Which of the following is an example of convergent evolution?

• A. Wings of bats and birds due to flight.
• B. Human and chimpanzee share recent common ancestor with similar hands.
• C. Dolphins (mammals) and ichthyosaurs developing streamlined bodies independently.
• D. Whales and fish share gills.

Answer: (C)

Convergent evolution happens when unrelated lineages evolve similar traits because they face similar environmental challenges, not because they share a recent ancestor. The case of dolphins and ichthyosaurs is a clear example: both groups are distantly related, yet each independently evolves a streamlined, fishlike body plan with tail-driven propulsion to move efficiently through water. This shows how the same ecological niche—a fully aquatic lifestyle—can shape very similar solutions in different lineages, even though their evolutionary histories are separate.

The other options involve different ideas. A trait like wings for flight can also arise in different groups, but the key point here is that dolphins and ichthyosaurs illustrate the classic pattern of distant relatives converging on the same body plan due to similar life in water. Human and chimpanzee hands reflect inheritance from a common ancestor (a homologous trait), not convergence. Whales are mammals with lungs, while fish have gills; they do not share a gill feature, so that example isn’t about convergence.