Taxonomy Taxonomy is the science of naming organisms and classifying them. It was initiated by Carolus Linnaeus. A good illustration of the Linnaean Classification System can be found on page 520 of your textbook. Rules 1. 2. 3. 4. All names must be in Latin. Two different organisms cannot have the same scientific name. If they share some levels of classification, they must share characteristics. Series of classification infers their phylogeny or evolutional history. This shows relationships between organisms. All living things have scientific names that came from the Latin language. All are two word unique names, no two are the same. Common names can not be used in a scientific setting because they are not specific , the common name change according to location and the common name is often misleading. Binomial Nomenclature- is a standard naming system that gives each species a two-part name using Latin words. The first part the genus and the second the species. ~Genus species Rules 1. The Genus must begin with a capital letter. 2. The Genus is a general description of the organism. 3. The species name must all be in lowercase. 4. Both words are either underlined (if handwritten) or can be in italics if typing. For some organisms the species is divided into even more specific categories. 1. subspecies - animals that are structurally different and are often geographically separated. example- Northern Timber Wolf Canis lupis ssp. occidentalis 2. variety - plants that are structurally different and may have been produced by humans. examples - peaches Prunus persica var persica and nectarines - Prunus persica var nectarina. 3. strain - microorganisms - bio chemically dissimilar group within a species are usually labeled with letters or numbers. example - Serrata marcescens D1 versus Serrata marcescens 933. Once you have stated the genus name once, you may abbreviate the scientific name as follows - Homo sapiens to H. sapiens. Evidence for Classification 1. Morphology - internal and external appearance. Main tool used in classification comparing organisms to one another. 2. Embryology - how an organism develops 3. Biochemistry - DNA similarities 4. Behavior patterns 5. Methods of reproduction Levels of Classification - the more levels two organisms share, the more closely related they are.