EXERCISE 2. LESSON 2

CLASSIFICATION IN HISTORY

The great thinkers of antiquity were already aware of the need to classify living beings. The first classification was made by Aristotle, who grouped living beings according to their external appearance. Aristotles' classification prevailed for many years but it was the Swedish naturalist Carl Von Linnaeus in the eighteenth century, who established the current classification system. This is based on criteria that take into account the internal structural characteristics, and not only the external appearance.

At present the Linnaeus system has been completed and improved due to continuous advances in Biology. In the nineteenth century, Darwin and his theory of evolution provided new knowledge to reorganize the classification of species. The current classification system is also known as the natural classification system since they use as a criterion the degree of kinship between species The classification system of Linnaeus is hierarchical and includes seven taxonomic categories:   

The name of the species must be understood by all, that is, a name that is the same in all languages. In this way there will be no communication problem between scientists from different countries when studying the same species. This name consists of two words, the first one begins with a capital letter and refers to the genus, and the second with a lower case letter and refers to the species. Thus, the scientific name should always be written in italics or underlined. For example, Canis familiaris (dog).