Prompt 1: Biological Mechanisms Against Cold

On pages 33-34, Dr. Moalem describes a rapid plunge in temperatures that occurred roughly 12,000 years ago, known as Young Dryas. During this time, average yearly temperatures dropped a tremendous 30 degrees, causing a sharp decline in human population. This prompted the question: what allowed survivors to withstand these extreme frigid conditions of Young Dryas? Dr. Moalem explores the biological mechanisms utilized by living organisms to cope with cold. This concept correlates with Big Idea 2: Biological systems utilize free energy and molecular building blocks to grow, reproduce, and maintain dynamic homeostasis because this is an example of living organisms responding to changes in their environment, in this case temperature decrease, and using various defense mechanisms in order to maintain internal conditions suitable for survival.

 

For "common" people, what are the body's defense mechanisms against cold? Compare these mechanisms to the mechanisms of people accustomed to cold climates. Which are more effective and why?

Describe the benefits of high sugar concentration and water loss to cold resistance in grapes and wood frogs. Based on these ideas, what are the characteristics of diabetes that may have allowed diabetics during Young Dryas to survive?

Brown fat tissue (AKA Brown adipose tissue/ BAT) is briefly described on pages 36 and 37 as a tissue that generates and preserves heat. BAT's functions prove that BAT is a useful mechanism against cold, but some experts also believe that these functions could make BAT an effective treatment for obesity and diabetes. Conduct further research regarding brown fat. Consider the following questions: What organelle is brown fat rich in? What is BAT's relation to glucose metabolism? Where is BAT located? How is it activated? etc. Based on your findings, do you think that BAT is a viable solution for the common conditions of obesity and diabetes?

(Michelle Liang, mliang4@students.d125.org)