In the 18th century, the Swedish scientist Carolus Linnaeus more or less invented our modern system of taxonomy and classification. Linnaeus was one of the leading naturalists of the 18th century, a time when the study of natural history was considered one of the most prestigious areas of science.
Unlike his predecessors, Linnaeus adhered rigidly to the principle that each species must be identified by a set of names, which are termed the "genus" and "species," and classified on the basis of their similarities and differences.
Although he was primarily a botanist, Linnaeus produced a comprehensive list of all organisms then known worldwide, some 7, plant and 4, animal species. It is a benchmark of modern taxonomy, an important reference to help biologists keep the many names straight.
This is why when we come across taxonomic names, such as the official-looking labels identifying an animal in the zoo, Linnaeus's authorship is often acknowledged, and no dates of authorship are ever earlier than For instance, the plaque outside a gorilla exhibit may read as:. This is more than a simple caption.
Its purpose is to let us know, clearly, that the gorillas on display are the same type of animal that the French naturalist Isidore Geoffroy named Gorilla in his publication of As far as we know, it was introduced to Europe by the Greek explorer Hanno, who visited northwestern Africa during the sixth century BCE.
It was the word that Hanno thought the local African people used to call gorillas and supposedly meaning wild or hairy women. In other words, it was adopted by Hanno and is still in fashion today after being introduced into the formal Linnaean taxonomic system by Geoffroy in How was the classification system devised by Carolus Linnaeus different from previous systems? Modern taxonomy officially began in with Systema Naturae , the classic work by Carolus Linnaeus.
But, no matter how many levels are involved, finally only one form of an organism occupies the last group at the last level. After that there is no point in making more levels.
Linnaeus followed the practice, started by Aristotle, of naming each unique form of an organism by it's genus name followed by a differentia phrase. As today, the genus defined the second lowest group and was general a way of describing the set for example 'canines'. The differentia phrase added more information and said what made that particular organism special.
For example 'canine' that 'lives in woods'. This system of naming creatures worked well until it became overcrowded. As the list of different species within a genus expanded so did the length and complexity of the differentia 'lives in woods; dark coat in winter; found only in the north'. Eventually, in some of his works Linnaeus took to writing a short, easy to remember name in the margin. This static view of nature was overturned in science by the middle of the 19th century by a small number of radical naturalists, most notably Charles Darwin.
He provided conclusive evidence that evolution of life forms has occurred. In addition, he proposed natural selection as the mechanism responsible for these changes. Late in his life, Linnaeus also began to have some doubts about species being unchanging. Crossbreeding resulting in new varieties of plants suggested to him that life forms could change somewhat.
However, he stopped short of accepting the evolution of one species into another. Why do we classify living things today? Since Darwin's time, biological classification has come to be understood as reflecting evolutionary distances and relationships between organisms. The creatures of our time have had common ancestors in the past. In a very real sense, they are members of the same family tree.
The great diversity of life is largely a result of branching evolution or adaptive radiation. This is the diversification of a species into different lines as they adapt to new ecological niches and ultimately evolve into distinct species.
Natural selection is the princip a l mechanism driving adaptive radiation. All rights reserved. Your students can learn more about how the Linnaean classification system works with this activity, Insect mihi. Classification is not a field that stays still and this means scientists and taxonomists sometimes have to reassess classifications. Learn more in Leon Perrie 's thought provoking blog, Why do scientific names change?
Learn more about the five kingdoms on the Biology Online website. Add to collection. Nature of science Improved technologies have altered our understanding of the world. Activity idea Your students can learn more about how the Linnaean classification system works with this activity, Insect mihi. Find out more Classification is not a field that stays still and this means scientists and taxonomists sometimes have to reassess classifications.
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