With the help of an example each, differentiate between divergent and convergent evolution.

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‘‘Darwin’s finches represent one of the best examples of adaptive radiation.’’ Justify how. Give another example of adaptive radiation.

OR

According to Darwin’s Theory of Evolution, living species change their physical and anatomical structure over a long period of time for better adaptations to the changing environment. Adaptive radiation is the evolutionary process by which many species originate from one species in an area and spread to different areas.

Darwin travelled to an island called Galapagos Island. There he observed that there were finches (birds) with different kind of beaks. He stated that all of these finches developed beaks according to the kind of food available to them. Hence, they evolved from the conventional seed-eating finches to vegetarian and insectivorous finches. They later came to be known as Darwin’s finches.

Darwin finches are seed-eating songbirds native to northern hemisphere.

Hence Darwin’s finches represent one of the best examples of adaptive radiation.

More examples of adaptive radiations are:

- Australian Marsupials – they developed from a single ancestral stock in the Australian subcontinent. This explains divergent evolution for the ancestral stock from which a number of species arise.

- Placental Mammals in Australia – They evolved into varieties of such placental mammals each of which appears to be ‘similar’ to a corresponding marsupial like placental wolf and Tasmanian wolf.