Knuckle-Walking and the Origin of Human Bipedalism

  • David R. Begun


Functional analysis of fossil great apes and humans indicate that no known fossil taxon was a habitual knuckle-walker. However, the phylogenetic relations among hominoids suggests that the last common ancestor of the African apes and humans was in fact a knuckle-walker. Anatomical, fossil and molecular evidence of relations among the Hominoidea strongly suggest than Pan and Homo share a common ancestor not shared by any other living taxon. If this is correct, then knuckle-walking must have evolved once in the common ancestor of Pan, Gorilla and Homo (in which it was lost), or twice, independently in each African ape lineage. In addition to being less parsimonious, most multiple origins hypotheses for knuckle-walking also fail to account for characters shared by African apes and humans that are plausibly functionally related to increased terrestriality. These include vertebral, limb and intra-limb proportions, and limb long bone, carpal, tarsal and metapodial, and phalangeal morphology. In theory, knuckle-walking and obligate bipedalism could have evolved from an unknown type of terrestrial quadrupedalism, possibly associated with high frequencies of facultative bipedality. This would also account for characters and positional behavior shared by African apes and humans, the differences between Pan and Gorilla, and the apparent retention of primitive features of the trunk in humans. However, it implies a substantial increase in homoplasy as well as a hypothetical ancestral morphotype unkown in any group or out group. Functional anatomy and phylogeny together continue to suggest that humans are most likely to have evolved from a knuckle-walker. However, a functionally plausible, though less parsimonious facultative bipedality hypothesis is also possible. In this regard, hints of the unique functional morphology of Ardipithecus ramidus suggest that this taxon would serve to test these two alternatives.


Joint Surface Positional Behavior Physical Anthropology Fossil Hominid Fossil Human 
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  1. Alberch, P. and Alberch, J., 1980, Heterochronic mechanisms of morphological diversification and evolutionary change in the neotropical salamander, Bolitoglossa occidentalis (Amphibia, Plethodontidae). Journal of Morphology 167:249–264.CrossRefGoogle Scholar
  2. Beard, K. C., Teaford, M. K., and Walker, A., 1986, New wrist bones of Proconsul africanus and Proconsul nyanzae from Rusinga Island, Kenya. Folia Primatologica 47:97–118.CrossRefGoogle Scholar
  3. Begun, D. R., 1988, Catarrhine phalanges from the Late Miocene (Vallesian) of Rudabanya. Journal of Human Evolution 17:413–438.CrossRefGoogle Scholar
  4. Begun, D. R., 1992a, Miocene fossil hominids and the chimp-human clade. Science 257:1929–1933.CrossRefGoogle Scholar
  5. Begun, D. R., 1992b, Phyletic diversity and locomotion in primitive European hominids. American Journal of Physical Anthropology 87:311–340.CrossRefGoogle Scholar
  6. Begun, D. R., 1993, New catarrhine phalanges fron Rudabanya (Northeastern Hungary) and the problem of parallelism and convergence in hominoid postcranial morphology. Journal of Human Evolution 24:373–402.CrossRefGoogle Scholar
  7. Begun, D. R., 1994, Relations among the great apes and humans: New interpretations based on the fossil great ape Dryopithecus. Yearbook of Physical Anthropoogy 37:11–63.Google Scholar
  8. Begun, D. R., 1999, Hominid family values: morphological and molecular data on relations among the great apes and humans. In The Mentalities of Gorillas and Orangutans. Comparative perspectives, edited by S. T. Parker, R. W. Mitchell, and H. L. Miles, pp. 3–42. Cambridge University Press, Cambridge.CrossRefGoogle Scholar
  9. Begun, D. R., 2001, African and Eurasian Miocene hominoids and the origins of the Hominidae. In Hominoid Evolution and Environmental Change in the Neogene of Europe, edited by P. Andrews, G. Koufos, and L. d. Bonis, pp. 231–253. Cambridge University Press, Cambridge.Google Scholar
