Question

Adaptive radiation refers to

• A. Evolution of different species from a common ancestor
• B. Migration of members of a species to different geographical areas
• C. Power of adaptation in an individual to a variety of environments
• D. Adaptation due to geographical isolation

Answer 1

The Correct Option is A

In biology, the term adaptive radiation refers to the process by which organisms diversify rapidly into a multitude of new forms, particularly when a change in the environment makes new resources available, creates new challenges, or opens new environmental niches. This concept is often associated with the evolution of different species from a common ancestor. Here's a detailed explanation:

1. Definition and Concept:
   Adaptive radiation usually occurs when a single species or a small group of species rapidly evolves into several different forms that occupy diverse ecological niches. This process is driven by mutation and natural selection.
2. Example of Adaptive Radiation:
   A classic example is Darwin's finches on the Galápagos Islands, which evolved from a common ancestor into a variety of species with different beak shapes and sizes, each adapted to a specific food source or environment.
3. Reasons why 'Evolution of different species from a common ancestor' is correct:
   This option aligns with the biological definition of adaptive radiation because it involves rapid speciation from a common lineage. The resulting species evolve to fill various ecological roles.
4. Why the other options are incorrect:
   • Migration of members of a species to different geographical areas: This option refers to geographical distribution, but not necessarily to evolutionary changes into different species.
   • Power of adaptation in an individual to a variety of environments: This pertains more to an individual's ability to adjust to different conditions, rather than the evolution of new species.
   • Adaptation due to geographical isolation: While geographical isolation can lead to speciation, it is not the primary focus of adaptive radiation, which emphasizes rapid diversification.

In conclusion, adaptive radiation is characterized by the rapid evolution of various species from a single common ancestor, each species adapting to exploit different ecological niches.