1. Classification
Book Chapter 18

2. What is a Species?
A species is a population of organisms that share similar characteristics and can breed with one another to produce fertile offspring
~1.5 millions species have been identified and named already
Scientists estimate there are between 2 and 100 million species yet to be discovered

3. Diversity of Life Diversity of life
There are so many different species on Earth
Why are there differences?
Unity of life
All creatures have similarities/Common characteristics
Why are they so alike?
Taxonomy is the discipline of classifying organisms

4. Why Does Classification Matter?
By using a scientific name, everyone can be sure they are talking about the same organism
EX. Bird vs. Paradisaea rudolphi

6. Paradisaea rudolphi

7. Assigning Scientific Names
By the eighteenth century, scientists realized that using common names was not working
Panther vs. Cougar vs. Puma vs. Mountain Lion
Scientists started using Greek and Latin to name organisms
At first, they used words to describe the organisms
Some names could be 20 words long!

8. Problems with Traditional Classification
Sometimes due to convergent evolution, organisms that are different from each other evolve similar body structures
These similarities made it difficult for scientists to decide how some organisms should be classified

9. How do dolphins cause confusion within traditional classification?

10. Carolus Linnaeus 1707-1778 “Father of Modern Taxonomy”
Swedish botanist, physician, and zoologist
Brought order to the process of naming species by binomial nomenclature

11. Binomial Nomenclature
In binomial nomenclature, each species is assigned a two-part name
The first word is capitalized, the second word is not
The first part of the name is the genus
The second part of the name is unique to the species

12. Ursus arctos vs. Ursus maritimus

13. Linnaeus’s Classification
Each group or level of organization is called a taxon
Linnaeus’s system uses 7 taxonomic categories

14. Kingdom
Phylum
Class
Order
Family
Genus
Species

15. Evolutionary Classification
Grouping organisms based on their evolutionary history is evolutionary classification
Cladograms are diagrams that show the evolutionary relationship among a group of organisms

16. He’s Back!
When Darwin brought forth the idea of evolution, it shifted the way organisms are classified
Biologists now group organisms into categories that represent lines of evolutionary descent, not just physical similarities

17. Modern Day Descendants
Distinctive
Characteristics
Common Ancestor

18. Names of Kingdoms 1700s Plantae 1800s Protista 1950s Monera Fungi
First Introduced
Names of Kingdoms
1700s
Plantae
Animalia
1800s
Protista
1950s
Monera
Fungi
1990s
Eu-bacteria
Archae-bacteria

19. The Tree of Life
A domain is a larger, more inclusive group than a kingdom
There are 3 domains:
Domain Bacteria
Domain Archaea
Domain Eukarya