Question

another way to calculate evolutionary distance is to look at divergence in certain dna sequences between the lineages. scientists have discovered that some stretches of dna accumulate mutations in a predictable way. for example, a protein may accumulate 1 mutation every million years. when mutation rate is reliable, we can use the number of accumulated mutations between lineages as a way to determine time since divergence or evolutionary distance. this is called the molecular clock hypothesis. the lower left section of the table below shows the number of nucleotide differences between some of the viruses. for example, there are 44 differences between virus a and b. in this hypothetical example, assume scientists determined that this sequence accumulates 2 mutations per year. use the nucleotide changes to determine the evolutionary distance between viruses a and b.

Explanation:

Step1: Identify mutation - count and rate

The number of nucleotide differences (mutations) between virus A and B is 44, and the mutation rate is 2 mutations per year.

Step2: Calculate evolutionary distance

Evolutionary distance = $\frac{\text{Number of mutations}}{\text{Mutation rate}}$ = $\frac{44}{2}$

Answer:

22 years