Phylogenomic evidence for multiple losses of flight in ratite birds

John Harshman, Edward L. Braun, Michael J. Braun, Christopher J. Huddleston, Rauri C.K. Bowie, Jena L. Chojnowski, Shannon J. Hackett, Kin Lan Han, Rebecca T. Kimball, Ben D. Marks, Kathleen J. Miglia, William S. Moore, Sushma Reddy, Frederick H. Sheldon, David W. Steadman, Scott J. Steppan, Christopher C. Witt, Tamaki Yuri

Research output: Contribution to journalArticlepeer-review

164 Scopus citations


Ratites (ostriches, emus, rheas, cassowaries, and kiwis) are large, flightless birds that have long fascinated biologists. Their current distribution on isolated southern land masses is believed to reflect the breakup of the paleocontinent of Gondwana. The prevailing view is that ratites are monophyletic, with the flighted tinamous as their sister group, suggesting a single loss of flight in the common ancestry of ratites. However, phylogenetic analyses of 20 unlinked nuclear genes reveal a genome-wide signal that unequivocally places tinamous within ratites, making ratites polyphyletic and suggesting multiple losses of flight. Phenomena that can mislead phylogenetic analyses, including long branch attraction, base compositional bias, discordance between gene trees and species trees, and sequence alignment errors, have been eliminated as explanations for this result. The most plausible hypothesis requires at least three losses of flight and explains the many morphological and behavioral similarities among ratites by parallel or convergent evolution. Finally, this phylogeny demands fundamental reconsideration of proposals that relate ratite evolution to continental drift.

Original languageEnglish (US)
Pages (from-to)13462-13467
Number of pages6
JournalProceedings of the National Academy of Sciences of the United States of America
Issue number36
StatePublished - Sep 9 2008
Externally publishedYes


  • Convergence
  • Flightlessness
  • Homoplasy
  • Paleognath
  • Vicariance biogeography


Dive into the research topics of 'Phylogenomic evidence for multiple losses of flight in ratite birds'. Together they form a unique fingerprint.

Cite this