Leslie Andrew B, Simpson Carl, Mander Luke
Geological Sciences Department, Stanford University, 450 Jane Stanford Way, Building 320, Room 118, Stanford, CA 94305, USA.
Geological Sciences, University of Colorado Museum of Natural History, University of Colorado Boulder, Campus Box 265, Boulder, CO 80304, USA.
Science. 2021 Sep 17;373(6561):1368-1372. doi: 10.1126/science.abi6984. Epub 2021 Sep 16.
Morphological complexity is a notable feature of multicellular life, although whether it evolves gradually or in early bursts is unclear. Vascular plant reproductive structures, such as flowers, are familiar examples of complex morphology. In this study, we use a simple approach based on the number of part types to analyze changes in complexity over time. We find that reproductive complexity increased in two pulses separated by ~250 million years of stasis, including an initial rise in the Devonian with the radiation of vascular plants and a pronounced increase in the Late Cretaceous that reflects flowering plant diversification. These pulses are associated with innovations that increased functional diversity, suggesting that shifts in complexity are linked to changes in function regardless of whether they occur early or late in the history of vascular plants.
形态复杂性是多细胞生命的一个显著特征，尽管它是逐渐演化还是在早期爆发式演化尚不清楚。维管植物的繁殖结构，如花朵，就是形态复杂的常见例子。在本研究中，我们采用一种基于部分类型数量的简单方法来分析复杂性随时间的变化。我们发现，繁殖复杂性在两个脉冲式增长中增加，中间间隔约2.5亿年的停滞期，包括泥盆纪随着维管植物辐射出现的首次增长，以及白垩纪晚期反映开花植物多样化的显著增长。这些脉冲式增长与增加功能多样性的创新相关，这表明复杂性的转变与功能变化相关，无论它们发生在维管植物历史的早期还是晚期。
