Scientists hypothesize that a major factor promoting the adaptive radiation of mammals was probably
A) their development of fur.
B) the mass extinction of most dinosaurs.
C) internal fertilization.
D) the origin and diversification of flowering plants.

Question

Quizplus · Accepted Answer

The mass extinction of most dinosaurs eliminated many competitors for resources and ecological niches, allowing mammals to expand and diversify. This hypothesis is supported by the timing of the adaptive radiation of mammals, which occurred shortly after the end-Cretaceous extinction event. While fur, internal fertilization, and the origin and diversification of flowering plants may have played a role in the evolution of mammals, they are not as significant as the extinction of dinosaurs in promoting their adaptive radiation.

Scientists Hypothesize That a Major Factor Promoting the Adaptive Radiation