Hard data to swallow : an interrupted case study
Group 6: Evolution (aka team Roadkill)
Kirsten Deane-Coe, Jocelyne Dolce, Thomas Fox, Jan Janecka,
Kristina Jones, Brady Porter

Background Information
Intended Course: Introductory Biology for majors or non-majors
Unit: Selection
Teachable Unit Learning Goals
• See selection as an ongoing, visible, and relevant process
• Understand how selection works
• Resolve misconceptions about selection
Teachable Tidbit Learning Objectives
• Interpret scientific data and draw conclusions
• Predict the response of a population to selection
• Describe adaptation to change in environment

American cliff swallow ( Petrochelidon pyrrhonota )

American cliff swallow ( Petrochelidon pyrrhonota )
• Average life span: 5-8 y
• Aerial insectivores
• Agile flyers
• Build nests on cliffs, increasingly under bridges/overpasses
• Behavior: rest on ground, launch into flight for feeding / return to nests

Charles R. Brown and Mary B. Brown (2013) Current Biology

The figure drawn on the board depicts initial results from
Brown & Brown (2013) on the number of road-killed swallows found over a 30 year period
Turn to your neighbor, and take 2 minutes to:
1) Interpret the data shown
2) Develop at least one hypothesis that would explain this trend

Brown & Brown 2013

Brown & Brown 2013

In your group, take a minute to discuss what, if anything, this histogram tells us
20%
Population Road Kills
16%
12%
8%
4%
0%
103 104 105 106 107 108 109 110 111 112 113
Wing Length, mm
Brown & Brown 2013

1) Copy and label the following set of axes onto the back of the concept map handout:
2) Draw your prediction of wing length of live birds over time if wing length is under selection
1983
Time, years
2012

112
111
110
109
108
107
106
105
104
1980 1985 1990 1995
Years
2000 2005 2010 2015
Brown & Brown 2013

Final activity / homework: revisit concept map
Revisit the concept map the class created last week (handout).
The Brown & Brown (2013) study published in
Current Biology is provided for your reference.
Work with your partner to match the terms on p1 of the the Cliff Swallow Case Study to the concepts in the map .

Concept map: evolution by natural selection
A Variation in trait
Selection pressure
F
Differences in survival/reproduction
C
Heritability of trait
B
Response to selection
Adaptation
E

Teachable Tidbit Learning Objectives:
 Interpret scientific data and draw conclusions
 Describe adaptation to environmental change
 Predict the response of a population to selection
Group 6: Evolution (aka team Roadkill)
Kirsten Deane-Coe, Jocelyne Dolce, Thomas Fox, Jan Janecka,
Kristina Jones, Brady Porter