Question

Write a note on Darwin's Finches.

Hint:

Key words: Galapagos Islands, common ancestor, beak variation, adaptive radiation.

Answer 1

Step 1: Background:
During his voyage on HMS Beagle, Charles Darwin studied a group of about 13-14 closely related species of finches on the Galapagos Islands, now called Darwin's finches.

Step 2: Their significance:
All these finch species are believed to have descended from a single common mainland ancestral seed-eating finch that reached the islands. Over time, geographic isolation on different islands and natural selection for different food sources (seeds, insects, cactus flowers) led to marked differences in beak size and shape among the species.

Final Answer:
Darwin's finches are a classic example of adaptive radiation — evolutionary diversification of a single ancestral species into several new forms, each adapted to a different mode of feeding within the same geographic region.