1J4, Canada.
Evolution. 2012 Jun;66(6):1773-87. doi: 10.1111/j.1558-5646.2011.01558.x. Epub 2012 Jan 23.
Violation of the molecular clock has been amply documented, and is now routinely taken into account by molecular dating methods. Comparative analyses have revealed a systematic component in rate variation, relating it to the evolution of life-history traits, such as body size or generation time. Life-history evolution can be reconstructed using Brownian models. However, the resulting estimates are typically uncertain, and potentially sensitive to the underlying assumptions. As a way of obtaining more accurate ancestral trait and divergence time reconstructions, correlations between life-history traits and substitution rates could be used as an additional source of information. In this direction, a Bayesian framework for jointly reconstructing rates, traits, and dates was previously introduced. Here, we apply this model to a 17 protein-coding gene alignment for 73 placental taxa. Our analysis indicates that the coupling between molecules and life history can lead to a reevaluation of ancestral life-history profiles, in particular for groups displaying convergent evolution in body size. However, reconstructions are sensitive to fossil calibrations and to the Brownian assumption. Altogether, our analysis suggests that further integrating inference of rates and traits might be particularly useful for neontological macroevolutionary comparative studies.
分子钟的违反已经得到充分的证明，现在分子定年方法通常会考虑到这一点。比较分析揭示了速率变化中的系统成分，将其与生活史特征的进化联系起来，如体型或世代时间。可以使用布朗模型重建生活史进化。然而，由此产生的估计通常是不确定的，并且可能对基础假设敏感。作为获得更准确的祖先特征和分歧时间重建的一种方法，可以将生活史特征与替代率之间的相关性用作附加信息来源。在这方面，先前已经引入了一种用于联合重建速率、特征和日期的贝叶斯框架。在这里，我们将该模型应用于 73 个胎盘分类群的 17 个蛋白质编码基因对齐。我们的分析表明，分子与生活史之间的耦合可能导致对祖先生活史特征的重新评估，特别是对于在体型上表现出趋同进化的群体。然而，重建对化石校准和布朗假设敏感。总的来说，我们的分析表明，进一步整合速率和特征的推断可能对新的宏观进化比较研究特别有用。
