Rocks Kept in a Warehouse For Decades Held a Major Clue to Complex Life

21 May 2026, ByM. Lechte & L. A. Riedman, The Conversation

https://www.sciencealert.com/rocks-kept-in-a-warehouse-for-decades-held-a-major-clue-to-complex-life

Delicate microfossils were preserved in deeper rock layers. 

(UC Santa Barbara)

Stored in an open-air warehouse in tropical Darwin, Australia, are dozens of trays containing cylindrical cores of rock.

They are from drill holes bored hundreds of meters below the surface by mineral exploration companies decades ago.

Some of these cores at the Northern Territory Geological Survey are mudstone – a type of sedimentary rock formed from hardened seafloor mud.

The companies that drilled these cores were largely unaware that within these mudstones were fossils of microscopic organisms buried on the seafloor of an ancient inland sea that covered much of northern Australia over 1.5 billion years ago.

As our new study, published today in Nature, shows, these fossils are crucial for addressing a longstanding puzzle about the major evolutionary leap that led to all complex life on Earth: the origin of eukaryotes.

Layers of 1.7 billion-year-old sedimentary rocks, Kakadu National Park, Northern Territory.

(Maxwell Lechte)

Small but complex

All life on Earth can be placed into one of two types, which are fundamentally different at the cellular level.

Prokaryotes (bacteria and archaea) have simple cellular organization and are mostly single-celled.

Eukaryotes – including all animals, plants, algae, and fungi – are very different. They have much more complicated cells featuring a nucleus and other specialized structures such as organelles, which perform specific jobs.

The eukaryotic revolution transformed the planet. It led to the rise of animals and, eventually, to us.

Based on observations from the genes of living organisms, it is now widely agreed that the last common ancestor of all living eukaryotes resulted from the symbiotic union of (at least) two prokaryotic microbes: an archaeon and a bacterium.

The first evidence for eukaryotic life comes in the form of these fossils of single-celled organisms. They show a level of cellular complexity not seen among prokaryotes, but common in eukaryotes.

Drill cores of sedimentary rock containing microscopic fossils. 

(Maxwell Lechte)

Eukaryote fossils can be found around the world in rocks dating back at least 1.5 billion years. The fossils of the Northern Territory, the oldest of which date back to 1.75 billion years ago, are the oldest currently known eukaryote fossils globally.

But the ancient world in which early eukaryotes evolved remains shrouded in mystery. And so many fundamental aspects regarding their nature are unknown.

Oxygen – friend or foe?

Many types of bacteria can live and grow in places without oxygen. But nearly all eukaryotes alive today use oxygen for their survival.

That's because aerobic respiration – breaking down food using oxygen – provides the vast amounts of energy that complex life demands.

But the idea that oxygen has always been beneficial for all eukaryotes has come under fire in recent years. This follows the surprising discoveries of enigmatic eukaryotes that can thrive in conditions without oxygen.

Fossils of single-celled eukaryotic organisms with complex surface features, such as extensions and plates. 

(Leigh Anne Riedman)



There is also mounting evidence from the geological record that when eukaryotes were first evolving, oxygen was likely much scarcer.

This means oxygen-free marine habitats would have been the norm.

Collectively, these observations have called into question the assumption that eukaryotes have depended on oxygen since their inception.

Genetic studies of living microbes belonging to groups considered closest to the ancestors of the first eukaryote can offer key insights into eukaryote ancestry.

But only the fossil record can tell us about long-extinct lineages.

And only geology can offer a window into the kind of world these organisms lived in.

Delicate microfossils don't last when exposed to the surface. But they remain preserved in deeper rock layers.

 (UC Santa Barbara)

More than 12,000 fossils

For our new study, we crushed up samples of the mudstone cores stored in Darwin, then dissolved them. We identified more than 12,000 fossils by analyzing the organic residue left behind by this dissolution under a microscope.

We also studied the mudstones the fossils were preserved in to better understand what the environment was like when the sediments were deposited.

This offered insight about the habitats in which these eukaryotes lived. And by analyzing the chemistry of these mudstones, we could determine whether oxygen was present in the ancient seawater.

Our results show that eukaryote fossils were found in environments ranging from coastal mudflats to the open sea. But they were present only in samples deposited in oxygenated settings.

Samples from oxygen-free environments contained only simple, prokaryotic forms.

This suggests that even the oldest known eukaryotes that lived on Earth 1.7 to 1.4 billion years ago were dependent on oxygen. These data lend support to a long-held hypothesis that oxygen played a key role in driving the evolution of early eukaryotes.

Resolving the drivers and context of the major evolutionary leap represented by early eukaryotes is one of the major outstanding questions in the life sciences.

Ongoing studies of these enigmatic, ancient microfossils will no doubt tell us more about our own origins – and our place in the cosmos.

The Life of Earth

https://chuckincardinal.blogspot.com/

Study Shows Meat Eaters Are More Likely to Live to 100, But There's a Catch

21 May 2026, By Carly Cassella

https://www.sciencealert.com/study-shows-meat-eaters-are-more-likely-to-live-to-100-but-theres-a-catch

(punhha/Canva)

Humans are living longer than ever before. By 2050, scientists predict that nearly half a billion people could be older than 80.

The rise in human life expectancy is partly due to improvements in nutrition, but which food choices lead to the longest and healthiest outcomes in older age?

