The study is reminiscent of another recent paper on Penguins, and strikes another blow against the idea that over long time periods genetic diversity accumulates at a slow rate.
Trends in Genetics, Volume 25, Issue 11, doi:10.1016/j.tig.2009.09.005
High mitogenomic evolutionary rates and time dependency
Sankar Subramanian et al.
Using entire modern and ancient mitochondrial genomes of Adélie penguins (Pygoscelis adeliae) that are up to 44000 years old, we show that the rates of evolution of the mitochondrial genome are two to six times greater than those estimated from phylogenetic comparisons. Although the rate of evolution at constrained sites, including nonsynonymous positions and RNAs, varies more than twofold with time (between shallow and deep nodes), the rate of evolution at synonymous sites remains the same. The time-independent neutral evolutionary rates reported here would be useful for the study of recent evolutionary events.