Determination of mitochondrial genetic diversity in mammals.
Mitochondrial DNA (mtDNA) is one of the most popular population genetic markers. Its relevance as an indicator of population size and history has recently been questioned by several large-scale studies in animals reporting evidence for recurrent adaptive evolution, at least in invertebrates. Here we focus on mammals, a more restricted taxonomic group for which the issue of mtDNA near neutrality is crucial. By analyzing the distribution of mtDNA diversity across species and relating it to allozyme diversity, life-history traits, and taxonomy, we show that (i) mtDNA in mammals does not reject the nearly neutral model; (ii) mtDNA diversity, however, is unrelated to any of the 14 life-history and ecological variables that we analyzed, including body mass, geographic range, and The World Conservation Union (IUCN) categorization; (iii) mtDNA diversity is highly variable between mammalian orders and families; (iv) this taxonomic effect is most likely explained by variations of mutation rate between lineages. These results are indicative of a strong stochasticity of effective population size in mammalian species. They suggest that, even in the absence of selection, mtDNA genetic diversity is essentially unpredictable, knowing species biology, and probably uncorrelated to species abundance.
Nabholz
Benoit
B
CNRS UMR 5554-Institut des Sciences de l'Evolution, Montpellier, France. bnabholz@univ-montp2.fr
Mauffrey
Jean-François
JF
Bazin
Eric
E
Galtier
Nicolas
N
Glemin
Sylvain
S
D000704:Analysis of Variance; D000818:Animals; D004272:DNA, Mitochondrial / Q000235:genetics*; D004463:Ecology; D014644:Genetic Variation; D005843:Geography; D006579:Heterozygote; D008322:Mammals / Q000145:classification / Q000235:genetics*; D008957:Models, Genetic; D009154:Mutation / Q000235:genetics; D010802:Phylogeny; D019655:Quantitative Trait, Heritable
D004272:DNA, Mitochondrial