Scientists are still trying to figure that out.

In younger cohorts, some particular diets are associated with years of added life, especially those focused on whole, plant-based foods and healthy fats.

But meat choices are more controversial, and they typically come with a catch.

A study from China has now added another wrinkle to the research. Among more than 5,000 people aged 80 and over, researchers found that female meat eaters were more likely to reach age 100 than female vegetarians.

There was no significant association between longevity and vegetarianism among males, when the researchers analyzed the data by sex.

Before you go sending this article to every female vegetarian you know, you should stay for the nuance.

It was only vegetarian participants deemed underweight who were less likely to live to 100 than meat eaters.

"Daily consumption of meat was associated with a 44 percent higher likelihood of reaching 100 years old [compared to a vegetarian diet] in the underweight group, whereas this association did not present in the normal weight or overweight group," the study authors conclude.

(Ella Olsson/Pexels)



What's more, vegetarians who ate fish, dairy, or eggs had a similar chance of reaching 100 as meat eaters.

This suggests that older female adults who eat enough calories and essential nutrients may increase their odds of becoming a centenarian.

The findings support recent research that suggests protecting muscle mass by eating protein is vital to healthy aging.

The new data come from one of the largest studies on older adults anywhere in the world: the Chinese Longitudinal Healthy Longevity Survey (CLHLS).

Researchers at Fudan University, the Chinese Center for Disease Control and Prevention, and Shanghai Jiao Tong University compared the outcomes of 1,459 centenarians with those of 3,744 non-centenarians in their 80s and 90s.

The team found that body mass index (BMI) partly explained the association between vegetarianism and shorter life expectancy.

Given that older populations are more likely to be underweight, the authors suggest that the role of BMI in longevity is "worth exploring" further.

The "obesity paradox", for instance, is a term that describes how more body weight seems to be associated with better health outcomes in older populations. This is the opposite of what is found in younger populations.

The centenarian study in China can only reveal associations, which means it's possible that other factors are impacting the results.

The study, for instance, doesn't account for how eating habits might change over time; the surveys only assessed what participants ate in their later years, and that may be influenced by how easy the foods are to chew.

Previous research, however, supports the idea that lifestyle choices, such as diet, could be major reasons why some people live to 100.

In fact, by some estimates, reaching age 90 can be explained by 70 percent healthy behaviors, such as sleep, physical activity, or diet.

Diet is not the only factor that has been linked to longer lifespans.

(Ruben Bonilla Gonzalo/Getty Images)



It's possible that older adults may have different nutritional needs, yet many studies on vegetarianism focus on younger cohorts.

One study of more than 65,000 people, young and old, found that those who eat a vegetarian diet may face a higher risk of fractures, possibly due to lower calcium and protein intake.

In fact, some evidence shows that older people require more dietary protein than current guidelines suggest.

Nutrition, however, is an extremely complex area of research, and health outcomes can be influenced by a plethora of societal, environmental, and individual factors.

In all probability, the best food choices for extending life require diversity and balance, differing from person to person.

Vegetarian diets, plant-based diets, and low-meat diets have been linked to lower risks of certain health issues, such as heart disease, stroke, type 2 diabetes, and obesity.

Still, not all meat is equally associated with negative health outcomes, and the amount can matter. Processed meats and red meat, for instance, are often linked to poorer health and shorter longevity, which is why they are generally recommended to be eaten in moderation.

"Our findings emphasized the importance of a balanced diet from both animal- and plant-derived food for healthy longevity," write the team.

"Future studies focusing on older adults of advanced age are needed for the formulation of dietary guidance."

The Life of Earth

https://chuckincardinal.blogspot.com/

The Type of Alcohol You Drink Could Affect How Long You Live

By American College of Cardiology, May 21, 2026

https://scitechdaily.com/the-type-of-alcohol-you-drink-could-affect-how-long-you-live/

Low to moderate wine consumption was linked to a lower risk than drinking spirits, beer, or cider. 

Credit: Shutterstock

Researchers analyzing more than 340,000 adults uncovered an intriguing pattern linking alcohol type with long-term health outcomes.

For decades, scientists have debated whether some alcoholic drinks are “healthier” than others. While heavy drinking is widely known to raise the risk of serious diseases and early death, the effects of lighter drinking have remained far less clear — especially when it comes to wine, beer, cider, and spirits.

Now, a major study involving more than 340,000 adults in the United Kingdom suggests that the type of alcohol people drink may influence long-term health outcomes at low to moderate levels of consumption. The findings, presented at the American College of Cardiology’s Annual Scientific Session (ACC.26), add new nuance to growing evidence that when it comes to alcohol and health, both quantity and beverage choice may matter.

“These results come from the general population, and in certain high-risk groups, such as people with chronic diseases or cardiovascular conditions, the risks could be even higher,” said Zhangling Chen, MD, PhD, a professor at the Second Xiangya Hospital, Central South University in China and the study’s senior author.

Beverage type changed the picture

Researchers examined drinking patterns and mortality outcomes for 340,924 adults who took part in the UK Biobank study from 2006 to 2022. When participants joined the study, they completed a dietary questionnaire and were assigned to one of four alcohol intake groups based on grams of pure alcohol consumed per day and per week.

