Life Lines by Dr. Dolittle

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Some organisms self-destruct after reproduction

Most mammals are iteroparous, meaning they can undergo multiple cycles of reproduction and gradually advance in age. In stark contrast, semelparous species only reproduce once before they die, as the physiological toll of mating is quite high. Examples of semelparous species include Pacific salmon, which swim upstream where they die after spawning, thus becoming nutrients for their own offspring and the environment. By only 10 months of age, male kalutas […]

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Males are not always bigger…unless they are northern elephant seals

A new study published in Nature Communications challenges the popular notion that males are usually bigger than females – at least in mammals. Their findings are consistent with Dr. Katherine Ralls who also challenged this idea in the late 1970s. In this new study, researchers looked at data collected for 429 species of animals. Rather than using averaged values from the literature, they turned to large-published datasets that included values […]

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Gray wolves living within the Chernobyl Exclusion Zone develop cancer resilience

Like humans, dogs are at risk of spontaneously developing cancer as they age. In fact, cancer is the leading cause of death for dogs (Gardner et al., 2016). Research suggests that dogs may better model cancer than rodents because the disease progression is similar to humans including involvement of the immune system, molecular pathways, variations between animals, tumor resistance to chemotherapy, and metastasis (Gardner et al., 2016). Thus, understanding and […]

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Role of sphingolipids in metabolic syndrome

Sedentary horses, like humans, have an increased risk of developing metabolic syndrome characterized by obesity and abnormal elevations in insulin concentrations (hyperinsulinemia). Insulin is a hormone released from the pancreas that is responsible for lowering blood sugar after a meal by promoting the uptake of glucose into tissues. People and animals with insulin resistance are not able to respond normally to the hormone resulting in high blood sugar.    Sphingolipids […]

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New research shows that muscles in hibernating animals consume energy

Hibernation allows animals to reduce their energy needs during winter, when food may be scarce and high amounts of energy would be required to maintain body temperature. These animals prepare for winter by storing body fat that can be used as fuel during hibernation. Skeletal muscles in particular have high energy needs as they make up nearly half of an animal’s body mass. They also play important roles in regulating […]

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Let’s stop lactate-shaming

As wisely stated in an editorial by Dr. George Brooks, UC Berkeley (2001), “Nature is smarter, and things are more complex than we mortals imagine.” Sure lactate is produced during exercise and is often blamed for causing muscles to fatigue, but there is much more to the story. In fact, research has shown that lactate plays many important physiological roles in the body such as serving as a metabolic fuel […]

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Roses are red, violets are blue, beluga whales and dolphins have higher carbon monoxide than you

The lifespan of a red blood cell (RBC) in a healthy human is about 120 days and approximately 200 billion red blood cells (RBCs) are replaced every day in healthy adult humans! Most (80%) of the carbon monoxide produced in humans comes from the breakdown of heme which is released when these red blood cells (RBC) are broken down through normal homeostatic processes. Sickle cell anemia shortens the lifespan of […]

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Improving the health of fish exposed to arsenic and increasing environmental temperatures

Speaking of stress…scientists at the ICAR – National Institute of Abiotic Stress Management in India are exploring the use of dietary copper to help reduce stress and improve the health of fish exposed to environmental pollutants such as arsenic. Copper is an essential element for animals and humans. It is involved in bone formation and growth, nervous system function, metabolism, immune system function, and antioxidant production.1 Warming aquatic temperatures are […]

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Study examines how statin exposure affects cholesterol metabolism in fish

Despite its bad reputation, cholesterol serves many important functions in the body. It is necessary for normal cell structure and is a precursor for the formation of steroid hormones, vitamin D, and bile acids. Too much “bad” cholesterol (LDL), however, can promote cardiovascular diseases and nonalcoholic fatty liver disease. For this reason, many animals tightly regulate cholesterol levels in the body. Fish often have higher cholesterol levels than humans and […]

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Is it just a fluke?

Lung flukes, Hematoloechus sp., are pesky little parasites. Up to 89 species of lung flukes have been identified to date. Their life cycle includes two intermediate hosts, the first of which are freshwater snails that swallow fluke eggs. After ingestion, the eggs hatch and produce a larval form of the parasite called cercaria, which are shed from the snails and taken up by damselflies or dragonflies. These are quite the […]

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