1. Classification

2. How did classification begin?
Biologists want to better understand organisms so they organize them into groups based on similarities – classification.
Taxonomy – the branch of biology that groups organisms based on different characteristics.

3. Aristotle’s system Two groups: Plants and Animals
Plants subdivided into shrubs, herbs, and trees.
Animals subdivided into land, air, and water.

4. Linnaeus’s System
In the 18th century, Linnaeus grouped organisms based on physical and structural similarities.
His system is the basis of modern classification systems.

5. Binomial Nomenclature
A two-word naming system that identifies the genus and species of an organism.
Genus – a group of similar species.
Scientific names are Latin, italicized or underlined when written.
The genus is capitalized and the species name is not.

6. Binomial Nomenclature cont.
Organisms may have many common names, but only have one scientific name that does not change.

7. Modern Taxonomy
Biologists try to identify evolutionary relationships by comparing structures and chemical makeup.
Classifications provides a framework for studying relationships between living and extinct species.

8. Modern Taxonomy cont.
Classification allows organisms to be easily identified.
A dichotomous key is used to identify organisms.

9. How are organisms classified?
Organisms are ranked starting in very broad categories down to very specific ones.
Species
Genus
Family
Order
Class
Phylum
Kingdom
Domain

10. Species - sapiens
Genus - Homo
Family - Hominidae
Order - Primata
Class - Mammalia
Phylum - Chordata
Kingdom - Anamaila
Domain - Eukarya