Tempo and mode of modern bird evolution observed with large-scale taxonomic sampling

Abstract

Macroevolutionists continue to disagree about the evolutionary history of birds. Their debate centers on the apparent discrepancy between molecular- and fossil-derived times of certain events. In this study we will show that there is much more agreement than discrepancy. We do it by simultaneously using both molecules (DNA hybridization and DNA sequence) and fossils to study a large set of avian taxa. Our analysis focuses on the time of origin and diversification of most of the orders and families of extant birds. Both tools show that the Cretaceous–Tertiary transition witnessed a major ordinal diversification within extant birds. Both also show a pulse of family diversification near the Eocene–Oligocene transition. Thus both of these pulses occurred close to times of mass extinction. The presented evolutionary time scale for extant birds launches testing of novel inter-disciplinary hypotheses.

Keywords:

• Avian
• molecular clock
• divergence time
• fossil record
• cretaceous
• tertiary

Acknowledgements

We would like to thank Gareth Dyke, Blair Hedges, Sylvia Hope, Gerald Mayr and Kevin Padian for many discussions of the bird fossil record and members of the Hadly lab for additional comments. Michael Foote, Hirohisa Kishino, Arne Mooers, Kevin Padian, Michael Rosenzweig, Chris Simon, Jeff Thorne, and an anonymous reviewer provided many constructive comments. This work was supported in part by a postdoctoral TALENT fellowship from the Netherlands Organization for Scientific Research. TAS was supported by postdoctoral funding through the Laboratory of Human Evolutionary Studies, UC Berkeley.