Question

Explain divergent evolution in detail. What is the driving force behind it?

Answer 1

Definition

Divergent evolution is a type of evolution where similar body structures have evolved to perform different functions based on the need of the organism.

Cause/driving force

Due to the presence of different environments, certain body parts of organisms have modified their functions so that they can adapt to these habitats. These body parts are called homologous organs as they have similar body structure but different functions.

Significance

Divergent evolution indicates that the organisms have a common ancestor but they develop different characteristics (due to the changing environment) giving rise to new species.

Examples

In animals :

● The forelimbs of Whales, Bats, Cheetahs and Humans have a similar bone structure (contain humerus, radius, ulna, carpels, phalanges) but they perform different functions. In whales it is used for swimming, Bats use it for flying, Cheetahs for running and Humans for different functions.



The hearts in various vertebrates (fishes, amphibians, reptiles, birds, and mammals) have similar structure but vary in the number of chambers they have due to diverse habitats and energy requirements.



In plants

● The thorns of Bougainvillea and the tendrils of Cucurbita are modified branches i.e. they have the same basic structure and common ancestor but the functions are different. The thorns are used for protection and the tendrils are used as support to the plant.