1. Bell Work
List 2 sister groups in the phylogeny.

2. Intro to Biology – Lecture 60
Cladograms

3. Cladogram
A diagram used to show relations among organisms.

4. What Does a Cladogram Look Like?
Uses lines that branch off in different directions ending at groups of organisms.
Many shapes but all have lines that branch off from other lines.
The lines can be traced back to where they branch off.

5. Branching Off Points
Branching off points represent a hypothetical ancestor which would have the combined traits of the lines above it.
This hypothetical ancestor might then provide clues about what to look for in an actual evolutionary ancestor.

6. How are Cladograms Made
Originally – made by observing morphological characteristics
Today – made by sequencing DNA and RNA

7. Minor Differences Between Cladograms and Phylogeny
The length of branches represents the time for a species to change.
Relates organisms based on comparisons of the similarities/dissimilarities of their anatomies.
Measures degrees of similarity.
Concerned with who appears most similar to whom at one point in time.
Branch length has no relevance to time.
Attempts to trace evolutionary relationships directly by analyzing gene sequences.
Traces the sharing of derived characters.
Does not show how ancestors are related to descendants or how much they have changed

8. Cladogram vs Phylogeny

9. Cladogram and Phylogeny
Often the two methods give the same tree, but sometimes they differ because of the minor differences in the way they are formed.

10. Cladogram and Phylogeny
For the purpose of this class, we will assume that the two are the same.

11. The Same

12. More of the Same

13. Example Cladogram

14. Create a Cladogram Characteristic/Organism Cells Backbone Legs Hair
Opposable Thumbs
Slug
Catfish
Frog
Tiger
Human

15. Practice - Cladogram
cells
legs
6 legs
wings
Worm
Spider
Ant
Fly

16. Cladogram Practice Characters Shark Bullfrog Kangaroo Human VertebraeX
Two pairs of limbs
Mammary glands
Placenta

17. Cladogram Practice TRAITS Kangaroo Monkey Bullfrog Human
Snapping Turtle
Tuna
Dorsal Nerve Cord Notochord X
Paired Appendages Vertebral column
Paired legs
Amnion (Amniotic sac)
Mammary Glands
Placenta
Canine teeth short Foramen magnum fwd

18. Cladogram Practice Organism Vascular Tissue Flowers Seeds Mosses
Pine Trees 1
Flowering Plants
Ferns

19. DERIVED CHARACTERISTIC
Cladogram Practice
ORGANISM
DERIVED CHARACTERISTIC
BACKBONE
LEGS
HAIR
EARTHWORM
ABSENT
TROUT
PRESENT
LIZARD
HUMAN

20. Pop Quiz

21. Pop Quiz – Fill in the Chart and the Cladogram Correctly
hair
legs
thumbs
eyes
Human
Snake
Monkey
Mouse