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Polymorphisms: Origins and Maintenance

  1. Kenneth M Weiss

Published Online: 30 APR 2008

DOI: 10.1002/9780470015902.a0005449.pub2



How to Cite

Weiss, K. M. 2008. Polymorphisms: Origins and Maintenance. eLS. .

Author Information

  1. Pennsylvania State University, University Park, Pennsylvania, USA

Publication History

  1. Published Online: 30 APR 2008


Polymorphism is variation in specific locations in the deoxyribonucleic acid (DNA) sequence. Some authors use the term only for variant alleles with at least 1% frequency in a population. This shows the population dependence of the concept itself. Variation arises initially by some form of mutation in a single individual but, because DNA is transmitted from parent to offspring, over time the frequency and geographical distribution of a genetic variant is essentially a population concept that depends on history.


  • variation;
  • evolution;
  • polymorphism;
  • single nucleotide polymorphism;
  • population genetics