Life Lines by Dr. Dolittle

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Tag Archive for ‘evolution’

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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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The evolution of sugar addiction

I have been opening Christmas cards and pondering the science of sugar addiction, admittedly while snacking on sugar cookies – ‘tis the season after all! Excess consumption of highly palatable (i.e. quite tasty) foods as well as sedentary lifestyles are thought to be at the root of the current obesity epidemic. In fact, it is thought that as many as 30% of people living in developed countries are either overweight […]

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Evolution of pain resistance

Could you imagine eating a pile of chile peppers or spicy hot mustard and not feeling any pain? The ability to sense pain is physiologically quite important as it alerts us to potentially dangerous or poisonous chemicals. Many plants (stinging nettles, pungent bulbs, hot chilies) and animals (stinging ants, scorpions, snakes) produce noxious chemicals to protect themselves from predators. In turn, some predators have evolved resistance to these chemicals. An […]

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Evolving to thrive on land

Scientists Xueping Wang, Deidra M. Balchak, Clayton Gentilcore, Nathan L. Clark, and Ossama B. Kashlan from the University of Pittsburgh are presenting their research today on how sodium channels evolved as animals moved onto land at the 9th Aldosterone and ENaC in Health and Disease: The Kidney and Beyond Conference in Colorado. Sodium channels found in epithelial cells (ENaCs) are very important in regulating salt and water balance especially in the […]

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Breathing air

Researchers interested in the evolution of air breathing in bony fishes (Osteicthyes) recently published a fascinating review in the Physiologist. The ability to breathe air made life on land as we know it possible. What is interesting though is that the ability to breathe air actually evolved independently possibly 38-67 times in history. Currently, there are over 400 air-breathing fishes belonging to the Sarcopterygii and Actinopterygii classes. To adapt to life on land, […]

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Importance and dangers of oxygen for air-breathing animals

Although oxygen is essential for air-breathing species and allowed for the evolution of multicellular organisms, it is also a dangerous molecule that can lead to cellular toxicity through the generation of reactive oxygen species (ROS). However, it is important to point out that cellular ROS also play several physiological roles in the body. I just read an interesting review article published in Physiological Reviews that explored natural oxygen delivery and availability […]

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Fish offer clues to fixing broken hearts

About a year ago we talked about how Mexican tetra (Astyanax mexicanus) may hold the clues to treating diabetes. New research shows that is not all these tiny fish can teach us. Researchers at the University College London and the University of Oxford now think these fish may hold clues to regenerating damaged heart tissue. Their findings were published in Cell Reports. Mexican tetra are freshwater fish. Over millions of years, […]

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Green-blooded lizards

Researchers have known that some lizards have green blood due to bile pigments: In fact, six species of lizards found in New Guinea are known to have green blood. The levels of bile found in their blood are four times higher than the toxic level for humans. New research shows that green blood evolved independently 4 times in evolutionary history. These findings suggest that high levels of circulating green bile […]

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Environmental impact on physiology

Several of the comparative physiology posters and talks presented at the Experimental Biology conference today focused on the impact of environmental changes on the physiology of animals. Here are some highlights: Rachel Heuer, a postdoctoral fellow at the University of Miami working with Dr. Martin Grosell, examined the effects of crude oil on heart function in mahi-mahi. As the Deepwater Horizon spill occurred when these fish were spawning, it is […]

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