1. Unit Two, Day 8
Cladograms

2. Opener Describe the Linnean system of classifying organisms.
What does the term “phylogeny” mean? 1.
2. The evolutionary history of a species or group of related species

3. Dear King Phillip Climbed Over the Fence and Got Shot!1.
2. The evolutionary history of a species or group of related species

4. Linnean system

5. Agenda
Homework: read and annotate the reading on Gorillas and lice. Try to create a cladogram of the information. Grade practice quiz Introduction to Cladograms Cladogram practice Plants

6. Corrections B D C A Correct your quiz
You have FIVE MINUTES
Correct your quiz
If you want to discuss the answer, put a STAR by the question
Here are the answers: B D C A B
Natural Selection D A C B
2. A
3. C

7. New Learning Targets
I can analyze the data provided by a phylogenetic tree or cladogram to determine the evolutionary history of the organisms described in the diagram
In short: I can read cladograms
I can use a data set to create a cladogram that represents a reasonable hypothesis about the evolutionary history of a group of related organisms
In short: I can make a cladogram

8. Our Focus: Cladograms

9. Cladograms and Phylogenetic trees
Diagrams that represent the evolutionary history of a group of related organisms
Considered to be a hypothesis
Best fit with existing data
Subject to revision
Based on whether or not an organism or group of organism has a specific trait
What represents data?
Fossil record
Morphology (shape form)
Molecular homologies (DNA, proteins)
Big Question: who is the ancestor of who?

10. A Phylogenetic Tree

11. A Cladogram
Time

12. Cladistics Based on 3 assumptions:
Evolution happens: traits change over time
Any group of organisms is related by descent from a common ancestor
The pattern of descent is one of bifurcation (splitting in two)

13. Cladogram Terms Taxon (plural: taxa): a group of organisms
Node: the point at which two branches on a cladogram meet; represents a common ancestor
Can also represent a speciation event
Synapomorphy: a characteristic shared by two or more taxa and the most recent common ancestor
Clade: a group of taxa defined by a synapomorphy
Show linnean relationships in terms of TREES

14. Generalized Cladogram
Node
common ancestor to A, B, and C
Node

15. Vertebrate Cladogram
synapomorphies

16. Clades Hair Amniotic Egg Four Limbs
What makes different clades different it what they share
Four Limbs

17. Assignment: Interpreting Cladograms
Read each cladogram and answer the questions You will need to know the terms taxon, clade and synapomorphy You can work together to complete this assignment, but your goal is to LEARN Don’t let someone else carry the weight for you Cladograms increase in complexity

18. Plants
We need to start counting the hairs on each of the plants and recreate the histogram