For comparison, a 12 ounce beer, a 5 ounce glass of wine, and a 1.5 ounce serving of spirits each contain roughly 14 grams of pure alcohol. People who drank less than 20 g (about 1.5 standard drinks) per week were categorized as never or occasional drinkers.

Men who consumed between 20 g per week and 20 g per day, and women who consumed between 20 g per week and 10 g per day, were placed in the low alcohol group. Moderate intake was defined as 20 g to 40 g (about 1.5 to three standard drinks) per day for men and 10 g to 20 g per day for women. High intake was defined as more than 40 g (about three drinks) per day for men and more than 20 g (about 1.5 drinks) per day for women. Participants’ health outcomes were followed for an average of more than 13 years.

Wine diverged at lower intake

Compared with people who never drank or drank only occasionally, high intake drinkers had a 24% higher risk of death from any cause, a 36% higher risk of death from cancer, and a 14% higher risk of death from heart disease. At low and moderate intake levels, the pattern differed by drink type. Spirits, beer, and cider were associated with a significantly higher risk of death, while similar levels of wine intake were associated with a significantly lower risk of death.

For cardiovascular disease deaths specifically, moderate wine drinkers had a 21% lower risk of dying from cardiovascular disease than never or occasional drinkers. In contrast, even low consumption of spirits, beer, or cider was linked to a 9% higher risk of cardiovascular death compared with never or occasional drinking.

“Our findings help clarify previously mixed evidence on low to moderate alcohol consumption,” Chen said. “These findings can help refine guidance, emphasizing that the health risks of alcohol depend not only on the amount of alcohol consumed, but also on the type of beverage. Even low to moderate intake of spirits, beer, or cider is linked to higher mortality, while low to moderate intake of wine may carry lower risk.”

Lifestyle may shape the signal

Researchers said several explanations could help account for the different patterns seen by beverage type. Red wine contains compounds such as polyphenols and antioxidants, which may support cardiovascular health. Wine is also more often consumed with meals and by people who tend to have higher-quality diets and healthier overall habits. Spirits, beer, and cider are more often consumed outside meals and were linked with lower overall diet quality and other lifestyle risk factors.

“Taken together, these factors suggest that the type of alcohol, how it is consumed, and the associated lifestyle behaviors all contribute to the observed differences in mortality risk,” Chen said.
Caution remains despite scale

The researchers adjusted their analyses for demographic factors, socioeconomic status, lifestyle factors, cardiometabolic factors, and family history of diabetes, cardiovascular disease, and cancer. Still, they noted that the work has built-in limitations because it is observational.

They said high-quality randomized trials would be useful for better understanding the effects of alcohol intake. Drinking habits were self-reported at the beginning of the study, and the analysis did not capture changes in alcohol consumption over time. UK Biobank participants also tend to be healthier than the broader population, which may limit how widely the findings apply.

Even with those limitations, the large number of participants and long follow-up period give the study substantial statistical strength. Researchers said the analysis offers a more detailed view of alcohol’s health effects than many earlier studies, with finer distinctions by drinking amount, beverage type, and different mortality outcomes.

The Life of Earth

https://chuckincardinal.blogspot.com/

Scientists Discover Metformin Doesn’t Work the Way We Thought

By K. Samuelson, Northwestern U., May 20, 2026

https://scitechdaily.com/scientists-discover-metformin-doesnt-work-the-way-we-thought/

Scientists discovered metformin mainly targets the gut, helping intestinal cells absorb excess glucose by slowing mitochondrial activity. 

Credit: Shutterstock



Scientists have uncovered evidence that metformin’s effects may begin in an unexpected place: the intestine.

For years, researchers believed metformin, the most widely used medication for type 2 diabetes, worked mainly by reducing glucose production in the liver. However, a new study from Northwestern University using mice suggests the drug’s primary target is actually the gut. Researchers found metformin lowers blood sugar by increasing glucose use in cells that line the intestine, helping prevent excess sugar from building up in the bloodstream.

Glucose is an essential source of energy for the body, but chronically high levels can contribute to insulin resistance and damage to blood vessels and organs. The study indicated that metformin reduces mitochondrial energy production in intestinal cells, forcing those cells to burn more glucose.

“Metformin essentially helps the intestine suck the glucose out of the bloodstream, which further highlights that the gut plays a major role in regulating blood sugar levels,” said corresponding author Navdeep Chandel, professor of biochemistry and molecular genetics at Northwestern University Feinberg School of Medicine.

The study was published in Nature Metabolism.

New Clues About How Metformin Works

The new findings build on earlier research from Chandel’s laboratory showing that metformin lowers blood sugar by blocking mitochondrial complex I, a critical component of the cell’s energy production system. The latest work identifies the intestine as the main tissue responsible for this effect. According to Chandel, the results suggest that targeting the gut with future drugs or supplements could become an effective way to control blood sugar.

A study co-author pipettes liquified metforming in the lab in Chicago.

 Credit: Kristin Samuelson, Northwestern University



Chandel is also the David W. Cugell, MD, Professor of Medicine (Pulmonology and Critical Care), Biochemistry and Molecular Genetics, and an investigator with the Chan Zuckerberg Initiative. The study’s lead author, Zach Sebo, is a postdoctoral fellow in the Chandel laboratory who will soon launch his own research group at the University of Kansas School of Medicine.

“Our study suggests that revisiting assumptions about metformin’s mechanism may offer a more detailed understanding of how it works,” Sebo said.

