Spencer, R. W.

Mutations occur throughout the 16,569 basepair human mitochondrial genome and most are under strong purifying selection. Archaeologically and genealogically useful mutations, in contrast, are neutral and remain stable for centuries. In new results, multiple lines of evidence show that the latter appear on average every 2900 years and the effective genealogical chromosome is limited to about 4800 basepairs, 28% of its physical length. These mutations are already three-fold oversampled in the haplotree; all those in protein-coding genes are translationally synonymous. This evidence offers a limited prospect that additional testing can significantly increase the branching or temporal resolution of the haplotree.