1. Heredity and Adaptation Teaching Slides, 2.1 Part 2
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2. Science Log Q 3 week 9 Tuesday 3/7:
Emma read that frog populations are decreasing over time in Washington. What data should be collected to determine whether the Pacific tree frog population is decreasing near her school?
Heredity and Adaptation Course, 2.1: Lines of Descent

3. Classification Cards
You are going to explore how these different kinds of animals might be related.
Follow the steps in the FOSS Investigations Guide to guide students through the cladogram-building process.
Heredity and Adaptation Course, 2.1: Lines of Descent
Step 7

4. Classification Cards
Sort the cards into groups that you think represent close relationships.
Follow the steps in the FOSS Investigations Guide to guide students through the cladogram-building process.
Heredity and Adaptation Course, 2.1: Lines of Descent
Step 7

5. Classification cards Remember Alans family tree
All organisms have family trees, not just people.
We can represent how different kinds of organisms might be related using a model that is somewhat like a family tree.
It is a branching diagram called a cladogram.
A cladogram is a family tree of life on Earth.
A cladogram is based on characteristics that a common ancestor passes on to its descendants.
Heredity and Adaptation Course, 2.1: Lines of Descent

6. Review vertebrate information
Teacher master Q, Cladogram Teacher master P, Model Analysis Chart Before you start working with the cladogram to answer questions about the animals, you need to start a model analysis chart for the cladogram on the back of master P Discuss in your groups what part of the real world you think the lines represent.
Heredity and Adaptation Course, 2.1: Lines of Descent
Steps 8, 11

7. Review vertebrate information
Teacher master Q, Cladogram Teacher master P, Model Analysis Chart Teacher master R, Vertebrate Information
Heredity and Adaptation Course, 2.1: Lines of Descent
Steps 8, 11

8. Place cards on the cladogram
A branch refers to one line that ends at the top of the diagram .
How many branches does this cladogram have?
Seven
Pairs will work together using one copy of the Caldogram sheet and then transfer information to the other.
There are 7 cards and 7 endpoints
Heredity and Adaptation Course, 2.1: Lines of Descent

9. Place cards on the cladogram
Quickly add tips to your model analysis charts and think back to the family tree to respond to this question.
How do the lines and tips show who is most related?
Look at the lines and where they connect.
The first/second and third/fourth lines on the right are connected just below the pair, so they are probably closely related.
Heredity and Adaptation Course, 2.1: Lines of Descent

10. Place cards on the cladogram
On the far right of the diagram the two animals at the tips of these lines would be closely related.
Look at your sorted cards and choose one pair that you think might be closely related.
Place the two cards on the cladogram, above the rightmost two lines.
Find a second pair of related animals to place above the next pair of lines.
Heredity and Adaptation Course, 2.1: Lines of Descent

11. 10. Continue placing cards
How do the lines and tips show who is least related?
Look at the lines and where they connect.
The line on the far left has to go through a lot of connections to get to the tips/pairs on the far right.
Heredity and Adaptation Course, 2.1: Lines of Descent

12. 10. Continue placing cards
The line tip to the far left represents an organism that is not as closely related to the pairs they have on the far right.
Place an animal card that is least related to the animals you have placed on the right.
Write the names of the animals in the parentheses at the tips of the lines.
Heredity and Adaptation Course, 2.1: Lines of Descent

13. 11. Vertebrate Set your hypothetical cladogram aside
You’re going to look at other characteristics of the animals and then determine if your hypotheses should be revised.
Master R vertebrate information
Cladistics Table NBS 6 page 70
Transfer the vertebrate information to the table.
Heredity and Adaptation Course, 2.1: Lines of Descent

14. 12. Transfer vertebrate info to cladogram
What do all the animals have in common?
All are vertebrates; they all have backbones
How can we represent that on the cladogram?
Dark bar below the first intersection
Heredity and Adaptation Course, 2.1: Lines of Descent

15. 12. Transfer vertebrate info to cladogram
What characteristic should go on the next bar?
Bony skeleton
Why did you select that characteristic?
All the animals but one have that characteristic.
Heredity and Adaptation Course, 2.1: Lines of Descent

16. 13. Revisit original classification hypothesis.
Revisit your original sort.
Rearrange the cards according to the new information you have.
Start on the left and write in the names of the organisms on your projected cladogram.
Do not erase your original hypothesis.
Cross them out and write the revised version above what you first thought.
Heredity and Adaptation Course, 2.1: Lines of Descent

17. Interpret cladogram
What do the alligator and bird have in common that other animals do not have?
Two extra skull openings in their fossil skulls
What do the human and rabbit have in common that other animals do not have?
Hair
What do the human, rabbit, bird, and alligator have in common?
An amniotic egg, four limbs, a bony skeleton, and a backbone.
Heredity and Adaptation Course, 2.1: Lines of Descent
Step 14

18. Interpret cladogram
Which characteristic does the shark share with the other animals on the cladogram?
It is a vertebrate
Which of these are most closely related? Bird and alligator, or bird and human, and how do you know?
Bird and alligator; they branch off from the same point and share a characteristic that humans don’t have.
How does using the model help you answer questions about relationships?
Heredity and Adaptation Course, 2.1: Lines of Descent
Step 14

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Heredity and Adaptation Course, 2.1: Lines of Descent