Organizing Life’s Diversity Classification: the grouping of objects or organisms based on their similarities Biologists use a system of classification to organize information about the diversity of living things Taxonomy is a branch of Biology that is the science of classifying/grouping and naming of organisms

Aristotle’s Classification System Greek philosopher who developed first classification system Divided all organisms into 2 GROUPS: Non motile (plants) Plants were grouped by: Size small, medium, large for things like herbs, shrubs, and trees Motile (animals) Animals were grouped by: Animals were grouped by Their Habitat (air, water, land) Morphology (form or structure) “Red-Blooded” and “Bloodless”

Linnaeus's Classification System 18 th Century Swedish Naturalist who broadened Aristotle’s classification method Created a system of naming organisms by their structures and their behavior. (He didn’t realize it but he was also classifying them by evolutionary relationship). Linnaeus’s system of naming and grouping organisms is called “Binominal Nomenclature” and this system is still valid today. Written in Latin Gives each species a scientific name that has two parts: First part: Genus Second part: Species

Binomial Nomenclature Genus: CAPITALIZED (noun) means beginning Species: lowercase (adj.) Example: Humans: Homo (man) sapien (wise/thinking) Whitetail Deer: Odocoileus virginianus Italicized if printed, Underlined if written Organisms have a scientific name and a common name. Scientific name is the Genus species name Common name is what the organism is commonly called and is not used in the scientific community

Binomial Nomenclature The common name of an organism is not used by scientists because one species may have many different common names depending on where the animal lives. For example, the Mountain Lion, Mountain Cat, Black Panther, Painter, Catamount, Ghost Cat, Cougar and the Puma are all the same organism. People that live in different areas just call it different things. Can you think of any other organisms that have multiple common names?

The “New” Evolutionary Classification Categories represent lines of evolutionary descent, not just physical and behavioral similarities This new method is called: Evolutionary Classification Scientists classify organisms based on their Evolutionary beginnings Cladograms are useful diagrams that are used to show evolutionary relationships between organisms (You may also hear this called a Phylogenetic Tree).

Cladograms/Phylogenetic Trees Scientists use these to understand how one lineage branched from another in the course of evolution To place organisms in a Cladogram, scientists consider ancestry and homologous characteristics not found in other organisms. A small number of characteristics are used to define each group. Claddists assume that each successive group has a more recent common ancestor that other previously branched species don’t share.

Cladograms/Phylogenetic Trees Scientists use these to understand how one lineage branched from another in the course of evolution To place organisms in a Cladogram, scientists consider ancestry and homologous characteristics not found in other organisms. A small number of characteristics are used to define each group. Claddists assume that each successive group has a more recent common ancestor that other previously branched species don’t share.