Mitochondrial DNA clonality in the dock: can surveillance swing the case?

Mitochondrial DNA (mtDNA) is a favoured tool of evolutionary biologists because its high mutation rate generates enough signal to make inferences about population history over short time frames. Furthermore, mtDNA inheritance is clonal, being transmitted only through the maternal line. This enables evolutionary histories to be assembled without the complexities introduced by biparental recombination. Recently, a single case of human biparental inheritance has been reported. Given this, and the role supposed clonal inheritance has had in shaping our knowledge of human population history, it is essential to establish a method for identifying any recombinant mtDNA molecules in our population. A reliable surveillance mechanism would either maintain our confidence in clonal inheritance or indicate the inaccuracy of our inferences.