Authors: Sydney Quinn Chizmeshya and Katherine E. Brent
Sources: Adapted from Doris Hexsel et al. 2010. Recommendations for Performing and Evaluating the Results of the Minor Test According to a Sweating Intensity Visual Scale. Dermatologic Surgery.
Adapted from Sigfrid A. Muller and Robert R. Kierland. 1959. The Use of a Modified Starch-Iodine Test for Investigating Local Sweating Responses to Intradermal Injection of Methacholine. Journal of Investigative Dermatology.
Time needed: 30 - 40 minutes
Supplies Needed
Timer
Cold source (e.g. ice cubes, cold pack)
Heat source (e.g. hair dryer, hand warmers)
Blank paper cut into small squares of 3x3 cm (4 per group)
Cotton balls (24 per group)
Rubbing alcohol
Iodine
Cornstarch
Student worksheet (attached)
Readings
Fitzpatrick, Leslie. 2019. Chapter 14: Human Variation: An Adaptive Significance Approach. Explorations.
Introduction
This lab allows students to experience thermal stressors on a small scale so as to observe the benefits of and physical reactions associated with thermoregulation and homeostasis. Furthermore, this activity will allow the students to explore the nuances of “adjustments” and “adaptations,” as defined in Chapter 14 of Explorations. The lab includes two scientific procedures: the Minor Test (which is qualitative), and Randall’s Modification to the Minor Test (which is quantitative).
Steps
Organize the class into small groups (consisting of 4 or 5 students). Each group should have the following materials:
Timer
Cold source (e.g. ice cubes, cold pack)
Heat source (e.g. hair dryer, hand warmers)
Blank paper cut into small squares of 3x3cm (4 per group)
Cotton balls (24 per group)
Rubbing alcohol
Iodine
Cornstarch
Student worksheet(s) (attached)
Students will follow the directions on their worksheet to complete the activity. This laboratory exercise consists of four experiments, and each experiment should be undertaken by a different individual in the group, and then discussed among group members.
1. Heat stress exposure
2. Cold stress exposure
3. Exercise/heart rate increase exposure
4. A control exercise with no stressor.
When the activity has been completed, reunite the class for a discussion based on the review questions below.
Review Questions
What do the dots on the paper pressed to the left palm represent? (Answer: the dots quantify the activation of sweat glands.)
What does a color change on the right palm represent? (Answer: the color change is a qualitative measure of the activation of sweat glands.)
What does sweating accomplish for the body? (Answer: Sweating is the body’s attempt to lower overall body temperature and maintain homeostasis.)
What does shivering accomplish for the body? (Answer: Shivering is the body’s attempt to raise overall body temperature through heat generation to maintain homeostasis.)
How is body temperature regulated in humans? (Answer: The hypothalamus, a small part of the brain, regulates body temperature.)
What are the differences between “adjustments” and “adaptations” in relation to human evolution? (Answer: Adjustments can be behavioral, acclimatory, or developmental, and occur exclusively at the individual level. Adjustments are non-genetic coping mechanisms used to face environmental stressors. They are temporary in nature. On the other hand, adaptations are genetic and micro-evolutionary, permanent in nature, and occur at the population level.)
Why do we turn paler in response to cold, and redder in response to heat? Is this an example of an adaptation or an adjustment? (Answer: Paleness is a result of vasoconstriction and redness is a result of vasodilation. These are examples of adjustments.)
Adapting for Online Learning
Rank how adaptable to online learning it would be: Possible to adapt
With clear directions students could complete the experiment in their home, though they may need to purchase some supplies. Additionally, using heat and cold sources irresponsibly could be dangerous, so instructors should provide cautions. Instructors could alternatively record a short video showing the experiment for students to watch and reflect on at home.
Fitzpatrick, Leslie. 2019. “Chapter 14: Human Variation: An Adaptive Significance Approach.” In Explorations: An Open Invitation to Biological Anthropology, edited by Beth Shook, Katie Nelson, Kelsie Aguilera, and Lara Braff. Arlington, VA: American Anthropological Association.http://explorations.americananthro.org/
Hexsel, Doris, Ticiana C. Rodrigues, Mariana Soirefmann, and Debora P. Zechmeister-Prado. 2010. “Recommendations for Performing and Evaluating the Results of the Minor Test According to a Sweating Intensity Visual Scale.” Dermatologic Surgery, 36(1): 120-122.
Muller, Sigfrid A., and Robert R. Kierland. 1959. “The Use of a Modified Starch-Iodine Test for Investigating Local Sweating Responses to Intradermal Injection of Methacholine.” Journal of Investigative Dermatology 32(2): 126-128.
