Q20 of 41 Page 190

With the help of given information write your comment on evidence of evolution. (AS4)

Mammals have four limbs as do birds, reptiles, and amphibians. The basic structure of the limbs is similar, though it has been modified to perform different functions.

i. The organs which have the same basic structure but different functions are called homologous organs.

ii. The homologous organs of different animals provide evidence for evolution. The that internal structure of forelimb of a whale (swimmer), a wing of a bird (flyer) the leg leopard (runner), the claw of mole (digger) and hand of a man (grasping) has the same origin.


iii. If we carefully observe the anatomy of all these animals have a common pattern in the arrangement of bones even through their external from and functions are different.


iv. This indicates that all the vertebrates have evolved from a common ancestor and these organs are called homologous organs and this type of evolution is known as divergent evolution.


More from this chapter

All 41 →