Chapter 29, Problem 8TE

Why are internal nostrils in the lobe-finned fishes an important step in the evolution of life on Earth?

To determine

Theimportance of the evolution of internal nostrils in lobe finned fishes.

Answer to Problem 8TE

The importance of the evolution of internal nostrils in lobe finned fishes is the evolution of the ability to breathe air.

Explanation of Solution

During the Devonian period, moist and warm climates, together with the changes in the landmasses, lead to the development of marine life forms. The Devonian age is known as the “age of the fishes.” The fishes evolved to have lobed fins which were strong enough to support their bodies. Some of these fishes developed internal nostrils which allowed them to breathe air. This way, the evolution of the first forms of terrestrial vertebrates took place. As the bony fishes had developed strong fins that could support their bodies, they became terrestrial vertebrates, developing the first form of walking. The importance of internal nostrils is the ability to breathe air.

Conclusion:

Therefore, the importance of the evolution of internal nostrils in lobe finned fishes is the evolution of the ability to breathe air.