Posgrado en Ciencias Biológicas, Universidad Nacional Autónoma de México, Edificio D, 1° Piso, Circuito de Posgrados, Ciudad Universitaria, Coyoacán, Ciudad de México 04510, Mexico.
Departamento de Botánica, Instituto de Biología, Universidad Nacional Autónoma de México, 3er Circuito de Ciudad Universitaria, Coyoacán, Ciudad de México 04510, Mexico.
Syst Biol. 2023 Aug 7;72(4):837-855. doi: 10.1093/sysbio/syad017.
Fossils are essential to infer past evolutionary processes. The assignment of fossils to extant clades has traditionally relied on morphological similarity and on apomorphies shared with extant taxa. The use of explicit phylogenetic analyses to establish fossil affinities has so far remained limited. In this study, we built a comprehensive framework to investigate the phylogenetic placement of 24 exceptionally preserved fossil flowers. For this, we assembled a new species-level data set of 30 floral traits for 1201 extant species that were sampled to capture the stem and crown nodes of all angiosperm families. We explored multiple analytical approaches to integrate the fossils into the phylogeny, including different phylogenetic estimation methods, topological-constrained analyses, and combining molecular and morphological data of extant and fossil species. Our results were widely consistent across approaches and showed minor differences in the support of fossils at different phylogenetic positions. The placement of some fossils agrees with previously suggested relationships, but for others, a new placement is inferred. We also identified fossils that are well supported within particular extant families, whereas others showed high phylogenetic uncertainty. Finally, we present recommendations for future analyses combining molecular and morphological evidence, regarding the selection of fossils and appropriate methodologies, and provide some perspectives on how to integrate fossils into the investigation of divergence times and the temporal evolution of morphological traits. [Angiosperms; fossil flowers; phylogenetic uncertainty; RoguePlots.].
化石对于推断过去的进化过程至关重要。传统上，化石与现存进化枝的归属依赖于形态相似性以及与现存分类群共享的特徵。利用明确的系统发育分析来确定化石亲缘关系的方法迄今为止仍然有限。在这项研究中，我们构建了一个综合框架来研究 24 个保存异常完好的化石花的系统发育位置。为此，我们为 1201 个现存物种组装了一个新的 30 个花部性状的种级数据集，这些物种被采样以捕获所有被子植物科的茎和冠群节点。我们探索了多种分析方法将化石纳入系统发育，包括不同的系统发育估计方法、拓扑约束分析以及结合现存和化石物种的分子和形态数据。我们的结果在不同的方法之间广泛一致，并显示了在不同系统发育位置化石支持程度的微小差异。一些化石的位置与先前提出的关系一致，但对于其他化石，则推断出一个新的位置。我们还确定了一些在特定现存科中得到很好支持的化石，而其他化石则显示出较高的系统发育不确定性。最后，我们就如何结合分子和形态证据提出了未来分析的建议，包括化石和适当方法的选择，并就如何将化石纳入对分歧时间和形态特徵的时间演化的研究提出了一些观点。[被子植物；化石花；系统发育不确定性； RoguePlots]。
