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Vestibular evidence for the evolution of aquatic behaviour in early cetaceans

Nature volume 417, pages 163–166 (2002)Cite this article

Abstract

Early cetaceans evolved from terrestrial quadrupeds to obligate swimmers, a change that is traditionally studied by functional analysis of the postcranial skeleton 1 . Here we assess the evolution of cetacean locomotor behaviour from an independent perspective by looking at the semicircular canal system, one of the main sense organs involved in neural control of locomotion2. Extant cetaceans are found to be unique in that their canal arc size, corrected for body mass, is approximately three times smaller than in other mammals. This reduces the sensitivity of the canal system, most plausibly to match the fast body rotations that characterize cetacean behaviour. Eocene fossils show that the new sensory regime, incompatible with terrestrial competence, developed quickly and early in cetacean evolution, as soon as the taxa are associated with marine environments. Dedicated agile swimming of cetaceans thus appeared to have originated as a rapid and fundamental shift in locomotion rather than as the gradual transition suggested by postcranial evidence. We hypothesize that the unparalleled modification of the semicircular canal system represented a key ‘point of no return’ event in early cetacean evolution, leading to full independence from life on land.

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Figure 1: Lateral view of left bony labyrinths.
Figure 2: Relationship of semicircular canal and cochlea sizes to body mass.
Figure 3: Cladogram showing the phylogenetic relationship of Eocene cetacean taxa examined here, their sister group the artiodactyls and the modern mysticetes and odontocetes.

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References

  1. Thewissen, J. G. M. in The Emergence of Whales (ed. Thewissen, J. G. M.) 451–464 (Plenum, New York, 1998).

    Google Scholar 

  2. Schwartz, D. W. F. & Tomlinson, R. D. in Neurotology (eds Jackler, R. K. & Brackmann, D. E.) 59–98 (Mosby, St Louis, 1994).

    Google Scholar 

  3. Gingerich, P. D., Smith, B. H. & Simons, E. L. Hind limbs of Eocene Basilosaurus: evidence of feet in whales. Science 249, 154–157 (1990).

    Article  ADS  CAS  PubMed  Google Scholar 

  4. Thewissen, J. G. M., Hussain, S. T. & Arif, M. Fossil evidence for the origin of aquatic locomotion in archaeocete whales. Science 263, 210–212 (1994).

    Article  ADS  CAS  PubMed  Google Scholar 

  5. Gingerich, P. D., Arif, M., Clyde, W. C. New archeocetes (Mammalia, Cetacea) from the middle Eocene Domanda Formation of the Sulaiman Range, Punjab (Pakistan). Contrib. Mus. Paleontol. Univ. Michigan 29, 291–330 (1995).

    Google Scholar 

  6. Hulbert, R. C. in The Emergence of Whales (ed. Thewissen, J. G. M.) 235–267 (Plenum, New York, 1998).

    Book  Google Scholar 

  7. Bajpai, S. & Thewissen, J. G. M. A new, dimunitive Eocene whale from Kachchh (Gujarat, India) and its implications for locomotor evolution of cetaceans. Curr. Sci. 79, 1478–1482 (2000).

    Google Scholar 

  8. Gingerich, P. D., Ul Haq, M., Zalmout, L. S., Khan, I. H. & Malkani, M. S. Origin of whales for early artiodactyls: hand and feet of Eocene Protocetidae from Pakistan. Science 293, 2239–2242 (2001).

    Article  ADS  CAS  PubMed  Google Scholar 

  9. Thewissen, J. G. M., Williams, E. M. & Hussain, S. T. Skeletons of terrestrial cetaceans and the relationship of whales to artiodactyls. Nature 413, 277–281 (2001).

    Article  ADS  CAS  PubMed  Google Scholar 

  10. Uhen, M. in The Emergence of Whales (ed. Thewissen, J. G. M.) 29–61 (Plenum, New York, 1998).

    Book  Google Scholar 

  11. Thewissen, J. G. M. & Fish, F. E. Locomotor evolution in the earliest cetaceans: functional model, modern analogues, and paleontological evidence. Paleobiology 23, 482–490 (1997).

    Article  Google Scholar 

  12. Oman, C. M., Marcus, E. N. & Curthoys, I. S. The influence of the semicircular canal morphology on endolymph flow dynamics. Acta Otolaryngol. 103, 1–13 (1987).

    Article  CAS  PubMed  Google Scholar 

  13. Muller, M. Semicircular duct dimensions and sensitivity of the vertebrate vestibular system. J. Theor. Biol. 167, 239–256 (1994).

    Article  Google Scholar 

  14. Spoor, F. & Zonneveld, F. Comparative review of the human bony labyrinth. Yb. Phys. Anthropol. 41, 211–251 (1998).

    Article  Google Scholar 

  15. Spoor, F. The semicircular canal system and locomotor behaviour, with special reference to hominin evolution. Courier Forschungsinstitut Senckenberg (in the press).