  10. Begun, D. R., Ward, C. V., and Rose, M. D., 1997, Events in hominoid evolution. In Function, Phylogeny and Fossils: Miocene Hominoid Origins and Adaptations., edited by D. R. Begun, C. V. Ward, and M. D. Rose, pp. 389–415. Plenum Press, New York.Google Scholar
  11. Benton, M. J., 1990, Origin and interrelationships of Dinosaurs, in The Dinosauria, edited by D. B. Weishampel, P. Dodson, and H. Osmolska, pp. 11–30. University of California Press, Berkeley.Google Scholar
  12. Bergman, R. A., Thompson, S. A., Afifi, A. K., and Saadeh, F. A., editors, 1988, Compendium of Human Anatomic Variation. Urban & Schwarzenberg, Baltimore.Google Scholar
  13. Berman, D. S., Reisz, R. R., Scott, D., Henrici, A. C., Sumida, S. S., and Martens, T., 2000, Early Permian bipedal reptile. Science 290:969–972.CrossRefGoogle Scholar
  14. Bromage, T. G., 1987, The biological and chronological maturation of early hominids. Journal of Human Evolution 16:257–272.CrossRefGoogle Scholar
  15. Bush, M. E., Lovejoy, C. O., Johanson, D. C., and Coppens, Y., 1982, Hominid carpal, metacarpal, and phalangeal bones recovered from the Hadar formation: 1974-1977 collections. American Journal of Physical Anthropology 57:651–677.CrossRefGoogle Scholar
  16. Cerling, T., Harris, J. R., MacFadden, B. J., Leakey, M. G., Quade, J., Eisenmann, V., and Ehleringer, J. R., 1997, Global vegetation change through the Miocene/Pliocene boundary. Nature 389:153–158.CrossRefGoogle Scholar
  17. Collard, M., and Aiello, L., 2000, From forelimbs to two legs. Nature 404:339–340.CrossRefGoogle Scholar
  18. Corruccini, R. S., 1978, Comparative osteometrics of the hominoid wrist, with special reference to knuckle-walking. Journal of Human Evolution 7:307–321.CrossRefGoogle Scholar
  19. Corruccini, R. S., and McHenry, H. M, 2001, Knuckle-walking hominid ancestors. Journal of Human Evolution 40:507–511.CrossRefGoogle Scholar
  20. Dainton, M., 2001, Did our ancestors knuckle-walk? Nature 410:324–325.CrossRefGoogle Scholar
  21. Dainton, M., and Macho, G. A., 1999, Did knuckle walking evolve twice? Journal of Human Evolution, Vol. 36:171–194.CrossRefGoogle Scholar
  22. Dean, M. C., Benyon, A. D., Thackery, J. E., and Macho, G. A., 1993, Histological reconstruction of dental development and age at death of a juvenile Paranthropus robustus SK 63, from Swartskrans, South Africa. American Journal of Physical Anthropology 91:401–419.CrossRefGoogle Scholar
  23. Fischer, M., 1986, Die Stellung der Schliefer (Hyracoidea) im phylogenetischen System der Eutheria. Zugleich ein Beitrag zur Anpassungsgeschichte der Procaviidae. Cour. Forsch.-Inst. Senckenberg 84:1–132.Google Scholar
  24. Fleagle, J. G., Stern, J. T, Jungers, W. L., Susman, R. L., Vangor, A. K., and Wells, J. P., 1981, Climbing: A biomechanical link with brachiation and with bipedalism. In Vertebrate Locomotion, edited by M. H. Day, pp. 359–375. 48. Symposium of the Zoological Society of London, London.Google Scholar
  25. Gebo, D. L., 1992, Plantigrady and foot adaptation in African apes: Implications for hominid origins. American Journal of Physical Anthropology 89:29–58.CrossRefGoogle Scholar
  26. Gebo, D. L., 1993, Reply to Dr. Meldrum. American Journal of Physical Anthropology 91:382–385.CrossRefGoogle Scholar
  27. Gebo, D. L., 1996, Climbing, brachiation and terrestrial quadrupedalism: Historical precursors of hominid bipedalism. American Journal of Physical Anthropology 101:55–92.CrossRefGoogle Scholar
  28. Godfrey, L., Jungers, W. L., Wunderlich, R. E., and Richmond, B. G., 1997, Reappraisal of the postcranium of Hadropithecus (Primates, Indroidea). American Journal of Physical Anthropology 103:529–556.CrossRefGoogle Scholar
  29. Groves, C. P., 1986, Systematics of the great apes. In Comparative Primate Biology, vol. 1, edited by D. W. Swindler and J. Erwin, pp. 187–217. Alan R. Liss, New York.Google Scholar