Berberine and “Nature’s Ozempic” Comparisons

The study also uncovered similarities between metformin and berberine, a plant-derived supplement commonly promoted for blood sugar control. Berberine has gained popularity online as “nature’s Ozempic,” although experts warn that evidence supporting its use remains limited and it should not replace approved medications. Researchers found that berberine appears to activate the same intestinal pathway as metformin.

“Metformin has decades of clinical evidence behind it, whereas supplements like berberine are far less rigorously tested,” Chandel said. “If you’re going to use berberine, you may as well use the real deal.”

Corresponding author Navdeep Chandel in his lab in Chicago.

 Credit: Kristin Samuelson, Northwestern University



Clinical Clues Reveal Metformin’s Gut-Driven Effects

The findings may also explain several well-known effects seen in people taking metformin. According to Chandel, patients using metformin often:Experience lower blood sugar after meals. Metformin makes the intestine act like a “sponge” that absorbs extra glucose.
Have lower levels of circulating citrulline, which is a compound produced only by mitochondria in cells of the small intestine. When metformin suppresses mitochondrial activity, citrulline production decreases.
Have increased levels of GDF15, a hormone linked to appetite suppression and weight loss. Scientists believe the gut responds to energy stress by releasing GDF15, which signals the brain to reduce food intake and adjust metabolism.

Engineered Mice Reveal Metformin’s Mitochondrial Mechanism

“People have always wondered how one drug can do 10 things,” Chandel said. “Well, it can do that if the drug is hitting a big node in a cell, and hitting mitochondria in a cell is a big node. So, if you can get into those cells and inhibit mitochondria, it’s going to have huge effects.”

To test the mechanism, researchers used genetically engineered mice that produced a yeast enzyme called NDI1. This enzyme mimics mitochondrial complex I but cannot be blocked by metformin. When NDI1 was expressed specifically in intestinal cells, those cells became resistant to the drug’s effects. In these mice, metformin lost much of its ability to lower blood sugar, providing strong evidence that blocking mitochondrial complex I in the gut is central to how the medication works.

The birth of modern Man

https://chuckincardinal.blogspot.com/

Exercise Changes the Heart in a Way Researchers Never Expected

By SciTechDaily.com, May 19, 2026

https://scitechdaily.com/exercise-changes-the-heart-in-a-way-researchers-never-expected/

Exercise may do far more than strengthen the heart and muscles. New research suggests regular aerobic activity can physically reshape the nervous system that controls the heartbeat, altering key nerve clusters differently on the left and right sides of the body. 

Credit: Stock

Researchers discovered that exercise changes heart-related nerve structures in surprisingly uneven ways.

Your workout may be changing your heart in ways scientists never realized. Beyond strengthening muscles and improving endurance, exercise appears to rewire the nervous system that controls the heartbeat itself, and it does so differently on the left and right sides of the body.

In a surprising discovery, researchers found that regular aerobic exercise reshapes tiny nerve clusters linked to the heart, creating dramatic side-specific changes that could eventually influence how doctors treat arrhythmias, chronic chest pain, and even stress-related “broken-heart” syndrome.

Exercise Alters the Heart’s Nerve Network

The study, led by the University of Bristol and published in Autonomic Neuroscience, focused on the stellate ganglia, paired bundles of sympathetic nerve cells located in the lower neck and upper chest. These nerve hubs help regulate heart rate and blood pressure by sending signals that can speed up the heart during stress or physical activity. Scientists sometimes describe them as part of the body’s automatic “fight or flight” circuitry.

Although exercise is already known to improve cardiovascular health and lower resting heart rate, far less is understood about how physical activity physically reshapes the nerves controlling the heart. These findings suggest the nervous system may be far more adaptable than previously thought.

Using advanced 3D imaging and stereological analysis, researchers examined the stellate ganglia in rats after 10 weeks of moderate treadmill exercise. The results revealed a striking imbalance between the two sides of the body. Exercised rats developed roughly four times more neurons in the right stellate ganglion than in the left, a pattern not seen in untrained animals.

Left and Right Sides Responded Differently

At the same time, the neurons themselves changed in opposite ways depending on location. Cells on the left side grew substantially larger, increasing by about 1.8-fold, while neurons on the right side became slightly smaller. The overall volume of the nerve clusters also shrank after training.

The findings challenge the long-standing assumption that exercise affects the autonomic nervous system uniformly. Instead, the study suggests the nervous system responds to exercise in a surprisingly uneven way, with the left and right sides undergoing distinct structural changes over time.

Lead author Augusto Coppi, Senior Lecturer in Veterinary Anatomy at the University of Bristol, said: “The discovery points to a previously hidden left-right pattern in the body’s ‘autopilot’ system that helps run the heart.

“These nerve clusters act like the heart’s dimmer switch and we’ve shown that regular, moderate exercise remodels that switch in a side-specific way. This could help explain why some treatments work better on one side than the other and, in future, help doctors target therapies more precisely and effectively.”

Potential Implications for Heart Treatments

That possibility could have important medical implications. Cardiologists already target the stellate ganglia in some severe heart conditions by using nerve blocks or denervation procedures to reduce excessive sympathetic activity. These treatments are sometimes used for dangerous arrhythmias, difficult-to-control angina, and Takotsubo cardiomyopathy, commonly known as “broken-heart” syndrome, a temporary heart condition often triggered by extreme emotional or physical stress.

