What do scientists think about the common ancestor of whales and hippos?
The animal lived millions of years ago.
The animal had two limbs.
The animal lived in water.
The animal is still alive today.
Scientists generally accept the hypothesis that the common ancestor of whales and hippos was a semi-aquatic, four-limbed mammal that lived around 50 million years ago. This common ancestor is thought to have possessed features such as four limbs adapted for both land and water, with reduced hind limbs and elongated front limbs that could support some degree of aquatic locomotion.
The fossil record provides evidence of early whale ancestors, often referred to as "archaeocetes," which shared various anatomical features with both whales and terrestrial mammals like hippos. These fossils exhibit a transitional form, showing adaptations for aquatic life while retaining some characteristics of land-dwelling mammals.
Regarding the statement that the common ancestor is still alive today, it is important to clarify that the direct descendants of the common ancestor would include modern whales and dolphins, which are highly adapted to aquatic life. Hippos, on the other hand, belong to a separate branch of mammals that evolved independently from the common ancestor and are not direct descendants.