Department of Evolution, Ecology, and Organismal Biology, University of California, Riverside, CA 92521, USA.
Department of Veterinary Integrative Biosciences, Texas A&M University, College Station, TX 77843, USA.
Mol Phylogenet Evol. 2018 Apr;121:158-165. doi: 10.1016/j.ympev.2018.01.007. Epub 2018 Jan 10.
The mammalian order Eulipotyphla includes four extant families of insectivorans: Solenodontidae (solenodons); Talpidae (moles); Soricidae (shrews); and Erinaceidae (hedgehogs). Of these, Solenodontidae includes only two extant species, which are endemic to the largest islands of the Greater Antilles: Cuba and Hispaniola. Most molecular studies suggest that eulipotyphlan families diverged from each other across several million years, with the basal split between Solenodontidae and other families occurring in the Late Cretaceous. By contrast, Sato et al. (2016) suggest that eulipotyphlan families diverged from each other in a polytomy ∼58.6 million years ago (Mya). This more recent divergence estimate for Solenodontidae versus other extant eulipotyphlans suggests that solenodons must have arrived in the Greater Antilles via overwater dispersal rather than vicariance. Here, we show that the young timetree estimates for eulipotyphlan families and the polytomy are due to an inverted ingroup-outgroup arrangement of the tree, the result of using Tracer rather than TreeAnnotator to compile interfamilial divergence times, and of not enforcing the monophly of well-established clades such as Laurasiatheria and Eulipotyphla. Finally, Sato et al.'s (2016) timetree includes several zombie lineages where estimated divergence times are much younger than minimum ages that are implied by the fossil record. We reanalyzed Sato et al.'s (2016) original data with enforced monophyly for well-established clades and updated fossil calibrations that eliminate the inference of zombie lineages. Our resulting timetrees, which were compiled with TreeAnnotator rather than Tracer, produce dates that are in good agreement with other recent studies and place the basal split between Solenodontidae and other eulipotyphlans in the Late Cretaceous.
鳞甲目(穿山甲);鼹形目(鼹鼠);鼩鼱目(鼩鼱);和刺猬目(刺猬)。在这些中,鳞甲目只包括两个现存的物种,它们是大安的列斯群岛中最大的岛屿的特有种:古巴和伊斯帕尼奥拉岛。大多数分子研究表明,真兽下目家族在几百万年内彼此分化,鳞甲目与其他家族的基部分裂发生在白垩纪晚期。相比之下,Sato 等人(2016 年)表明,真兽下目家族在约 5860 万年前(Mya)的一个多系发生分歧。这种对鳞甲目与其他现存真兽下目动物的更近的分化估计表明,穿山甲一定是通过跨海扩散而不是地理隔离到达大安的列斯群岛的。在这里,我们表明,真兽下目家族的年轻时间树估计和多系发生是由于树的内向群-外向群排列倒置的结果,这是使用 Tracer 而不是 TreeAnnotator 来编译种间分歧时间的结果,并且没有强制执行诸如劳亚兽总目和真兽下目等已确立的进化枝的单系性。最后,Sato 等人(2016 年)的时间树包括几个僵尸谱系,其中估计的分歧时间比化石记录所暗示的最小年龄年轻得多。我们用 TreeAnnotator 而不是 Tracer 重新分析了 Sato 等人(2016 年)的原始数据,强制执行了已确立的进化枝的单系性,并更新了化石校准,消除了僵尸谱系的推断。我们的结果时间树,是用 TreeAnnotator 而不是 Tracer 编译的,产生的日期与其他最近的研究一致,并将鳞甲目与其他真兽下目动物的基部分裂置于白垩纪晚期。