Final answer:
mtDNA is maternally inherited DNA that allows researchers to trace back to a Maternal Eve, providing insight into the divergence and migration of ancient human populations. This relationship to the mtMRCA aids in constructing a molecular timeline to support the Out of Africa theory and refine the molecular clock used in evolutionary studies.
Step-by-step explanation:
mtDNA, or mitochondrial DNA, and the most recent common ancestor (mtMRCA) are closely related in the study of human evolution. mtDNA is inherited matrilineally and mutations in mtDNA provide a tool for tracing ancestry back to a common ancestor known as Mitochondrial Eve, who is believed to have lived in Africa between 100,000 and 200,000 years ago. Unlike nuclear DNA, mtDNA does not undergo recombination and thus retains a clear lineage back to the MRCA.Researchers analyze the pattern of mutations in mtDNA to establish a molecular timeline, which helps to map out the divergence of human populations. This molecular evidence supports the Out of Africa theory, suggesting that Homo sapiens first developed in Africa and then spread throughout the world. The study of mtDNA, alongside other methods like examining the Y chromosome, contributes to a comprehensive understanding of human phylogeny and evolutionary history.Molecular anthropologists refine a molecular clock by comparing sequences of conserved proteins across different species to determine a mutation rate. This approach aids the estimation of the timeline for various divergences, including the evolution of prokaryotes and other ancient ancestors.