Skip to main content
SpringerLink
Log in

Hominid Brain Evolution

Testing Climatic, Ecological, and Social Competition Models

  • Published:
Human Nature Aims and scope Submit manuscript

Abstract

Hypotheses regarding the selective pressures driving the threefold increase in the size of the hominid brain since Homo habilis include climatic conditions, ecological demands, and social competition. We provide a multivariate analysis that enables the simultaneous assessment of variables representing each of these potential selective forces. Data were collated for latitude, prevalence of harmful parasites, mean annual temperature, and variation in annual temperature for the location of 175 hominid crania dating from 1.9 million to 10 thousand years ago. We also included a proxy for population density and two indexes of paleoclimatic variability for the time at which each cranium was discovered. Results revealed independent contributions of population density, variation in paleoclimate, and temperature variation to the prediction of change in hominid cranial capacity (CC). Although the effects of paleoclimatic variability and temperature variation provide support for climatic hypotheses, the proxy for population density predicted more unique variance in CC than all other variables. The pattern suggests multiple pressures drove hominid brain evolution and that the core selective force was social competition.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Fig. 1
Fig. 2

Similar content being viewed by others

References

  • Aiello, L. C., & Wheeler, P. (1995). The expensive-tissue hypothesis: the brain and digestive system in human and primate evolution. Current Anthropology, 36, 199–221.

    Article  Google Scholar 

  • Alexander, R. D. (1989). Evolution of the human psyche. In P. Mellars, & C. Stringer (Eds.), The human revolution: Behavioural and biological perspectives on the origins of modern humans (pp. 455–513). Princeton, NJ: Princeton University Press.

    Google Scholar 

  • Ash, J., & Gallup Jr., G. G. (2007). Paleoclimatic variation and brain expansion during human evolution. Human Nature, 18, 109–124.

    Article  Google Scholar 

  • Barton, R. A. (1996). Neocortex size and behavioural ecology in primates. Proceedings of the Royal Society of London B, 263, 173–177.

    Article  Google Scholar 

  • Beaver, P. C., Jung, R. C., & Cupp, E. W. (1984). Clinical Parasitology. Philadelphia, PA: Lea and Febinger.

    Google Scholar 

  • Brace, C. L. (1995). Biocultural interaction and the mechanism of mosaic evolution in the emergence of “modern” morphology. American Anthropologist, 97, 711–721.

    Article  Google Scholar 

  • Brothers, L. (1990). The social brain: a project for integrating primate behavior and neurophysiology in a new domain. Concepts in Neuroscience, 1, 27–51.

    Google Scholar 

  • Colorado State University, Leprosy Research Support (2005). Global Leprosy Map. Available online at http://www.cvmbs.colostate.edu/mip/leprosy/largemap.html.

  • Dunbar, R. I. M. (1998). The social brain hypothesis. Evolutionary Anthropology, 6, 178–190.

    Article  Google Scholar 

  • Dunbar, R. (2003). Evolution of the social brain. Science, 302, 1160–1161.

    Article  Google Scholar 

  • Falk, D. (1983). Cerebral cortices of East African early hominids. Science, 221, 1072–1074.

    Article  Google Scholar 

  • Flinn, M. V., Geary, D. C., & Ward, C. V. (2005). Ecological dominance, social competition, and coalitionary arms races: why humans evolved extraordinary intelligence. Evolution and Human Behavior, 26, 10–46.

    Article  Google Scholar 

  • Foley, R., & Lahr, M. M. (1997). Mode 3 technologies and the evolution of modern humans. Cambridge Archaeology Journal, 7, 3–36.

    Article  Google Scholar 

  • Fox, J., & Monette, G. (1992). Generalized collinearity diagnostics. JASA, 87, 178–183.

    Google Scholar 

  • Gavrilets, S., & Vose, A. (2006). The dynamics of Machiavellian intelligence. Proceedings of the National Academy of Sciences USA, 103, 16823–16828.

    Article  Google Scholar 

  • Geary, D. C. (2005). The origin of mind: Evolution of brain, cognition, and general intelligence. Washington, DC: American Psychological Association.

    Book  Google Scholar 

  • Hill, K., Boesch, C., Goodall, J., Pusey, A., Williams, J., & Wrangham, R. (2001). Mortality rates among wild chimpanzees. Journal of Human Evolution, 40, 437–450.

    Article  Google Scholar 

  • Holloway Jr., R. L. (1967). The evolution of the human brain: Some notes toward a synthesis between neural structure and the evolution of complex behavior. General Systems, 12, 3–19.

    Google Scholar 

  • Holloway, R. L. (1975). The role of human social Behavior in the Evolution of the Brain. The 43rd James Arthur Lecture on the evolution of the human brain at the American Museum of Natural History, 1973. New York: American Museum of Natural History.

    Google Scholar 

  • Holloway, R. L., & de la Coste-Lareymondie, M. C. (1982). Brain endocast asymmetry in pongids and hominids: some preliminary findings on the paleontology of cerebral dominance. American Journal of Physical Anthropology, 58, 101–110.

    Article  Google Scholar 

  • Holloway, R. L., Broadfield, D. C., & Yuan, M. S. (2004). The human fossil record, Vol. 3: Brain endocasts—The paleoneurological record. Hoboken, NJ: Wiley.

