With the extinction of the dinosaurs 65 million years ago,multiple niches that the dinosaurs once filled opened up and allowed mammals the opportunity to evolve and exploit those niches.In other words,mammals underwent a(an)
A) sympatric speciation.
B) adaptive radiation.
C) exaptation.
D) behavioral isolation.
E) phylogenetic isolation.

Question

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Adaptive radiation is the evolution of multiple species from a common ancestor, each adapted to exploit different niches. With the extinction of the dinosaurs, numerous niches opened up, providing opportunities for mammals to diversify and radiate into new forms. Therefore, the most appropriate choice is B, adaptive radiation. Sympatric speciation (A) is the evolution of new species from a single ancestral species while living in the same geographic area, which is not relevant to the scenario given. Exaptation (C) is a process in which a trait that evolved to serve one function is later adapted for a different function, which is also not relevant to the extinction of dinosaurs. Behavioral isolation (D) and phylogenetic isolation (E) are types of reproductive isolation that prevent two groups of organisms from interbreeding, which is not relevant to the scenario given.

With the Extinction of the Dinosaurs 65 Million Years Ago,multiple