Population size does not influence mitochondrial genetic diversity in animals.
Within-species genetic diversity is thought to reflect population size, history, ecology, and ability to adapt. Using a comprehensive collection of polymorphism data sets covering approximately 3000 animal species, we show that the widely used mitochondrial DNA (mtDNA) marker does not reflect species abundance or ecology: mtDNA diversity is not higher in invertebrates than in vertebrates, in marine than in terrestrial species, or in small than in large organisms. Nuclear loci, in contrast, fit these intuitive expectations. The unexpected mitochondrial diversity distribution is explained by recurrent adaptive evolution, challenging the neutral theory of molecular evolution and questioning the relevance of mtDNA in biodiversity and conservation studies.
Bazin
Eric
E
CNRS UMR 5171-Génome, Populations, Interactions, Adaptation-Université Montpellier 2 34095 Montpellier Cedex 5, France.
Glémin
Sylvain
S
Galtier
Nicolas
N
D000220:Adaptation, Biological; D000818:Animals; D005075:Biological Evolution; D049628:Body Size; D004247:DNA / Q000235:genetics; D004272:DNA, Mitochondrial / Q000235:genetics*; D017753:Ecosystem; D019143:Evolution, Molecular; D050259:Genes, Mitochondrial; D005819:Genetic Markers; D014644:Genetic Variation; D005828:Genetics, Population; D007448:Invertebrates / Q000235:genetics*; D007527:Isoenzymes / Q000235:genetics; D009154:Mutation; D011110:Polymorphism, Genetic; D011156:Population Density; D011995:Recombination, Genetic; D012641:Selection, Genetic; D014714:Vertebrates / Q000235:genetics*
D004272:DNA, Mitochondrial; D005819:Genetic Markers; D007527:Isoenzymes; D004247:DNA