Concerted Evolution


Concerted evolution is a genetic process by which repetitive deoxyribonucleic acid (DNA) sequences are homogenized so that the sequence of a given multigene family within a species shares much higher sequence identity than that of the homologous gene family between two different species. Concerted evolution occurs in all living organisms, from bacteria to humans. DNA recombination mechanisms, especially unequal crossover and gene conversion, are responsible for concerted evolution.

Keywords: molecular evolution; repetitive sequence; multigene family; sequence homogenization; DNA recombination; gene conversion

Figure 1.

Structures of multigene families undergoing concerted evolution. (a) Structure of human ribosomal DNA (rDNA) arrays. Genic regions are shown as red rectangles and sequences flanking the tandem arrays as hatched rectangles. Other sequence elements such as Cytosine–Thymine‐like (CT dinucleotide) microsatellites and CDC27 pseudogene are also shown. ITS, internal transcribed spacer; IGS, intergenic spacers; NTS, nontranscribed spacer and ETS, external transcribed spacer. The repeat unit is drawn to scale based on data from GenBank entry U13369. (b) Structure of human U2 small nuclear RNA (snRNA) repeat and tandem array. (c) Array structure of yeast Saccharomyces cerevisiae rDNA. (d) Operon structure of Escherichia coliribosomal RNA (rRNA).

Figure 2.

Mechanism of concerted evolution of tandemly repeated genes. Tandem arrays on two different chromosomes are shown. Species‐specific mutation (dot) may arise after speciation, which may either be eliminated or spread to all copies in a tandem array by intrachromosomal recombination such as intrachromatid conversion and/or unequal sister chromatid exchange (USCE). Gene conversion between two homologues leads to spread of the mutation and eventual homogenization within a species. Adapted from Liao .



Bettencourt BR and Feder ME (2002) Rapid concerted evolution via gene conversion at the Drosophila hsp70 genes. Journal of Molecular Evolution 54: 569–586.

Brown DD, Wensink PC and Jordan E (1972) A comparison of the ribosomal DNA's of Xenopus laevis and Xenopus mulleri: the evolution of tandem genes. Journal of Molecular Biology 63: 57–73.

Eickbush TH and Eickbush DG (2007) Finely orchestrated movements: evolution of the ribosomal RNA genes. Genetics 175: 477–485.

Elder JF Jr and Turner BJ (1995) Concerted evolution of repetitive DNA sequences in eukaryotes. Quarterly Review of Biology 70: 297–320.

Ganley AR and Kobayashi T (2007) Highly efficient concerted evolution in the ribosomal DNA repeats: total rDNA repeat variation revealed by whole‐genome shotgun sequence data. Genome Research 17: 184–191.

Gonzalez IL and Sylvester JE (2001) Human rDNA: evolutionary patterns within the genes and tandem arrays derived from multiple chromosomes. Genomics 73: 255–263.

Han K, Konkel MK, Xing J et al. (2007) Mobile DNA in Old World monkeys: a glimpse through the rhesus macaque genome. Science 316: 238–240.

Hillis DM and Dixon MT (1991) Ribosomal DNA: molecular evolution and phylogenetic inference. Quarterly Review of Biology 66: 411–453.

Kuick R, Asakawa J, Neel JV et al. (1996) Studies of the inheritance of human ribosomal DNA variants detected in two‐dimensional separations of genomic restriction fragments. Genetics 144: 307–316.

Liao D (1999) Concerted evolution: molecular mechanism and biological implications. American Journal of Human Genetics 64: 24–30.

Liao D (2000) Gene conversion drives within genic sequences: concerted evolution of ribosomal RNA genes in bacteria and archaea. Journal of Molecular Evolution 51: 305–317.

Liao D, Pavelitz T, Kidd JR, Kidd KK and Weiner AM (1997) Concerted evolution of the tandemly repeated genes encoding human U2 snRNA (the RNU2 locus) involves rapid intrachromosomal homogenization and rare interchromosomal gene conversion. EMBO Journal 16: 588–598.

