1. 1 18.1 The Importance of Classification I. The need for systems A. Taxonomy 1. The practice of naming & classifying organisms 1. The practice of naming & classifying organisms B. Aristotle 1. grouped plants & animals based on structural similarities 1. grouped plants & animals based on structural similarities C. Greeks and Romans 1. grouped in basis categories such as oaks, dogs, & horses 1. grouped in basis categories such as oaks, dogs, & horses 2. Each unit called a “genus”/ Latin meaning “group” 2. Each unit called a “genus”/ Latin meaning “group” D. Starting in the middle ages genus names were made Latin 1. cats = Felis, dogs = Canis 1. cats = Felis, dogs = Canis

2. 2 E. Polynomials 1. Until 1700’s biologists referred to specific organisms with a genus name followed by several descriptive words 1. Until 1700’s biologists referred to specific organisms with a genus name followed by several descriptive words a. sometimes as many as 12 words were used example = European Honeybee example = European Honeybee Apis pubescens, thorace subgriseo, abdomine fusco, Pedibus posticis glabis, untrinque margine ciliatus Apis pubescens, thorace subgriseo, abdomine fusco, Pedibus posticis glabis, untrinque margine ciliatus F. Carl Linnaeus F. Carl Linnaeus 1. Swedish biologist published several books on polynomial taxonomy 1. Swedish biologist published several books on polynomial taxonomy

3. 3 2. As short hand he included a two word Latin name for each species - example = European Honeybee – Apis mellifera 3. Binomial nomenclature 3. Binomial nomenclature a. Two word system for naming an organism a. Two word system for naming an organism II. Scientific Names are Universal A. For 250 yrs. binomial nomenclature has been standard A. For 250 yrs. binomial nomenclature has been standard B. Scientific Name = the unique 2 word name for a species B. Scientific Name = the unique 2 word name for a species

4. 4 C. Rules 1. Must be Latin words or terms constructed according to the rules of Latin grammar 1. Must be Latin words or terms constructed according to the rules of Latin grammar 2. Two different organisms can’t have the same scientific name 2. Two different organisms can’t have the same scientific name a. They can have the same genus name a. They can have the same genus name 1. ex. = Homo sapiens & Homo ergaster 1. ex. = Homo sapiens & Homo ergaster b. They can have the same species name b. They can have the same species name 1. ex. = green anole lizard = Anolis carolinensis 1. ex. = green anole lizard = Anolis carolinensis 2. ex = Carolina chickadee = Parus carolinensis 2. ex = Carolina chickadee = Parus carolinensis 3. The 1st word is the genus 3. The 1st word is the genus a. first letter ALWAYS capitalized a. first letter ALWAYS capitalized b. an organism is assigned based on major characteristics. Ex = oak trees – all produce acorns b. an organism is assigned based on major characteristics. Ex = oak trees – all produce acorns

5. 5 4. The 2nd word is the species a. first letter is ALWAYS lowercase a. first letter is ALWAYS lowercase b. identifies one particular kind of organism in a genus b. identifies one particular kind of organism in a genus 5. ALL words are ITALICIZED or UNDERLINED 5. ALL words are ITALICIZED or UNDERLINED D. Scientific names are the same throughout the world D. Scientific names are the same throughout the world 1. Allows for less confusion when discussing organisms that may have same common name 1. Allows for less confusion when discussing organisms that may have same common name

6. 6 III. Hierarchy of Organisms A. Eight levels to classification (Humans as an example) A. Eight levels to classification (Humans as an example) 1. Domain – Eukarya 2. Kingdom – Animalia 3. Phylum – Chordata 4. Class – Mammalia 5. Order – Primates 6. Family – Hominidae 7. Genus – Homo 8. Species – sapiens B. The 8 level system can be subdivided into more than 30 levels 1. ex – superclass, subclass, superorder, suborder 1. ex – superclass, subclass, superorder, suborder

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