1. Classification of Living Things

2. Non-Science Example of Classification
The item in this picture is
Automobile:
Truck, Car, or SUV? Car
Made by? Ford
Type of Ford car? Mustang
-Was made in what year? 2002
-Is it Convertible? No
-Color? Silver
Car Lot Example Scenario

3. Classification: Goes from General to Specific
Automobile – Biggest
Car
Ford
Mustang
2002
-Non Convertible
-Silver - Specific

4. Classification
Classify – to group things together based on similarities
Why Classify?
To make organisms easier to identify
To make organisms easier to compare
How do we classify?
Compare Traits – features or characteristics of an organisms

5. Little Known Fact:
There are over ___1.5 Million_____; and more are discovered each year.
What do we classify? Somewhere between 2 and 100 million have yet to be discovered.
Classification serves as an organization system for all the existing and new organisms
The Science of Classification is called Taxonomy

6. Early Classification – Aristotle 384-322 B.C.
2 Groups: Plants and Animals
Plants – Green, Non Mobile
Animals – Not Green, Mobile
Something that moves and is green would fit into both categories

7. How would you classify this using the Plant/Animal system?
Praying Mantis
Green but..
Mobile
Aristotle’s Grouping of life not specific enough

8. Updating the Classification Process: Tools Used to Classify Organisms
1. Comparative Anatomy
Compares Physical Structures, Traits
2. Biochemistry – DNA and RNA
3. Embryology – Developing Embryos
4. Molecular Basis – Cellular Structure
5. Phylogeny
Related Organisms with common ancestors, Derived Characters

9. Linnaeus Divisions Still Used in Modern Classification
1. Kingdom – largest group
2. Phylum
3. Class
4. Order
5. Family
6. Genus
7. Species
(Most Closely Related)
We have now added DOMAIN which is bigger then Kingdom
Do not write this slide

10. Mnemonic Device – To help remember categories and order
Domain - Did
Kingdom - King
Phylum - Phillip
Class – Came
Order – Over
Family From
Genus Great
Species - Spain

11. Taxons Within each category, a particular group is called a Taxon
Many Taxons for each category
Ex: Mammalia is the Taxon for the Class category in Humans
Ex: Homo is the Taxon for the Genus category in Humans
Carnivora is the Taxon for the Order category in Lions

12. From Kingdom to Species

13. Example Classification
Lion
1. Kingdom – Animalia (all Animals)
2. Phylum – Chordata (All vertebrate animals)
3. Class – Mammalia (All Mammals – mammary glands)
4. Order – Carnivora (Meat eaters)
5. Family – Felidae (includes all Cats)
6. Genus – Panthera (Includes all roaring Cats)
7. Species – leo (Lions)

14. Which two animals are most closely related?
At what taxon do they diverge?

15. Linnaeus Introduced Scientific Naming
Binomial Nomenclature is the 2 word scientific name of an organism
Uses Genus and Species
Genus is capitalized, not species, all italicized
In writing the name, can’t italicize, so underline
Homo sapien (Genus and species of Human)
Panthera leo (Genus and species of Lion)
Used Latin –
Felis concolor or Felis concolor

16. Practice
Scientific name for….
Humans? Squirrel?
Gorilla? Katydid?

17. If we find things we don't know and we want to know what they are what should we do?
We use something’s characteristics in a similar way using…

18. Dichotomous Keys
A dichotomous key is a tool that allows the user to determine the identity of items in the natural world based on the items characteristics
"Dichotomous" means “divided into two parts”
Greek origin
Dichotomous keys always give two distinct choices in each step, often they are opposites
ex) Black/white
antennae present/antennae not present
pointed/rounded

19. Here are creatures we don’t know!
How to use a Dichotomous Key?
Here are creatures we don’t know! 19

20. How to use a Dichotomous Key?
Choose only one creature at a time. 20

21. Decide which statement is true
How to use a Dichotomous Key?
Read steps 1a and 1b
Decide which statement is true
1b is true

22. Then follow the directions after that step.
How to use a Dichotomous Key?
Then follow the directions after that step.
Go to step 5!

23. At choice 5, you make another dichotomous choice
How to use a Dichotomous Key?
At choice 5, you make another dichotomous choice
5a is true
Go to step 6!

24. C How to use a Dichotomous Key? Keep going until you come to a step
that gives you the creature’s name.
6 a. The creature has one antennae Go to Step 7. C

25. How to use a Dichotomous Key?
Choose a new creature and start at step 1a and 1b again. Continue until you find the creature’s name. C
Where do you start Again?

26. Then, find the names of all the creatures26

27. 1. a. wings covered by an exoskeleton – go to step 2
b. wings freely observed – Go to step 3
2. a. body has a round shape ……….ladybug, a red beetle with black spots
b. body has an elongated shape ……….grasshopper, a green insect that hops
3. a. wings point out from the side of the body ……….dragonfly, an insect that is cm long and lives in marshes
b. wings point to the posterior of the body ……….housefly, a flying insect with red eyes and an annoying buzz

28. What if I needed to make a key:
- Use constant characteristics rather than variable ones. (Flowers change with the seasons)
- Use measurements rather than terms like "large" and "small".
Make the choice a positive one
- something "is" instead of "is not".
- Ex: snake ears are internal only
If possible, start both choices of a pair with the same word or item.
- the body is “round” vs the body is “square”
- Finish the dichotomous key with a full description of the organism

29. Dichotomous key
Another Example of a dichotomous key…

30. Dichotomous key
the dichotomous key can also be expressed in a diagram form

31. Cladograms (Phylogenetic Trees)
Show relationships between organisms.
All organisms have at least one thing in common in order to be on the same tree, each branch shows how they differ from those before them, these are the derived characteristics.
You read from the “roots” forward.

32. EXAMPLES

33. Practice Which organism is the first to have lungs? How many have fur?
Which organism contains none of the identified derived characteristics?