College of Life Sciences, Nanjing Normal University, Nanjing, China.
Department of Geosciences and Global Change Center, Virginia Tech, Blacksburg, VA, USA.
Nat Commun. 2022 Mar 22;13(1):1610. doi: 10.1038/s41467-022-29282-9.
The Ulvophyceae, a major group of green algae, is of particular evolutionary interest because of its remarkable morphological and ecological diversity. Its phylogenetic relationships and diversification timeline, however, are still not fully resolved. In this study, using an extensive nuclear gene dataset, we apply coalescent- and concatenation-based approaches to reconstruct the phylogeny of the Ulvophyceae and to explore the sources of conflict in previous phylogenomic studies. The Ulvophyceae is recovered as a paraphyletic group, with the Bryopsidales being a sister group to the Chlorophyceae, and the remaining taxa forming a clade (Ulvophyceae sensu stricto). Molecular clock analyses with different calibration strategies emphasize the large impact of fossil calibrations, and indicate a Meso-Neoproterozoic origin of the Ulvophyceae (sensu stricto), earlier than previous estimates. The results imply that ulvophyceans may have had a profound influence on oceanic redox structures and global biogeochemical cycles at the Mesoproterozoic-Neoproterozoic transition.
绿藻门是一类重要的绿藻，由于其显著的形态和生态多样性，具有特殊的进化意义。然而，其系统发育关系和多样化时间线仍未完全解决。在这项研究中，我们使用了广泛的核基因数据集，应用了合并分析和串联分析方法来重建绿藻门的系统发育，并探讨了先前系统基因组学研究中冲突的来源。绿藻门被重建为一个并系群，其中 Bryopsidales 是 Chlorophyceae 的姐妹群，其余类群形成一个分支（严格意义上的 Ulvophyceae）。使用不同校准策略的分子钟分析强调了化石校准的巨大影响，并表明 Ulvophyceae（严格意义上的）起源于中-新元古代，早于先前的估计。研究结果表明，绿藻门可能在中元古代-新元古代过渡时期对海洋氧化还原结构和全球生物地球化学循环产生了深远的影响。
