Question

A new insect species is discovered on an island. The species features are compared to mainland species to determine the most closely related species.
Genetic analysis is performed on a chitin gene of both the island species and its mainland relative. The gene in both species is 4,000 bases long and there are 10 differences in the bases between the two species.
If the estimated mutation rate for this family of insects is .000001 per nucleotide per year, how long ago did the common ancestor of both species exist?

• A. 2,500 years
• B. 10,000 years
• C. 10 million years
• D. 400 million years

Answer 1

Answer: (B)

10,000 years

The nucleotide undergoes mutation at the rate of 0.000001 per nucleotide per year, the differences arouse after 10 of the 4000 bases were mutated. The common ancestor would have existed before any of the mutation took place.That is about 10,000 years ago

So, the correct answer is '10,000 years'