Include bibliographic references and index.

Biology is the study of the diverse forms, processes, and systems of life including microbes, fungi, plants, and animals. Biologists work in all natural environments, and agricultural and clinical venues as well. Biologists understand that life is connected across recent and geologic time, and across the molecular-to-biome-spectrum. Biologists employ natural selection and evolution as mechanisms that explain both the diversity and connectedness of life. To understand this great biological complexity, biologists utilize integrative and comparative approaches for the resolution of the general processes, principles, and unifying themes that govern living systems. The field of biology us therefore very interdisciplinary, and biologists rely on knowledge from the physical sciences and mathematics to advance knowledge and create breakthroughs in applies and basic research problems, Aspects of biological science range from the study of molecular mechanisms in cells, to the classification and behaviour of organisms, how species evolve and interaction between ecosystems. Biology often overlaps with other sciences; for example, biochemistry and toxicology with biology, chemistry and medicine; biophysics with biology and physics; stratigraphy with biology and geography; astrobiology with biology and astronomy. Social sciences such as geography, philosophy, psychology and sociology can also interact with biology, for psychology and ethics. This text covers prospective biology majors and a grasp of the structure of evolutionary theory, the evidence for it, and the scope of its explanatory significance.