Sansom Robert S, Wills Matthew Albion, Williams Tamara
School of Earth and Environmental Sciences, University of Manchester, Oxford Road, Manchester M13 9PT, UK.
Department of Biology and Biochemistry, University of Bath, Claverton Down, Bath BA2 7AY, UK.
Syst Biol. 2017 Sep 1;66(5):813-822. doi: 10.1093/sysbio/syw116.
Phylogenetic trees underpin reconstructions of evolutionary history and tests of evolutionary hypotheses. They are inferred from both molecular and morphological data, yet the relative value of morphology has been questioned in this context due to perceived homoplasy, developmental linkage, and nonindependence of characters. Nevertheless, fossil data are limited to incomplete subsets of preserved morphology, and different regions are treated as equivalent. Through meta-analysis of 40 data sets, we show here that the dental and osteological characters of mammals convey significantly different phylogenetic signals, and that osteological characters are significantly more compatible with molecular trees. Furthermore, the application of simplified paleontological filters (retaining only dental data) results in significantly greater loss of phylogenetic signal than random character ablation. Although the mammal fossil record is largely comprised of teeth, dental data alone are generally found to be less reliable for phylogenetic reconstruction given their incongruence with osteological and molecular data. These findings highlight the need for rigorous meta-analyses of distributions of homoplasy in morphological data. These tests, and consequent refinements to phylogenetic analyses that they permit, promise to improve the quality of all macroevolutionary studies that hinge on accurate trees. [Homoplasy; Mammalia; morphology; osteology; phylogeny; teeth.
系统发育树是进化历史重建和进化假说检验的基础。它们是从分子和形态学数据中推断出来的,然而,由于存在趋同演化、发育联系和性状非独立性等问题,形态学在这方面的相对价值受到了质疑。尽管如此,化石数据仅限于保存形态的不完整子集,而且不同区域被视为等同。通过对40个数据集的荟萃分析,我们在此表明,哺乳动物的牙齿和骨骼特征传递出显著不同的系统发育信号,并且骨骼特征与分子树的兼容性显著更高。此外,应用简化的古生物学筛选方法(仅保留牙齿数据)导致系统发育信号的损失比随机去除性状要大得多。尽管哺乳动物化石记录大多由牙齿组成,但鉴于牙齿数据与骨骼和分子数据不一致,通常发现仅靠牙齿数据进行系统发育重建的可靠性较低。这些发现凸显了对形态学数据中趋同演化分布进行严格荟萃分析的必要性。这些检验以及由此允许对系统发育分析进行的改进,有望提高所有依赖准确树的宏观进化研究的质量。[趋同演化;哺乳纲;形态学;骨学;系统发育;牙齿。