Download Evolution of a Graph (PowerPoint) Madison 2011

The Evolution of a Graph: displaying
and interpreting data
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
Context
• 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.
Our teaching unit = snapshot
Of larger coverage of gathering,
displaying & interpreting data
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.
Threespine stickleback
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
Complete
Morph
Low Morph
1991
100
0.76
0.160
2001
3304
0.112
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
B
Which of these graphs most
effectively conveys the data
from our stickleback study?
A
C
Clicker question 2
B
Which of these graphs includes
the most complete set of
appropriate components?
A
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/
Threespine stickleback as a
supermodel
in evolutionary biology
Adaptive radiation
Insert image of Darwin’s finches