NEET BIOLOGY

Detailed explanation-1: -However, DNA segments found only in whales and hippos indicate that they have a common ancestor that is not part of the evolutionary history of the other animals. “Ours is the first study to provide reliable confirmation that hippos are the sister-group to whales, ” says Rooney.

Detailed explanation-2: -According to molecular evidence, the closest living relatives of whales are, quite surprisingly, the artiodactyls, a group of hoofed mammals that includes deer, cows, sheep, pigs, giraffes, camels and hippos.

Detailed explanation-3: -Furthermore, the DNA testing revealed that whales share a DNA sequence found only in one other animal – indicating that among all the non-whale mammals alive today, whales’ closest living relatives are none other than hippopotamus!

Detailed explanation-4: -Hippos and whales may look different in many ways, but they are actually each others’ closest living relatives-sharing a common ancestor that lived about 55 million years ago.