Question

Which of these is NOT an example for Adaptive radiation?

• A. Long-necked Giraffe
• B. Darwin's finches
• C. Australian marsupials
• D. Placental mammals

Answer 1

The Correct Option is A

• Adaptive radiation refers to the process where organisms diversify rapidly into a variety of forms, typically when they occupy different ecological niches.
• Darwin's finches (Option B): These finches are a classic example of adaptive radiation. Over time, they evolved different beak shapes to exploit different food sources on the Galápagos Islands.
• Australian marsupials (Option C): Marsupials in Australia (such as kangaroos, koalas, and wombats) evolved through adaptive radiation to fill various ecological niches.
• Placental mammals (Option D): Placental mammals represent a major group of mammals that have diversified through adaptive radiation, evolving various forms to adapt to different environments.
• Long-necked Giraffe (Option A): While the long neck of giraffes is an adaptation to feeding on high tree branches, it does not represent adaptive radiation. The long neck evolved in a specific environment and does not demonstrate the broad diversification of species seen in true adaptive radiation events.

The correct answer is (A) : Long-necked Giraffe.

Answer 2

Which of these is NOT an example of Adaptive radiation?

The correct answer is: (A) Long-necked Giraffe.

Adaptive radiation is a process where organisms evolve rapidly into a wide range of forms to adapt to different ecological niches. The examples of adaptive radiation usually involve a single ancestral species diversifying into different species that occupy various ecological roles.

While the long-necked giraffe's evolutionary trait is an adaptation to access food from taller trees, it is not an example of adaptive radiation. Instead, it reflects a gradual evolutionary change within a species. On the other hand, organisms like Darwin’s finches, Cichlid fish, and Hawaiian honeycreepers are well-known cases of adaptive radiation where one species diversifies into multiple species with specialized traits suited to different environments.

In contrast, the long-necked giraffe’s evolution is more of a specialization within a single lineage rather than a rapid diversification of species, which is the essence of adaptive radiation.