Life Lines by Dr. Dolittle

Sponsored by the American Physiological Society

Nature’s Solutions

Shape-shifting animals adapting to climate change

A recent review of the existing scientific literature found evidence suggesting that warm-blooded animals may be literally shape-shifting to adapt to climate changes. According to Allen’s rule, animals living in warmer climates have larger appendages than those living in cold climates, which helps increase the available surface area for heat loss to the environment. Such heat exchange mechanisms are very important in thermoregulation to avoid retaining excess heat. The authors […]

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Tenrecs may shed light on the evolution of body temperature regulation

The common tenrec (Tenrec ecaudatus) just may be a living representative of ancestral placental mammals and they are very interesting when it comes to body temperature regulation and torpor. Torpor is a complex series of physiological changes that reduce an animal’s physical activity as well as heart, breathing and metabolic rates, which also results in decreases in body temperature than can be as low as their surrounding environment. Many mammalian […]

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High altitude survival and adaptation

Life at high altitude presents unique physiological challenges for organisms that were explored in a recent review published in the American Journal of Physiology – Regulatory, Integrative and Comparative Physiology. For placental mammals, offspring born at high altitude (>2500 m above sea level) typically weigh less at birth compared to lowland animals. Fetal growth restriction is problematic as it is associated with long-term health risks and reduced survival. It is […]

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Oddity of mammalian red blood cells

Mammalian red blood cells do not have a nucleus, which is different from birds, amphibians, reptiles, and fish (see image above). Many textbooks report that the absence of a nucleus provides room for more hemoglobin within the cells, which is important to fuel the relatively high metabolic rates of mammals. Hemoglobin is an important oxygen-binding molecule that allows the red blood cells to transport oxygen to tissues throughout the body […]

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What can hibernators teach us about obesity? Q&A with Dr. Courtney Kurtz, University of Wisconsin

We are pleased to talk with Dr. Courtney Kurtz, Associate Professor of Biology at the University of Wisconsin, Oshkosh about her research on hibernation and how her research might lead to treatments for obesity. Ground squirrels are a natural model organism for many physiological processes. Can you tell us why you use ground squirrels in your research?  ​Ground squirrels are hibernators.  They spend the majority of the winter in a […]

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Can lobsters lead us to the proverbial ‘Fountain of Youth’?

When thinking about lobsters, some people may think of: Aside from being a favorite menu item, did you know that American lobsters (Homarus americanus) are one of the largest bottom dwelling (i.e. benthic) invertebrate in the ocean? In fact, they seem to be able to grow indefinitely and have been observed to reach over 1 meter in length? For this reason, scientists suspect they may be a rather long-lived species […]

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A whale shark’s superpower: Healing

Da-dum, da-dum…that’s right! Shark week is back!! It starts tonight on Discovery channel. Grab some popcorn, it’s going to be a wild ride! To kick off the week in our own way, I found this interesting study that examined wound healing in whale sharks, the world’s largest fish. These animals often exhibit scars resulting from collisions with boats and new research shows they have impressive wound healing capabilities. In the […]

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Q&A with Dr. Jon Harrison, Meredith Johnson, and Jordan Glass

We recently interviewed Meredith Johnson (graduate student), Jordan Glass (graduate student), and Dr. Jon Harrison from the School of Life Sciences at Arizona State University about the research they presented at the 2021 annual Experimental Biology conference.   Q: You mentioned in one of your presentations that insects have an ‘unusual’ respiratory system. Can you explain how it differs from mammals?  Dr. Harrison: Insects exchange gases through blind-ended air-filled tubes called tracheae. There […]

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Why shrews don’t need sweaters

Research presented by Dr. Tobias Fromme (Technical University of Munich) and colleagues at the 2021 Experimental Biology conference shows that Etruscan shrews (pictured above) have a rather large amount of fat located between their kidneys, which is close to their major blood vessels. This fat depot is a mixture of both brown and beige adipose tissue and is thought to help generate metabolic heat to keep these tiny mammals warm […]

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Extreme Physiology of Diving

Can you imagine what would happen to your body if you dove up to 1700 meters deep in the ocean for an hour and a half, or experienced months of food deprivation? In the case of deep diving, the high pressure causes the collapse of the lungs of terrestrial mammals (including humans!) and depletion of body oxygen stores, whereas long fasting periods compromise health and induce muscle wasting. Northern elephant […]

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