Variation, Within Species: Introduction


Individuals within a species will have similar genes but will differ in phenotypic characteristics and behaviour because of slight differences in the genotype and response to environmental conditions. This was first reported by Charles Darwin and Alfred Wallace in the paper ‘On the Tendency of Species to form Varieties; and on the Perpetuation of Varieties and Species by Natural Means’ read to the Linnean Society in London on 1 July 1858.

Keywords: DNA; mutations; biodiversity; population dynamics; evolution

Figure 1.

Variation of the Galapagos finches. The founder finches were blue‐black grassquit. The descendants now include the seed eaters, genus Geospiza, the bud eater, Camarhynchus crassirostris, and the insect eaters, including Certhidea olivacea and the remaining genus Camarhynchus individuals. (The author wishes to acknowledge the artistic contribution of Anne Morvant.)


Further Reading

Cummings MR (1991) Human Heredity, Principles and Issues, 2nd edn. New York: West Publishing.

Lewontin R (1982) Human Diversity. New York: Scientific American Books.

Purves WK, Orians GH and Heller HC (1992) Life, The Science of Biology, 3rd edn. Sunderland, MA: Sinauer Associates.

Scandalios JG (1995) Environmental stress, Genomic response to. Meyers RA (ed.) Molecular Biology and Biotechnology: A Comprehensive Desk Reference, pp. 284–289. New York: VCH Publishers

Snustad DP (1995) Genetics. Meyers RA (ed.) Molecular Biology and Biotechnology: A Comprehensive Desk Reference, pp. 369–374. New York: VCH Publishers

Ridley M (1996) Evolution, 2nd edn. Cambridge, MA: Blackwell Science.

Mayr E (1997) Evolution and the Diversity of Life. Selected Essays. Cambridge, MA: Harvard University Press.

Williams GC (1996) Adaptation and Natural Selection. Princeton, NJ: Princeton University Press.

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Harrison, Richard M(Jan 2006) Variation, Within Species: Introduction. In: eLS. John Wiley & Sons Ltd, Chichester. [doi: 10.1038/npg.els.0004161]