Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Asa Issie, Aramis and the origin of Australopithecus

Abstract

The origin of Australopithecus, the genus widely interpreted as ancestral to Homo, is a central problem in human evolutionary studies. Australopithecus species differ markedly from extant African apes and candidate ancestral hominids such as Ardipithecus, Orrorin and Sahelanthropus. The earliest described Australopithecus species is Au. anamensis, the probable chronospecies ancestor of Au. afarensis. Here we describe newly discovered fossils from the Middle Awash study area that extend the known Au. anamensis range into northeastern Ethiopia. The new fossils are from chronometrically controlled stratigraphic sequences and date to about 4.1–4.2 million years ago. They include diagnostic craniodental remains, the largest hominid canine yet recovered, and the earliest Australopithecus femur. These new fossils are sampled from a woodland context. Temporal and anatomical intermediacy between Ar. ramidus and Au. afarensis suggest a relatively rapid shift from Ardipithecus to Australopithecus in this region of Africa, involving either replacement or accelerated phyletic evolution.

This is a preview of subscription content, access via your institution

Access options

Rent or buy this article

Prices vary by article type

from$1.95

to$39.95

Prices may be subject to local taxes which are calculated during checkout

Figure 1: Geography, stratigraphy, chronology and faunal background for the Asa Issie hominids.
Figure 2: Aramis and Asa Issie fossil hominids.
Figure 3: Dental features of the Asa Issie hominid dentition.
Figure 4: Phylogenetic hypotheses.

Similar content being viewed by others

References

  1. Asfaw, B. The Belohdelie frontal: New evidence of early hominid cranial morphology from the Afar of Ethiopia. J. Hum. Evol. 16, 611–624 (1987)

    Article  Google Scholar 

  2. White, T. D., Suwa, G. & Asfaw, B. Australopithecus ramidus, a new species of early hominid from Aramis, Ethiopia. Nature 371, 306–312 (1994)

    Article  ADS  CAS  Google Scholar 

  3. Haile-Selassie, Y. Late Miocene hominids from the Middle Awash, Ethiopia. Nature 412, 178–181 (2001)

    Article  ADS  CAS  Google Scholar 

  4. White, T. D. in The Primate Fossil Record (ed. Hartwig, W.) 407–417 (Cambridge Univ. Press, Cambridge, 2002)

    Google Scholar 

  5. Leakey, M. G., Feibel, C. S., McDougall, I. & Walker, A. New four-million-year-old hominid species from Kanapoi and Allia Bay, Kenya. Nature 376, 565–571 (1995)

    Article  ADS  CAS  Google Scholar 

  6. Leakey, M. G., Feibel, C. S., McDougall, I., Ward, C. & Walker, A. New specimens and confirmation of an early age for Australopithecus anamensis. Nature 393, 62–66 (1998)

    Article  ADS  CAS  Google Scholar 

  7. Ward, C., Leakey, M. & Walker, A. C. The new hominid species Australopithecus anamensis. Evol. Anthropol. 7, 197–205 (1999)

    Article  Google Scholar 

  8. Ward, C., Leakey, M. G. & Walker, A. Morphology of Australopithecus anamensis from Kanapoi and Allia Bay, Kenya. J. Hum. Evol. 41, 255–368 (2001)

    Article  CAS  Google Scholar 

  9. Haile-Selassie, Y., Suwa, G. & White, T. D. Late Miocene teeth from Middle Awash, Ethiopia, and early hominid dental evolution. Science 303, 1503–1505 (2004)

    Article  ADS  CAS  Google Scholar 

  10. Senut, B. et al. First hominid from the Miocene (Lukeino Formation, Kenya). C.R. Acad. Sci. (Paris) 332, 134–144 (2000)

    Google Scholar 

  11. Pickford, M., Senut, B., Grommery, D. & Treil, J. Bipedalism in Orrorin tugenensis revealed by its femora. C.R. Palevol 1, 191–203 (2002)

