Evolutionary Biology

, Volume 35, Issue 3, pp 159–175 | Cite as

Mechanical Properties of Plant Underground Storage Organs and Implications for Dietary Models of Early Hominins

  • Nathaniel J. Dominy
  • Erin R. Vogel
  • Justin D. Yeakel
  • Paul Constantino
  • Peter W. Lucas
Research Article


The diet of early human ancestors has received renewed theoretical interest since the discovery of elevated δ13C values in the enamel of Australopithecus africanus and Paranthropus robustus. As a result, the hominin diet is hypothesized to have included C4 grass or the tissues of animals which themselves consumed C4 grass. On mechanical grounds, such a diet is incompatible with the dental morphology and dental microwear of early hominins. Most inferences, particularly for Paranthropus, favor a diet of hard or mechanically resistant foods. This discrepancy has invigorated the longstanding hypothesis that hominins consumed plant underground storage organs (USOs). Plant USOs are attractive candidate foods because many bulbous grasses and cormous sedges use C4 photosynthesis. Yet mechanical data for USOs—or any putative hominin food—are scarcely known. To fill this empirical void we measured the mechanical properties of USOs from 98 plant species from across sub-Saharan Africa. We found that rhizomes were the most resistant to deformation and fracture, followed by tubers, corms, and bulbs. An important result of this study is that corms exhibited low toughness values (mean = 265.0 J m−2) and relatively high Young’s modulus values (mean = 4.9 MPa). This combination of properties fits many descriptions of the hominin diet as consisting of hard-brittle objects. When compared to corms, bulbs are tougher (mean = 325.0 J m−2) and less stiff (mean = 2.5 MPa). Again, this combination of traits resembles dietary inferences, especially for Australopithecus, which is predicted to have consumed soft-tough foods. Lastly, we observed the roasting behavior of Hadza hunter-gatherers and measured the effects of roasting on the toughness on undomesticated tubers. Our results support assumptions that roasting lessens the work of mastication, and, by inference, the cost of digestion. Together these findings provide the first mechanical basis for discussing the adaptive advantages of roasting tubers and the plausibility of USOs in the diet of early hominins.


Australopithecus Paranthropus Diet Hypogeous plant foods Geophytes Tubers Fracture toughness Young’s modulus 


  1. Ackermann, R. R., & Cheverud, J. M. (2004). Detecting genetic drift versus selection in human evolution. Proceedings of the National Academy of Sciences of the United States of America, 101, 17946–17951. doi:10.1073/pnas.0405919102.PubMedCrossRefGoogle Scholar
  2. Agnew, A. D. Q., & Agnew, S. (1994). Kenya upland wild flowers. Nairobi: East African Natural History Society.Google Scholar
  3. Altmann, S. A. (1998). Foraging for survival: Yearling baboons in Africa. Chicago: University of Chicago Press.Google Scholar
  4. Altmann, S. A., & Altmann, J. (1970). Baboon ecology: African field research. Basel: S. Karger.Google Scholar
  5. Barton, R. A. (1993). Sociospatial mechanisms of feeding competition in female olive baboons, Papio anubis. Animal Behaviour, 46, 791–802. doi:10.1006/anbe.1993.1256.CrossRefGoogle Scholar
  6. Boag, P. T., & Grant, P. R. (1981). Intense natural selection in a population of Darwin’s finches (Geospizinae) in the Galapagos. Science, 214, 82–85. doi:10.1126/science.214.4516.82.PubMedCrossRefGoogle Scholar