Coppi noted that the research remains at an early stage and was conducted in rats, meaning human studies will be needed before the findings can influence clinical care. Researchers next plan to investigate how these structural changes affect heart function during exercise and rest, and whether the same left-right patterns appear in larger animals and people using noninvasive measurements.

Coppi added: “Understanding these left-right differences could help us personalize treatments for heart rhythm disorders and angina. Our next step is to test how these structural changes map onto function and whether similar patterns appear in larger animals and humans.”

The Life of Earth

https://chuckincardinal.blogspot.com/

80% of Earth's Rivers Are Quickly Losing Oxygen, Study Reveals

20 May 2026, By J. Cockerill

https://www.sciencealert.com/80-of-earths-rivers-are-quickly-losing-oxygen-study-reveals

The River Ganges is one of many waterways across Earth experiencing accelerating deoxygenation. 

(artfotoss/iStock/Getty Images Plus)

Oxygen levels have decreased in almost 80 percent of rivers worldwide, and they're going to continue losing this precious resource unless we make some serious changes.

Satellite and climate data collected between 1985 and 2023 reveal that over 16,000 rivers across the world have been losing their dissolved oxygen.

On average, these rivers have been losing 0.045 milligrams of oxygen per liter each decade.

Without enough dissolved oxygen essential to sustain life underwater, rivers – and the communities that rely on their water and resources – are under serious threat.

These findings come from a team at the Chinese Academy of Sciences, led by environmental scientist Qi Guan.

The team compiled data from 3.4 million satellite images across the past four decades to detect patterns in the dissolved oxygen of rivers across the world and forecast their futures under different climate scenarios.

By the end of the century, assuming carbon dioxide emissions continue to rise at similar rates (as opposed to some of the worst-case scenarios), rivers across most of South America, India, the Arctic, and the Eastern United States are expected to lose around 10 percent of their dissolved oxygen.

The most severe shifts so far have occurred in tropical rivers, such as the Ganges in India and the Amazon River in South America. The Ganges River in particular is losing oxygen 20 times faster than the global average.

Scientists didn't see this coming.

Previously, they assumed that high-latitude rivers would experience the worst deoxygenation because these regions are climate change hotspots.

But tropical rivers had a disadvantage from the start: Since their waters were already warmer, they already had lower levels of dissolved oxygen. This means they're already closer to reaching hypoxia (insufficient oxygen to sustain most life).

Aerial view of the low water level of the Amazon River in Colombia in 2024.

 (Luis Acosta/AFP via Getty Images)



Guan and team found many factors are contributing to global river deoxygenation, but none more so than climate change.

Climate change driven by human activities is reducing oxygen solubility (the ability of a body of water to hold dissolved oxygen). According to the new study, oxygen solubility accounts for about 63 percent of global river deoxygenation.

Water temperature is most likely driving this change in oxygen solubility. Warmer waters hold less dissolved oxygen because the oxygen and water molecules are receiving more energy in the form of heat.

Dissolved oxygen is very different from the oxygen atoms that pair with a hydrogen to form water. Dissolved oxygen is what aquatic life needs to 'breathe': that goes for animals, plants, plankton, bacteria, and anything else living underwater.

But the bonds that keep oxygen gas dissolved in water are relatively weak. Just a slight shift in temperature is enough to rip them apart, allowing the oxygen to escape.

https://www.youtube.com/watch?v=oVW5LAzd7Ec&t=1s

Aquatic species vary widely in terms of how much dissolved oxygen they need to survive. Still, a change of 0.1 milligrams per liter of river water – which is roughly how much has been lost, on average, across the past four decades – is enough to cause some serious shifts in river ecosystems.

Aquatic life can add to the dissolved oxygen levels by photosynthesizing, which is why underwater plants keep waterways healthy. Oxygen from the atmosphere can also become dissolved in water via physical forces, such as burbling river rapids or the aerators used in human-made ponds.

That's why, in many of the rivers included in this study, dams in shallow waterways and heatwaves have contributed to waning levels of dissolved oxygen. Reduced water flow means less oxygen is folded into the water from the air; heatwaves essentially squeeze the oxygen out of rivers.

Water composition also has a major impact on the levels of dissolved oxygen a river can hold. Human activities are changing water composition at both ends, by reducing the amount of water in rivers, and adding to the water's load of solutes, such as salt, nutrients, and organic matter (which further reduces oxygen solubility).

Since aquatic life relies on dissolved oxygen to survive, even a small drop in levels can quickly lead to mass die-off events.

Once that happens, a river full of dead fish and algae quickly uses up any remaining dissolved oxygen as bacteria get to work on breaking down the organic matter left behind.

With increasing rates of river deoxygenation across the world, dead zones like this may become more common.

"Deoxygenation is a very slow process. If we have a long period, the negative impact will attack the river ecosystems," Guan told Seth Borenstein at Associated Press.

"The low level of oxygen can cause a series of ecological crises such as biodiversity decline [and] water quality degradation."

Those scenarios are far more likely if rivers lose an additional four or five percent of their dissolved oxygen: the same amount that they're expected to lose within the next seven decades, unless humanity takes urgent action to prevent further fossil fuel emissions.

"Systematically understanding these changes is crucial for enhancing the resilience of fluvial ecosystems to sustained deoxygenation risks through targeted measures and strategies, and helps to achieve sustainable management in global rivers," Guan and team conclude.

