A Protocol for Diagnosing the Effect of Calibration Priors on Posterior Time Estimates: A Case Study for the Cambrian Explosion of Animal Phyla
A Protocol for Diagnosing the Effect of Calibration Priors on Posterior Time Estimates: A Case Study for the Cambrian Explosion of Animal Phyla
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DOI：
10.1093/molbev/msv075
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发表时间：
2015-07-01
影响因子：
10.7
通讯作者：
Kumar, Sudhir
中科院分区：
文献类型：
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作者：
Battistuzzi, Fabia U.;Billing-Ross, Paul;Kumar, Sudhir
我们提出了一个程序来测试校准先验估计时间的影响，它适用于最近开发的校准免费的方法（RelTime）的方法，产生相对发散时间的树中的所有节点。我们通过将其应用于后生动物多样化的一个树来说明该协议（Erwin DH，Laflamme M，Tweedt SM，Sperling EA，Pisani D，Peterson KJ。2011.寒武纪之谜：动物早期历史中的早期分歧和后来的生态成功。Science 334：1091-1097.），这使得动物门的分化与从化石记录中推断的寒武纪大爆发的时间接近。这些分析表明，在前寒武纪的两个最大的校准先验是在这项研究中的动物门之间的年轻的分歧时间的主要决定因素。事实上，这两个仅最大值校准产生的发散时间严重违反了几乎所有其他22个校准约束的最小边界。使用这22个校准产生的日期后生动物的分歧是数亿年前的元古代。我们的研究结果鼓励使用免校准方法来确定最有影响力的校准约束，并评估其影响，以实现生物学上的强大解释。
We present a procedure to test the effect of calibration priors on estimated times, which applies a recently developed calibration-free approach (RelTime) method that produces relative divergence times for all nodes in the tree. We illustrate this protocol by applying it to a timetree of metazoan diversification (Erwin DH, Laflamme M, Tweedt SM, Sperling EA, Pisani D, Peterson KJ. 2011. The Cambrian conundrum: early divergence and later ecological success in the early history of animals. Science 334: 1091-1097.), which placed the divergence of animal phyla close to the time of the Cambrian explosion inferred from the fossil record. These analyses revealed that the two maximum-only calibration priors in the pre-Cambrian are the primary determinants of the young divergence times among animal phyla in this study. In fact, these two maximum-only calibrations produce divergence times that severely violate minimum boundaries of almost all of the other 22 calibration constraints. The use of these 22 calibrations produces dates for metazoan divergences that are hundreds of millions of years earlier in the Proterozoic. Our results encourage the use of calibration-free approaches to identify most influential calibration constraints and to evaluate their impact in order to achieve biologically robust interpretations.