Final answer:
A molecular clock is a technique that uses mutation rates to estimate the time of divergence between two groups of animals. It relies on comparing the differences in DNA sequences between species to calculate the amount of time that has passed since they shared a common ancestor.
Step-by-step explanation:
Molecular Clock
A molecular clock is a technique used to estimate the time when two groups of animals diverged in the past. It relies on the assumption that mutations accumulate in DNA sequences at a steady average rate over time. By comparing the differences in DNA sequences between species, scientists can calculate the amount of time that has passed since they shared a common ancestor.
For example, let's say we have two species, A and B, and we know the mutation rate for a particular region of their DNA. If species A has accumulated more differences in their DNA sequence compared to species B, we can infer that they diverged from their common ancestor earlier in the past. Conversely, if species A has fewer differences in their DNA sequence compared to species B, we can infer that they diverged more recently.
Molecular clocks can use different regions of DNA or even proteins to estimate divergence times. By combining the results from multiple regions, we can achieve greater accuracy in our estimations.