Presented by the ‘Model Organisms’:
Stephanie Gardner and Laurie Iten, Purdue University
Elizabeth Derryberry, David Heins, and Donata Henry, Tulane University
Facilitators: Robin Wright and Jeffrey Gardner NAS/HHMI Summer Institute 2011

• 100-level biology majors’ class that covers evolutionary biology
• Before this teaching unit, students introduced to:
- Different data types
- Collecting data
Instruments & techniques
Methods & limitations
- Basic descriptive & inferential statistics
• Teaching unit takes two 50 min. lecture or lab periods.

Teachable Unit: “The Evolution of a Graph”
Learning Goals
Students will understand:
• the importance of quantitative approaches to interpret data.
• that evolution is the change in frequency of phenotypes (alleles) over time (across generations).
Learning Outcomes
Students will be able to:
• make a prediction in a real scientific context.
• choose the appropriate test to analyze a set of evolutionary data.
• create an appropriate graph of their data.
• interpret the result and scope of the inferential statistic in the context of the hypothesis that there has been evolutionary change.

Mini-lecture: Threespine stickleback
“Complete Morph”
• More armor
• Advantageous where there are no hiding places.
“Low Morph”
• Less armor
• Advantageous where there are places to hide.
Bell et al 2004 Evolution

OCEAN HABITAT LAKE HABITAT
Q: Which of the following relationships between stickleback plate phenotype and habitat would you expect to find?
A. Complete in ocean & complete in lake
B. Low in ocean & complete in lake
C. Complete in ocean & low in lake
D. Low in ocean & low in lake

Group Activity
Using your knowledge of the biology of these fishes (see your handout), take 10 minutes and write a prediction about how the frequency of occurrence of the two phenotypes might change over time.
Work in pairs .

Group Activity
In pairs ,
Take the data from your field sampling efforts (see table below) and produce a graph (remember to include appropriate components). You have 5 minutes
(10-15 minutes for students).
Table: Frequency of occurrence of two stickleback morphs in
Loberg Lake, Alaska. n = sample size
Year n Low Morph
1991
2001
100
3304
Complete
Morph
0.76
0.112
0.160
0.752
From: Bell et al 2004 Evolution

Group assessment
Exchange your graph with another pair
Annotate (i.e. make changes to) the other group’s graph, with two thoughts in mind:
1. Is this type of graph the most effective format for conveying the information?
2. Are all the appropriate components included?
You have 3 minutes (10 for students) minutes for this exercise.
Give the graph back to the original group.

Class discussion
Let’s come up with some ideas about what makes a graph effective and what the appropriate components of a graph are.
These ideas will be used to guide in the creation and evaluation of future graphs.

Clicker question 1
Which of these graphs most effectively conveys the data from our stickleback study?
A
B
C

Clicker question 2 B
A
Which of these graphs includes the most complete set of appropriate components?
C

Homework
Synthesize your work from today!
Take your prediction and your corrected graph and write two sentences to explain:
(1) whether or not your data supported your prediction
(2) how representing these data in a graphical format aided in your understanding of the evolution of morphology in stickleback.
Bring your written statement to the next class!

Teachable Unit: “The Evolution of a Graph”
Learning Goals
Students will understand:
• the importance of quantitative approaches to interpret data.
• that evolution is the change in frequency of phenotypes (alleles) over time (across generations).
Learning Outcomes
Students will be able to:
• make a prediction in a real scientific context.
• choose the appropriate test to analyze a set of evolutionary data.
• create an appropriate graph of their data.
• interpret the result and scope of the inferential statistic in the context of the hypothesis that there has been evolutionary change.

Teachable Unit: “The Evolution of a Graph”
Learning Goals
Students will understand:
• the importance of quantitative approaches to interpret data.
• that evolution is the change in frequency of phenotypes (alleles) over time (across generations).
Learning Outcomes
Students will be able to:
• make a prediction in a real scientific context.
• choose the appropriate test to analyze a set of evolutionary data.
• create an appropriate graph of their data.
• interpret the result and scope of the inferential statistic in the context of the hypothesis that there has been evolutionary change.

Additional fun stuff http://learn.genetics.utah.edu/content/variation/stickleback/

Insert image of Darwin’s finches