Large-scale, worldwide adaptive radiations have occurred in which of the following situations? (A)when there are no available ecological niches (B)after each of the big five mass extinctions (C)after colonization of an isolated island that contains suit-able habitat and few competitor species (D)whenever an evolutionary innovation was needed for or-ganisms to thrive

Verified step by step guidance

1. Identify the concept of adaptive radiation, which refers to the rapid evolution of diversely adapted species from a common ancestor when they invade new, varied environments.
2. Consider the conditions necessary for adaptive radiation, such as availability of ecological niches, reduced competition, and new environments that demand different survival strategies.
3. Evaluate option (A) by recognizing that adaptive radiation requires available ecological niches to allow different species to evolve and occupy these niches.
4. Assess option (B) by understanding that mass extinctions can create available niches by removing existing species, but adaptive radiation specifically following each of the big five mass extinctions isn't universally supported by evidence.
5. Analyze option (C) by considering that colonization of an isolated island with suitable habitat and few competitors provides an ideal condition for adaptive radiation, as seen in famous examples like Darwin's finches in the Galápagos Islands.

Key Concepts

Adaptive Radiation

Adaptive radiation is an evolutionary process where organisms diversify rapidly into a wide variety of forms to adapt to different environments. This often occurs when a species colonizes a new habitat with available ecological niches, leading to the emergence of new species that exploit these niches. Understanding this concept is crucial for analyzing how and why certain species proliferate in response to environmental changes.

Mass Extinctions

Mass extinctions are significant and rapid decreases in biodiversity on Earth, often resulting in the loss of a large number of species in a relatively short geological time frame. The five major mass extinctions have been followed by periods of adaptive radiation, where surviving species diversify to fill the ecological roles left vacant. Recognizing the impact of these events helps explain patterns of biodiversity and species evolution.

Ecological Niches

An ecological niche refers to the role and position a species has in its environment, including its habitat, resource use, and interactions with other organisms. The availability of ecological niches is a critical factor in adaptive radiation, as it provides opportunities for species to evolve and thrive. Understanding niches is essential for grasping how species adapt and diversify in response to environmental changes.