  7. Boag, P. T., & Grant, P. R. (1984). Darwin’s finches (Geospiza) on Isla Daphne Major, Galapagos: Breeding and feeding ecology in a climatically variable environment. Ecological Monographs, 54, 463–489. doi:10.2307/1942596.CrossRefGoogle Scholar
  8. Bonyongo, M. C., Bredenkamp, G. J., & Veenendaal, E. (2000). Floodplain vegetation in the Nxaraga Lagoon area, Okavango Delta, Botswana. South African Journal of Botany, 66, 15–21.Google Scholar
  9. Campbell, A. (1986). The use of wild food plants, and drought in Botswana. Journal of Arid Environments, 11, 81–91.Google Scholar
  10. Codron, J., Codron, D., Lee-Thorp, J. A., Sponheimer, M., Bond, W. J., de Ruiter, D., et al. (2005). Taxonomic, anatomical, and spatio-temporal variations in the stable carbon and nitrogen isotopic compositions of plants from an African savanna. Journal of Archaeological Science, 32, 1757–1772. doi:10.1016/j.jas.2005.06.006.CrossRefGoogle Scholar
  11. Conklin-Brittain, N. L., Wrangham, R. W., & Smith, C. C. (2002). A two-stage model of increased dietary quality in early hominid evolution: The role of fiber. In P. S. Ungar & M. F. Teaford (Eds.), Human diet: Its origin and evolution (pp. 61–76). London: Bergin and Garvey.Google Scholar
  12. Coursey, D. G. (1973). Hominid evolution and hypogeous plant foods. Man, 8, 634–635.Google Scholar
  13. Cowling, R. M., Esler, K. J., & Rundel, P. W. (1999). Namaqualand, South Africa—An overview of a unique winter-rainfall desert ecosystem. Plant Ecology, 142, 3–21. doi:10.1023/A:1009831308074.CrossRefGoogle Scholar
  14. Daegling, D. J., & Grine, F. E. (1999). Terrestrial foraging and dental microwear in Papio ursinus. Primates, 40, 559–572. doi:10.1007/BF02574831.CrossRefGoogle Scholar
  15. Darvell, B. W., Lee, P. K. D., Yuen, T. D. B., & Lucas, P. W. (1996). A portable fracture toughness tester for biological materials. Measurement Science & Technology, 7, 954–962. doi:10.1088/0957-0233/7/6/016.CrossRefGoogle Scholar
  16. Deacon, H. J. (1976). Where hunters gathered: A study of Holocene Stone Age people in the Eastern Cape. Claremont: South African Archaeological Society.Google Scholar
  17. Deacon, H. J. (1995). Two late Pleistocene-Holocene archaeological depositories from the southern Cape, South Africa. South African Archaeological Bulletin, 50, 121–131. doi:10.2307/3889061.CrossRefGoogle Scholar
  18. Demes, B., & Creel, N. (1988). Bite force, diet, and cranial morphology of fossil hominids. Journal of Human Evolution, 17, 657–670. doi:10.1016/0047-2484(88)90023-1.CrossRefGoogle Scholar
  19. Elgart-Berry, A. (2004). Fracture toughness of mountain gorilla (Gorilla gorilla beringei) food plants. American Journal of Primatology, 62, 275–285. doi:10.1002/ajp.20021.PubMedCrossRefGoogle Scholar
  20. Ellery, K., & Ellery, W. (1997). Plants of the Okavango Delta: A field guide. Durban: Tsaro Publishers.Google Scholar
  21. Goldblatt, P., & Manning, J. C. (2002). Plant diversity of the Cape Region of southern Africa. Annals of the Missouri Botanical Garden, 89, 281–302. doi:10.2307/3298566.CrossRefGoogle Scholar
  22. Grant, P. R., & Grant, B. R. (2002). Unpredictable evolution in a 30-year study of Darwin’s finches. Science, 296, 707–711. doi:10.1126/science.1070315.PubMedCrossRefGoogle Scholar
  23. Gregory, W. K., & Hellman, M. (1939). The South African fossil man-apes and the origin of the human dentition. The Journal of the American Dental Association, 26, 558–564.Google Scholar
  24. Grine, F. E., & Kay, R. F. (1988). Early hominid diets from quantitative image analysis of dental microwear. Nature, 333, 765–768. doi:10.1038/333765a0.PubMedCrossRefGoogle Scholar
