Department of Biology, University of Fribourg, Fribourg, Switzerland.
Swiss Institute of Bioinformatics, Fribourg, Switzerland.
Nat Ecol Evol. 2021 Apr;5(4):449-457. doi: 10.1038/s41559-020-01387-8. Epub 2021 Jan 28.
Flowering plants (angiosperms) are the most diverse of all land plants, becoming abundant in the Cretaceous and achieving dominance in the Cenozoic. However, the exact timing of their origin remains a controversial topic, with molecular clocks generally placing their origin much further back in time than the oldest unequivocal fossils. To resolve this discrepancy, we developed a Bayesian method to estimate the ages of angiosperm families on the basis of the fossil record (a newly compiled dataset of ~15,000 occurrences in 198 families) and their living diversity. Our results indicate that several families originated in the Jurassic, strongly rejecting a Cretaceous origin for the group. We report a marked increase in lineage accumulation from 125 to 72 million years ago, supporting Darwin's hypothesis of a rapid Cretaceous angiosperm diversification. Our results demonstrate that a pre-Cretaceous origin of angiosperms is supported not only by molecular clock approaches but also by analyses of the fossil record that explicitly correct for incomplete sampling.
开花植物(被子植物)是所有陆地植物中最多样化的,在白垩纪变得丰富,并在新生代占据主导地位。然而,它们的确切起源时间仍然是一个有争议的话题,分子钟通常将它们的起源时间设定在比最古老的明确化石还要久远的时间。为了解决这一差异,我们开发了一种贝叶斯方法,根据化石记录(一个包含约 15000 个在 198 个科中的出现的新数据集)和它们的现存多样性来估计被子植物科的年龄。我们的结果表明,有几个科起源于侏罗纪,强烈反对该群体的白垩纪起源说。我们报告了从 1.25 亿年前到 7200 万年前谱系积累的显著增加,这支持了达尔文关于白垩纪被子植物快速多样化的假说。我们的结果表明,被子植物的早白垩纪起源不仅得到了分子钟方法的支持,也得到了明确纠正不完全采样偏差的化石记录分析的支持。