The Life of Earth

https://chuckincardinal.blogspot.com/

Scientists Discover Hidden Sleep Switch That Boosts Brainpower, Builds Muscle, and Burns Fat

By U. of California - Berkeley, May 20, 2026

https://scitechdaily.com/scientists-discover-hidden-sleep-switch-that-boosts-brainpower-builds-muscle-and-burns-fat/

A new study reveals how the brain carefully balances sleep, growth hormone release, and wakefulness — a connection that may influence everything from metabolism to cognition.

 Credit: Shutterstock

Scientists have uncovered a previously unknown brain feedback system that links deep sleep, growth hormone release, and wakefulness.

Most people think of sleep as a time when the body simply rests. In reality, the brain is carrying out a complex series of processes that regulate everything from metabolism and tissue repair to memory and hormone production. One of the most important of these hormones is growth hormone, which helps build muscle and bone, regulate fat metabolism, and support overall health.

Scientists have known for decades that growth hormone is closely tied to deep sleep, especially the early stages of non-REM sleep. Even a lack of sleep for a single night can reduce hormone levels. But exactly how the brain controls this process has remained poorly understood.
Researchers Map the Brain Circuit Behind Growth Hormone Release

Now, researchers at the University of California, Berkeley, have identified the brain circuits responsible for controlling growth hormone release during sleep. Their study, published in Cell, also uncovered a previously unknown feedback system in the brain that helps keep hormone levels balanced while regulating wakefulness.

The findings provide a clearer picture of how sleep and hormone regulation are connected. Researchers say the discovery could eventually contribute to new treatments for sleep disorders linked to metabolic diseases such as diabetes, as well as neurodegenerative conditions including Parkinson’s and Alzheimer’s disease.

During sleep, the brain produces growth hormone to help build muscle and bone and reduce fat. UC Berkeley research in mice reveals the brain circuits that regulate growth hormone release, along with a brainstem feedback mechanism that promotes wakefulness after a good night’s sleep. 

Credit: Yang Dan lab/UC Berkeley



“People know that growth hormone release is tightly related to sleep, but only through drawing blood and checking growth hormone levels during sleep,” said study first author Xinlu Ding, a postdoctoral fellow in UC Berkeley’s Department of Neuroscience and the Helen Wills Neuroscience Institute. “We’re actually directly recording neural activity in mice to see what’s going on. We are providing a basic circuit to work on in the future to develop different treatments.”

Because growth hormone also affects glucose and fat metabolism, poor sleep may increase the risk of obesity, diabetes, and cardiovascular disease.

Key Brain Regions Involved in Sleep and Hormone Regulation

The neurons responsible for regulating growth hormone release during the sleep-wake cycle are located deep within the hypothalamus, a brain region shared across mammals. These include growth hormone releasing hormone (GHRH) neurons and two types of somatostatin neurons.

After growth hormone is released, it increases activity in the locus coeruleus, a brainstem region involved in attention, arousal, cognition, and responses to new experiences. Problems affecting the locus coeruleus have been associated with several psychiatric and neurological disorders.

“Understanding the neural circuit for growth hormone release could eventually point toward new hormonal therapies to improve sleep quality or restore normal growth hormone balance,” said Daniel Silverman, a UC Berkeley postdoctoral fellow and study co-author. “There are some experimental gene therapies where you target a specific cell type. This circuit could be a novel handle to try to dial back the excitability of the locus coeruleus, which hasn’t been talked about before.”

Working in the lab of Yang Dan, a professor of neuroscience and molecular and cell biology, the researchers implanted electrodes into mouse brains and monitored neural activity while stimulating hypothalamic neurons with light. Because mice sleep in short bursts lasting only a few minutes throughout the day and night, they provided researchers with repeated opportunities to examine hormone activity during sleep cycles.

Distinct Hormone Activity During REM and Non-REM Sleep

Using advanced neural circuit tracing techniques, the researchers found that the two peptide hormones involved in growth hormone release behave differently depending on the stage of sleep. GHRH stimulates growth hormone release, while somatostatin suppresses it.

During REM sleep, levels of both hormones rise sharply, increasing growth hormone release. During non-REM sleep, somatostatin levels drop while GHRH levels rise more moderately, which also boosts growth hormone production.

The researchers also found evidence of a feedback system involving the locus coeruleus. As growth hormone gradually builds during sleep, it stimulates this brain region and encourages wakefulness. However, when the locus coeruleus becomes overly active, it can unexpectedly increase sleepiness, according to earlier work by Silverman.

“This suggests that sleep and growth hormone form a tightly balanced system: Too little sleep reduces growth hormone release, and too much growth hormone can in turn push the brain toward wakefulness,” Silverman said. “Sleep drives growth hormone release, and growth hormone feeds back to regulate wakefulness, and this balance is essential for growth, repair, and metabolic health.”

Because the locus coeruleus also helps regulate overall brain arousal during wakefulness, researchers believe maintaining the right balance in this system could influence attention and cognitive function as well.

“Growth hormone not only helps you build your muscle and bones and reduce your fat tissue, but may also have cognitive benefits, promoting your overall arousal level when you wake up,” Ding said.