    Article  Google Scholar 

  12. Brunet, M. et al. A new hominid from the upper Miocene of Chad, central Africa. Nature 418, 145–151 (2002)

    Article  ADS  CAS  Google Scholar 

  13. Ohman, J., Lovejoy, C. O. & White, T. D. Questions about Orrorin femur. Science 307, 845b (2005)

    Article  Google Scholar 

  14. White, T. D. Early hominid femora: The inside story. Palevol (in the press)

  15. White, T. D. in Paleoclimate and Evolution, with Emphasis on Human Origins (eds Vrba, E., Denton, G., Partridge, T. & Burkle, L.) 369–384 (Yale Univ. Press, New Haven, 1995)

    Google Scholar 

  16. Renne, P. R., WoldeGabriel, G., Hart, W. K., Heiken, G. & White, T. D. Chronostratigraphy of the Miocene-Pliocene Sagantole Formation, Middle Awash Valley, Afar Rift, Ethiopia. Geol. Soc. Am. Bull. 111, 869–885 (1999)

    Article  ADS  CAS  Google Scholar 

  17. Renne, P. R. et al. Intercalibration of standards, absolute ages and uncertainties in 40Ar/39Ar dating. Chem. Geol. Isot. Geosci. Sect. 145, 117–152 (1998)

    ADS  CAS  Google Scholar 

  18. Hlusko, L. J. A new large Pliocene colobine species (Mammalia: Primates) from Asa Issie, Ethiopia. Geobios 39, 57–69 (2006)

    Article  Google Scholar 

  19. Cerling, T. E., Bowman, J. R. & O'Neil, J. R. An isotopic study of a fluvial-lacustrine sequence: The Plio-Pleistocene Koobi Fora sequence, East Africa. Palaeogeogr. Palaeoclimatol. Palaeoecol. 63, 335–356 (1988)

    Article  CAS  Google Scholar 

  20. Levin, N. E., Quade, J., Simpson, S. W., Semaw, S. & Rogers, M. Isotopic evidence for Plio-Pleistocene environmental change at Gona, Ethiopia. Earth Planet. Sci. Lett. 219, 93–110 (2004)

    Article  ADS  CAS  Google Scholar 

  21. WoldeGabriel, G. et al. Geology and palaeontology of the Late Miocene Middle Awash Valley, Afar Rift, Ethiopia. Nature 412, 175–178 (2001)

    Article  ADS  CAS  Google Scholar 

  22. Haile-Selassie, Y. et al. Mio-Pliocene mammals from the Middle Awash, Ethiopia. Geobios 37, 536–552 (2004)

    Article  Google Scholar 

  23. Wynn, J. G. Paleosols, stable carbon isotopes, and paleoenvironmental interpretation of Kanapoi, Northern Kenya. J. Hum. Evol. 39, 411–432 (2000)

    Article  CAS  Google Scholar 

  24. Flessa, K. et al. The Geological Record of Ecological Dynamics: Understanding the Biotic Effects of Future Environmental Change (National Academy of Sciences, Washington, 2005)

    Google Scholar 

  25. Kono, R. T. Molar enamel thickness and distribution patterns in extant great apes and humans: New insights based on a 3-dimensional whole crown perspective. Anthropol. Sci. 112, 121–146 (2004)

    Article  Google Scholar 

  26. Suwa, G. & Kono, R. A micro-CT based study of linear enamel thickness in the mesial cusp section of human molars: Reevaluation of methodology and assessment of within-tooth, serial, and individual variation. Anthropol. Sci. 113, 273–289 (2005)

    Article  Google Scholar 

  27. Coffing, K., Feibel, C., Leakey, M. & Walker, A. Four-million-year-old hominids from east Lake Turkana, Kenya. Am. J. Phys. Anthropol. 93, 55–65 (1994)

