Genetic Variation: Human


Many different types of genetic variation can be observed in the deoxyribonucleic acid (DNA) of modern humans. Nevertheless, humans have relatively little genetic variation compared with many other species, suggesting a recent common origin for Homo sapiens. Some of this variation may have functional consequences, for example in disease states and complex characters such as stature or intelligence, but much variation in DNA appears to be neutral.

Keywords: variation; polymorphism; disease; population; genetics

Figure 1.

Two examples of human DNA polymorphism. (a) A base‐substitutional polymorphism, at which the base shown in bold can be either a C or a T. (b) Tandem repeat polymorphism, showing three allelic forms, containing 5, 6 or 8 copies of a 4 base pair (GGAA) repeat motif.


Further Reading

Cavalli‐Sforza LL (1998) The DNA revolution in population genetics. Trends in Genetics 14: 60–65.

Jobling MA and Tyler‐Smith C (2003) The human Y chromosome: an evolutionary marker comes of age. Nature Reviews. Genetics 4: 598–612.

Johnson GCL and Todd JA (2000) Strategies in complex disease mapping. Current Opinion in Genetics and Development 10: 330–334.

McCarthy GWA, Abescasis GR, Cardon LR et al. (2008) Genome‐wide association studies for complex traits: consensus, uncertainty and challenges. Nature Reviews. Genetics 9: 356–369.

Paabo S (2003) The mosaic that is our genome. Nature 421: 409–412.

Perry GH, Dominy NJ, Claw KG et al. (2007) Diet and the evolution of human amylase gene copy number variation. Nature Genetics 39: 1256–1260.

Przeworski M, Hudson RR and Di Rienzo A (2000) Adjusting the focus on human variation. Trends in Genetics 16: 296–302.

Smith R, Healy E, Siddiqui S et al. (1998) Melanocortin 1 receptor variants in an Irish population. Journal of Investigative Dermatology 111: 119–122.

Contact Editor close
Submit a note to the editor about this article by filling in the form below.

* Required Field

How to Cite close
Hollox, Edward J(Mar 2009) Genetic Variation: Human. In: eLS. John Wiley & Sons Ltd, Chichester. [doi: 10.1002/9780470015902.a0001464.pub2]