Zoology

Zoology

The study of zoology can be viewed as a series of efforts to analyse

and classify animals. Attempts at classification as early as 400 BC

are known from documents in the Hippocratic Collection. Aristotle,

however, was the first to devise a system of classifying animals that

recognized a basic unity of plan among diverse organisms; he arranged

groups of animals according to mode of reproduction and habitat.

Observing the development of such animals as the dogfish, chick, and

octopus, he noted that general structures appear before specialized

ones, and he also distinguished between asexual and sexual

reproduction. His Historia Animalium contains accurate descriptions of

extant animals of Greece and Asia Minor. He was also interested in

form and structure and concluded that different animals can have

similar embryological origins and that different structures can have

similar functions.

In Roman times Pliny the Elder compiled four volumes on zoology in his

37-volume treatise called Historia Naturalis. Although widely read

during the Middle Ages, they are little more than a collection of

folklore, myth, and superstition. One of the more influential figures

in the history of physiology, the Greek physician Galen, dissected

farm animals, monkeys, and other mammals and described many features

accurately, although some were wrongly applied to the human body. His

misconceptions, especially with regard to the movement of blood,

remained virtually unchanged for hundreds of years. In the 17th

century, the English doctor William Harvey established the true

mechanism of blood circulation.

Until the Middle Ages, zoology was a co...

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...0 years. It has revealed the deleterious

effects of pesticides and industrial pollutants and has provided

important insights into wiser management of agriculture, forestry, and

fisheries.

Evolutionary zoology, which draws on all of the fields just mentioned,

is concerned with the mechanisms of evolutionary change—speciation and

adaptation—and with the evolutionary history of animal groups.

Particularly relevant to evolutionary studies are systematics,

phylogenetics, palaeontology, and zoogeography. Systematics deals with

the delineation and description of animal species and with their

arrangement into a classification. Phylogenetics is the study of the

developmental history of groups of animals. Zoogeography, the study of

the distribution of animals over the Earth, is closely related to

ecology and systematics.