1. The Classification of Life

2. Classification of Life Biology » The study of life Taxonomy » Classification and naming of organisms

3. Classification of Life  Classification is the grouping of organisms according to their similarities and differences.  The main purpose of classification is to simplify the diversity among living organisms

4. Basis of Classification 1. comparative morphology (form and structure) 2. DNA 3. Cell structure 4. Biochemistry 5. Nutrition

5. History of Classification  More than 2000 years ago a Greek philosopher named Aristotle started classifying life.  Aristotle divided life into plants and animals.  The classification of plants was based on structure.  The basis for classification of animals was habitat.  Two major problems arose from his system: numbers numbers overlapping organisms overlapping organisms

6.  Carolus Linnaeus (1707-1778) developed a system of grouping organisms into hierarchical categories  He is considered to be the founder of modern taxonomy  Linnaeus based his classification system on structural similarities  Latin was the language for his new classification system  Purpose for using Latin: universal language universal language dead/unchanging dead/unchanging descriptive descriptive eliminate confusion eliminate confusion History of Classification

7. Linnaeus’ Seven Level Hierarchical System 1. Kingdom (the most general grouping) 2. Phylum 3. Class 4. Order 5. Family 6. Genus 7. Species

8.  Within his seven level system he gave every organism a scientific name using the genus and species descriptors. This naming system is called Binomial Nomenclature (two name system). Linnaeus’ Seven Level Hierarchical System

9. Binomial Nomenclature  Genus is a noun and is always capitalized  Species is an adjective and always lower case  Species is the lowest level of classification  To be in the same species the organisms have to be able to interbreed under natural conditions and produce fertile offspring.  Horse and donkey produce a mule (infertile)