  30. Hall, B. K., 1994, Homology: the hierarchical basis of comparative biology. Academic Press, San Diego.Google Scholar
  31. Hamrick, M. W., Simons, E. L., and Jungers, W. L., 2000, New wrist bones of the Malagasy giant subfossil lemurs. Journal of Human Evolution 38:635–650.CrossRefGoogle Scholar
  32. Hartwig-Scherer, S., 1993, Body weight prediction in early fossil hominids: Towards a taxon “independent” approach. American Journal of Physical Anthropology 92:17–36.CrossRefGoogle Scholar
  33. Inouye, S. E., 1992, Ontogeny and allometry of African ape manual rays. Journal of Human Evolution 26:459–485.CrossRefGoogle Scholar
  34. Jenkins, F. A., and Fleagle, J. G., 1975, Knuckle-Walking and the Functional Anatomy of the Wrists in Living Apes. In Primate Functional Morphology and Evolution, edited by R. H. Tuttle, pp. 213–227. Mouton, The Hague.Google Scholar
  35. Kappelman, J., 1996, The evolution of body mass and relative brain size in fossil hominids. Journal of Human Evolution 30:243–276.CrossRefGoogle Scholar
  36. Larson, S. G., 1988, Subscapularis function in gibbons and chimpanzees: Implications for interpretation of humeral head torsion in hominoids. American Journal of Physical Anthropology 76:449–462.CrossRefGoogle Scholar
  37. Larson, S. G., 1996, Estimating humeral head torsion on incomplete fossil anthropoid humeri. Journal of Human Evolution 31:239–257.CrossRefGoogle Scholar
  38. Le Gros Clark, W. E., and Leakey, L. S. B., 1951, The Miocene Hominoidea of East Africa. British Museum of Natural History: Fossil Mammals of Africa 1:1–117.Google Scholar
  39. Leakey, M. G., Feibel, C. S., Bernor, R. L., Harris, J. M., Cerling, T. E., Stewart, K. M., Storrs, G. W, Walker, A., Werdelin, L., and Winkler, A. J., 1996, Lothagam: a record of faunal change in the Late Miocene of East Africa. Journal of Vertebrate Paleontology 16:556–570.CrossRefGoogle Scholar
  40. Leakey, R. E. F., and Leakey, M. G., 1989, A New Miocene small-bodied ape from kenya. American Journal of Physical Anthropology 16:369–387.Google Scholar
  41. Lewis, O. J., 1969, The hominoid wrist joint. American Journal of Physical Anthropology 30:251–268.CrossRefGoogle Scholar
  42. Lewis, O. J., 1974, The wrist articulations of the Anthropoidea. In Primate Locomotion, edited by F. A. Jenkins, pp. 143–169. Academic Press, New York.Google Scholar
  43. Lewis, O. J., 1985, Derived morphology of the wrist articulations and theories of hominoid evolution. Part I. The lorisine joints. Journal of Anatomy 140:447–460.Google Scholar
  44. Lieberman, D. E., Wood, B. A., and Pilbeam, D. R., 1996, Homoplasy and early Homo: an analysis of the evolutionary relationships of H. habilis senso stricto and H. rudolfensis. Journal of Human Evolution 30:97–120.CrossRefGoogle Scholar
  45. Lovejoy, C. O., Heiple, K. G. and Meindl, R. S., 2001, Did our ancestors knuckle-walk? Nature 410:325–326.CrossRefGoogle Scholar
  46. Marino, L., 1998, A comparison of encephalization between odontocete cetaceans and anthropoid primates. Brain, Behavior and Evolution 51:230–238.CrossRefGoogle Scholar
  47. Marzke, M. W., 1971, Origin of the human hand. American Journal of Physical Anthropology 34:61–84.CrossRefGoogle Scholar
  48. Marzke, M. W., Wullstein, K. L., and Viegas, S. E., 1992, Evolution of the power (“squeeze”) grip and its morphological correlates in hominids. American Journal of Physical Anthropology 89:283–298.CrossRefGoogle Scholar
  49. McHenry, H. M., 1983, The capitate of Australopithecus afarensis and A. africanus. American Journal of Physical Anthropology 62:187–198.CrossRefGoogle Scholar
  50. Meldrum, D. J., 1993, On plantigrady and quadrupedalism. American Journal of Physical Anthropology 91:379–381.CrossRefGoogle Scholar
  51. Mendel, F. C., 1985, Adaptations for suspensory behavior in the limbs of two-toed sloths. In The Evolution and Ecology of Armadillos, Sloths, and Vermilinguas., edited by G. G. Montgomery, pp. 151–162. Smithsonian Institution Press, Washington, D.C.Google Scholar
