Temperature regulation is a crucial function in every organism on the planet. For most modern day humans, regulating temperature can be as simple as turning the A/C up when you’re warm or putting on socks if you’re cold. For other organisms it can be a little more complicated. Many different things can affect temperature in organisms and how they regulate temperature, some of these things include: body size, habitat, shape, climate, and behavior. There are two different classifications of organisms based on how they regulate temperature- endotherms and ectotherms. Endotherms in general are larger than ectotherms, have some form of insulation, and have a higher metabolic rate than ectotherms. In turn ectotherms are generally small, tend to have no form of insulation or very little, and exchange heat with their environment. To put the difference in simple terms: endotherms can regulate their body temperature without much influence from their environment (examples would be humans and birds), whereas ectotherms rely on their environment and other outside factors to regulate and maintain their body temperatures (common examples are snakes and lizards).

In our Ecology lab this past week we took a look at thermoregulation. Unlike labs we have done in the past, we had more freedom with our lab activity. The entire lab was investigating how environmental factors affect an animal’s ability to heat and cool. We teamed up in pairs to come up with a hypothesis to test.  In order to test the class’s hypotheses we didn’t use live animals, instead we made our own animals out of aluminum foil. We decided to test how insulation affects thermoregulation. I chose these factors to study because understanding how temperature affects endotherms and ectotherms could possibly help with future understanding in my studies of how climate change could impact the different regulators. In general, scientists focus on ectotherms more than endotherms when looking at how temperatures impact organisms. There is, in fact, considerable variation in the ability of endotherms to tolerate high body temperatures and/or high environmental temperatures, but a better understanding of this variation will likely be critical for predicting responses to future climatic scenarios. (Boyles, Justin G., et al.)

My lab partner, Jessie, and I came up with the hypothesis: Animals with insulation will warm faster and maintain heat longer than animals without any form of insulation. In order to test our hypothesis, my lab partner and I each created an animal to test- one with “fur” (aka cotton balls) and the other without. Thus, Alpaca vs. Jellyfish was born. It may sound like a cheesy sci-fi movie on Netflix, but it was a very serious experiment by two very serious science students.

            VS.             

(Photo credit: me)

The photos above show the Alpaca (handcrafted by yours truly) and the Jellyfish (sculpted with love by my lab partner). The alpaca represents the endotherm with cotton balls used as fur/insulation and the jellyfish represents the ectotherm without any form of insulation. Before we could properly test our hypothesis on these two, we had to create a cooling curve to compare our animals to. In order to do that we first made a hollow cube of aluminum foil and stuck a thermometer inside of it and then placed it under a heating lamp. We measured the starting room temperature in degrees Celsius (it read at 21 degrees Celsius) and then checked back in with the thermometer every five minutes until the temperature leveled off. Once the temperature was staying constant, we turned off the lamp and repeated watching the thermometer at five minute intervals until it cooled off and leveled off. Once we had our curve set, then we could start testing our animals. The jellyfish went first.

The graph above depicts the heating and cooling curve as set by our control of the aluminum foil cube.

The starting room temperature recorded at 24 degrees Celsius. When we started the control experiment the room temperature was at 21 degrees Celsius. My lab partner and I believe that the slight raise in temperature is due to the fact that there around twelve different heating lamps on in the room. Like with the aluminum cube, we stuck the thermometer inside the jellyfish to record the temperature. Instead of five minute intervals we checked the thermometer every two minutes for the animals. We changed the time intervals because we felt at five minutes apart did not let us see very significant changes in temperature. Checking every two minutes gave us more precise data. After ten minutes, the temperature had leveled off at 36 degrees Celsius. After that, we turned the heating lamp off and observed the temperature drop for another ten minutes.

Once we had recorded the data for the jellyfish we took the thermometer out to let it go back to room temperature. Once it was back at 24 degrees Celsius, we stuck it inside the Alpaca and turned the lamp on again. Like with the jellyfish, we checked the thermometer at two minute intervals to monitor how fast the aluminum animal heated up. After ten minutes the temperature leveled off at 46 degrees Celsius. Again, we turned off the lamp and checked in every two minutes to see how long it took the alpaca to cool.

After we collected both sets of data, we sat down to compare. To remind everyone, our hypothesis was: Animals with insulation will warm faster and maintain heat longer than animals without any form of insulation. The highest temperature the jellyfish got to in our test was 36 degrees Celsius, the highest the alpaca got to was 46 degrees Celsius. The alpaca got ten degrees warmer than the jellyfish which could prove our hypothesis true. We still had to compare how long the animals maintained heat to be sure. After two minutes of cooling time, the jellyfish’s temperature dropped from 36 Celsius to 28 degrees Celsius. After six minutes the temperature dropped to 24 Celsius and stayed that way for the remainder of the time observed. The alpaca rose to a high temperature of 46 celsius. After two minutes it dropped down to 38 degrees Celsius, then after six minutes went down to 27 degrees Celsius. So the alpaca warmed faster, got hotter, and maintained heat longer. Because of this, our hypothesis was tested to be true. In order to be completely sure we could repeat this experiment several more times with the same animals and different animals as well. Our results weren’t that surprising because it was what we were expecting. From our basic background science knowledge we figured that fur or other types of insulation would help an organism maintain it’s body heat.

For the last part of our lab assignment, we had to read two articles on thermoregulation in monkeys. One article from researchers at the University of Lincoln  focus on how some breeds of monkey huddle together to help regulate body heat. Some benefits of this include a higher survival rate in winter based in the population studied. The higher survival may possibly be helped by the fact that huddling for warmth requires less energy spent to regulate heat. The second article comes from researchers from the University of Sydney. Their research shows that monkeys in the mountains in China consume more fats and carbohydrates in the winter than in the spring. Though not the same subjects exactly as my endotherm and ectotherm research, the monkey studies relate to mine in that they have to do with endotherms. With the University of Sydney, their research on fats and carbs could relate to mine in that fats and carbs help with additional insulation of an animal, therefore allowing them to maintain heat better.

 

References:

Boyles, Justin G., et al. “Adaptive Thermoregulation in Endotherms May Alter Responses to Climate Change.” Integrative and Comparative Biology, vol. 51, no. 5, 2011, pp. 676–690., doi:10.1093/icb/icr053.

University of Lincoln. “Huddling for survival: monkeys with more social partners can winter better.” ScienceDaily. ScienceDaily, 30 May 2018. <www.sciencedaily.com/releases/2018/05/180530113118.htm>.

University of Sydney. “Monkeys eat fats and carbs to keep warm: Golden snub-nosed monkeys adjust nutrient intake in winter.” ScienceDaily. ScienceDaily, 8 June 2018. <www.sciencedaily.com/releases/2018/06/180608093646.htm>.