Many crustaceans (for example, lobsters, shrimp, and crayfish) use their tails to swim, but crabs have reduced tails that curl under their shells and are not used in swimming. This is an example of ________.
A) convergent evolution
B) a homologous structure
C) natural selection
D) a vestigial trait

Question

Quizplus · Accepted Answer

The reduced tail of crabs that is no longer used in swimming is a vestigial trait, meaning it was once functional in a common ancestor but has since been reduced or lost over time. This is not an example of convergent evolution or a homologous structure, as crabs and other crustaceans have different tail structures. Natural selection may have played a role in the evolution of this trait, but it is not the most fitting choice for this specific example.

Many Crustaceans (For Example, Lobsters, Shrimp, and Crayfish) Use Their