Uma nova árvore temporal revela a impressão da história da Terra na evolução das aves modernas

segunda-feira, dezembro 21, 2015

A new time tree reveals Earth history’s imprint on the evolution of modern birds

Santiago Claramunt* and Joel Cracraft*

- Author Affiliations

Department of Ornithology, American Museum of Natural History, Central Park West at 79th Street, New York, NY 10024, USA.

↵*Corresponding author. E-mail: (S.C.); (J.C.)

Science Advances 11 Dec 2015:

Vol. 1, no. 11, e1501005

DOI: 10.1126/sciadv.1501005


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.

Keywords avian evolution global biogeography divergence times diversification rates K-Pg mass extinction

Copyright © 2015, The Authors

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