Question

Name the process/term for the following statements.

Organs that are present in a greatly reduced form.

Answer 1

Disuse of Organs

1. In different species including human beings, some organs are present in a greatly reduced form. They are known as vestigial organs.
2. These organs were fully developed and functional in related ancestral species of organisms but are no longer functional in the presently existing, recently evolved organisms.
3. The occurrence of vestigial organs provides solid evidence that the organisms with vestigial organs have evolved from such ancestors which processed these organs in fully developed and functional form.
4. In human beings, there are about 180 vestigial organs are found. Some prominent vestigial organs are • Vermiform appendix, wisdom teeth, ear pinna, etc.

Thus, organs that are present in a greatly reduced form are called vestigial organs.