Question

What are homologous structures? Give an example. Is it necessary that homologous structures always have a common ancestor?

Answer 1

Homologous structure:

1. Homologous structures are those that have the same basic structure but serve different tasks.
2. Reptiles, amphibians, and mammals' forelimbs are examples.
3. Homologous structures share a similar ancestor.
4. They are modified to perform distinct tasks.
5. Yes, they must share a common ancestor; otherwise, there will be no similarity in their basic plan, origin, or internal structure.
6. For example, a human arm, a bat wing have similar basic structure but serve very distinct purposes.
7. The basic structure of a human arm and a bat wing is identical, but they have been adapted to perform distinct functions in different animals.
8. As a result, they must have descended from a single ancestor.