Phylogenomics and Morphology of Extinct Paleognaths Reveal the Origin and Evolution of the Ratites
Phylogenomics and Morphology of Extinct Paleognaths Reveal the Origin and Evolution of the Ratites
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DOI：
10.1016/j.cub.2016.10.029
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发表时间：
2017-01
期刊：
影响因子：
9.2
通讯作者：
Takahiro Yonezawa;T. Segawa;Hiroshi Mori;P. Campos;Yuichi Hongoh;H. Endo;Ayumi Akiyoshi;N. Kohno;S. Nishida;Jiaqi Wu;Haofei Jin;J. Adachi;H. Kishino;K. Kurokawa;Y. Nogi;H. Tanabe;H. Mukoyama;Kunio Yoshida;Armand Rasoamiaramanana;S. Yamagishi;Y. Hayashi;A. Yoshida;H. Koike;F. Akishinonomiya;E. Willerslev;M. Hasegawa
中科院分区：
文献类型：
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作者：
Takahiro Yonezawa;T. Segawa;Hiroshi Mori;P. Campos;Yuichi Hongoh;H. Endo;Ayumi Akiyoshi;N. Kohno;S. Nishida;Jiaqi Wu;Haofei Jin;J. Adachi;H. Kishino;K. Kurokawa;Y. Nogi;H. Tanabe;H. Mukoyama;Kunio Yoshida;Armand Rasoamiaramanana;S. Yamagishi;Y. Hayashi;A. Yoshida;H. Koike;F. Akishinonomiya;E. Willerslev;M. Hasegawa
古颚类包括不会飞的平胸类和会飞的翼颚类，与新颚类一起组成现存的鸟纲。人们普遍认为古颚类起源于冈瓦纳，因为大多数现存物种都在南半球发现[1-3]。然而，这一假设受到质疑，因为化石古颌大多来自最早期（古新世）的北方半球，并具有许多假定的祖先特征[4]。古颌类起源和演化的不确定性源于难以估计它们的分歧时间[1，2]和它们显着的形态趋同。在这里，我们从灭绝的象鸟中恢复了核基因组片段，这使我们能够重建一个可靠的古颌类的基因组时间树。在此基础上，我们确定了古颌类形态特征的同源性，并重建了它们的形态学系统发育，包括没有分子数据的化石物种。与流行的理论相反，来自北方的古颌化石被放置为基底谱系。结合我们的稳定的分歧时间估计，使一个有效的参数与地质事件的相关性，我们提出了一个新的进化的情况下，与传统的观点相矛盾。根据分子进化速率估计，古颚类祖先是可迁的，起源于晚白垩世，生活在北方半球。它们迁移到南半球，并在古近纪-古近纪界线附近爆发性地形成。然后，他们通过海外扩散将分布范围扩大到冈瓦纳大陆，如新西兰和马达加斯加。巨人症随后在每个大陆上独立发生。
The Palaeognathae comprise the flightless ratites and the volant tinamous, and together with the Neognathae constitute the extant members of class Aves. It is commonly believed that Palaeognathae originated in Gondwana since most of the living species are found in the Southern Hemisphere [1–3]. However, this hypothesis has been questioned because the fossil paleognaths are mostly from the Northern Hemisphere in their earliest time (Paleocene) and possessed many putative ancestral characters [4]. Uncertainties regarding the origin and evolution of Palaeognathae stem from the difficulty in estimating their divergence times [1, 2] and their remarkable morphological convergence. Here, we recovered nuclear genome fragments from extinct elephant birds, which enabled us to reconstruct a reliable phylogenomic time tree for the Palaeognathae. Based on the tree, we identified homoplasies in morphological traits of paleognaths and reconstructed their morphology-based phylogeny including fossil species without molecular data. In contrast to the prevailing theories, the fossil paleognaths from the Northern Hemisphere were placed as the basal lineages. Combined with our stable divergence time estimates that enabled a valid argument regarding the correlation with geological events, we propose a new evolutionary scenario that contradicts the traditional view. The ancestral Palaeognathae were volant, as estimated from their molecular evolutionary rates, and originated during the Late Cretaceous in the Northern Hemisphere. They migrated to the Southern Hemisphere and speciated explosively around the Cretaceous-Paleogene boundary. They then extended their distribution to the Gondwana-derived landmasses, such as New Zealand and Madagascar, by overseas dispersal. Gigantism subsequently occurred independently on each landmass.