Question

Approximately 5 percent of the present human genome consists of segmental duplications that have arisen during the past 35 million years. How do you suppose researchers are able to estimate how long it has been since a particular region of a chromosome was duplicated

Answer 1

Answer:

by using molecular clocks which are based on the mutation rates among molecular sequences (e.g., DNA sequences). The mutation ​rate can be used to estimate the times of divergence between sequences (in this case, between duplicated sequences in the target species and non-duplicated sequences in the most recent common ancestor).

Explanation:

A molecular clock is a technique that uses the mutation rate (μ) to measure the association between evolutionary rate and time. A mutation rate can be used to estimate the time in prehistory when two or more molecular sequences diverged. For example, assuming a generation time of 20 years, a species that has 100 mutations per generation is divided by 20 years to yield a mutation rate equal to 5 mutations per year. In consequence, the times of divergence can be estimated by dividing half of the target genomic region length (in nucleotides) by the mutation rate (t = d/2 ÷ μ).