  52. Middleton, K. M., and Gatesy, S. M., 2000, Theropod forelimb design and evolution. Zoological Journal of the Linnean Society 128:149–187.CrossRefGoogle Scholar
  53. Napier, J., 1974, The antiquity of human walking. In Vertebrate Structures and Functions: Readings from Scientific American, pp. 48–58. W. H. Freeman and Company, San Francisco.Google Scholar
  54. Pickford, M., and Senut, B., 2001, Contexte géologique et faunique des restes d’hominidés du Miocène supérieur de Lukeino, Kenya. Comptes Rendus de V Académie des Sciences. Paris-Series IIA-Earth and Planetary Science 332:145–152.CrossRefGoogle Scholar
  55. Preuschoft, H., 1973, Functional anatomy of the upper extremity. The Chimpanzee 6:34–120.Google Scholar
  56. Richmond, B. G., Begun, D. R., and Strait, D. S., 2001, Origin of human bipedalism: The knuckle-walking hypothesis revisited. Yearbook of Physical Anthropology 44: 70–105.CrossRefGoogle Scholar
  57. Richmond, B. G., and Strait, D. S., 2000, Evidence that humans evolved from a knuckle-walking ancestor. Nature 404:382–385.CrossRefGoogle Scholar
  58. Richmond, B. G. and Strait, D. S., 2001, Knuckle-walking hominid ancestors: A reply to Corruccini & McHenry. Journal of Human Evolution 40:513–520.CrossRefGoogle Scholar
  59. Rogers, J., 1993, The phylogenetic relationships among Homo, Pan, and Gorilla: A population genetics perspective. Journal of Human Evolution 25:201–215.CrossRefGoogle Scholar
  60. Rose, M. D., 1988, Another look at the anthropoid elbow. Journal of Human Evolution 17:193–224.CrossRefGoogle Scholar
  61. Ruvolo, M., 1994, Molecular evolutionary processes and conflicting gene trees: The hominoid case. American Journal of Physical Anthropology 94:89–113.CrossRefGoogle Scholar
  62. Sarmiento, E. E., 1988, Anatomy of the hominoid wrist joint: Its evolutionary functional implications. International Journal of Primatology 9:281–345.CrossRefGoogle Scholar
  63. Satta, Y., Klein, J., and Takahata, N., 2000, DNA archives and our nearest relative: The trichotomy revisited. Molecular Phylogenetics and Evolution 14:259–275.CrossRefGoogle Scholar
  64. Schmitt, D. and Larson, S. G., 1995, Heel contact as a function of substrate type and speed in primates. American Journal of Physical Anthropology 96:39–50.CrossRefGoogle Scholar
  65. Schultz, A. H., 1936, Characters common to higher primates and characters specific to man. Quarterly Review of Biology 11:425–455.CrossRefGoogle Scholar
  66. Schultz, A. H., 1969, The Life of Primates. New York: Universe Books.Google Scholar
  67. Schwartz, J. H., and Yamada, T. K., 1998, Carpal anatomy and primate relationships. Anthropological Science 106 (suppl.):47–65.CrossRefGoogle Scholar
  68. Senut, B., Pickford, M., Gommery, D., Mein, P., Cheboi, K., and Coppens, Y., 2001, Premier hominidé du Miocène (formation de Lukeino, Kenya). Comptes Rendus de V Académie des Sciences. Paris-Series IIA-Earth and Planetary Science 332:137–144.CrossRefGoogle Scholar
  69. Shoshani, J., Groves, C. P., Simons, E. L., and Gunnel, G. E., 1996, Primate phylogeny: Morphological vs. molecular results. Molecular Phylogenetics and Evolution 5:101–153.CrossRefGoogle Scholar
  70. Skelton, R. R., and McHenry, H. M., 1992, Evolutionary relationships among early hominids. Journal of Human Evolution 23:309–350.CrossRefGoogle Scholar
  71. Smith, B. H., 1991, Dental development and the evolution of life history in the Hominidae. American Journal of Physical Anthropology 86:157–174.CrossRefGoogle Scholar
  72. Smith, R. J., Gannon, P. J., and, Smith, B. H., 1995, Ontogeny of australopithecines and early Homo: Evidence from cranial capacity and dental eruption. Journal of Human Evolution 29:155–168.CrossRefGoogle Scholar
  73. Sterling, E. J., and Povinelli, D. J., 1999, Tool use, aye-ayes, and sensorimotor intelligence. Folia Primatologica 70:8–16.CrossRefGoogle Scholar
  74. Stern, J. T., 1975, Before bipedality. Yearbook of Physical Anthropology 19:59–68.Google Scholar
