Which statement best explains why the adaptive radiation of mammals was possible?

• A. Mammals evolved from reptiles, allowing them to adapt to new environments.
• B. The development of fur allowed mammals to become dominant predators.
• C. The extinction of dinosaurs created ecological niches for mammals to exploit.
• D. Mammals have a higher metabolic rate, enabling them to survive in diverse climates.

Answer: (C)

Verified step by step guidance

1. Understand the concept of adaptive radiation: Adaptive radiation is 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.
2. Identify the key event that allowed for the adaptive radiation of mammals: The extinction of dinosaurs is a significant event that led to the availability of ecological niches that mammals could exploit.
3. Consider the impact of the extinction event: With the dinosaurs gone, many ecological roles and habitats were left unoccupied, providing opportunities for mammals to diversify and adapt to these new niches.
4. Evaluate the other statements: While mammals did evolve from reptiles and have characteristics like fur and a high metabolic rate, these factors alone do not explain the rapid diversification seen in adaptive radiation. The extinction of dinosaurs was the catalyst that allowed these traits to be advantageous in new environments.
5. Conclude with the best explanation: The extinction of dinosaurs created ecological niches for mammals to exploit, leading to their adaptive radiation and diversification into various forms and habitats.