In the United States , as a result of the rapid growth of molecular and cell biology , many universities have split ( or aggregated ) their biology departments into molecular and cell biology-style departments and ecology and evolutionary biology-style departments . These have included older departments such as paleontology , zoology and the like . In the United States , as a result of the rapid growth of molecular and cell biology , many universities have split ( or aggregated ) their biology departments into molecular and cell biology-style departments and ecology and evolutionary biology-style departments ( which often have subsumed older departments in paleontology , zoology and the like ) .