Zoology

‘Zoology’ (Greek ‘zōion’, an animal) is a science addressed to animals, or alternatively the collective animal biota of a defined region, as in ‘the zoology of the British Isles’ or the characteristics of a particular group, as in ‘the zoology of mammals’. A modern heuristic definition holds that an animal is a unicellular or multicellular heterotrophic eukaryote (requiring external organic resources as food, having cellular nuclei and 18S ribosomal RNA), though some protists do not fully comply. Animals will have at least some motility powered by themselves and will show irritability (reversible behaviours in response to external stimuli). This entry describes animal phylogeny and then examines how zoology has been organised within universities. The entry closes with a discussion of job prospects for zoology graduates.