Why is mitochondrial DNA a good clock by which to time genet

Why is mitochondrial DNA a good “clock” by which to time genetic change among human beings? What does “mitochondrial Eve” tell us about the size of the population from which modern humans evolved?

Solution

Mitochondria in the cytoplasam has a DNA which transfers genetic infromation from mother to daughter and not from mother to son without recombination changes. Mitochondrial DNA only changes when the DNA is replicated under normal mutation. This mitochondrial DNA is easier to analyse as it has less genetic material. Mitochondrial Eve is considered as the common ancestor to all the modern humanity. different mutations in this DNA creates different branches to this Mitochondrial eve lineage.

The evolutionary studies on mitochondrial DNA says that the common ancestor lived almost200,000 years back. It differs from the modern DNA for 0.57%.and it supports the out of the Africa theory by saying that all the humanity originated from Africa.