Department of Ornithology, American Museum of Natural History, Central Park West at 79th Street, New York, NY 10024, USA.
Sci Adv. 2015 Dec 11;1(11):e1501005. doi: 10.1126/sciadv.1501005. eCollection 2015 Dec.
Determining the timing of diversification of modern birds has been difficult. We combined DNA sequences of clock-like genes for most avian families with 130 fossil birds to generate a new time tree for Neornithes and investigated their biogeographic and diversification dynamics. We found that the most recent common ancestor of modern birds inhabited South America around 95 million years ago, but it was not until the Cretaceous-Paleogene transition (66 million years ago) that Neornithes began to diversify rapidly around the world. Birds used two main dispersion routes: reaching the Old World through North America, and reaching Australia and Zealandia through Antarctica. Net diversification rates increased during periods of global cooling, suggesting that fragmentation of tropical biomes stimulated speciation. Thus, we found pervasive evidence that avian evolution has been influenced by plate tectonics and environmental change, two basic features of Earth's dynamics.
确定现代鸟类多样化的时间一直很困难。我们将大多数鸟类家族的类似时钟的基因的 DNA 序列与 130 种鸟类化石相结合，为新鸟纲生成了一个新的时间树，并研究了它们的生物地理和多样化动态。我们发现，现代鸟类的最近共同祖先大约在 9500 万年前生活在南美洲，但直到白垩纪-古近纪过渡时期（6600 万年前），新鸟纲才开始在世界各地迅速多样化。鸟类使用了两种主要的扩散路线：通过北美洲到达旧大陆，通过南极洲到达澳大利亚和新西兰。净多样化率在全球变冷期间增加，这表明热带生物群落的破碎刺激了物种形成。因此，我们发现了普遍的证据表明，鸟类进化受到了板块构造和环境变化的影响，这是地球动力学的两个基本特征。
