Wu Shaoyuan, Tao Ziqi, Liu Liang, Marshall Charles R, Edwards Scott V, Zhou Zhonghe, Rheindt Frank E
Jiangsu Key Laboratory of Phylogenomics & Comparative Genomics, School of Life Sciences, Jiangsu Normal University, Xuzhou 221116, China.
Linguistic Science Laboratory of Jiangsu Normal University, Laboratory of Philosophy and Social Sciences at Universities in Jiangsu Province, Xuzhou 221009, China.
Natl Sci Rev. 2025 Jun 9;12(7):nwaf238. doi: 10.1093/nsr/nwaf238. eCollection 2025 Jul.
Macroevolutionary forces, such as rare catastrophes, have repeatedly disrupted and reset the evolutionary trajectories of Earth's major organismal groups. The Cretaceous-Paleogene (K/Pg) extinction event, approximately 66 Ma, resulted in the demise of ∼75% of all species at the time, yet despite its magnitude, many major organismal lineages successfully passed through this mass extinction. The evolutionary origins of modern birds (crown-group Aves) remain a subject of substantial debate, as they are often thought to have undergone their primary diversification following the K/Pg boundary. In this review, we summarize the various approaches that have been applied to understanding the timing of avian diversification. We examine the inferred divergence times derived from modern phylogenomic studies based on datasets comprising 50 to over 300 whole genomes. Additionally, we evaluate the factors contributing to the continued discrepancies in divergence time estimates. Furthermore, we discuss significant new fossil discoveries from the Late Jurassic and Late Cretaceous periods that reshape our understanding of key evolutionary events in early avian diversification. Taken together, the paleontological evidence increasingly supports a Cretaceous origin for many extant bird lineages, with the major burst of ordinal diversification likely occurring prior to the K/Pg boundary-concurrent with the early radiations of flowering plants, pollinating insects, mammals, fishes and other groups that characterized the Cretaceous Angiosperm Terrestrial Revolution.
宏观进化力量，如罕见的灾难，多次扰乱并重置了地球上主要生物类群的进化轨迹。大约6600万年前的白垩纪-古近纪（K/Pg）灭绝事件导致当时约75%的物种灭绝，然而尽管其规模巨大，许多主要生物谱系还是成功地度过了这次大灭绝。现代鸟类（冠群鸟类）的进化起源仍然是一个备受争议的话题，因为人们通常认为它们在K/Pg边界之后经历了主要的多样化过程。在这篇综述中，我们总结了用于理解鸟类多样化时间的各种方法。我们研究了基于包含50到300多个全基因组的数据集从现代系统发育基因组学研究中推断出的分歧时间。此外，我们评估了导致分歧时间估计持续存在差异的因素。此外，我们讨论了来自晚侏罗世和晚白垩世时期的重大新化石发现，这些发现重塑了我们对早期鸟类多样化关键进化事件的理解。综合来看，古生物学证据越来越支持许多现存鸟类谱系起源于白垩纪，目级多样化的主要爆发可能发生在K/Pg边界之前——与开花植物、传粉昆虫及其它构成白垩纪被子植物陆地革命特征的类群的早期辐射同时发生。