  25. Grine, F. E., Ungar, P. S., & Teaford, M. F. (2006a). Was the early Pliocene hominin ‘Australopithecusanamensis a hard object feeder? South African Journal of Science, 102, 301–310.Google Scholar
  26. Grine, F. E., Ungar, P. S., Teaford, M. F., & El-Zaatari, S. (2006b). Molar microwear in Praeanthropus afarensis: Evidence for dietary stasis through time and under diverse paleoecological conditions. Journal of Human Evolution, 51, 297–319. doi:10.1016/j.jhevol.2006.04.004.PubMedCrossRefGoogle Scholar
  27. Hamilton, W. J., Buskirk, R. E., & Buskirk, W. H. (1978). Omnivory and utilization of food resources by chacma baboons, Papio ursinus. American Naturalist, 112, 911–924. doi:10.1086/283331.CrossRefGoogle Scholar
  28. Hatley, T., & Kappelman, J. (1980). Bears, pigs, and Plio-Pleistocene hominids: A case for the exploitation of belowground food resources. Human Ecology, 8, 371–387. doi:10.1007/BF01561000.CrossRefGoogle Scholar
  29. Hernandez-Aguilar, R. A., Moore, J., & Pickering, T. R. (2007). Savanna chimpanzees use tools to harvest the underground storage organs of plants. Proceedings of the National Academy of Sciences of the United States of America, 104, 19210–19213. doi:10.1073/pnas.0707929104.PubMedCrossRefGoogle Scholar
  30. Hladik, A., Bahuchet, C., Ducatillion, C., & Hladik, C. M. (1984). Les plantes à tubercules de la forêt dense d’Afrique Centrale. Revue d’Ecologie: La Terre et la Vie, 39, 249–290.Google Scholar
  31. Hesla, B. I., Tieszen, L. L., & Imbamba, S. K. (1982). A systematic survey of C3 and C4 photosynthesis in the Cyperaceae of Kenya, East Africa. Photosynthetica, 16, 196–205.Google Scholar
  32. Hylander, W. L. (1988). Implications of in vivo experiments for interpretating the functional significance of “robust” australopithecine jaws. In F. E. Grine (Ed.), Evolutionary history of the “robust” australopithecines (pp. 55–83). New York: Aldine de Gruyter.Google Scholar
  33. Jolly, C. J. (1970). The seed-eaters: A new model of hominid differentiation based on a baboon analogy. Man, 5, 5–26. doi:10.2307/2798801.CrossRefGoogle Scholar
  34. Kay, R. F. (1985). Dental evidence for the diet of Australopithecus. Annual Review of Anthropology, 14, 315–341. doi:10.1146/annurev.an.14.100185.001531.CrossRefGoogle Scholar
  35. Kinzey, W. G., & Norconk, M. A. (1990). Hardness as a basis of fruit choice in two sympatric primates. American Journal of Physical Anthropology, 81, 5–16. doi:10.1002/ajpa.1330810103.PubMedCrossRefGoogle Scholar
  36. Kinzey, W. G., & Norconk, M. A. (1993). Physical and chemical properties of fruit and seeds eaten by Pithecia and Chiropotes in Surinam and Venezuela. International Journal of Primatology, 14, 207–227. doi:10.1007/BF02192632.CrossRefGoogle Scholar
  37. Laden, G., & Wrangham, R. W. (2005). The rise of the hominids as an adaptive shift in fallback foods: Plant underground storage organs (USOs) and australopith origins. Journal of Human Evolution, 49, 482–498. doi:10.1016/j.jhevol.2005.05.007.PubMedCrossRefGoogle Scholar
  38. Lambert, J. E., Chapman, C. A., Wrangham, R. W., & Conklin-Brittain, N. L. (2004). Hardness of cercopithecine foods: Implications for the critical function of enamel thickness in exploiting fallback foods. American Journal of Physical Anthropology, 125, 363–368. doi:10.1002/ajpa.10403.PubMedCrossRefGoogle Scholar
