Your marine biology instructor tells your that on a particular homologous gene, bottlenose dolphins (Odontocetes) and Right whales (Mysticetes) have 80 nucleotide differences. Based on that information and the phylogenetic tree below, how many nucleotide differences do you expect between Right whales

The options

A. 58 nucleotide differences

B. 102 nucleotide differences

C. 110 nucleotide differences

D. 222 nucleotide differences

The CORRECT ANSWER IS C.

C. 110 nucleotide differences

Explanation:

Based on the attached phylogenetic tree, we can deduce that odontocetes diverged from mysticetes around 40 million years ago, and we can infer that hippopotamus diverged distinctively from the other group members around 55 million years ago.

If 80 nucleotide differences is noted in 40 million years (2 nucleotide differences per million years), we can infer around ~110 nucleotide differences would be gathered or accumulated in 55 million years. This therefore proves that, we should be able to have ~110 nucleotide differences between hippopotamus and right whales.

Calculation:

80/40,000,000 = x/55,000,000

Make x the subject of the formula

We Have,

X = (80*55,000,000)/40,000,000

X = 110