The Life of Earth

https://chuckincardinal.blogspot.com/

Scientists Turn Wool Into Bone-Healing Material in Medical Breakthrough

By King's College London, May 20, 2026

https://scitechdaily.com/scientists-turn-wool-into-bone-healing-material-in-medical-breakthrough/

A protein extracted from wool has shown surprising potential for guiding bone regeneration in living systems.

 Credit: Shutterstock

Wool-derived keratin membranes helped regenerate organized, stable bone tissue and may offer a promising alternative to collagen in regenerative medicine.

A new study found that keratin, a structural protein taken from wool, can support bone regeneration in living animals. The material produced bone tissue that more closely matched healthy natural bone than collagen, which is currently considered the standard material for these treatments.

Researchers at King’s College London tested the wool-derived keratin in animal models and discovered it could guide new bone growth across damaged areas. The findings suggest the material could become a promising alternative for regenerative medicine and dental procedures.

“We are really excited to show for the first time how a wool-based material has been successfully tested in a living animal to repair bones,” said Dr. Sherif Elsharkawy at King’s Faculty of Dentistry, Oral & Craniofacial Sciences.

The researchers also highlighted the sustainability benefits of the material. Wool is naturally sourced and is often discarded as waste by the farming industry, making keratin a renewable and scalable option for medical applications.

Collagen’s Longstanding Role in Bone Repair

For many years, collagen has been widely used as a scaffold in regenerative medicine and dentistry. It works as a protective barrier that keeps soft tissue from disrupting healing while allowing bone to regrow in damaged areas.

Despite its widespread use, collagen has several drawbacks. The material is relatively weak and can degrade too quickly, especially in situations where healing bone must withstand pressure or support weight. Extracting collagen can also be expensive and technically challenging.

Dr. Sherif Elsharkawy holding a human skull. 

Credit: King’s College London



“From a research perspective, this is a major milestone. It positions keratin as a potential new class of regenerative biomaterial that could challenge the long-standing reliance on collagen,” said Elsharkawy.

To investigate alternatives, the researchers created membranes from keratin extracted from wool. The material was chemically treated to produce stable and durable scaffolds designed to support bone regeneration.

Keratin Membranes Show Early Promise in Lab Tests

The team first tested the keratin membranes on human bone cells in the lab. The cells grew successfully and showed strong signs of healthy bone development.

The researchers then implanted the membranes into rats with skull defects large enough that they would not heal on their own. Over the following weeks, the team observed how the keratin scaffolds supported bone growth across the damaged sections.

While collagen membranes generated a greater amount of bone overall, the keratin scaffolds produced bone that was more organized and structurally stable. The fibers were also better aligned and more closely resembled the structure of healthy natural bone.

Stable Healing Brings Keratin Closer to Human Use

The keratin membranes also blended well with surrounding tissue and stayed stable throughout the healing process. Researchers said these qualities are important for potential real-world medical use.

“We’ve effectively demonstrated the technology in an animal model, which makes this much more than an early materials concept. It shows that keratin can support bone regeneration in a living biological system, bringing the technology significantly closer to use in real patients,” said Elsharkawy.

The Life of Earth

https://chuckincardinal.blogspot.com/

Scientists Keep Finding Major Discoveries Lurking in Museum Backrooms

18 May 2026, By M. Starr

https://www.sciencealert.com/scientists-keep-finding-major-discoveries-lurking-in-museum-backrooms

(Hill Street Studios/DigitalVision/Getty Images)

Museums are among the most expansive resources humans have created.

For most of us, these edifices display rich collections of treasures and knowledge that transport us through time.

For scientists, they're a treasure of a different kind.

In vast warehouses inaccessible to the public, many museums store hoards of more artifacts that rarely see the light of day, and were accumulated faster than humans can study them.

That's why so many discoveries are made not in the field, but in museum backrooms, among wonders half-forgotten for decades.

To celebrate International Museum Day, here are some of our favorite recent discoveries that only emerged when the right person came along to make them.

The oldest known whale bone tools

In a bid to make sense of the hundreds of prehistoric artifacts squirreled away in museums across Europe, a team of archaeologists sat down and compiled a comprehensive catalog using a suite of techniques to date the artifacts and find out what they were made of.

Their results yielded around 150 tools made from whale bone, arising from the Magdalenian culture that occupied coastal and inland regions of western Europe some 19,000 to 14,000 years ago – the earliest known of their kind.

This whale bone point was found in the Duruthy rock shelter in France. 

(Alexandre Lefebvre)



This discovery reveals interesting new details about the whales that once inhabited the Bay of Biscay and how humans interacted with their remains.

"Even old collections, excavated more than one century ago with field methods now outdated, and stored in museums for a long time, can bring new scientific information when approached with the right analytical tools," University of Toulouse-Jean Jaurès archaeologist Jean-Marc Pétillon told ScienceAlert.

Metal from the sky

The Treasure of Villena – discovered more than 60 years ago in 1963 in what is now Alicante in Spain – wasn't exactly moldering away in a storeroom.

As one of the most important examples of ancient goldsmithing in Europe, forged more than 3,000 years ago during the Iberian Bronze Age, it was revered but still somewhat overlooked.

The iron-and-gold hemisphere, which has a maximum diameter of 4.5 centimeters (1.77 inches). 

(Villena Museum)

Then, in 2024, it yielded a surprise. Scientists analyzed two oddities in the collection, a bracelet and a hemisphere made from dull brown material – and found they were made, not from earthly metal, but with iron from meteorites that fell from the sky – in a time before the advent of iron smelting technology.

