Selection: Units and Levels


Analysis of units and levels of selection allows determination of where and how natural selection takes place, and how it causes evolutionary change in genes and organisms.

Keywords: selection; altruism; genes; evolution


Alexander RD and Borgia G (1978) Group selection, altruism, and the levels of organization of life. Annual Review of Ecology and Systematics 9: 449–474.

Dawkins R (1982) Replicators and vehicles. In: King's College Sociobiology Group (eds) Current Problems in Sociobiology, pp. 45–64. Cambridge: Cambridge University Press.

Hamilton WD (1964) The genetical evolution of social behavior, I and II. Journal of Theoretical Biology 7: 1–52.

Hamilton WD (1967) Extraordinary sex ratios. Science 156: 477–488.

Hurst LD, Atlan A and Bengtsson BO (1996) Genetic conflicts. Quarterly Review of Biology 71: 317–364.

Lewontin RC (1970) The units of selection. Annual Review of Ecology and Systematics 1: 1–18.

Queller D (1992) Quantitative genetics, inclusive fitness, and group selection. American Naturalist 139: 540–558.

Sober E and Wilson DS (1998) Unto Others: The Evolution and Psychology of Unselfish Behavior. Cambridge, CA: Harvard University Press.

Wade MJ (1978) A critical review of the models of group selection. Quarterly Review of Biology 53: 101–114.

Williams GC (1992) Natural Selection: Domains, Levels and Challenges. Oxford: Oxford University Press.

Further Reading

Alexander RD (1979) Darwinism and Human Affairs. Seattle, WA: University of Washington Press.

Alexander RD (1987) The Biology of Moral Systems. Hawthorne, NY: Aldine de Gruyter.

Buss LW (1987) The Evolution of Individuality. Princeton, NJ: Princeton University Press.

Dawkins R (1989) The Selfish Gene, 2nd edn. Oxford: Oxford University Press.

Keller L (1999) Levels of Selection in Evolution. Princeton, NJ: Princeton University Press.

Maynard‐Smith J and Szathmary E (1999) The Origins of Life: From the Birth of Life to the Origin of Language. Oxford: Oxford University Press.

Werren JH and Beukenboom LW (1998) Sex determination, sex ratios, and genetic conflict. Annual Review of Ecology and Systematics 29: 233–261.

Williams GC (1966) Adaptation and Natural Selection: A Critique of Some Current Evolutionary Thought. Princeton, NJ: Princeton University Press.

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Crespi, Benard J(Apr 2001) Selection: Units and Levels. In: eLS. John Wiley & Sons Ltd, Chichester. [doi: 10.1038/npg.els.0001712]