Today's diversity of mammals originated with an adaptive radiation that occurred 65 million years ago.This adaptive radiation occurred because
A) ecological niches were opened up and predators were removed.
B) the evolution of a novel trait that gave the animals an advantage.
C) the ancestral species colonized a new continent.
D) increased competition led to rapid natural selection.

Question

Quizplus · Accepted Answer

The extinction of the dinosaurs at the end of the Cretaceous period created ecological niches that were previously unavailable, allowing for the diversification of mammals. Additionally, the removal of large predatory dinosaurs also allowed for smaller mammals to thrive and evolve.

Today's Diversity of Mammals Originated with an Adaptive Radiation That