1. Cladograms

2. Cladistics
Cladistics – a method of classifying animals and plants by the characteristics they have in common.
Clade - A group that includes a common ancestor and all the descendants (living and extinct) of that ancestor.

3. Cladogram A diagram that shows evolutionary relationships.
Assumption- The more characteristics two organisms share, the more recently they diverged from a common ancestor.
Diagrams based on patterns of shared, derived traits that show evolutionary relationship between groups of organisms

4. How to read a Cladogram
This diagram shows a relationship between 4 relatives.
These relatives share a common ancestor at the root of the tree.
Note that this diagram is also a timeline. The older organism is at the bottom of the tree.
Branches on the tree represent SPECIATION.
Speciation - the formation of a new species.
The four descendants at the top of the tree are DIFFERENT species.

5. How to read a Cladogram
Species A, B and C each have characteristics that are unique only to them.
But they also share some part of their history with species A.
This shared history is the common ancestor.
Unique history of A

6. Practice Reading a Cladogram
Jaws
Amniotic Egg
Turtle
4 legs-jaws-vertebral column-

7. What trait separates amphibians from primates on this cladogram?
What separates rabbits and primates from crocodiles on this cladogram?
Which organism is most related to the bird on this cladogram?
What 5 traits do these two organisms share?
Amniotic egg & Hair
Eggs with shells & hair
Crocodile

8. First, Identify Characteristics
Lamprey
Snapping Turtle
Tuna
Bullfrog
Nerve Cord X
Paired Legs
Paired appendages vertebrae column
Amniotic Sac
Total X’s

9. Paired appendages vertebrae column
Lamprey
Snapping Turtle
Tuna
Bullfrog
Nerve Cord X
Paired Legs
Paired appendages vertebrae column
Amniotic Sac
Total X’s 1 4 2 3
Lamprey-bullfrog-tuna-snapping turtle

10. First, Identify Characteristics
Lynx
Chimpanzee
Lizard
Newt
Human
Bipedal X
Hair
No Tail
Amniotic Membrane
Lungs
Total X’s

11. Lynx Chimpanzee Lizard Newt Human Bipedal X Hair No Tail
Lynx
Chimpanzee
Lizard
Newt
Human
Bipedal X
Hair
No Tail
Amniotic Membrane
Lungs
Total X’s
Newt-Lizard-Lynx-Champanzee-Human