1. Animal Classification and Dichotomous Keys

2. Why classify? In order for biologists to study the diversity of life, organisms are classified in a universal manner. We classify in a universal manner using scientific names, because common names refer to different things in different places. Taxonomy – The science of classifying and naming animals.

3. Animal Classification

4. How do we classify animals? We use –1) Characteristics (backbone, feathers, etc.) –2) Evolutionary History – How has the organism changed in the fossil record, what other organism is it related to.

5. History of Classification

10. 4. Same organisms have different names in different countries. European call our moose an elk.

12. Binomial Nomenclature SOLUTION: Use a Latin name! Created by Carolus Linnaeus, it is still used today. It takes a species and gives them a two part scientific name. It is always written in italics (or underlined), the first word is capitalized and the second is lowercased. Example: Gray Wolf: Canis lupus Genus Species

13. Linnaeus's used 7 taxonomic categories. Kingdom - The broadest category Phylum Class Order Family Genus Species

14. Kingdom: Animalia Phylum: Chordota Class: Mammalia Order: Carnivora Family: Ursidae Genus: Ursus Species: arctos

15. Problems with Linnaeus’s Classification He placed animals in categories based on structures of animals as well as anatomy. Body structure may lead you astray in classification. If you used only structure types mammals like whales would be classified as fish.

16. Changes from the past We still use Linnaeus’s naming and hierarchical system of classification Minor additions / modifications: 3 Domains (larger than kingdoms) 6 Kingdom system

18. Modern classification We now group animals based on both evolution and physical characteristics. If families are of the same genus, the have extremely similar DNA. Many biologists now use cladograms. They classify animals based on evolutionary innovations; which means new characteristics that have evolved fairly recently.

21. Modern Classification Evolutionary relationships can be shown in a diagram called a PHYLOGENETIC TREE.

22. CLADISTICS Shows evolutionary relationships based on DERIVED CHARACTERISTICS. Derived characteristics are “innovations” or adaptations. These characteristics were new, never seen before adaptations.

23. Cladistic relationships are shown in a diagram called a CLADOGRAM.