after the mass extinction that occurred 65 million years ago mammals rapidly diversified to occupy habitats that were previously unavailable to them. What concept does this illustrate

Diversity in organisms occur due to change in the environmental conditions of the earth.

Explanation:

This concept illustrate that diversity in organisms occur due to change in the environmental conditions of the earth. Changes occur in the physical features of organisms due to exposure to different types of environmental conditions. These physical features helps organisms to survive in that environment so we can conclude that diversification occurs in the organisms due to change occur in the environment.