  39. Lanjouw, A. (2002). Behavioural adaptations to water scarcity in Tongo chimpanzees. In C. Boesch, G. Hohmann, & L. F. Marchant (Eds.), Behavioural diversity in chimpanzees and bonobos (pp. 52–60). Cambridge: Cambridge University Press.Google Scholar
  40. Le Roux, A. (2005). Namaqualand: South African wildflower guide no. 1. Cape Town: Botanical Society of South Africa.Google Scholar
  41. Lee-Thorp, J., & Sponheimer, M. (2006). Contributions of biogeochemistry to understanding hominin dietary ecology. Yearbook of Physical Anthropology, 49, 131–148. doi:10.1002/ajpa.20519.CrossRefGoogle Scholar
  42. Lockwood, C. A., Menter, C. G., Moggi-Cecchi, J., & Keyser, A. W. (2007). Extended male growth in a fossil hominin species. Science, 318, 1443–1446. doi:10.1126/science.1149211.PubMedCrossRefGoogle Scholar
  43. Lovegrove, B. G., & Jarvis, J. U. M. (1986). Coevolution between mole-rats (Bathyergidae) and a geophyte, Micranthus (Iridaceae). Cimbebasia, 8, 80–85.Google Scholar
  44. Lucas, P. W. (2004). Dental functional morphology: How teeth work. Cambridge: Cambridge University Press.Google Scholar
  45. Lucas, P. W., Beta, T., Darvell, B. W., Dominy, N. J., Essackjee, H. C., Lee, P. K. D., et al. (2001). Field kit to characterize physical, chemical and spatial aspects of potential primate foods. Folia Primatologica, 72, 11–25. doi:10.1159/000049914.CrossRefGoogle Scholar
  46. Lucas, P. W., Corlett, R. T., & Luke, D. A. (1985). Plio-Pleistocene hominid diets: An approach combining masticatory and ecological analysis. Journal of Human Evolution, 14, 187–202. doi:10.1016/S0047-2484(85)80006-3.CrossRefGoogle Scholar
  47. Lucas, P. W., & Peters, C. R. (2000). Function of postcanine tooth shape in mammals. In M. F. Teaford, M. M. Smith, & M. W. J. Ferguson (Eds.), Development, function and evolution of teeth (pp. 282–289). Cambridge: Cambridge University Press.Google Scholar
  48. Macho, G. A., Shimizu, D., Jiang, Y., & Spears, I. R. (2005). Australopithecus anamensis: A finite-element approach to studying the functional adaptations of extinct hominins. The Anatomical Record. Part A, Discoveries in Molecular, Cellular, and Evolutionary Biology, 283, 310–318. doi:10.1002/ar.a.20175.PubMedCrossRefGoogle Scholar
  49. Malaisse, F., & Parent, G. (1985). Edible wild vegetable products in the Zambezian woodland area: A nutritional and ecological approach. Ecology of Food and Nutrition, 18, 43–82.Google Scholar
  50. Manning, J. C., Goldblatt, P., & Snijman, D. (2002). The color encyclopedia of Cape bulbs. Portland: Timber Press.Google Scholar
  51. Marlowe, F. W. (2002). Why the Hadza are still hunter-gatherers. In S. Kent (Ed.), Ethnicity, hunter-gatherers, and the “other”: Association or assimilation in Africa (pp. 247–275). Washington, D.C.: Smithsonian Institution Press.Google Scholar
  52. Marlowe, F. W. (2003). A critical period for provisioning by Hadza men: Implications for pair bonding. Evolution and Human Behavior, 24, 217–229. doi:10.1016/S1090-5138(03)00014-X.CrossRefGoogle Scholar
  53. Marshall, A. J., & Wrangham, R. W. (2007). Evolutionary consequences of fallback foods. International Journal of Primatology, 28, 1219–1235. doi:10.1007/s10764-007-9218-5.CrossRefGoogle Scholar
  54. Mason, H. (1972). Western Cape sandveld flowers. Cape Town: Struik Publishers.Google Scholar
  55. McCarthy, T. S., & Ellery, W. N. (1998). The Okavango Delta. Transactions of the Royal Society of South Africa, 53, 157–182.Google Scholar
  56. van der Merwe, N. J., Thackeray, J. F., Lee-Thorp, J. A., & Luyt, J. (2003). The carbon isotope ecology and diet of Australopithecus africanus at Sterkfontein, South Africa. Journal of Human Evolution, 44, 581–597. doi:10.1016/S0047-2484(03)00050-2.PubMedCrossRefGoogle Scholar
