Human Genetic Diversity

Abstract

Genetic diversity within and between human populations is being studied extensively. The results of these studies can be applied to questions about human evolutionary history, forensics and gene identification.

Keywords: human evolution; population genetics; mutation; genetic distances

Figure 1.

Three major forms of genetic diversity. (a) Diversity at the level of single nucleotides. The individual is heterozygous for one nucleotide in this sequence having inherited a C from the father and a T from the mother. (b) Short tandem repeat polymorphisms exhibit varying numbers of short repeats, such as the CAGA sequence shown here. The individual has inherited eight CAGA repeats from the father and five from the mother. (c) Interspersed repeats are scattered in a single copy throughout the genome. In this case, the middle interspersed repeat is present on the paternal chromosome but absent on the maternal chromosome.

Figure 2.

Comparison of genetic diversity at the nucleotide level in humans and chimpanzees. The nuclear DNA sequence consists of 10 154 bp of DNA from the X‐chromosome, and the mitochondrial DNA consists of 320 bp of DNA. Data taken from Kaessmann H, Wiebe V and Pääbo S (1999) Extensive nuclear DNA sequence diversity among chimpanzees. Science286: 1159–1162.

Figure 3.

Illustration of the coalescent process. Although the ancestral population contains multiple individuals, all lineages but one eventually become extinct. Thus, all of the variation in the current population can ultimately be traced to one common ancestor.

Figure 4.

Tree diagram illustrating the genetic distances among 22 human populations. Genetic distances were estimated using 100 Alu insertion polymorphisms (Watkins WS, Rogers AR, Ostler CT et al. (2003) Genetic variation among world populations: inferences from 100 Alu insertion polymorphisms. Genome Research13: 1607–1618).

Figure 5.

Tree diagram illustrating the genetic distances between 15 human populations, using 11 078 SNPs to estimate genetic distances. Data from Shriver MD, Mei R, Parra EJ et al. (2005) Large‐scale SNP analysis reveals clustered and continuous patterns of human genetic variation. Human Genomics2(2): 81–89.

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Further Reading

Butler JM (2005) Forensic DNA Typing. Burlington, MA: Elsevier.

Cavalli‐Sforza LL, Menozzi P and Piazza A (1994) The History and Geography of Human Genes. Princeton: Princeton University Press.

Conrad DF and Hurles ME (2007) The population genetics of structural variation. Nature Genetics 39: S30–S31.

Excoffier L (2002) Human demographic history: refining the recent African origin model. Current Opinion in Genetics & Development 12: 675–682.

Frazer KA, Ballinger DG, Cox DR et al. (2007) A second generation human haplotype map of over 3.1 million SNPs. Nature 449: 851–861.

International Human Genome Sequencing Consortium (2004) Finishing the euchromatic sequence of the human genome. Nature 431: 931–945.

Jobling MA, Hurles ME and Tyler‐Smith C (2003) Human Evolutionary Genetics: Origins, Peoples, and Disease. New York: Garland Science.

Jorde LB (2005) Human genetic variation and disease. In: Meyers RA (ed.) Encyclopedia of Molecular Biology and Molecular Medicine, 2nd edn. vol. 6, pp. 323–337. Weinheim: Wiley‐VCH Publishers.

Jorde LB, Watkins WS and Bamshad MJ (2000) The distribution of human genetic diversity: a comparison of mitochondrial, autosomal, and Y chromosome data. American Journal of Human Genetics 66: 979–988.

Noonan JP, Coop G, Kudaravalli S et al. (2006) Sequencing and analysis of Neanderthal genomic DNA. Science 314: 1113–1118.

Stearns SC and Koella JC (eds) (2008) Evolution in Health and Disease. Oxford: Oxford University Press.

West M, Ginsburg GS, Huang AT and Nevins JR (2006) Embracing the complexity of genomic data for personalized medicine. Genome Research 16: 559–566.

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How to Cite close
Jorde, Lynn B(Jul 2008) Human Genetic Diversity. In: eLS. John Wiley & Sons Ltd, Chichester. http://www.els.net [doi: 10.1002/9780470015902.a0005079.pub2]