Mantovani B (1998) Satellite sequence turnover in parthenogenetic systems: the apomictic triploid hybrid Bacillus lynceorum (Insecta, Phasmatodea). Molecular Biology Evolution 15: 1288–1297.

Matera AG, Weiner AM and Schmid CW (1990) Structure and evolution of the U2 small nuclear RNA multigene family in primates: gene amplification under natural selection? Molecular and Cellular Biology 10: 5876–5882.

Nei M, Gu X and Sitnikova T (1997) Evolution by the birth‐and‐death process in multigene families of the vertebrate immune system. Proceedings of the National Academy of Sciences of the USA 94: 7799–7806.

Nei M and Rooney AP (2005) Concerted and birth‐and‐death evolution of multigene families. Annual Review of Genetics 39: 121–152.

Nenoi M, Ichimura S and Mita K (2000) Interspecific comparison in the frequency of concerted evolution at the polyubiquitin gene locus. Journal of Molecular Evolution 51: 161–165.

Ostertag EM and Kazazian HH Jr (2001) Biology of mammalian L1 retrotransposons. Annual Review of Genetics 35: 501–538.

Pavelitz T, Liao D and Weiner AM (1999) Concerted evolution of the tandem array encoding primate U2 snRNA (the RNU2 locus) is accompanied by dramatic remodeling of the junctions with flanking chromosomal sequences. EMBO Journal 18: 3783–3792.

Pavelitz T, Rusche L, Matera AG, Scharf JM and Weiner AM (1995) Concerted evolution of the tandem array encoding primate U2 snRNA occurs in situ, without changing the cytological context of the RNU2 locus. EMBO Journal 14: 169–177.

Piontkivska H, Rooney AP and Nei M (2002) Purifying selection and birth‐and‐death evolution in the histone H4 gene family. Molecular Biology Evolution 19: 689–697.

Schlötterer C and Tautz D (1994) Chromosomal homogeneity of Drosophila ribosomal DNA arrays suggests intrachromosomal exchanges drive concerted evolution. Current Biology 4: 777–783.

Schueler MG, Higgins AW, Rudd MK, Gustashaw K and Willard HF (2001) Genomic and genetic definition of a functional human centromere. Science 294: 109–115.

Seperack P, Slatkin M and Arnheim N (1988) Linkage disequilibrium in human ribosomal genes: implications for multigene family evolution. Genetics 119: 943–949.

Tachikui H, Saitou N, Nakajima T et al. (2003) Lineage‐specific homogenization of the polyubiquitin gene among human and great apes. Journal of Molecular Evolution 57: 737–744.

Warburton PE and Willard HF (1995) Interhomologue sequence variation of alpha satellite DNA from human chromosome 17: evidence for concerted evolution along haplotypic lineages. Journal of Molecular Evolution 41: 1006–1015.

Further Reading

Carmon A, Wilkin M, Hassan J, Baron M and MacIntyre R (2007) Concerted evolution within the Drosophila dumpy gene. Genetics 176: 309–325.

Ogoh K and Ohmiya Y (2007) Concerted evolution of duplicated control regions within an ostracod mitochondrial genome. Molecular Biology and Evolution 24: 74–78.

Stage DE and Eickbush TH (2007) Sequence variation within the rRNA gene loci of 12 Drosophila species. Genome Research 17: 1888–1897.

Stewart FJ and Cavanaugh CM (2007) Intragenomic variation and evolution of the internal transcribed spacer of the rRNA operon in bacteria. Journal of Molecular Evolution 65: 44–67.

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

* Required Field

How to Cite close
Liao, Daiqing(Mar 2008) Concerted Evolution. In: eLS. John Wiley & Sons Ltd, Chichester. [doi: 10.1002/9780470015902.a0005132.pub2]