  57. O’Connell, J. F., Hawkes, K., & Blurton Jones, N. G. (1999). Grandmothering and the evolution of Homo erectus. Journal of Human Evolution, 36, 461–485. doi:10.1006/jhev.1998.0285.PubMedCrossRefGoogle Scholar
  58. O’Connell, J., Hawkes, K., & Jones, N. B. (2002). Meat-eating, grandmothering, and the evolution of early human diets. In P. S. Ungar & M. F. Teaford (Eds.), Human diet: Its origin and evolution (pp. 49–60). London: Bergin and Garvey.Google Scholar
  59. O’Connell, J. F., Hawkes, K., & Jones, N. B. (1988). Hadza hunting, butchering, and bone transport and their archaeological implications. Journal of Anthropological Research, 44, 113–161.Google Scholar
  60. Orthen, B. (2001). A survey of the polysaccharide reserves in geophytes native to the winter-rainfall region of South Africa. South African Journal of Botany, 67, 371–375.Google Scholar
  61. Pate, J. S., & Dixon, K. W. (1982). Tuberous, cormous and bulbous plants: Biology of an adaptive strategy in Western Australia. Nedlands: University of Western Australia Press.Google Scholar
  62. Perry, G. H., Dominy, N. J., Claw, K. G., Lee, A. S., Fiegler, H., Redon, R., et al. (2007). Diet and the evolution of human amylase gene copy number variation. Nature Genetics, 39, 1256–1260. doi:10.1038/ng2123.PubMedCrossRefGoogle Scholar
  63. Peters, C. R. (1987). Nut-like oil seeds: Food for monkeys, chimpanzees, humans, and probably ape-men. American Journal of Physical Anthropology, 73, 333–363. doi:10.1002/ajpa.1330730306.PubMedCrossRefGoogle Scholar
  64. Peters, C. R. (1990). African wild plants with rootstocks reported to be eaten raw: The monocotyledons, part I. Mitteilungen aus dem Institut fur Allgemeine Botanik Hamburg, 23, 935–952.Google Scholar
  65. Peters, C. R. (1993). Shell strength and primate seed predation of nontoxic species in eastern and southern Africa. International Journal of Primatology, 14, 315–344. doi:10.1007/BF02192636.CrossRefGoogle Scholar
  66. Peters, C. R. (1994). African wild plants with rootstocks reported to be eaten raw: The monocotyledons, part II. In J. H. Seyani & A. C. Chikuni (Eds.), Proceedings of the XIIIth Plenary Meeting of AETFAT, Zomba, Malawi (pp. 25–38). Zomba: National Herbarium and Botanic Gardens of Malawi.Google Scholar
  67. Peters, C. R. (1996). African wild plants with rootstocks reported to be eaten raw: The monocotyledons, part III. In L. J. G. van der Maesen, X. M. van der Burgt, J. M. van Medenbach, & de Rooy (Eds.), The biodiversity of African plants (pp. 665–677). Dordrecht: Kluwer Academic.Google Scholar
  68. Peters, C. R., & Maguire, B. (1981). Wild plant foods of the Makapansgat area: A modern ecosystems analogue for Australopithecus africanus adaptations. Journal of Human Evolution, 10, 565–583. doi:10.1016/S0047-2484(81)80048-6.CrossRefGoogle Scholar
  69. Peters, C. R., & O’Brien, E. M. (1981). The early hominid plant-food niche: Insights from an analysis of plant exploitation by Homo, Pan, and Papio in eastern and southern Africa. Current Anthropology, 22, 127–140. doi:10.1086/202631.CrossRefGoogle Scholar
  70. Peters, C. R., O’Brien, E. M., & Drummond, R. B. (1992). Edible wild plants of sub-Saharan Africa: An annotated check list, emphasizing the woodland and savanna floras of eastern and southern Africa, including plants utilized for food by chimpanzees and baboons. Kew: Royal Botanic Gardens.Google Scholar
