Please refer to the image Your marine biology instructor tel

Please refer to the image.

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 and hippopotamus? 58 nucleotide differences 102 nucleotide differences 110 nucleotide differences 222 nucleotide differences

Solution

Based on the given data, it seems that odontocetes diverged from mysticetes about 40 mya, and the hippopotamus diverged from the rest of the group about 55 mya. If the nucleotide difference that occurred in 40 mya is 80 nucleotides, then for 55x10⁶ years the expected nucleotide difference might be 110 nucleotides. Hence, the difference between right whales and hippopotamus are 110 nucleotides.