Chapter 9, Problem 21ESP

As mentioned in Section 9.3, mtDNA accumulates mutations at a rate approximately ten times faster than nuclear DNA. Thus geneticists can use mtDNA variations as a “molecular clock” to study genetic variation and the movement of ancestral human populations from Africa to different areas of the world more than 125,000 years ago. Propose an explanation for how an analysis of mtDNA can be used to construct family trees of human evolution.