Genus (biology)
In biology, a genus is a taxonomic rank that is higher than species but lower than family, serving as an important category in the classification of living organisms. Each organism is named using a binomial nomenclature system, which includes two parts: the genus name, which is capitalized, and the species name, which is written in lowercase. For example, in the name Felis catus, Felis is the genus that includes domestic cats and several wild cat species. The concept of genus is essential for organizing the vast diversity of life on Earth, which scientists estimate includes millions of species, many of which are still undiscovered.
The system of classification was significantly advanced by Carolus Linnaeus in the 18th century, who sought a standard method for identifying and naming organisms. Although Linnaeus popularized the use of genus, the concept was originally defined by the botanist Joseph Pitton de Tournefort in the 17th century. The hierarchical structure of biological classification, often represented as a phylogenetic tree, illustrates the relationships among various organisms, aiding in the understanding of evolutionary traits and common ancestry. The use of Latin and Greek for scientific names helps ensure clarity and provides descriptive insights, reflecting characteristics of the organisms. Overall, the genus plays a crucial role in the field of taxonomy, facilitating the ongoing exploration and documentation of life forms.
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Genus (biology)
Genus is a taxonomic classification higher than species yet lower than family. Therefore, genus is a broader category than species. The first part of a scientific name is the genus; the second part is the species. For instance, the genus Felis refers to cats: domestic cats, wild cats, Chinese desert cats, sand cats, black-footed cats, and the Pallas’ cat. The scientific name for domestic cats is Felis catus. Catus is the species name. A species is a group of organisms with similar anatomical structures who can reproduce sexually and interbreed to produce fertile offspring. Scientific names in this binomial nomenclature are of Latin and Greek origin and are always italicized (or underlined if handwritten). The genus is capitalized while the species is lowercase. The naming is always in Latin. In the twenty-first century Latin is mostly unused in most fields, however it is still prevalent in scientific names.
Brief History
Carolus Linnaeus lived from 1707 to 1778. He believed in the importance of having a standard way of identifying, grouping, and naming living things known to man. His Systema Naturae, a small pamphlet describing his new system of classification, was published in 1735. Linnaeus collected over forty thousand specimens of plants, animals, and shells over his lifetime. He continued to update and republish Systema Naturae to include more species. Using his binomial nomenclature system Linnaeus named 4,400 animal species and 7,700 plant species. In 1758 he published an updated catalogue whose full title translated into English is "a system of nature through the three kingdoms of nature, according to classes, orders, genera and species, with characters, differences, synonyms, places."
Although using genus became popular with the publication of Systema Naturae, it was not invented by Linnaeus; rather it was first described by Joseph Pitton de Tournefort (1656–1708). Tournefort was a botanist from France and first to clearly define the concept of genus for plants. His Eléments de botanique, ou Méthode pour reconnaître les Plantes was first published in 1694 in three volumes. In it, Tournefort included 10,146 species and 698 genera along with an explanation of his system of classification. His system was the first to detail shared characteristics of a plant as the basis for genera (genus). This system of cataloging plants became popular throughout Europe. It was this system, and the order of genus specifically, which Linnaeus adopted.
Overview
The Linnaean system of taxonomy, still in use some more than 250 years after its first publication, has been likened to the Dewey decimal system but for evolution. There are about two million known species; however, scientists believe there are between five million and one hundred million species total. Clearly, there are many life forms on earth; organizing all life forms on earth makes it easier to understand. This can be complicated and time consuming, as scientists are continually discovering new species. As new species are identified names change to reflect this. Hence, taxonomy is a continually evolving science.
There is a hierarchy of biological classification. Life can be organized into increasingly specific and often smaller groups. This grouping is described as the "tree of life," or the phylogenetic tree. This tree, organized from largest to smallest category, includes domain, kingdom, phylum, class, order, family, genus, and species. Binomial nomenclature (sometimes referred to as binary nomenclature) is the formal system of naming life using two Latin names, genus and species. All living things from the micro (cells) to the macro (whales) are given a scientific name. The phylogenetic tree provides a diagram which represents how all organisms are related by creating a visual organization of biological diversity. It allows for classification and the linking of evolutional traits. Trees show a common ancestor making them important tools in understanding the theory of evolution.
At the time of Carolus Linnaeus, Latin was used in Europe as the language of science; thus, scientific names were Latin or Greek. Greek and Latin words have descriptive meanings which would leave clues for scientists, making them easier to remember. For example, the Latin word caecus means blind in English and so caecus informs the scientific name of Talpa caeca, the blind mole.
Bibliography
Adrain, Jonathan M., Gregory D. Edgecombe, and Bruce S. Lieberman. Fossils, Phylogeny, and Form: An Analytical Approach. New York: Springer Science and Business Media, 2012. Print.
Baum, David. "Reading a Phylogenetic Tree: The Meaning of Monophyletic Groups." Nature.com. Nature Publishing Group, 2008. Web. 30 Dec. 2015.
Bennett, Bradley C., and Michael J. Balick. "Does the name really matter? The importance of botanical nomenclature and plant taxonomy in biomedical research." Journal of Ethnopharmacology 152.3 (2014): 387–92. Print.
De Tournefort, Joseph Pitton. A Voyage into the Levant. Vol. 2. Cambridge: Cambridge UP, 2014. Print.
Diogo, Rui, and Bernard A. Wood. Comparative Anatomy and Phylogeny of Primate Muscles and Human Evolution. Boca Raton: CRC, 2012. Print.
Felsenstein, Joseph. Inferring Phylogenies. Sunderland: Sinauer Associates, 2004. Print.
Finlay, Graeme. Human Evolution Genes, Genealogies and Phylogenies. Cambridge: Cambridge UP, 2013. Print.
Gascuel, Olivier, and Mike Steel. Reconstructing Evolution: New Mathematical and Computational Advances. Oxford: Oxford UP, 2007. Print.