How long ago did two species of birds share an ancestor?
Explanation:
Molecular clocks estimates the time of divergence of two species or populations from each other. The process compares the total number of different nucleotide present in genome of two organisms. The average rate at which the specific gene evolves tells about the dates of evolutionary branch points. By comparing the total number of different nucleotides present in genome of two birds species, molecular clock can answer "How long ago did two species of birds share an ancestor?"
