Zoology is the discipline of biology that involves the study of animals. Zoology has a variety of branches that focus on particular types of animal or aspects of animal functioning or behavior. There are also a variety of more general biological approaches that can be applied to the study of animals. Historically, an important difference is between zoology in pre-Darwinian and post-Darwinian times with Charles Darwin's theory of evolution by natural selection now fundamental to the discipline.
One branch of zoology is called arachnology, which is the study of arachnids such as spiders and scorpions. Another branch is cetology which studies the species of the order Cetacea such as whales and dolphins. Entomology is the study of insects in general, with the term apiology being used for the study of specifically bees, and myrmecology used for the study of ants. Herpetology is the study of reptiles and amphibians whilst icthyology looks at fish. Mammalogy is the general study of mammals whilst primatology looks specifically at primates such as apes and monkeys. Ornithology is the study of birds.
A number of branches cut across species groupings. Ethology is the general study of animal behavior. Anthrozoology is the interdisciplinary study of the interaction between humans and animals. Neuroethology looks at the neural mechanisms underlying natural animal behavior. Paleozoology studies prehistoric animals and attempts to identify species from their remains and reconstruct their environments and ecosystems.
There are also a variety of general biological approaches used in the various branches of zoology. One approach concerns the study of the physical structure of animals and can be looked at through anatomy, physiology, and embryology. Another approach focuses more on genetic and developmental questions through the methods of molecular biology, molecular genetics and developmental biology. Evolutionary biology can be used to examine the evolution of animal species. Meanwhile biogeography, cladistics, phylogenetics, phylogeography, systematics, and taxonomy can all be used in the determining the classification of animal species.