Kidneys are thought to have evolved first among the ______________.
A)amphibians
B)freshwater bony fishes
C)saltwater bony fishes
D)reptiles

Question

Quizplus · Accepted Answer

Freshwater bony fishes were the first vertebrates to live in freshwater habitats, which provided them with an abundance of water but also posed challenges with regards to osmoregulation. The kidneys evolved as a way to help these fishes maintain a proper balance of water and electrolytes in their bodies.

Kidneys Are Thought to Have Evolved First Among the ______________