All the varieties, he conjectured, evolved on the island itself. From the original seed-eating features, many other forms with altered beaks arose, enabling them to become insectivorous and vegetarian finches. This process of evolution of different species in a given geographical area starting from a point and literally radiating to other areas of geography (habitats) is called adaptive radiation. Darwin's finches represent one of the best examples of this phenomenon. Another example is Australian marsupials. A number of marsupials, each different from the other evolved from an ancestral stock, but all within the Australian island continent. When more than one adaptive radiation appeared to have occurred in an isolated geographical area (representing
Adaptive radiation is the evolution of multiple species from a common ancestor in an isolated geographical area, with Darwin's finches as the textbook example. Students often confuse adaptive radiation with simple mutation or natural selection alone—it requires both geographic isolation AND diversification into different ecological niches. The key trap: mistaking it for convergent evolution or thinking all radiations happen at the same rate. Remember: finches started with seed-eating beaks but evolved different beak shapes (insectivorous, vegetarian) to exploit different food sources on the same island. This concept appears repeatedly in NEET (2021, 2023, 2024) because it combines evolution mechanisms, speciation, and real-world evidence—expect direct questions on examples or mechanisms.
This paragraph was tested 3 times in NEET.
Which evolutionary phenomenon is depicted by the sketch given in figure? (NEET 2024)
Select the correct group/set of Australian Marsupials exhibiting adaptive radiation. (NEET 2023)
Match List-I with List-II: (NEET 2021) List-I: (a) Adaptive radiation (b) Convergent evolution (c) Divergent evolution (d) Evolution by anthropogenic action List-II: (i) Selection of resistant varieties due to excessive use of herbicides and pesticides (ii) Bones of forelimbs in Man and Whale (iii) Wings of Butterfly and Bird (iv) Darwin Finches Choose the correct answer from the options given below:
MedicNEET's Biology question bank is built from the same NCERT lines NTA picks repeatedly. Not random MCQs — questions crafted exactly like NTA crafts them.