Taxonomy Biology 8(A)

Taxonomy Learning Objectives Define taxonomy Understand the importance of a standardized taxonomic system After this lesson you will be able to define the term taxonomy and recognize the importance of a standardized taxonomic system.

Taxonomy Taxonomy – the branch of biology that classifies and names living things Uses characteristics of organisms and a universal system Every organism has a specific name Organisms are assigned to levels of classification Taxonomy is a branch of biology that classifies and names living things. Taxonomists use characteristics of organisms and a universal system of classification. Every organism has a specific name and is assigned to multiple nested levels of classification.

Common Name vs. Scientific Name Common name – name given to an organism by the people of a certain area Causes great deal of confusion Examples: Mountain lion Puma Cougar Most of us call organisms by their common names. The common name is the name given to an organism by the people of a certain area who speak the same language. These common names can potentially cause a great deal of confusion because different people in different areas may call the same organism a different name. For example, a mountain lion is the same animal as a puma and a cougar.

Linnaeus’ System Carolus Linnaeus – Swedish botanist who developed new classification system that revolutionized taxonomy Contributions Created two-word (binomial) scientific naming system Suggested that organisms with similar structures be placed in same taxonomic group Early attempts at taxonomy created long, unstandardized names. During the 1700’s, a Swedish botanist named Carolus Linnaeus developed a new classification system that revolutionized the field of taxonomy. He created a scientific naming system that we still use today in which every species has a two-word (or binomial) name. He also suggested that organisms with similar structures be placed in the same taxonomic group, allowing for comparisons across different species.

Common Name vs. Scientific Name Scientific name – standard name accepted by all scientists Binomial nomenclature – scientific naming system using Latin language First name – genus Second name – specific name Both names – species Felis concolor or Felis concolor F. concolor or F. concolor The scientific name of an organism is universally accepted by all scientists around the world. The two-part method of naming species is called binomial nomenclature. The first name is the “genus” and should be capitalized. The second name is the “specific name” and should be written in lower case. Both names together identify the organism’s species which should be underlined or written in italics. For example, the scientific name of a mountain lion is Felis concolor or F. concolor.

Levels of Taxonomy Kingdom Phylum Class Order Family Genus Species Taxonomists use seven levels of classification to orderly arrange all organisms. From the most general group to the most specific group, the classification levels are kingdom, phylum, class, order, family, genus, and species. These levels are nested within one another. For example, if two organisms are in the same order they will share the same class, phylum, and kingdom. If they are in different families, then they will also be in different genera.

Taxonomy Levels of Classification Kingdom Phylum Class Order Family Genus Species Classification of Humans: Animalia Chordata Mammalia Primates Hominidae Homo Homo Sapiens Every organism is categorized at each level. The last level is specific to each species. For example, the seven levels of classification of a human are as follows: kingdom – Animalia, phylum – Chordata, class – Mammalia, order – Primates, family – Hominidae, genus – Homo, and species – Homo sapiens. Other mammals such as dogs and cats share the first three levels of classification. Remember that the scientific name of an organism should be italicized and contain both the genus and the specific name.

Taxonomy Levels of Classification Kingdom Phylum Class Order Family Genus Species Levels of Classification Kings Play Chess On Fancy Glass Squares It may help to use a mnemonic device to remember the order of taxonomic levels. The sentence “Kings play chess on fancy glass squares” will provide you with the first letter of each level.

Taxonomy Importance of a standardized taxonomic system Needed to orderly classify vast diversity of organisms Allows for universal understanding Ability for similarities to be compared Show common ancestry A standardized taxonomic system is important in a number of ways. Taxonomy is needed to orderly classify the vast diversity of organisms. Information is collected by scientists from all over the world. A standardized, or universal, system allows for universal understanding among scientists across the world, regardless of language or cultural barriers. Taxonomy allows for similarities to be compared between organisms. If two organisms share some levels of their taxonomy, some characteristics can be inferred. For example, if two organisms are both in the class Mammalia, scientists can deduce that they will both have hair. The taxonomic system also helps show common ancestry. If two organisms are both in the class Mammalia, they, and all other mammals, share a common ancestor.

Taxonomy Learning Objectives Define taxonomy Understand the importance of a standardized taxonomic system You should now be able to define the term taxonomy and recognize the importance of a standardized taxonomic system.