1. Bellwork: Why do scientists use latin or greek names for organisms (which can be hard to remember/understand). Wouldn’t it be easier simply to refer to their common name?

2. Finding order in diversity
Section 18.1

3. How are scientific names assigned?
Common names often vary between languages or countries
Cougar, puma, panther and mountain lion
In UK a buzzard is a hawk, whereas here it is a vulture
In the 18th Century, European scientists recognized this confusion, and assigned Latin or Greek names to each species to help clear this up
Names were often very log due to the amount of detail
Hard to standardize, as scientists focused on different things

4. What is a Dichotomous key?
A Dichotomous key is used to identify organisms through a series of paired statement or questions that describe alternative possible characteristics

5. Binomial Nomenclature
With binomial nomenclature each species is assigned a two part scientific name
Always written in italics
Polar Bear is Ursus maritimus
Ursus - genus organism belongs to (bear)
Maritimus – unique to each species
Grizzly bear – Ursus arctos
System created by Carolus Linnaeus in 1730s

6. Classifying species in larger groups
Both living and fossil organisms are classified into larger groups
These groups must have biological significance
Organisms in one group are more similar to each other than to organisms in other groups
This science is called systematics
Goal – to organize living things into groups that have biological meaning
Groups are refereed to as taxa

7. The Linnaean Classification system
Carolus Linnean also created a classification system that organized species into taxa that formed a hierarchy
Over time his hierarchy expanded to include seven hierarchical taxa
Kingdom – All multicellular animals are placed in the kingdom Animalia
Phylum – Shared body plan features
Class – Similar orders grouped into a class. Example - mammals
Order – Closely related families. Example - Camel, llama, deer and cattle – linkage (hoofed animals, even number of toes)
Family – Several genera that share many similarities (camel, Llama)
Genus - Camels
Species – one hump vs two humps
King Phillip Came Over For Good Soup!

8. Classification system

9. Problems with traditional classification
Members of a species determine which organisms belong to a species through who they mate with and produce fertile offspring
How is this different from how Linnaean assigned individuals to a species?
What do we know that Linnaean did not?
Linnaean had no idea about genetics and evolution, but was a hood scientists, and chose his characteristics carefully
Many of his groups are still valid under modern classification schemes
Modern day systems assign species on the basis of how closlely related organisms are