ABSTRACT The evolution of avian flight remains one of biology’s major controversies, with a long history of functional interpretations of fossil forms given as evidence for either an

arboreal or cursorial origin of flight. Despite repeated emphasis on the ‘wing-stroke’ as a necessary avenue of investigation for addressing the evolution of flight1,2,3,4, no empirical data

exist on wing-stroke dynamics in an experimental evolutionary context. Here we present the first comparison of wing-stroke kinematics of the primary locomotor modes (descending flight and

incline flap-running) that lead to level-flapping flight in juvenile ground birds throughout development (Fig. 1). We offer results that are contrary both to popular perception and

ontogenetic-transitional wing hypothesis that posits that the incremental adaptive stages leading to the evolution of avian flight correspond behaviourally and morphologically to

transitional stages observed in ontogenetic forms. Access through your institution Buy or subscribe This is a preview of subscription content, access via your institution ACCESS OPTIONS

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institutional subscriptions * Read our FAQs * Contact customer support SIMILAR CONTENT BEING VIEWED BY OTHERS POWERED FLIGHT IN HATCHLING PTEROSAURS: EVIDENCE FROM WING FORM AND BONE

STRENGTH Article Open access 22 July 2021 LOW MORPHOLOGICAL DISPARITY AND DECELERATED RATE OF LIMB SIZE EVOLUTION CLOSE TO THE ORIGIN OF BIRDS Article 05 June 2023 MORPHOLOGICAL EVOLUTION OF

BIRD WINGS FOLLOWS A MECHANICAL SENSITIVITY GRADIENT DETERMINED BY THE AERODYNAMICS OF FLAPPING FLIGHT Article Open access 18 November 2023 REFERENCES * Gauthier, J. A. & Padian, K. in

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Biewener, M. Bundle, R. Callaway, H. Davis, S. Gatesy, D. Irschick, F. Jenkins, Jr, J. Maron, T. Martin, K. Padian and B. Tobalske. AUTHOR CONTRIBUTIONS K.P.D. provided the conceptual

foundation, funding and facilities. K.P.D. and B.E.J. wrote the manuscript. B.E.J. and P.S. performed most data acquisition and analyses. AUTHOR INFORMATION AUTHORS AND AFFILIATIONS *

Division of Biological Sciences, Flight Laboratory, University of Montana, 32 Campus Drive, Missoula, Montana 59812, USA, Kenneth P. Dial, Brandon E. Jackson & Paolo Segre Authors *

Kenneth P. Dial View author publications You can also search for this author inPubMed Google Scholar * Brandon E. Jackson View author publications You can also search for this author

inPubMed Google Scholar * Paolo Segre View author publications You can also search for this author inPubMed Google Scholar CORRESPONDING AUTHOR Correspondence to Kenneth P. Dial.

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ARTICLE Dial, K., Jackson, B. & Segre, P. A fundamental avian wing-stroke provides a new perspective on the evolution of flight. _Nature_ 451, 985–989 (2008).

https://doi.org/10.1038/nature06517 Download citation * Received: 20 August 2007 * Accepted: 27 November 2007 * Published: 23 January 2008 * Issue Date: 21 February 2008 * DOI:

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