The consensus among evolutionists seems to be (and has been for at least a century) that the morphological complexity of organisms increases in evolution, although almost no empirical evidence for such a trend exists. Most studies of complexity have been theoretical, and the few empirical studies have not, with the exception of certain recent ones, been especially rigorous; reviews are presented of both the theoretical and empirical literature. The paucity of evidence raises the question of what sustains the consensus, and a number of suggestions are offered, including the possibility that certain cultural and/or perceptual biases are at work. In addition, a shift in emphasis from theoretical to empirical inquiry is recommended for the study of complexity, and guidelines for future empirical studies are proposed.
This is a preview of subscription content, access via your institution.
Buy single article
Instant access to the full article PDF.
Tax calculation will be finalised during checkout.
Subscribe to journal
Immediate online access to all issues from 2019. Subscription will auto renew annually.
Tax calculation will be finalised during checkout.
Atlan, H.: 1974, ‘On a Formal Definition of Organization’, Journal of Theoretical Biology 45, 295–304.
Ayala, F.J.: 1974, ‘The Concept of Biological Progress’, in F.J. Ayala and T. Dobzhansky (eds.), Studies in the Philosophy of Biology, MacMillan Press Ltd., London, pp. 339–355.
Bonner, J.T.: 1988, The Evolution of Complexity, Princeton University Press, Princeton.
Brooks, D.R. and E.O. Wiley: 1988, Evolution as Entropy, 2nd edition, University of Chicago Press, Chicago.
Castrodeza, C.: 1978, ‘Evolution, Complexity, and Fitness’, Journal of Theoretical Biology 71, 469–471.
Cisne, J.L.: 1974, ‘Evolution of the World Fauna of Aquatic Free-Living Arthropods’, Evolution 28, 337–366.
Cole, B.J.: 1985, ‘Size and Behavior in Ants: Constraints on Complexity’, Proceedings of the National Academy of Sciences USA 82, 8548–8551.
Cope, E.D.: 1871, ‘The Method of Creation of Organic Forms’, Proceedings of the American Philosophical Society 12, 229–263.
Darwin, C.: 1859 (1964), On the Origin of Species (A facsimile of the first edition), Harvard University Press, Cambridge, MA.
Darwin, C.: 1987, ‘Notebook E’, in P.H. Barett et al. (eds.), Charles Darwin's Notebooks, Cornell University Press, Ithaca, NY.
Denbigh, K.G.: 1975, ‘A Non-Conserved Function for Organized Systems’, in L. Kubat and J. Zeman (eds.), Entropy and Information in Science and Philosophy, American Elsevier, New York, pp. 83–92.
Fisher, D.C.: 1986, ‘Progress in Organismal Design’, in D.M. Raup and D. Jablonski (eds.), Patterns and Processes in the History of Life, Springer-Verlag, Berlin, pp. 99–117.
Gatlin, L.L.: 1972, Information Theory and the Living System, Columbia University Press, New York.
Goudge, T.A.: 1961, The Ascent of Life, George Allen and Unwin Ltd., London, p. 39.
Gould, S.J.: 1977a, ‘Eternal Metaphors of Paleontology’, in A. Hallam (ed.), Patterns of Evolution, Elsevier, Amsterdam, pp. 1–26.
Gould, S.J.: 1977b, Ontogeny and Phytogeny, Harvard University Press, Cambridge, MA.
Gould, S.J., N.L. Gilinsky, and R.Z. German: 1987, ‘Asymmetry of Lineages and the Direction of Evolutionary Time’, Science 236, 1437–1441.
Gould, S.J.: 1988, ‘On Replacing the Idea of Progress with an Operational Notion of Directionality’, in N.H. Nitecki (ed.), Evolutionary Progress, University of Chicago Press, Chicago, pp. 319–338.
Gregory, W.K.: 1934, ‘Polyisomerism and Anisomerism in Cranial and Dental Evolution Among Vertebrates’, Proceedings of the National Academy of Sciences 20, 1–9.
