1. Taxonomy

2.  How organisms are classified and named

3. Why classify? Gives us information about  Similarities  Differences  Evolutionary history

4.  It is important to note that scientists do not always agree when classifying organisms  As more information becomes available, especially DNA evidence, classification schemes change.

5. Why name?

6. All are “correct”  Cougar  Mountain lion  Puma  Panther

7. Scientists call her  Puma concolor

8.  To better understand the unity and diversity of all organisms, scientists use phylogenetics.  A way to evaluate and categorize observable heritable traits to determine the evolutionary history (phylogeny) of a species or group of species

9. Species  A population that can interbreed and produce viable, fertile offspring

10. Dichotomous key  One tool that scientists use to categorize or classify living things based on physical characteristics.  “di”= two  “tom”= slice or cut  The goal is is identify organisms, usually species, by their unique visible characteristics.  Often used in field guides

11. Characteristics used in dichotomous keys must  Be readily measured or observed  Be mutually exclusive, no overlap  NOT be subjective or inferred, i.e. words like short, strong, pretty are not acceptable  Let’s try to create one