Why would the limb structures of a frog and a human be so similar in shape and organization compared to the limb structures of a whale and bat?

Question

A.
Both frogs and humans use their limbs in similar ways when gripping objects.

B.
Both frogs and humans evolved at the same time.

C.
Both frogs and ancestral humans moved on land using all of their limbs.

D.
Both frogs and humans derived from the same ancestors.

Answer 1

The best answer is:

D. Both frogs and humans derived from the same ancestors.

This option highlights the concept of homologous structures in biology, where different species have similar limb structures because they share a common evolutionary ancestor. Despite their different environments and adaptations, the fundamental anatomical layout is similar because of their shared lineage. In contrast, the limb structures of a whale and a bat illustrate adaptations for different functions (swimming and flying, respectively), despite being derived from a common ancestor as well.