Mitochondrial DNA as a tool for reconstructing past life-history traits in mammals

Reconstructing the ancestral characteristics of species is a major goal in evolutionary and comparative biology. Unfortunately, fossils are not always available and sufficiently informative, and phylogenetic methods based on models of character evolution can be unsatisfactory. Genomic data offer a new opportunity to estimate ancestral character states, through: (i) the correlation between DNA evolutionary processes and species life-history traits, and (ii) available reliable methods for ancestral sequence inference. Here we assess the relevance of mitochondrial DNA – the most popular molecular marker in animals – as a predictor of ancestral life-history traits in mammals, using the order of Cetartiodactyla as a benchmark. Using the complete set of 13 mitochondrial protein-coding genes, we show that the lineage-specific nonsynonymous over synonymous substitution rate ratio (dN/dS) is closely correlated with the species body mass, longevity and age of sexual maturity in Cetartiodactyla, a...