  71. Peters, C. R., & Vogel, J. C. (2005). Africa’s wild C4 plant foods and possible early hominid diets. Journal of Human Evolution, 48, 219–236. doi:10.1016/j.jhevol.2004.11.003.PubMedCrossRefGoogle Scholar
  72. Procheş, Ş., Cowling, R. M., & du Preez, D. R. (2005). Patterns of geophyte diversity and storage organ size in the winter rainfall region of southern Africa. Diversity & Distributions, 11, 101–109. doi:10.1111/j.1366-9516.2005.00132.x.CrossRefGoogle Scholar
  73. Procheş, Ş., Cowling, R. M., Goldblatt, P., Manning, J. C., & Snijman, D. A. (2006). An overview of the Cape geophytes. Biological Journal of the Linnean Society, 87, 27–43. doi:10.1111/j.1095-8312.2006.00557.x.CrossRefGoogle Scholar
  74. Reed, K. E. (1997). Early hominid evolution and ecological change through the African Plio-Pleistocene. Journal of Human Evolution, 32, 289–322. doi:10.1006/jhev.1996.0106.PubMedCrossRefGoogle Scholar
  75. Robinson, J. T. (1954). Prehominid dentition and hominid evolution. Evolution; International Journal of Organic Evolution, 8, 324–334. doi:10.2307/2405779.Google Scholar
  76. Rosenberger, A. L., & Kinzey, W. G. (1976). Functional patterns of molar occlusion in platyrrhine primates. American Journal of Physical Anthropology, 45, 281–298. doi:10.1002/ajpa.1330450214.PubMedCrossRefGoogle Scholar
  77. Rundel, P. W., Esler, K. J., & Cowling, R. M. (1999). Ecological and phylogenetic patterns of carbon isotope discrimination in the winter-rainfall flora of the Richtersveld, South Africa. Plant Ecology, 142, 133–148. doi:10.1023/A:1009878429455.CrossRefGoogle Scholar
  78. Ryan, A. S., & Johanson, D. C. (1989). Anterior dental microwear in Australopithecus afarensis. Journal of Human Evolution, 18, 235–268. doi:10.1016/0047-2484(89)90051-1.CrossRefGoogle Scholar
  79. Sage, R. F., & Monson, R. K. (1999). C 4 plant biology. New York: Academic Press.Google Scholar
  80. Schluter, D., & Grant, P. R. (1984). Determinants of morphological patterns in communities of Darwin’s finches. American Naturalist, 123, 175–196. doi:10.1086/284196.CrossRefGoogle Scholar
  81. Schoeninger, M. J., Bunn, H. T., Murray, S. S., & Marlett, J. A. (2001). Composition of tubers used by Hadza foragers of Tanzania. Journal of Food Composition and Analysis, 14, 15–25. doi:10.1006/jfca.2000.0961.CrossRefGoogle Scholar
  82. Schoeninger, M. J., Moore, J., & Sept, J. M. (1999). Subsistence strategies of two “savanna” chimpanzee populations: The stable isotope evidence. American Journal of Primatology, 49, 297–314. doi :10.1002/(SICI)1098-2345(199912)49:4<297::AID-AJP2>3.0.CO;2-N.Google Scholar
  83. Scott, R. S., Ungar, P. S., Bergstrom, T. S., Brown, C. A., Grine, F. E., Teaford, M. F., et al. (2005). Dental microwear texture analysis shows within-species diet variability in fossil hominins. Nature, 436, 693–695. doi:10.1038/nature03822.PubMedCrossRefGoogle Scholar
  84. Sealy, J. C. (1986). Stable carbon isotopes and prehistoric diets in the south-western Cape Province, South Africa. Oxford: British Archaeological Reports International Series 293.Google Scholar
  85. Sillen, A., Hall, G., & Armstrong, R. (1995). Strontium calcium ratios (Sr/Ca) and strontium isotopic ratios (87Sr/86Sr) of Australopithecus robustus and Homo sp. from Swartkrans. Journal of Human Evolution, 28, 277–285. doi:10.1006/jhev.1995.1020.CrossRefGoogle Scholar
  86. Sponheimer, M., de Ruiter, D., Lee-Thorp, J., & Späth, A. (2005a). Sr/Ca and early hominin diets revisited: new data from modern and fossil tooth enamel. Journal of Human Evolution, 48, 147–156. doi:10.1016/j.jhevol.2004.09.003.PubMedCrossRefGoogle Scholar
