Large Variation in the Ratio of Mitochondrial to Nuclear Mutation Rate across Animals: Implications for Genetic Diversity and the Use of Mitochondrial DNA as a Molecular Marker

摘要: It is commonly assumed that mitochondrial DNA (mtDNA) evolves at a faster rate than nuclear (nuDNA) in animals. This has contributed to the popularity of mtDNA as molecular marker evolutionary studies. Analyzing 121 multilocus data sets and four phylogenomic encompassing 4,676 species animals, we demonstrate ratio over mutation highly variable among animal taxa. In nonvertebrates, such insects arachnids, nuDNA varies between 2 6, whereas it above 20, on average, vertebrates scaled reptiles birds. Interestingly, this variation sufficient explain previous report similar level polymorphism, which was originally interpreted reflecting effect pervasive positive selection. Our analysis rather indicates among-phyla homogeneity within-species diversity due negative correlation per-generation effective population size, irrespective action natural Finally, explore absolute per-year both using reduced set for fossil calibration available, discuss potential determinants across genomes study important implications regarding DNA-based identification methods predicting barcoding should be less reliable nonvertebrates vertebrates.