Gregory, W.K.: 1935a, ‘Reduplication in Evolution’, Quarterly Review of Biology 10, 272–290.
Gregory, W.K.: 1935b, ‘“Williston's Law” Relating to the Evolution of Skull Bones in the Vertebrates’, American Journal of Physical Anthropology 20, 123–152.
Gregory, W.K.: 1951a, Evolution Emerging, Volume 1,The MacMillan Company, New York, pp. 548–549.
Gregory, W.K.: 1951b, Evolution Emerging, Volume 2, The MacMillan Company, New York, p. 899.
Hinegardner, R. and J. Engelberg: 1983, ‘Biological Complexity’, Journal of Theoretical Biology 104, 7–20.
Hull, D.L.: 1988, ‘Progress in Ideas of Progress’, in M.H. Nitecki (ed.), Evolutionary Progress, University of Chicago Press, Chicago, pp. 27–48.
Huxley, J.S.: 1953, Evolution in Action, Harper and Brothers, New York.
Kampis, G. and V. Csányi: 1987, ‘Notes on Order and Complexity’, Journal of Theoretical Biology 124, 111–121.
Katz, M.J.: 1987, ‘Is Evolution Random?’, in R.A. Raff and E.C. Raff (eds.), Development as an Evolutionary Process, Alan R. Liss, New York, pp. 285–315.
Lamarck, J.B.P.A.M.: 1809 (1984), Zoological Philosophy, University of Chicago Press, Chicago.
Landauer, R.: 1988, ‘A Simple Measure of Complexity’, Nature 336, 306–307.
Lewontin, R.C.: 1968, ‘Evolution’, in D.L. Sills (ed.), International Encyclopedia of the Social Sciences, Volume 5, The MacMillan Company and The Free Press, pp. 202–210.
Maddox, J.: 1990, ‘Complicated Measures of Complexity’, Nature 344, 705.
Maynard Smith, J.: 1970, ‘Time in the Evolutionary Process’, Studium Generale 23, 266–272.
Maynard Smith, J.: 1988, ‘Evolutionary Progress and Levels of Selection’, in M.H. Nitecki (ed.), Evolutionary Progress, University of Chicago Press, Chicago, pp. 219–230.
Maze, J. and R.K. Scagel: 1983, ‘A Different View of Plant Morphology and the Evolution of Form’, Systematic Botany 8, 469–472.
McCoy, J.W.: 1977, ‘Complexity in Organic Evolution’, Journal of Theoretical Biology 68, 457–458.
Needham, J.: 1936, Order and Life, Yale University Press, New Haven.
Owen, R.: 1866, Anatomy of Vertebrates, Volume 2, Longmans, Green, and Co., London.
Papentin, F.: 1980, ‘On Order and Complexity. I. General Considerations’, Journal of Theoretical Biology 87, 421–456.
Papentin, F.: 1982, ‘On Order and Complexity. II. Applications to Chemical and Biochemical Structures’, Journal of Theoretical Biology 95, 225–245.
Prigogine, I., G. Nicolis, and A. Babloyantz: 1972, ‘Thermodynamics of Evolution’, Physics Today, December, pp. 38–44.
Raup, D.M.: 1977, ‘Stochastic Models in Evolutionary Palaentology’, in A. Hallam (ed.), Patterns of Evolution, Elsevier, Amsterdam, pp. 59–78.
Rensch, B.: 1960, Evolution above the Species Level, Columbia University Press, New York, pp. 281–308.
Richardson, R.C. and T.C. Kane: 1988, ‘Orthogenesis and Evolution in the Nineteenth Century’, in M.H. Nitecki (ed.), Evolutionary Progress, University of Chicago Press, Chicago, pp. 149–168.
Robson, K.A., R.K. Scagel, and J. Maze: 1988, ‘Sources of Morphological Variation and Organization Within and Among Populations of Balsamorhiza sagittata’, Canadian Journal of Botany 66, 11–17.
Ruse, M.: 1988, ‘Molecules to Men: Evolutionary Biology and Thoughts of Progress’, in M.H. Nitecki (ed.), Evolutionary Progress, University of Chicago Press, Chicago, pp. 97–126.
