Carolus Linnaeus System for Classifying Organisms Unit 3 Lesson 2
Students will be able to: Conclude some of the classification benefits and importance. Define what is meant by species. Describe the binomial nomenclature of living organisms. Numerate the levels of taxonomic hierarchy of living organisms. Key Vocabulary: Kingdom, Phylum, Class, Order, Family, Genus, Species, Binomial nomenclature system, Dichotomous key and Taxonomic hierarchy.
Classification When you visit any library to read a book, how can you find this book among thousands of books in different fields? The library follow a specific system to categorize and organize the books according to their fields. These fields are subdivided into small categories with specific title and so on. By this way you can find any book in the library. Scientists also use a classification system in order to classify living organisms.
What is the Importance of Classification? All living organisms may look similar in their structure because all of the living organisms consist of one or more cells as well as having seven life features which are nutrition, excretion, respiration, movement, growth, reproduction and sensation but they differ in many features such as form, structure, way of living, nutrition and reproduction.
What is the Importance of Classification? Because of this enormous diversity in the living organisms, they need to be classified. Classification can be identified as the organization of living things into groups according to their shared features to make it easier to be studied and identified. The science field which concerns with classification of living organisms in groups is called taxonomy.
Classification systems Aristotle was the first one who classify life more than 2300 years ago. He classified animals into red blooded animals and bloodless animals and he also classified plants into trees, shrubs and weeds. Latterly, the classification system to living organisms was proposed by Carl Linnaeus in 18th Century.
Classification systems Carl Linnaeus is a Swedish naturalist who considered as the 'Father of Taxonomy' because of his contributions to the taxonomy. In the 1700s, Linnaeus developed a way to name and organize species that we still use today and his two most important contributions to taxonomy were: 1. A hierarchical classification system. 2. The system of binomial nomenclature.
Classification systems In 1735, Linnaeus developed a standard way of grouping and naming species in his first edition of Systema Naturae (The System of Nature). Laterally, he published more editions of Systema Naturae that included more named species. The Systema Naturae tenth edition was published in 1758 and is considered the most important edition.
Linnaeus's Classification System Linnaeus classified nature into a hierarchy in Systema Naturae. He proposed that there were three broad groups, called kingdoms, into which the whole of nature could fit. These kingdoms were animals, plants, and minerals. The kingdoms divided into classes followed by orders, genera then species. Biologists still use this system today, but they have made some modifications.
Classification systems Nowadays, researchers use this system to classify living things. They also added a few extra levels in the hierarchy. The classification broadest level of life is domain in which all living things fit into. Each domain consists of kingdoms. Eukarya domain includes the kingdoms. Each kingdom is divided into phyla followed by classes, order, family, genus, and species. Each level of classification is also called a taxon.
Taxonomic hierarchy There are 7 levels of organizing and grouping the living organisms. 1. Domain It's the highest taxonomic rank of organisms. The tree of life consists of three domains which are Archaea, Bacteria, and Eukarya. The first two comprise prokaryotic microorganisms and life that has a nucleus is included in the Eukarya.
Taxonomic hierarchy 2. Kingdom The kingdom contains a number of phyla. There are at least five kingdoms which are Monera, Protista, Fungi, Plantae and Animalia. Some researchers were proposed six kingdom classification system which includes Archaebacteria. Nowadays, some biologists include the viruses in seventh kingdom but it still argued around the world.
Taxonomic hierarchy 3. Phylum Each kingdom is divided into phyla. Kingdom Animalia contain major phyla such as Chordata, Arthropoda and Mollusca. Phyla have also been developed and rearranged as scientists discover more species, more categories and subcategories are put in place. 4. Class Each phylum contains a number of classes. For example, classes within the chordata phylum include Mammalia, Reptilia and Osteichthyes.
Taxonomic hierarchy 5. Order Each class contains a number of orders. For example, there are many orders in the Mammalia class such as Cetacea, Carnivora, Primates and Chiroptera. 6. Family From the order, the organisms will be grouped and classified into a family. For example, the order of Primates contain families which are Hominidae, Cercopithecidae, and Hylobatidae.
Taxonomic hierarchy 7. Genus Each family is classified into genera. These are the names that are most commonly used to describe an organism. Each Genus is classified into number of species. 8. Species It is a group of interbreeding individuals having similar morphological characteristics mate with each other and produce healthy fertile offspring similar to them.
Taxonomic hierarchy For example, The Taxonomic hierarchy of Human
Binomial Nomenclature system There are often different names for the same organism in the various Earth s regions and environments. Linnaeus overcome this problem and proposed the binomial system of nomenclature in which all species names should have two parts and written by Latin language. the first name represents the genus which begins with a capital letter and the second name represent the species that begins with a small letter.
Summary Classification can be identified as the organization of living things into groups according to their shared features or traits to make it easier to be studied and identified. Linnaeus contributions to taxonomy were: 1. A hierarchical classification system. 2. The system of binomial nomenclature. There are 7 levels of grouping the living organisms (Domain, Kingdom, Phylum, Class, Order, Family, Genus and Species). Each scientific name consists of two parts the first name represents the genus and the second name represent the species.