  87. Sponheimer, M., & Lee-Thorp, J. A. (1999). Isotopic evidence for the diet of an early hominid, Australopithecus africanus. Science, 283, 368–370. doi:10.1126/science.283.5400.368.PubMedCrossRefGoogle Scholar
  88. Sponheimer, M., & Lee-Thorp, J. A. (2003). Differential resource utilization by extant great apes and australopithecines: Towards solving the C4 conundrum. Comparative Biochemistry and Physiology. Part A, 136, 27–34.CrossRefGoogle Scholar
  89. Sponheimer, M., Lee-Thorp, J., de Ruiter, D., Codron, D., Codron, J., Baugh, A. T., et al. (2005b). Hominins, sedges, and termites: New carbon isotope data from the Sterkfontein valley and Kruger National Park. Journal of Human Evolution, 48, 301–312. doi:10.1016/j.jhevol.2004.11.008.PubMedCrossRefGoogle Scholar
  90. Stahl, A. B. (1984). Hominid dietary selection before fire. Current Anthropology, 25, 151–168. doi:10.1086/203106.CrossRefGoogle Scholar
  91. Stock, W. D., Chuba, D. K., & Verboom, G. A. (2004). Distribution of South African C3 and C4 species of Cyperaceae in relation to climate and phylogeny. Austral Ecology, 29, 313–319. doi:10.1111/j.1442-9993.2004.01368.x.CrossRefGoogle Scholar
  92. Teaford, M. F., & Ungar, P. S. (2000). Diet and the evolution of the earliest human ancestors. Proceedings of the National Academy of Sciences of the United States of America, 97, 13506–13511. doi:10.1073/pnas.260368897.PubMedCrossRefGoogle Scholar
  93. Terborgh, J. (1983). Five New World primates: A study in comparative ecology. Princeton: Princeton University Press.Google Scholar
  94. Tomita, K. (1966). The sources of food for the Hadzapi tribe: The life of a hunting tribe in East Africa. Kyoto University African Studies, 1, 157–171.Google Scholar
  95. Ungar, P. S. (2004). Dental topography and diets of Australopithecus afarensis and early Homo. Journal of Human Evolution, 46, 605–622. doi:10.1016/j.jhevol.2004.03.004.PubMedCrossRefGoogle Scholar
  96. Ungar, P. S. (Ed.). (2007). Evolution of the human diet: The known, the unknown, and the unknowable. Oxford: Oxford University Press.Google Scholar
  97. Ungar, P. S., Grine, F. E., & Teaford, M. F. (2006a). Diet in early Homo: A review of the evidence and a new model of adaptive versatility. Annual Review of Anthropology, 35, 209–228. doi:10.1146/annurev.anthro.35.081705.123153.CrossRefGoogle Scholar
  98. Ungar, P. S., Grine, F. E., & Teaford, M. F. (2008). Dental microwear and diet of the Plio-Pleistocene hominin Paranthropus boisei. PLoS ONE, 3, e2044. doi:10.1371/journal.pone.0002044.PubMedCrossRefGoogle Scholar
  99. Ungar, P. S., Grine, F. E., Teaford, M. F., & El Zaatari, S. (2006b). Dental microwear and diets of African early Homo. Journal of Human Evolution, 50, 78–95. doi:10.1016/j.jhevol.2005.08.007.PubMedCrossRefGoogle Scholar
  100. Vincent, A. S. (1985a). Plant foods in savanna environments: A preliminary report of tubers eaten by the Hadza of northern Tanzania. World Archaeology, 17, 131–148.PubMedCrossRefGoogle Scholar
  101. Vincent, A. S. (1985b). Wild tubers as a harvestable resource in the East African savannas: Ecological and ethnographic studies. PhD thesis, University of California, Berkeley.Google Scholar
  102. Vogel, E. R., van Woerden, J. T., Lucas, P. W., Utami Atmoko, S. S., van Schaik, C. P., & Dominy, N. J. (2008). Functional ecology and evolution of hominoid molar enamel thickness: Pan troglodytes schweinfurthii and Pongo pygmaeus wurmbii. Journal of Human Evolution, 55, 60–74. doi:10.1016/j.jhevol.2007.12.005.
