Molecular clock dating
The human mitochondrial molecular clock is the rate at which mutations have been accumulating in the mitochondrial genome of hominids during the course of human evolution.
The archeological record of human activity from early periods in human prehistory is relatively limited and its interpretation has been controversial.
For these reasons, the actual mutation rate will not be equivalent to the mutation rate observed from a population sample.
The mutation rate is also thought to be faster in recent times, since the beginning of the Holocene 11,000 years ago.The mutation rate across the mitochondrial genome is not uniformly distributed.Certain regions of the genome are known to mutate more rapidly than others.Mt DNA is only passed down along the matrilineal line, and therefore mutations passed down to sons are lost.Random genetic drift may also cause the loss of mutations.