Classification of Living Things
What is Classification? Putting things into groups based on similarities
The science of grouping and naming organisms is called taxonomy.
Early classification systems
Aristotle 2,000 years ago, Aristotle used 2 groups: plants and animals (those that live on land & those that live in water) Problem: where do you put amphibians?
Carolus Linnaeus
Grouped based on similarities Developed two-word naming system: binomial nomenclature Used Latin
8 Levels of Classification Go from largest to smallest groups Domain is largest; species is smallest
Classification of the DOG Domain > Eukarya
Binomial nomenclature First word identifies the genus and the second word identifies the species
Writing scientific names Genus species Ex: Panthera tigris
No two organisms have the same scientific name!
Why are scientific names useful? Avoid confusion Give descriptive info
3. Allow info to be organized easily 4.Allow organisms with similar evolutionary history to be grouped together
6 Kingdoms of Life
Archaebacteria Eubacteria
Bacteria
3. Kingdom Protista Vorticella Paramecium Amoeba
4. Kingdom Fungi
5. Kingdom Plantae
6. Kingdom Animalia
3 Domains
Classification Tools 1. Dichotomous keys: a series of descriptions arranged in pairs that leads to the identification of an unknown organism
A B C
2. Cladogram: a branched diagram that shows the relationships among organisms, including common ancestors