Abstract
The course of change in hominid cranial capacity through time is described for the period 3200-15 ky B P. Both analysis of variance and fitting of regression curves performed on a sample of 144 specimens point towards a smooth gradual change at an increasing rate. Residual variances around empirical and theoretical lines of regression are smaller than the total intraspecific variance in modernH sapiens testifying as to the goodness of fit. It is postulated that the gradual nature of the evolutionary process results from the operation of a typical darwinian mechanism of directional selection. Rates of selection themselves undergo increase as a result of self-amplifying nature of hominid evolution resulting from positive feedbacks between evolving elements of the bio-cultural complex. Therefore the theoretical regression is of a doubly exponential form: exponential increase of cranial capacity with time at rates that themselves increase exponentially. As the change is gradual and variance around the line of regression does not exceed that observed within a single species from the viewpoint of cranial capacity hominid evolution may be described as a continuous series of ill-separated chronospecies.
Similar content being viewed by others
References
Beals K.L. &Smith C.L., Dodd S.M., 1984.Brain size, cranial morphology, climate, and time machines. Current Anthropology, 25: 301–330.
Bielicki T. 1969.Niektore zwiazki zwrotne w procesie ewolucji Hominidae. Materialy i Prace Antropologiczne, 77: 3–60.
Blumenberg B., 1983.The evolution of the advanced hominid brain. Current Anthropology, 24: 589–623.
Blumenberg B., 1984.Allometry and evolution of Tertiary Hominoids. J. Hum. Evol., 13: 613–676.
Godfrey L. &Jacobs K.H., 1981.Gradual, autocatalytic and punctuational models of hominid brain evolution, A cautionary tale. J. Hum. Evol., 10: 255–272.
Gruesser O.-J. &Weiss L.-R., 1985.Quantitative models on phylogenetic growth of the hominid brain. In (P. Tobias ed.). Hominid Evolution, pp. 457–464. New York: A.R. Liss.
Henneberg M., 1986.Human cranial capacity decrease in Holocene: A result of generalized structural reduction. Am. J. Phys. Anthropo., 69: 213–214.
Henneberg M., 1987a.Decrease of human skull size in the Holocene. Human Biology (in press).
Henneberg M., 1987b.Intraspecific range of head size/body size proportions in Homo sapiens and encephalization of earlier hominids (in preparation).
Henneberg M., Budnik A., Pezacka M. &Puch A.E., 1985.Head size, body size, and intelligence, intraspecific correlations in Homo sapiens sapiens, Homo 37: 207–218.
Hollaway R.L., 1979.Brain size, allometry and reorganization, toward a synthesis. In (M.E. Hahn, C. Jensen, B.C. Dudek eds.). Development and Evolution of Brain Size, pp. 59–88. New York: Academic Press.
Kocetkova V.I., 1978.Paleoneurology. New York: Academic Press.
McHenry H., 1982.The pattern of human evolution. Annual Review of Anthropology, 11: 151–173.
Olivier G., 1973.Hominization and cranial capacity. In (M. H. Day ed.). Human Evolution, Symposia of the Society for the Study of Human Biology, vol. 11. pp. 87–101. London: Taylor & Francis.
Olivier G., Dricot J.M., 1975.Estimation of the cranial capacity of fossil hominids. In (R.H. Tuttle ed.). Primate Functional Morphology and Evolution, pp. 443–449. Hague: Mouton.
Pilbeam D., Gould S.J., 1974.Size and scaling in human evolution. Science, 186: 892–901.
Tobias P.V., 1971.The Brain in Hominid Evolution. New York: Columbia University Press.
Wiercinski A., 1978.Ontogenetic retardations and human evolution. In: Proc. Symp. Natur. Select. Libice, pp. 277–301. Praha: CSAV.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Henneberg, M. Hominid cranial capacity change through time: a darwinian process. Hum. Evol. 2, 213–220 (1987). https://doi.org/10.1007/BF03016107
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF03016107