  16. Hyrtl, J. Vergleichend-anatomische Untersuchungen Über das innere Gehörorgan des Menschen und der Säugethiere (Ehrlich, Prague, 1845).

    Google Scholar 

  17. Gray, A. A. The Labyrinth of Animals Vol. 2 (Churchill, London, 1908).

    Google Scholar 

  18. Yamada, M. & Yoshizaki, F. Osseous labyrinth of Cetacea. Sci. Rep. Whale Res. Inst. (Tokyo) 14, 291–304 (1959).

    Google Scholar 

  19. Fleischer, G. Hearing in extinct cetaceans as determined by cochlear structure. J. Paleontol. 50, 133–152 (1976).

    Google Scholar 

  20. Ketten, D. R. in Marine Mammals Sensory Systems (ed. Thomas, J.) 53–57 (Plenum, New York, 1992).

    Book  Google Scholar 

  21. Luo, Z. & Eastman, E. R. Petrosal and inner ear of a squalodontoid whale: implications for evolution of hearing in odontocetes. J. Vert. Palaeont. 15, 431–442 (1995).

    Article  Google Scholar 

  22. Luo, Z. & Marsh, K. Petrosal (periotic) and inner ear of a Pliocene kogiine whale (Kogiinae, Odontoceti): implications on the relationships and hearing evolution of toothed whales. J. Vert. Paleontol. 16, 328–348 (1996).

    Article  Google Scholar 

  23. Geisler, J. H. & Luo, Z. The petrosal and inner ear of Herpetocetus sp. (Mammalia: Cetacea) and their implications for the phylogeny and hearing of archaic mysticetes. J. Paleontol. 70, 1045–1066 (1996).

    Article  Google Scholar 

  24. Williams, E. M. in The Emergence of Whales (ed. Thewissen, J. G. M.) 1–28 (Plenum, New York, 1998).

    Book  Google Scholar 

  25. Madar, S. I. in The Emergence of Whales (ed. Thewissen, J. G. M.) 353–377 (Plenum, New York, 1998).

    Book  Google Scholar 

  26. Buchholtz, E. A. in The Emergence of Whales (ed. Thewissen, J. G. M.) 325–351 (Plenum, New York, 1998).

    Book  Google Scholar 

  27. Gingerich, P. D. in The Emergence of Whales (ed. Thewissen, J. G. M.) 423–449 (Plenum, New York, 1998).

    Book  Google Scholar 

  28. Spoor, C. F. & Zonneveld, F. W. Morphometry of the primate bony labyrinth: a new method based on high-resolution computed tomography. J. Anat. 186, 271–286 (1995).

    PubMed  PubMed Central  Google Scholar 

  29. Marino, L. et al. Endocranial volume of mid-late Eocene archaeocetes (order: Cetacea) revealed by computed tomography: implications for cetacean brain evolution. J. Mamm. Evol. 7, 81–94 (2000).

    Article  Google Scholar 

  30. Höhne, K. H. et al. A new representation of knowledge concerning human anatomy and function. Nature Med. 1, 506–511 (1995).

    Article  ADS  PubMed  Google Scholar 

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Acknowledgements

We thank E. Allen, H. Chatterjee, J. Hooker, J. Mead, C. Potter and T. Yamada for access to specimens, and R. Barton, E. Blum, M. Colbert, C. Dean, J. DePonte, B. Frohlich, K. Grecco, K. H. Höhne, N. Jeffery, B. Jonsdottir, W. Jungers, R. Ketcham, K. Kupczik, D. Lieberman, Z. Luo, J. Moore, M. Muller, J. Neiger, C. Pellow, D. Plummer, A. Pommert, C. Ross, G. B. Schneider and A. Walker for their help. This research was supported by grants for the UCL Graduate School to F.S. and from the NSF to J.G.M.T. and S.T.H.

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Authors and Affiliations

  1. Department of Anatomy & Developmental Biology, University College London, Rockefeller Building, University Street, London, WC1E 6JJ, UK

    F. Spoor

  2. Developmental Biology, University College London, Rockefeller Building,

    F. Spoor

  3. Department of Earth Sciences, Indian Institute of Technology, Roorkee, 247 667, India

    S. Bajpai

  4. Department of Anatomy, College of Medicine, Howard University, Washington, 20059, DC, USA

    S. T. Hussain

  5. Wadia Institute of Himalayan Geology, Dehradun, 248 001, India

    K. Kumar

  6. Department of Anatomy, Northeastern Ohio Universities College of Medicine, Rootstown, 44272, Ohio, USA

    J. G. M. Thewissen

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Correspondence to F. Spoor.

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Spoor, F., Bajpai, S., Hussain, S. et al. Vestibular evidence for the evolution of aquatic behaviour in early cetaceans. Nature 417, 163–166 (2002). https://doi.org/10.1038/417163a

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