Question

The diagram shows the structures of four similar limbs in marine animals.
An image of a diagram showing the structures of four similar limbs in marine animals. Text that reads: Shark, Penguin, Whale, Dolphin, Fin, Wing, Flipper, Flipper.
Based on limb structure, which two species are most closely related?

Shark
Penguin
Dolphin
Whale

Answer 1

Based on limb structure, the species that are most closely related are the **Dolphin** and **Whale**. Both of these animals have evolved flippers for swimming and share a common ancestor in the group of cetaceans, which includes both dolphins and whales. In contrast, sharks are fish and have a different type of limb structure, while penguins have wings adapted for flight and swimming but are birds, not mammals.