Question

The origin of different types of finches on Galapagos islands is an example of :

• A. Convergent evolution
• B. Divergent evolution
• C. Adaptive radiation
• D. Both B and C

Answer 1

The correct option is D Both B and C

During his voyage around the world, Charles Darwin made quite a few interesting observations at the Galapagos group of islands. He observed about 14 different varieties of the finch (which later came to be known as Darwin’s finches), on the various islands of the Galapagos. He noticed that these birds on each island had unique beak shapes. Darwin reasoned that though these birds had originated from a common ancestor, they had migrated to different islands and hence, their beaks got gradually modified according to their needs in the respective environments.
This “modification” was not a direct modification of traits by the environment. The birds which migrated to different islands had different kinds of food available. Those birds whose beaks were best suited to eat the food could survive, reproduce and pass on these “favourable” traits to the next generation, resulting in a population of a similar kind of birds. This type of evolution by which species diverge from a common ancestor and undergo morphological changes, eventually developing into a new species is known as divergent evolution. Adaptive radiation could be said to be a type of divergent evolution in which multiple new species diverge and radiate from a common ancestor.