The Rate of Mitochondrial Cytochrome b Gene Evolution according to the Analysis of Recent (about 12 000 Years) Isolation of Charrs Salvelinus of Lake Kronotskoe

Resumo

The nucleotide substitution rate of the mitochondrial cytochrome b gene is estimated on the basis of the genetic differences of charr populations (Salvelinus) with a known time of isolation (Upper Pleistocene–Holocene boundary) as 3.11 × 10^–8 substitutions/position/year (95% confidence interval: 2.59 × 10^–8–3.64 × 10^–8). This estimate is about five times higher than the one obtained for this gene when considering long time intervals of divergence of salmonid fishes (phylogenetic rate)—0.66 × 10^–8 (0.56 × 10^–8–0.77 × 10^–8). Thus, the rule of decrease in mtDNA nucleotide substitution rate estimates while moving from the recent calibration dates (thousand years) to the ancient ones (millions of years) applies also to the lineage of salmonid fishes.