    Article  CAS  Google Scholar 

  28. Schoeninger, J. J., Reeser, H. & Hallin, K. Paleoenvironment of Australopithecus anamensis at Allia Bay, East Turkana, Kenya: Evidence from mammalian herbivore enamel stable isotopes. J. Anthropol. Archaeol. 22, 200–207 (2003)

    Article  Google Scholar 

  29. Semaw, S. et al. Early Pliocene hominids from Gona, Ethiopia. Nature 433, 301–305 (2005)

    Article  ADS  CAS  Google Scholar 

  30. Wood, B. & Richmond, B. G. Human evolution: Taxonomy and paleobiology. J. Anat. (Lond.) 196, 19–60 (2000)

    Google Scholar 

  31. Kappelman, J. et al. Age of Australopithecus afarensis from Fejej, Ethiopia. J. Hum. Evol. 30, 139–146 (1996)

    Article  Google Scholar 

  32. Haile-Selassie, Y. & Asfaw, B. A newly discovered early Pliocene hominid-bearing paleontological site in the Mulu Basin, Ethiopia. Am. J. Phys. Anthropol. 30 (suppl.), 170 (2000)

    Google Scholar 

  33. Wood, B. The oldest hominid yet. Nature 371, 280–281 (1994)

    Article  ADS  CAS  Google Scholar 

  34. Stern, J. T. & Susman, R. L. The locomotor anatomy of Australopithecus afarensis. Am. J. Phys. Anthropol. 60, 279–317 (1983)

    Article  Google Scholar 

  35. Gould, S. J. The Structure of Evolutionary Theory (Belknap, Harvard, Cambridge, 2002)

    Google Scholar 

  36. Wagner, P. The quality of the fossil record and the accuracy of phylogenetic inferences about sampling and diversity. Syst. Biol. 49, 65–86 (2000)

    Article  CAS  Google Scholar 

  37. Hlusko, L. J., Suwa, G., Kono, R. T. & Mahaney, M. C. Genetics and the evolution of primate enamel thickness: A baboon model. Am. J. Phys. Anthropol. 124, 223–233 (2004)

    Article  Google Scholar 

  38. Malmgren, B. A., Berggren, W. A. & Lohman, G. P. Evidence for punctuated gradualism in the Late Neogene Globorotalia tumida lineage of planktonic foraminifera. Paleobiology 9, 377–389 (1983)

    Article  Google Scholar 

  39. McKinney, M. L. & McNamara, K. J. Heterochrony: The Evolution of Ontogeny (Plenum, New York, 1991)

    Book  Google Scholar 

  40. Stanley, S. M. Macroevolution: Pattern and Process (W. H. Freeman, San Francisco, 1979)

    Google Scholar 

  41. Teaford, M. F. & Ungar, P. S. Diet and the evolution of the earliest human ancestors. Proc. Natl Acad. Sci. USA 97, 13506–13511 (2000)

    Article  ADS  CAS  Google Scholar 

  42. Macho, G. A., Shimizu, D., Jiang, Y. & Spears, I. R. Australopithecus anamensis: A finite-element approach to studying the functional adaptations of extinct hominins. Anat. Rec. 283A, 310–318 (2005)

    Article  Google Scholar 

  43. Kingston, J. D., Marino, B. D. & Hill, A. Isotopic evidence for Neogene hominid paleoenvironments in the Kenya Rift Valley. Science 264, 955–959 (1994)

    Article  ADS  CAS  Google Scholar 

  44. DeMenocal, P. African climate change and faunal evolution during the Pliocene-Pleistocene. Earth Planet. Sci. Lett. 220, 3–24 (2004)

    Article  ADS  CAS  Google Scholar 

  45. Vrba, E. S. Mass turnover and heterochrony events in response to physical change. Paleobiology 31, 157–174 (2005)

    Article  Google Scholar 

  46. Cande, S. C. & Kent, D. V. Revised calibration of the geomagnetic polarity timescale for the Late Cretaceous and Cenozoic. J. Geophys. Res. 100, 6093–6095 (1995)

