Which statements help explain the scientist's conclusions? Select all of the answers that apply.
A. All 8 species of modern bears have the same adaptations.
B. The same ancestral bear species can give rise to two or more species of modern bears.
C. Each of the 8 species of modern bears may have high fitness in only some environments.
D. All of the 8 species of modern bears have equally high fitness in any environment where bears live.
E. One of the species of modern bears was the ancestor of all the other bear species.