1. Classification
Chapter 18

2. “Where can I find…?”

3. The Importance of Classification
In biology, the practice of naming and classifying organisms is called taxonomy
We classify organisms to make recognition and description easier
In order to better understand the organisms of Earth, Biologists organize them into groups

4. What would happen if we did not have a system of classifying organisms?
Mountain Lion?
Puma?
Cougar?
Panther?
WHO AM I?
Felis concolor

5. Who do we have to thank for this?
Swedish biologist Carl Linnaeus (in the 1750’s) developed the naming system we use today
His two word system is called binomial nomenclature
His system was based on physical and structural similarities of organisms

6. Naming Rules Homo sapiens
The two-word naming system of binomial nomenclature is now called a scientific name
Scientific names must follow rules!
They are made up of two Latin or Latin-like terms
They must be italicized (typing) or underlined (writing)
The first word (genus) must be capitalized and the second word (species) must not!
Homo sapiens

7. The Linnaean System
Linnaeus made more than just a naming system; he made a system to classify all organisms that were known during his time
The Linnaean system of classification groups organisms at successive levels of hierarchy based on similarities in their form and structure
The eight basic levels of modern classification are: Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species.

8. Organisms that look alike and successfully
Kingdom
Phylum
Class
Order
Family
Genus
Species
Organisms that look alike and successfully
interbreed belong to the same species
A group of similar species that have similar
features and are closely related.
A group of similar genera, each sharing
similar characteristics
The smallest group is the species, one or more species with similar characteristics make-up a genus, one or more genera with common traits compose a family, a group of families that share traits make up an order, orders with common characteristics compose a class, classes make up a phylum, and a Kingdom contains one or more phyla
Each of these categories is referred to as a TAXON or TAXA is plural. Each Taxon contains sub groups of the smaller taxa that have something in common.
Let’s take a look at cats – cats, lions, leopards, etc.
A lynx and a mountain lion do not belong to the same genus as domestic cats, lions and leopards this is because their jaws contain 30 teeth and the lynx and bobcat’s jaws contain 28 teeth.
They do however belong to the same family. All Cats within the family of Felidae share certain characteristics – short faces, small ears, forelimbs with five toes and hind limbs with four toes.
Is a taxon of similar families
Is a taxon of similar orders
Is a group of similar classes
A group of similar phyla or divisions

9. For Example HUMANS Domain Eukarya Kingdom Animalia Phylum Chordata
Class Mammalia
For Example
Order Primates
Family Hominidae
Genus Homo
Species sapiens

10. Traditional Systematics
Scientists traditionally used similarities in appearance and structure to group organisms

11. Traditional Systematics
This approach caused problems, though - why?
Some groups look similar but turn out to be distantly related
Some groups look different and turn out to be closely related
Scientists no longer simply use similarities in appearance and structure to group organisms

12. Phylogenetics & Cladistics
Phylogeny is the evolutionary history of a species
A cladogram is a diagram that assumes phylogenies (relationships) by comparing shared characteristics
How to build a cladogram

13. Types of Cladograms

14. Shared by the Following Organisms
Shared Feature
Shared by the Following Organisms
Bach
Beethoven
Chopin
Handel
Mozart
Schubert
Tchaikov-sky
Vivaldi
Antenna
Eyes
Split Antenna
Segmented Body
Leg-Like Appendages
Tongue
Jointed Leg-Like Appendages
Tail X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X

15. Bach
Tchaikovsky
Vivaldi
Chopin
Schubert
Beethoven
Handel
Mozart
Tail
Jointed Leg-Like Appendages
Tongue
Leg-Like Appendages
Segmented Body
Split Antenna
Eyes
Antenna

16. Tchaikovsky
Vivaldi
Mozart
Chopin
Bach
Schubert
Beethoven
Handel
Tail
Jointed Leg-Like Appendages
Tongue
Leg-Like Appendages
Segmented Body
Split Antenna
Eyes
Antenna