  75. Stern, J. T., and Susman, R. L., 1983, The locomotor anatomy of Australopithecus afarensis. American Journal of Physical Anthropology 60:279–317.CrossRefGoogle Scholar
  76. Strait, D. S., Grine, F. E., and Moniz, M. A., 1997, A reappraisal of early hominid phylogeny. Journal of Human Evolution 32:17–82.CrossRefGoogle Scholar
  77. Susman, R. L., 1979, Comparative and functional morphology of hominoid fingers. American Journal of Physical Anthropology 50:215–236.CrossRefGoogle Scholar
  78. Tardieu, C., 1997, Femur ontogeny in humans and great apes: Heterochronic implications for hominid evolution. Comptes Rendus de V Academie des Sciences. Paris-Series IIA-Earth and Planetary Science 325:899–904.Google Scholar
  79. Tuttle, R. H., 1967, Knuckle-walking and the evolution of hominoid hands. American Journal of Physical Anthropology 26:171–206.CrossRefGoogle Scholar
  80. Tuttle, R. H., 1969a, Knuckle-walking and the problem of human origins. Science 166:953–961.CrossRefGoogle Scholar
  81. Tuttle, R. H., 1969b, Quantitative and functional studies on the hands of the Anthropoidea. I. The Hominoidea. Journal of Morphology 128:309–364.CrossRefGoogle Scholar
  82. Tuttle, R. H., 1974, Darwin’s apes, dental apes, and the descent of man: Normal science in evolutionary anthropology. Current Anthropology 15:389–398.CrossRefGoogle Scholar
  83. Tuttle, R. H., 1975, Parallelism, brachiation, and hominoid phylogeny. In Phylogeny of the Primates, edited by W. P. Luckett and F. S. Szalay, pp. 447–480. Plenum Press, New York.CrossRefGoogle Scholar
  84. Tuttle, R. H., 1992, Hands from newt to Napier. In Topics in Primatology, Vol. 3: Evolutionary Biology, Reproductive Endocrinology and Virology, edited by S. Matano, R. H. Tuttle, H. Ishida, and M. Goodman, pp. 3–20. University of Tokyo Press, Tokyo.Google Scholar
  85. Ward, C. V., Leakey, M. G., Brown, B., Brown, E., Harris, J., and, Walker, A., 1999, South Turkwel: A new Pliocene hominid site in Kenya. Journal of Human Evolution 36:69–95.CrossRefGoogle Scholar
  86. Ward, C. V., Leakey, M. G. and Walker, A., 2001, Morphology of Australopithecus anamensis from Kanapoi and Allia Bay, Kenya. Journal of Human Evolution 41:255–368.CrossRefGoogle Scholar
  87. Washburn, S. L., 1971, The study of human evolution. In Background for Man: Readings in Physical Anthropology, edited by P. Dolhinow and V. Sarich, pp. 82–117. Little, Brown & Co., Boston.Google Scholar
  88. Webb, D., and Fabiny, S., 2001, Human hands are adapted for bipedalism, not tool use. American Journal of Physical Anthropology Suppliment 32:161.Google Scholar
  89. Weinert, H., 1932, Ursprung der Menschheit. Uber den engeren Anschkuss des Menschengeschlechts an die Men-schenaffen. Enke, Stuttgart.Google Scholar
  90. WoldeGabriel, G., Haile-Selassie, Y., Renne, P. R., Hart, W K., Ambrose, S. H., Asfaw, B., Heiken, G., White, T., 2001, Geology and palaeontology of the Late Miocene middle Awash valley, Afar rift, Ethiopia Nature 412:175–178.CrossRefGoogle Scholar
  91. Zapfe, H., 1960, Die primatenfunde aus der Miozänen spaltenfullung von Neudorf an der March (Dévinská Nová Ves), Tschechoslovakei. Mit anhang: Der primtenfund aus dem Miozän von Klein Hadersdorf in Niederosterreich. Schweizerische Paleontologische Abhandlungen 78:1–293.Google Scholar
  92. Zapfe, H., 1979, Chalicotherium grande aus der miozänen Spaltenfüllung von Neudorf an der March (Devinská Nová Ves), Tschechoslowakei. Vol. 2. Neue Denkschriften des Naturhistorischen Museums Wien. Ferdinand Bergerr & Söhne, Wien.Google Scholar
  93. Zylstra, M., 1998, Metacarpophalangeal joint morphology in non-human primates. American Journal of Physical Anthropology Suppl. 26:240.Google Scholar
  94. Zylstra, M., 1999, Functional morphology of the hominoid forelimb: Implications for knuckle-walking and the origin of hominid bipedalism. Ph.D. dissertation, University of Toronto. University Microfilms, Ann Arbor.Google Scholar

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