Peacock Butterfly Predator Defenses The photographs below represent the experimental and control groups used in the peacock butterfly experiment discussed in Section 1.6. See if you can identify the experimental groups and match them up with the relevant control group(s). Hint: Identify which variable is being tested in each group (each variable has a control).
A Wing spots painted out
B Wing spots visible; wings silenced
C Wing spots painted out; wings silenced
D Wings painted but spots visible
E Wings cut but not silenced
F Wings painted, spots visible; wings cut, not silenced
Peacock butterfly experiment
A With wings folded, a peacock butterfly resembles a dead leaf, so it is appropriately camouflaged from predatory birds.
B When a predatory bird approaches, a butterfly flicks its wings open and closed, revealing brilliant spots and producing hissing and clicking sounds.
C Researchers tested whether the wing-flicking and sound-making behaviors of peacock butterflies affected predation by blue tits (a type of songbird).
|Experimental Treatment||Number of Butterflies Eaten|
|Wing spots concealed||5 of 10 (50%)|
|Wings silenced||0 of 8 (0%)|
|Wing spots painted out and wings silenced||8 of 10 (80%)|
|No treatment||0 of 9 (0%)|
*Proceedings of the Royal Society of London, Series B (2005) 272: 1203–1207.
D The researchers painted out the spots of some butterflies, cut the soundmaking part of the wings on others, and did both to a third group; then exposed each butterfly to a hungry blue tit for 30 minutes. Results support only the hypothesis that peacock butterfly spots deter predatory birds.
FIGURE 1.12 Testing the defensive value of two peacock butterfly behaviors.
To match: The experimental groups with their relevant control groups.
Answer to Problem 1DAA
Explanation of Solution
The peacock butterfly predator defense experiment is a controlled experiment because it has both experimental and control groups.
The following are the groups that were studied:
Group A: Wing spots painted out
Group B: Wing spots visible and wings silenced
Group C: Wing spots painted out and wings silenced
Group D: Wings painted but spots visible
Group E: Wings cut but not silenced.
Group F: Wings painted, spots visible, wings cut, and not silenced
- Group A is an experimental group that has the wings painted, and nothing is mentioned about the noise produced by the wing. Group D has the wings painted, but the spots are visible, and nothing is mentioned about the noise produced by the wing. The wing is the independent variable, and the noise is the dependent variable. Therefore, Group D is the control group for experimental Group A.
- Group B is an experimental group that has the wing spots visible, but the noise produced by the wing is silenced. Group E has the wings cut, and the noise produced by the wing is silenced. The wing is the dependent variable, and the noise from the wing is the independent variable. Therefore, Group E is the control group for experimental Group B.
- Group C is an experimental group that has the wing painted, but the spots are visible, and the wings are silenced. Group F has the wings painted, spots visible, and cut, and the noise produced by the wing is not silenced. The wing spot is the dependent variable, and the noise from the wing is the independent variable. Therefore, Group F is the control group for experimental Group C.
Want to see more full solutions like this?
Chapter 1 Solutions
Biology: The Unity and Diversity of Life (MindTap Course List)
Additional Science Textbook Solutions
Human Anatomy & Physiology (11th Edition)
Campbell Essential Biology with Physiology (6th Edition)
Essentials of Human Anatomy & Physiology (12th Edition)
Human Physiology: An Integrated Approach (7th Edition)