Understanding natural selection and how traits are passed down. This provides the "why" behind animal diversity.
Study the transition from water to land—from fish to amphibians, reptiles, birds, and mammals. 4. Animal Physiology: How They Work Compare how different animals solve the same life problems: Respiration: Gills vs. Lungs vs. Skin breathing. Circulation: Open vs. Closed systems. TEXT-BOOKS OF ANIMAL BIOLOGY A General Zoology ...
Before diving into specific animals, you need to understand the "rules" of life. Focus on: Understanding natural selection and how traits are passed