Zoology

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Zoology is the branch of biology devoted to the study of the animal kingdom (Animalia). This article discusses the history and concerns of that study. For a discussion of animals and a description of animal groups.

The current study of zoology has two main focuses: on particular taxonomic groups, and on the structures and processes common to most of them.

Taxonomically oriented studies concentrate on the different divisions of animal life. Invertebrate zoology deals with multicellular animals without backbones; its subdivisions include entomology (the study of insects) and malacology (the study of mollusks). Vertebrate zoology, the study of animals with backbones, is divided into ichthyology (fish), herpetology (amphibians and reptiles), ornithology (birds), and mammalogy (mammals). Paleontology, the study of fossils, is subdivided by taxonomic groups. In each of these fields, researchers investigate the classification, distribution, life cycle, and evolutionary history of the particular animal or group of animals under study. Most zoologists are also specialists in one or more of the process-oriented disciplines described below.

Morphology, the study of structure, includes gross morphology, which examines entire structures or systems, such as muscles or bones; histology, which examines body tissues; and cytology, which focuses on cells and their components. Many great advances made in cytology in recent years are attributable to the electron microscope and the scanning electron microscope. Special staining techniques and radioactive tracers have been used to differentiate structural detail at the molecular level. Methods have been developed for mapping neural connections between parts of the brain and for stimulating and recording impulses from specific brain sites and even individual nerve cells.

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