A new time tree reveals Earth history’s imprint on the evolution of modern birds
- 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: sclaramunt@amnh.org (S.C.); jlc@amnh.org (J.C.)
Science Advances 11 Dec 2015:
Vol. 1, no. 11, e1501005
DOI: 10.1126/sciadv.1501005
Abstract
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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