Mitochondrial DNA as a marker of molecular diversity: a reappraisal


  • N.G. is interested in various aspects of molecular evolution, and especially the relationship between species biology and genome evolutionary trends in animals. B.N. studies the evolutionary genomics of vertebrates, with a preference for birds and interests in phylogeny, molecular dating, polymorphism, influence of population size, and of mutation rate. S.G. combines theoretical and empirical population genomic approaches to analyse the influence of mating systems and other life-history traits on genome evolution, with some focus on plants. G.H. is an evolutionary geneticist interested in genomic conflicts, and especially the interaction between maternally-transmitted symbiotic microbes and their arthropod hosts.

N. Galtier, Fax: (+33) 467 14 36 10; E-mail:


Over the last three decades, mitochondrial DNA has been the most popular marker of molecular diversity, for a combination of technical ease-of-use considerations, and supposed biological and evolutionary properties of clonality, near-neutrality and clock-like nature of its substitution rate. Reviewing recent literature on the subject, we argue that mitochondrial DNA is not always clonal, far from neutrally evolving and certainly not clock-like, questioning its relevance as a witness of recent species and population history. We critically evaluate the usage of mitochondrial DNA for species delineation and identification. Finally, we note the great potential of accumulating mtDNA data for evolutionary and functional analysis of the mitochondrial genome.