The first person who attempted to classify organisms was Aristotle. He grouped living things into two – plants and animals. He classified plants according to their size. Short plants with soft stems were grouped as herbs; those with short but hardy stems, shrubs; and the tall plants with trunks, tress. Animals were classified according to habitat—aquatic, terrestrial, and aerial. However, Aristotle’s classification system posed a lot of problems. Like, where do frogs and salamander fit? They spend their life both in land and water. Similarly, some plants, like the bamboo, may grow as tall as tree but they are grasses, not trees. Thus, there is a need for a more systematic classification.
During the Middle Ages, ordinary people used common names identifying organisms. Common names usually describe the structure or physical attributes of an organism. There are as varied common names as there are different localities in the world. To help biologists understand one another, the use of Latin in naming organisms was introduced. Latin was the widely used language during the Middle Ages. At first, the Latin name of each organism consisted of as many as fifteen words. Due to slow communication system, organisms that were distributed over large geographical areas had been given different Latin names. Thus, during those times, a species could have two or more names.
It was Karl von Linne (Carolus Linnaeus), a physician and botanist from Sweden, who began the modern system of classification in 1758. his works were contained in his book Systema Naturae. Linnaeus introduced the binomial system of nomenclature. In this system, an organism is given two Latin names. The first name, which begins in capital letter, is the genus. The second name, written in small letter, is the species. The genus tells about the organism’s closely related individuals, while the species identifies which of these individuals within the genus are talking about. E.g. Homo habilis, Homo erectus, and Homo sapiens are scientific names of human beings. They all belong to the same genus. The first two species are extinct. The Homo sapiens, are the only surviving human species on Earth.