Speciation
EVOLUTION #1 (Group 3)
Strawberry Frogs Forever
Participants: Lin Xiang
Ingo Schlupp
Tiffany Roberts
Anne Grippo
Jerry Farris
Facilitators: Brooke Dubansky,
Joe Siebenaller
Context
• Designed for: Introductory course for Science
majors
– Biology (mainly)
– Chemistry
– Historical Geology
• Class size: small or large
• Curriculum:
– After natural selection, sexual selection
– Some genetics background, genetic drift
– Prior to prokaryotic/eukaryotic differences
Rationale
•
•
•
•
Address misconceptions on speciation
Speciation is key to understanding biodiversity
Topic is scalable (not just class size)
Cross disciplinary
Learning goals
• Students will understand
– speciation is a core concept in biology
– the process of speciation
– different species concepts
– how selection pressures impact speciation
– how scientists study speciation
Learning outcomes
• Students will be able to
– apply their acquired knowledge of the role
of selection pressures in speciation to
predict frog color with varied female
preferences for male color
– evaluate the rates of color change with
varied female color preferences
– define species
Active Learning
• Activity outside of class
– NetLogo loaded onto computers
(http://ccl.northwestern.edu/netlogo/)
• Activity in class
– Simulation provided for each student to actively
work with it (students can work alone, in pairs,
groups)
• Alternative: in-class demonstration
Active Learning
• Assessment
– Formative: Pre/Post questions; Clicker questions;
Brainstorming
– Summative: Take-home exercise
• Diversity
– Different majors
– Varied learning styles
– Color blind awareness
Tidbit—1
(Pre-assessment, individual question)
On a flashcard, write down your thoughts on the
following question (instructor can lead a
discussion or TPS on this if wanted):
Is it possible for an organism living in a
particular area to split into different forms?
Why or why not?
Active learning activity
• Oophaga pumilio (Strawberry Poison-dart Frog)
Let’s read a histogram
Strawberry Frogs Forever
(Simulation module)
What will happen with the male frog
coloration distribution in this population?
Condition 1: no selection pressure
a.
b.
c.
d.
e.
Figure a
Figure b
Figure c
Figure d
Don’t
know
a
b
c
d
What will happen with the male frog
coloration distribution in this population?
Condition 2: Female preference for bright red
males
a.
b.
c.
d.
e.
Figure a
Figure b
Figure c
Figure d
Don’t
know
a
b
c
d
What will happen with the male frog
coloration distribution in this population?
Condition 3: New females emerge with preference for bright orange
males (On the back of your flashcard: Draw the graph on your own.)
Think back…
(Post assessment: Think-pair-share)
Is it possible for an organism living in a
particular area to split into different
forms?
Why or why not?
Brainstorming on given question regarding the
definition of species
Summative Assessment
Is color difference sufficient for distinguishing
separate species?
What are other selection pressures that could
cause the same phenomenon?
What is the phenomenon called?
Tidbit--2
• Design an experiment to explore speciation
further
A handout will be made including the following
guiding questions:
– What organism would you use?
– What question would you test?
– What are your hypotheses?
– How long would the experiment take?
–…