    Book  Google Scholar 

  • Humphrey, N. K. (1976). The social function of intellect. In P. P. G. Bateson, & R. A. Hinde (Eds.), Growing points in ethology (pp. 303–317). New York: Cambridge University Press.

    Google Scholar 

  • Ihaka, R., & Gentleman, R. (1996). R: a language for data analysis and graphics. Journal of Computational and Graphical Statistics, 5, 299–314.

    Article  Google Scholar 

  • Jerison, H. J. (1973). Evolution of the brain and intelligence. New York: Academic Press.

    Google Scholar 

  • Jolly, C. J. (1970). The seed eaters: a new model of hominid differentiation based on a baboon analogy. Man, 5, 5–26.

    Article  Google Scholar 

  • Kanazawa, S. (2008). Temperature and evolutionary novelty as forces behind the evolution of general intelligence. Intelligence, 36, 99–108.

    Article  Google Scholar 

  • Kaplan, H., Hill, K., Lancaster, J., & Hurtado, A. M. (2000). A theory of human life history evolution: diet, intelligence, and longevity. Evolutionary Anthropology, 9, 156–185.

    Article  Google Scholar 

  • Li, J. Z., Absher, D. M., Tang, H., Southwick, A. M., Castro, A. M., Ramachandran, S., et al. (2008). Worldwide human relationships inferred from genome-wide patterns of variation. Science, 319, 1100–1104.

    Article  Google Scholar 

  • Low, B. S. (1990). Marriage systems and pathogen stress in human societies. American Zoologist, 30, 325–339.

    Google Scholar 

  • Malthus, T. R. (1798). An essay on the principle of population as it affects the future improvement of society with remarks on the speculations of Mr. Godwin, M. Condorcet, and other writers. London: Printed for J. Johnson, in St. Paul’s Church-yard.

    Google Scholar 

  • Marlow, J. R., Lange, C. B., Wefer, G., & Rosell-Melé, A. (2000). Upwelling intensification as part of the Pliocene-Pleistocene climate transition. Science, 290, 2288–2291.

    Google Scholar 

  • Matarese, G., & La Cava, A. (2004). The intricate interface between immune system and metabolism. Trends in Immunology, 25, 193–200.

    Article  Google Scholar 

  • McHenry, H. M. (1994). Tempo and mode in human evolution. Proceedings of the National Academy of Sciences USA, 91, 6780–6786.

    Article  Google Scholar 

  • Noone, D., & Simmonds, I. (2002). Association between δ18O of water and climate parameters in a simulation of atmospheric circulation for 1979–95. Journal of Climate, 15, 3150–3169.

    Article  Google Scholar 

  • Potts, R. (1998). Variability selection in hominid evolution. Evolutionary Anthropology, 7, 81–96.

    Article  Google Scholar 

  • Ruff, C. B., Trinkaus, E., & Holliday, T. W. (1997). Body mass and encephalization in Pleistocene Homo. Nature, 387, 173–176.

    Article  Google Scholar 

  • Satellite Signals. (2007). Latitude and longitude. Retrieved from http://www.satsig.net/maps/lat-long-finder.htm

  • Shackleton, N. J., Berger, A., & Peltier, W. R. (1990). An alternative astronomical calibration of the lower Pleistocene timescale based on ODP site 677. Transactions of the Royal Society of Edinburgh: Geological Sciences, 81, 251–261.

    Google Scholar 

  • Tobias, P. V. (1987). The brain of Homo habilis: a new level of organization in cerebral evolution. Journal of Human Evolution, 16, 741–761.

    Article  Google Scholar 

  • Vrba, E. S. (1974). Chronological and ecological implications of the fossil Bovidae at the Sterkfontein Australopithecine site. Nature, 250, 19–23.

    Article  Google Scholar 

  • Wood, B., & Collard, M. (1999). The human genus. Science, 284, 65–71.

    Article  Google Scholar 

Download references

Acknowledgments

The authors thank Jessica Ash, Gordon Gallup, Christopher Ruff, and Satoshi Kanazawa for sharing their data and for helpful comments throughout the data collection process; Carol Ward and Deborah Cunningham for their help in the data collection process; Margie Gurwit and Phil Wood for their help with analyses; Mary Hoard, Lara Nugent, and Jon Oxford for their time throughout the project; and Ralph Holloway and two anonymous reviewers for their comments on an earlier draft.

Author information

Authors and Affiliations

  1. Department of Psychological Sciences, University of Missouri, 210 McAlester Hall, Columbia, MO, 65211-2500, USA

    Drew H. Bailey & David C. Geary

Authors
  1. Drew H. Bailey
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. David C. Geary
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to David C. Geary.

Electronic supplementary material

Below is the link to the supplementary material

ESM

(PDF 60.0 KB)

Rights and permissions

Reprints and permissions

About this article

Cite this article

Bailey, D.H., Geary, D.C. Hominid Brain Evolution. Hum Nat 20, 67–79 (2009). https://doi.org/10.1007/s12110-008-9054-0

Download citation

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s12110-008-9054-0

Keywords

Search

Navigation