    Article  ADS  Google Scholar 

  47. Hall, C. M., Walter, R. C., Westgate, J. A. & York, D. Geochronology, stratigraphy and geochemistry of Cindery Tuff in Pliocene hominid-bearing sediments of the Middle Awash, Ethiopia. Nature 308, 26–31 (1984)

    Article  ADS  CAS  Google Scholar 

  48. White, T. D. et al. New discoveries of Australopithecus at Maka, Ethiopia. Nature 366, 261–265 (1993)

    Article  ADS  CAS  Google Scholar 

  49. Hart, W. K., Walter, R. C. & WoldeGabriel, G. Tephra sources and correlations in Ethiopia: Application of elemental and neodymium isotope data. Quatern. Int. 13/14, 77–86 (1992)

    Article  Google Scholar 

  50. Haileab, B. & Brown, F. H. Turkana Basin–Middle Awash Valley correlations and the age of the Sagantole and Hadar Formations. J. Hum. Evol. 22, 453–468 (1992)

    Article  Google Scholar 

Download references

Acknowledgements

We thank the National Science Foundation (including the Revealing Hominid Origins Initiative/HOMINID program), the Institute of Geophysics and Planetary Physics of the University of California at Los Alamos National Laboratory (LANL), the Japan Society for the Promotion of Science, the Fondation Singer-Polignac, and the Philip and Elaina Hampton Fund for Faculty International Initiatives at Miami University for financial support of field and laboratory research. The Earth and Environmental Sciences Division Electron Microprobe laboratory at LANL assisted with access and use. We thank A. Ademassu, W. Amerga, A. Amzaye, A. Asfaw, G. Assefa, F. Bibi, M. Black, D. Brill, K. Brudvik, M. Chalachew, M. Chubachi, W. Demisse (in memoriam), N. Eldredge, H. Elema, E. Güleç, M. Haydera, R. Jabbour, A.-R. Jaouni, K. Kairento, F. Kaya, K. Kimeu, B. Kyongo, D. Kubo, W. Liu, S. Mahieu, W. Mangao, M. McCollum, E. Mekonnen, W. Mihel, L. Morgan, C. Pehlevan, P. Reno, G. Richards, B. Rosenman, M. Serrat, A. Shabel, L. Smeenk, B. Tegengne, A. Terrazas and S. Yoseph for fieldwork, laboratory work and discussion, and M. Leakey for collections access. We thank the Ministry of Youth, Sports and Culture, the Authority for Research and Conservation of the Cultural Heritage, and the National Museum of Ethiopia for permissions and facilitation. We also thank the Afar Regional Government, the Afar people of the Middle Awash, and many others for contributing directly to the research efforts.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Tim D. White.

Ethics declarations

Competing interests

Reprints and permissions information is available at npg.nature.com/reprintsandpermissions. The authors declare no competing financial interests.

Supplementary information

Supplementary Discussion 1

Dental metric comparisons. (PDF 734 kb)

Supplementary Discussion 2

Enamel thickness measurements. (PDF 47 kb)

Supplementary Discussion 3

Cladistic relationships. (PDF 652 kb)

Supplementary Figure 1

ASI paleosol carbonates. (PDF 154 kb)

Supplementary Figure 2

Comparative dental morphology. (PDF 1062 kb)

Supplementary Figure 3

Argon-argon results. (PDF 131 kb)

Supplementary Table 1

Hominid fossils. (PDF 42 kb)

Supplementary Table 2

Isotopic composition of paleosol carbonates. (PDF 21 kb)

Supplementary Table 3

Faunal list. (PDF 52 kb)

Supplementary Table 4

Radioisotopic dating results. (PDF 30 kb)

Rights and permissions

Reprints and permissions

About this article

Cite this article

White, T., WoldeGabriel, G., Asfaw, B. et al. Asa Issie, Aramis and the origin of Australopithecus. Nature 440, 883–889 (2006). https://doi.org/10.1038/nature04629

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nature04629

This article is cited by

Comments

By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing