Question

Temporary embryonic structures such as the notochord and gill clefts are significant in evolutionary studies because they:

Options

• Provide clues to ancestral forms and support organic evolution

• Appear only in adult organisms, never in embryos

• Prove that each species was created independently

• Remain fully functional in the adult organism

Answer 1

Temporary embryonic structures appear during early development and then disappear or are modified in the adult. Because they mirror structures found in ancestral forms, they provide direct clues to evolutionary history and support organic evolution.