Life Lines by Dr. Dolittle

Sponsored by the American Physiological Society

Environment

Day 1: Experimental Biology 2021

I attended a really great session this afternoon on the Evolutionary Physiology of Locomotor Behavior: Causes, Consequences, and Mechanisms.   The session started with a talk by Dr. David Raichlin from the University of Southern California who spoke about locomotion from a human perspective. He described how locomotion is not only essential for the survival of species, but also provides benefits for the aging brain. It was fascinating to learn […]

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Surviving the cold

The ability to regulate body temperature is critical for animals. This is especially true for small mammals as they have a larger surface area resulting in more heat loss to the environment than larger animals. Animals that stay active during the winter likewise have to spend more energy to stay warm. To do this well, they need to balance heat loss with heat generation through shivering as well as non-shivering […]

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Extreme tolerance of dehydration stress

Talk about an extreme animal. During the rainy season annual killifish, Austrofundulus limnaeus, lay eggs that are resistant to droughts. This is an important attribute for a fish that lives in temporary pools of water. The stress-resistant embryos within the eggs literally shut down their metabolism to survive months – possibly years without water. For many fish, exposure to air (and oxygen) can cause profound oxidative stress. Remarkably, this is […]

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Anoxia tolerance in goldfish

The reason mammals are not very good at tolerating hypoxic (i.e. low oxygen) environments, is because the brain relies heavily on oxygen for metabolism. It is so stingy, it uses about 20% of the oxygen in the body to make ATP. Without oxygen, the brain has to rely on glycolysis to make ATP and this process is not good at meeting the energy requirements of the neurons, ultimately resulting in […]

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Metabolic costs of reproduction, eating, and increasing temperatures

Planarians are rather cute little flatworms, although they tend to wreak havoc in fish tanks. Researchers have long been fascinated by their ability to regenerate body parts when injured with the help of adult stem cells. More recently, they have gained attention for their ability to survive long periods of time without eating by “degrowing”, i.e. getting smaller but still keeping their shape and functions intact. I would shrink too […]

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Top New Species in 2020

I think most of us can agree that we are delighted to see the end of 2020. As we say good riddance and look forward to a brighter future, I thought it would be fun to consider one of the positive aspects of this past year by taking a peek at some of my favorite newly discovered or described species in 2020. Achalinus zugorum While there are many species of […]

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Extreme Fasting

While giant pandas roll in horse manure to stay warm in the winter (that’s a different story), other animals spend up to 8 months hibernating to conserve energy during times of reduced food availability and freezing temperatures. During their long winter’s nap, animals such as the Arctic ground squirrel and 13-lined ground squirrel go without food or water while at the same time avoiding muscle wasting – a rather impressive […]

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Staying warm on a chilly day

Giant panda bears have a very unusual trick to staying warm. This unusual behavior was first noted by scientists at the Chinese Academy of Sciences in Beijing who observed a giant panda rolling around in horse manure in the Qinling mountains in central China during the winter of 2007. To see whether this was just a rogue panda or a more common behavior, scientists set up camera traps and observed […]

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Long sperm, short sperm, fast sperm, slow sperm

I read an interesting review published in Physiology that examined how sperm from different species are especially evolved to help promote fertilization, which if successful, results in the creation of an offspring. It is simply amazing to think of the multitude of ways this process occurs in nature. Take marine invertebrates and fish for example. These animals release eggs and sperm into the water. In contrast, fertilization happens internally in […]

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Live fast, die young

Researchers have long known that smaller animals have higher metabolisms and tend to die younger than larger animals. Think about it – a mouse typically only lives about 2 years whereas an elephant in the wild may live 50-70 years, depending on the species. After studying over 700 species of birds and 540 species of mammals, scientists discovered that migratory animals also live faster (mature and reproduce earlier) and die […]

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