¹ Muller, H. J. is quoted by Simpson, G. G. in This View of Life (New York: Harcourt, Brace & World, 1964), 36.Google Scholar

¹ See the following widely used textbooks: Roughgarden, J., Theory of Population Genetics and Evolutionary Ecology: An Introduction (New York: Macmillan, 1979);Google Scholar Hartl, D. L., Principles of Population Genetics (Sunderland, Mass.: Sinauer Associates, 1980);Google Scholar May, R. M. (ed.), Theoretical Ecology: Principles and Applications, 2nd edn (Sunderland, Mass.: Sinauer Associates, 1981);Google Scholar Krebs, J. R. and Davies, N. B. (eds), Behavioural Ecology: An Evolutionary Approach, 2nd edn (Sunderland, Mass.: Sinauer Associates, 1984).Google Scholar

³ Reviews of the various modes of selection, including forms that direct individuals away from competitive behaviour, can be found in Wilson, E. O., Sociobiology: The New Synthesis (Cambridge, Mass.: Belknap Press of Harvard University Press, 1975);Google Scholar Oster, G. F. and Wilson, E. O., Caste and Ecology in the Social Insects (Princeton University Press, 1978);Google Scholar Boorman, S. A. and Levitt, P. R., The Genetics of Altruism (New York: Academic Press, 1980);Google Scholar Wilson, D. S., The Natural Selection of Populations and Communities (Menlo Park, Calif.: Benjamin/Cummings, 1980).Google ScholarPubMed

⁴ For example, the debate over ‘punctuated equilibrium’ versus ‘gradualism’ among palaeontologists and geneticists. For most biologists, the issue is not the mechanism of evolution but the conditions under which evolution sometimes proceeds rapidly and sometimes slows to a crawl. There is no difficulty in explaining the variation in rates. On the contrary, there is a surplus of plausible explanations, virtually all consistent with Neo- Darwinian theory, but insufficient data to choose among them. See, for example, Gould, S. J. and Eldredge, N., ‘Punctuated Equilibria: The Tempo and Mode of Evolution Reconsidered’, Paleobiology 3 (1977), 115–151;CrossRefGoogle Scholar and Turner, J. R. G., ‘“The hypothesis that explains mimetic resemblance explains evolution”: the gradualist-saltationist schism’, in Grene, M. (ed.), Dimensions of Darwinism (Cambridge University Press, 1983), 129–169.Google Scholar

⁵ See footnote 2.

⁶ Kimura, M., The Neutral Theory of Molecular Evolution (Cambridge University Press, 1983).Google Scholar

⁷ Sibley, C. G. and Ahlquist, J. E., ‘The Phylogeny of the Hominoid Primates, as Indicated by DNA-DNA Hybridization’, Journal of Molecular Evolution 20 (1984), 2–15.CrossRefGoogle ScholarPubMed

⁸ We are grateful to Victor A. McKusick for providing the counts of identified and inferred human genes up to 1984.

⁹ Ashton, G. C., Polovina, J. J. and Vandenberg, S. G., ‘Segregation Analysis of Family Data for 15 Tests of Cognitive Ability’, Behaviour Genetics 9 (1979), 329–347.CrossRefGoogle ScholarPubMed

¹⁰ Smith, S. D., Kimberling, W. J., Pennington, B. F. and Lubs, H. A., ‘Specific Reading Disability: Identification of an Inherited Form through Linkage Analysis’, Science 219 (1982), 1345–1347.CrossRefGoogle ScholarPubMed

¹¹ See Hall, J. C. and Greenspan, R. J., ‘Genetic Analysis of Drosophila Neurobiology’, Annual Review of Genetics 13 (1979), 127–195.CrossRefGoogle ScholarPubMed

¹² 12 See, for example, the recent analysis by Anderson, J. R., The Architecture of Cognition (Cambridge, Mass.: Harvard University Press, 1983).Google ScholarPubMed

¹³ See footnote 3.

¹⁴ The evidence for biased epigenetic rules of mental development is summarized in Lumsden, C. J. and Wilson, E. O., Genes, Mind, and Culture (Cambridge, Mass.: Harvard University Press, 1981) and Promethean Fire: Reflections on the Origin of Mind (Cambridge, Mass.: Harvard University Press, 1983).Google Scholar

¹⁵ A new discipline of decision-making is being developed in cognitive psychology based upon the natural means–one can correctly say the epigenetic rules–by which people choose among alternatives and reach agreements. See, for example, Tversky, A. and Kahneman, D., ‘The Framing of Decisions and the Psychology of Choice’, Science 211 (1981), 453–458;CrossRefGoogle Scholar and Axelrod, R., The Evolution of Cooperation (New York: Basic Books, 1984).Google Scholar

¹⁶ Rosch, E., ‘Natural Categories’, Cognitive Psychology 4 (1973), 328–350.CrossRefGoogle Scholar

¹⁷ The epigenetic rules of cognitive development analysed through the year 1980 are reviewed by C. J. Lumsden and E. O. Wilson, op. cit.

¹⁸ Lassen, N. A., Ingvar, D. H. and Skinhøj, E., ‘Brain Function and Blood Flow’, Scientific American 239 (1978), 62–71.CrossRefGoogle ScholarPubMed

¹⁹ Wolf, A. P. and Huang, C. S., Marriage and Adoption in China, 1845–1945 (Stanford University Press, 1980);Google Scholar Shepher, J., Incest: A Biosocial View (New York: Academic Press, 1983);Google Scholar Berghe, P. L. van den, ‘Human Inbreeding Avoidance: Culture in Nature’, The Behavioural and Brain Sciences 6 (1983), 91–123.CrossRefGoogle Scholar

²⁰ Lumsden, C. J. and Wilson, E. O., op. cit. See also the précis of Genes, Mind, and Culture and commentaries on the book by twenty-three authors in The Behavioural and Brain Sciences 5 (1982), 1–37.Google Scholar

²¹ Rawls, J., A Theory of Justice (Cambridge, Mass.: Harvard University Press, 1971), 502–503.Google Scholar

²² This is the argument proposed by Nozick, R. in Philosophical Explanations (Cambridge, Mass.: Belknap Press of Harvard University Press, 1981) in order to escape the implications of sociobiology.Google Scholar

²³ See footnote 16.

²⁴ Jones, E. and Aoki, C., ‘Genetic and Cultural Factors in Alcohol Use’ (submitted to Science).Google Scholar

²⁵ C. J. Lumsden and E. O. Wilson, op. cit., who show the way to predict cultural diversity caused by random choice patterns in different societies.