Molecular and morphological clocks for estimating evolutionary divergence times

BMC Evolutionary Biology

article

Barba-Montoya, Jose¹  Tao, Qiqing¹  Kumar, Sudhir¹ 

[1] Institute for Genomics and Evolutionary Medicine, Temple University;Department of Biology, Temple University;Center for Excellence in Genome Medicine and Research, King Abdulaziz University

关键词: Species divergence time estimation;    Molecular clock;    Morphological clock;    Fossil calibration;    Bayesian inference;   

DOI  :  10.1186/s12862-021-01798-6

学科分类：护理学

来源: BioMed Central

【 摘 要 】

Matrices of morphological characters are frequently used for dating species divergence times in systematics. In some studies, morphological and molecular character data from living taxa are combined, whereas others use morphological characters from extinct taxa as well. We investigated whether morphological data produce time estimates that are concordant with molecular data. If true, it will justify the use of morphological characters alongside molecular data in divergence time inference. We systematically analyzed three empirical datasets from different species groups to test the concordance of species divergence dates inferred using molecular and discrete morphological data from extant taxa as test cases. We found a high correlation between their divergence time estimates, despite a poor linear relationship between branch lengths for morphological and molecular data mapped onto the same phylogeny. This was because node-to-tip distances showed a much higher correlation than branch lengths due to an averaging effect over multiple branches. We found that nodes with a large number of taxa often benefit from such averaging. However, considerable discordance between time estimates from molecules and morphology may still occur as  some intermediate nodes may show large time differences between these two types of data. Our findings suggest that node- and tip-calibration approaches may be better suited for nodes with many taxa. Nevertheless, we highlight the importance of evaluating the concordance of intrinsic time structure in morphological and molecular data before any dating analysis using combined datasets.

【 授权许可】

CC BY|CC0