Subfields
The study of evolution is the unifying concept in evolutionary biology. Evolutionary biology is a conceptual subfield of biology that intersects with other subfields that are delimited by organizational level (e.g. cell biology, population biology), taxonomic level (e.g. zoology, ornithology, herpetology) or angle of approach (e.g. field biology, theoretical biology, experimental evolution, paleontology). Usually, these intersections are combined into specific fields such as evolutionary ecology and evolutionary developmental biology.
Read more about this topic: Current Research In Evolutionary Biology