Corrected placement of Mus-Rattus fossil calibration forces precision in the molecular tree of rodents.
Corrected placement of Mus-Rattus fossil calibration forces precision in the molecular tree of rodents.
复制标题
校正的肌肉校准力精度在啮齿动物的分子树中精确的放置。
DOI：
10.1038/srep14444
复制
发表时间：
2015-09-28
影响因子：
4.6
通讯作者：
Flynn LJ
中科院分区：
文献类型：
--
作者：
Kimura Y;Hawkins MT;McDonough MM;Jacobs LL;Flynn LJ
由化石记录得出的时间校准对于分子系统发育和进化研究是必不可少的。在巴基斯坦的Siwalik组发现的小鼠和大鼠化石，是分子系统学研究中最著名的化石校准点之一。尽管这些化石被广泛用作Mus/Rattus分裂的12 Ma年龄，或更基本的分裂，但缺乏关于结节分配的确凿古生物学证据。这项研究分析了在Siwalik小鼠化石记录中新发现的证明谱系分离的特征，并通过祖先状态重建检查了分子系统发育树中分歧谱系的最合理节点位置。我们基于标本的方法强烈表明，Karnimata分支的Siwalik小鼠是Arvicansini-Otomyini-Millardini分支的化石成员，该分支排除了Rattus及其近亲。结合新的解释和被广泛接受的Progonomys支系包括Mus的假设，Siwalik化石记录中的谱系分离事件代表了Mus/Arvicanthis分裂。我们对贝叶斯年龄估计的测试分析表明，这个新的校准点比以前的应用程序提供了更准确的小鼠分歧估计。因此，我们定义了这个化石校准点，并提炼了另外两个基于化石的点用于分子测年。
Time calibration derived from the fossil record is essential for molecular phylogenetic and evolutionary studies. Fossil mice and rats, discovered in the Siwalik Group of Pakistan, have served as one of the best-known fossil calibration points in molecular phylogenic studies. Although these fossils have been widely used as the 12 Ma date for the Mus/Rattus split or a more basal split, conclusive paleontological evidence for the nodal assignments has been absent. This study analyzes newly recognized characters that demonstrate lineage separation in the fossil record of Siwalik murines and examines the most reasonable nodal placement of the diverging lineages in a molecular phylogenetic tree by ancestral state reconstruction. Our specimen-based approach strongly indicates that Siwalik murines of the Karnimata clade are fossil members of the Arvicanthini-Otomyini-Millardini clade, which excludes Rattus and its relatives. Combining the new interpretation with the widely accepted hypothesis that the Progonomys clade includes Mus, the lineage separation event in the Siwalik fossil record represents the Mus/Arvicanthis split. Our test analysis on Bayesian age estimates shows that this new calibration point provides more accurate estimates of murine divergence than previous applications. Thus, we define this fossil calibration point and refine two other fossil-based points for molecular dating.