Salthe, S.N.: 1985, Evolving Hierarchical Systems, Columbia University Press, New York.
Saunders, P.T. and M.-W. Ho: 1976, ‘On the Increase in Complexity in Evolution’, Journal of Theoretical Biology 63, 375–384.
Saunders, P.T. and M.-W. Ho: 1981, ‘On the Increase in Complexity in Evolution II. The Relativity of Complexity and the Principle of Minimum Increase’, Journal of Theoretical Biology 90, 515–530.
Schopf, T.J.M., D.M. Raup, S.J. Gould, and D.S. Simberloff: 1975, ‘Genomic Versus Morphologic Rates of Evolution: Influence of Morphologic Complexity’, Paleobiology 1, 63–70.
Simpson, G.G.: 1949, The Meaning of Evolution, Yale University Press, New Haven.
Simpson, G.G.: 1961, Principles of Animal Taxonomy, Columbia University Press, New York.
Spencer, H.: 1890, First Principles, 5th edition, Williams and Norgate, London.
Spencer, H.: 1893, The Principles of Biology, Volume 2, D. Appleton and Company, New York.
Stanley, S.M.: 1973, ‘An Explanation for Cope's Rule’, Evolution 27, 1–26.
Stebbins, G.L.: 1969, The Basis of Progressive Evolution, University of North Carolina Press, Chapel Hill.
Subba Rao, J., C.P. Geevan, and G. Subba Rao: 1982, ‘Significance of the Information Content of DNA in Mutations and Evolution’, Journal of Theoretical Biology 96, 571–577.
Swetlitz, M.: 1989, ‘Facts, Values, and Progress: Julian Huxley's Use of the Fossil Record’, A talk presented before the Society for the History, Philosophy and Social Studies of Biology, University of Western Ontario, 25 June 1989. (Copies are available from the author at the following address: History Department, University of Chicago, 1126 E. 59th Street, Chicago, IL 60637 USA.)
Vogt, P.R. and J.C. Holden: 1979, ‘The End-Cretaceous Extinctions: A Study of the Multiple Working Hypotheses Method Gone Mad’, in W.K. Christensen and T. Birkelund (eds.), Cretaceous/Tertiary Boundary Events Symposium Proceedings, Volume 2, University of Copenhagen, Copenhagen, p. 49.
Waddington, C.H.: 1969, ‘Paradigm for an Evolutionary Process’, in C.H. Waddington (ed.), Towards a Theoretical Biology, Volume 2, Aldine Publishing Company, Chicago, pp. 106–128.
Wake, D.B., E.F. Connor, A.J. de Ricqlès, J. Dzik, D.C. Fisher, S.J. Gould, M. LaBarbera, D.A. Meeter, V. Mosbrugger, W.-E. Reif, R.M. Rieger, A. Seilacher, and G.P. Wagner: 1986, ‘Directions in the History of Life’, in D.M. Raup and D. Jablonski (eds.), Patterns and Processes in the History of Life, Springer-Verlag, Berlin, pp. 47–67.
Wicken, J.S.: 1979, ‘The Generation of Complexity in Evolution: A Thermodynamic and Information-Theoretical Discussion’, Journal of Theoretical Biology 77, 349–365.
Wicken, J.S.: 1987, Evolution, Thermodynamics, and Information, Oxford University Press, Oxford.
Williams, G.C.: 1966, Adaptation and Natural Selection, Princeton University Press, Princeton, pp. 42–55.
Wright, R.: 1990, ‘The Intelligence Test’, The New Republic, 29 January, pp. 29–36.
Yagil, G.: 1985, ‘On the Structural Complexity of Simple Biosystems’, Journal of Theoretical Biology 112, 1–23.
About this article
Cite this article
McShea, D.W. Complexity and evolution: What everybody knows. Biol Philos 6, 303–324 (1991). https://doi.org/10.1007/BF00132234
- evolutionary trends
- Herbert Spencer