  103. Walker, A. (1981). Dietary hypotheses and human evolution. Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences, 292, 57–64. doi:10.1098/rstb.1981.0013.PubMedCrossRefGoogle Scholar
  104. White, T. D., WoldeGabriel, G., Asfaw, B., Ambrose, S., Beyene, Y., Bernor, R. L., et al. (2006). Asa Issie, Aramis and the origin of Australopithecus. Nature, 440, 883–889. doi:10.1038/nature04629.PubMedCrossRefGoogle Scholar
  105. Whiten, A., Byrne, R. W., & Henzi, S. P. (1987). The behavioral ecology of mountain baboons. International Journal of Primatology, 8, 367–388. doi:10.1007/BF02737389.CrossRefGoogle Scholar
  106. Wood, B., & Constantino, P. (2007). Paranthropus boisei: Fifty years of evidence and analysis. Yearbook of Physical Anthropology, 50, 106–132. doi:10.1002/ajpa.20732.CrossRefGoogle Scholar
  107. Wood, B., & Strait, D. (2004). Patterns of resource use in early Homo and Paranthropus. Journal of Human Evolution, 46, 119–162. doi:10.1016/j.jhevol.2003.11.004.PubMedCrossRefGoogle Scholar
  108. Woodburn, J. (1966). The Hadza: The food quest of a hunting and gathering tribe of Tanzania (16 mm. film). London: London School of Economics.Google Scholar
  109. Woodburn, J. (1968). An introduction to Hadza ecology. In R. B. Lee & I. DeVore (Eds.), Man the hunter (pp. 49–55). Chicago: Aldine.Google Scholar
  110. Woodburn, J. (1970). Hunters and gatherers: The material culture of the nomadic Hadza. London: British Museum.Google Scholar
  111. Wrangham, R. W. (2005). The delta hypothesis. In D. E. Lieberman, R. J. Smith, & J. Kelley (Eds.), Interpreting the past: Essays on human, primate, and mammal evolution (pp. 231–243). Leiden: Brill Academic.Google Scholar
  112. Wrangham, R. W. (2007). The cooking enigma. In P. S. Ungar (Ed.), Evolution of the human diet: The known, the unknown, and the unknowable (pp. 308–323). Oxford: Oxford University Press.Google Scholar
  113. Wrangham, R., & Conklin-Brittain, N. L. (2003). ‘Cooking as a biological trait’. Comparative Biochemistry and Physiology. Part A, 136, 35–46. doi:10.1016/S1095-6433(03)00020-5.CrossRefGoogle Scholar
  114. Wrangham, R. W., Conklin, N. L., Chapman, C. A., & Hunt, K. D. (1991). The significance of fibrous foods for Kibale Forest chimpanzees. Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences, 334, 171–178. doi:10.1098/rstb.1991.0106.PubMedCrossRefGoogle Scholar
  115. Wrangham, R. W., Jones, J. H., Laden, G., Pilbeam, D., & Conklin-Brittain, N. (1999). The raw and the stolen: Cooking and the ecology of human origins. Current Anthropology, 40, 567–594. doi:10.1086/300083.PubMedCrossRefGoogle Scholar
  116. Wrangham, R. W., Rogers, M. E., & Isabirye-Basuta, G. (1993). Ape food density in the ground layer in Kibale Forest, Uganda. African Journal of Ecology, 31, 49–57. doi:10.1111/j.1365-2028.1993.tb00517.x.CrossRefGoogle Scholar
  117. Wright, B. W. (2005). Craniodental biomechanics and dietary toughness in the genus Cebus. Journal of Human Evolution, 48, 473–492. doi:10.1016/j.jhevol.2005.01.006.PubMedCrossRefGoogle Scholar
  118. Yeakel, J. D., Bennett, N. C., Koch, P. L., & Dominy, N. J. (2007). The isotopic ecology of African mole rats informs hypotheses on the evolution of human diet. Proceedings of the Royal Society B: Biological Sciences, 274, 1723–1730. doi:10.1098/rspb.2007.0330.PubMedCrossRefGoogle Scholar
  119. Youngblood, D. (2004). Identifications and quantification of edible plant foods in the Upper (Nama) Karoo, South Africa. Economic Botany, 58, 43–65. doi:10.1663/0013-0001(2004)58[S43:IAQOEP]2.0.CO;2.CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC 2008

Authors and Affiliations

  • Nathaniel J. Dominy
    • 1
    • 2
  • Erin R. Vogel
    • 1
  • Justin D. Yeakel
    • 2
  • Paul Constantino
    • 3
  • Peter W. Lucas
    • 3
  1. 1.Department of AnthropologyUniversity of CaliforniaSanta CruzUSA
  2. 2.Department of Ecology and Evolutionary BiologyUniversity of CaliforniaSanta CruzUSA
  3. 3.Anthropology DepartmentThe George Washington UniversityWashingtonUSA

Personalised recommendations