"The available data suggest that the cap and bracelet from the Villena Treasure are currently the first two pieces attributable to meteoritic iron in the Iberian Peninsula," the researchers wrote.

https://www.youtube.com/watch?v=M4kUXxcS9Io&t=3s

Not a mammoth

It made sense that large bones found inland in the heart of Alaska were identified as belonging to a woolly mammoth and not examined for 70 years.

However, when researchers finally studied the bones as part of a program launched in 2022, radiocarbon dating revealed that the animal that left them lived long after mammoths had gone extinct.

Images of some of the bones. 

(University of Alaska Museum of the North)



Comparison of the bones' mitochondrial DNA with modern species revealed an even bigger surprise: It was not one animal, but two, and they were both whales.

"How did the remains of two whales that are more than 1,000 years old come to be found in interior Alaska, more than 400 km (250 miles) from the nearest coastline?" the researchers queried.

It's a question that remains to be answered.

Darwin meets lasers

Sometimes it's not the specimen, but the method of studying it that reveals new information.

Some of the specimens collected by Charles Darwin in the 19th century. (Dr Sara Mosca, STFC Central Laser Facility)



Some 200 years ago, legendary naturalist Charles Darwin collected hundreds of specimens, preserved in sealed jars. The problem is that many different fluids were used for specimen preservation, and it was unknown which of them Darwin had used.

We can't just unseal the jars and take a peek – that could destroy the delicate remains – so, in a paper published in January 2026, scientists detailed the way they used laser light to identify the methods Darwin had used.

Interestingly, he had different fluids for different kinds of animals – and this information, the scientists said, will help them continue to care for these precious specimens for future generations.

A dinosaur herd written in opal

Australia is one of the only places in the world with the right conditions for fossil opalization – the replacement of bone with shimmering rainbow opal.

An opalized Fostoria dhimbangunmal bone. 

(Robert A Smith/Australian Opal Center)



Many of these specimens are stunningly beautiful, but with opal being so valuable, they often have a checkered history. Some are squirreled away in private collections; others get traded; and some go unstudied for years.

A collection of opalized fossils first discovered in 1984 was finally examined by paleontologists decades later, after it was recovered and donated in 2015.

As described in a 2019 paper, the jumble of bones turned out to be the remains of at least four separate animals, all belonging to a previously unknown dinosaur species.

The species was named Fostoria dhimbangunmal. It roamed the eastern flank of Australia during the mid-Cretaceous, in herds large enough that this group stayed together even after death, turning into beautiful gemstones together.

Three-eyed brains

The Burgess Shale truly is a fossil cornucopia like no other. This spectacular, 508-million-year-old fossil bed is so rich that, often, paleontologists can only collect them and put them aside to create an archive that is slowly being worked through.

A reconstruction of Stanleycaris hirpex hovering above its fossil. 

(Sabrina Cappelli © Royal Ontario Museum)



One species, Stanleycaris hirpex, is a strange three-eyed animal known as a radiodont, related to modern arthropods.

Hundreds of Stanleycaris fossils have been collected, but it wasn't until a 2022 paper – two decades after they were discovered – that scientists revealed just how exciting these tiny animals really are.

In 84 specimens from a collection of 268 Stanleycaris fossils, the brain was preserved in exquisite detail – a discovery that shed new light on the evolution of arthropod brains.

"We can even make out fine details such as visual processing centers serving the large eyes and traces of nerves entering the appendages," said evolutionary biologist Joseph Moysiuk of the University of Toronto.

The world has more marvels than we currently have time to examine.

While museums offer a place of learning for many of us, for scientists, they provide a place to keep irreplaceable treasures safe until the right researcher arrives to unravel the secrets they hold.

The Life of Earth

https://chuckincardinal.blogspot.com/

Fog Is Teeming With Life, And It May Be Doing Us a Surprising Favor

19 May 2026, By M. Irving

https://www.sciencealert.com/fog-is-teeming-with-life-and-it-may-be-doing-us-a-surprising-favor

(Daniel Garrido/Moment/Getty Images)

There's something living in the fog – but you'll be glad to know that it's mostly friendly.

Researchers at Arizona State University and Susquehanna University have found that bacteria are living and growing inside droplets of water in fog, at concentrations comparable to seawater.

While it does mean fog isn't as sterile as it may seem, those microbes are at least earning their keep: They've been found to break down pollutants in the air.

From ground-level sneezes to the highest of clouds, it's long been known that bacteria are floating around in the atmosphere in decent numbers.

But it's less clear whether these microbes are actively living in these airborne environments, or are just passing through on their way to other habitats.

Fittingly, fog is even more mysterious.

"There's very limited knowledge about what kinds of bacteria are present in fogs, which are like clouds at the ground level," says Thi Thuong Thuong Cao, a microbiologist at Arizona State University (ASU).

The research team's experimental setup for capturing fog samples. 

(Thi Thuong Thuong Cao)



To investigate, the researchers on the new study collected air samples before, during, and after fog events on 32 different occasions over a two-year period.

To control for wind blowing everything around and messing with readings, the team specifically examined radiation fog, a type that forms in calm, still air overnight.

And sure enough, a sizable microbiome was detected in that chilly morning air.

Bacteria were present in less than one percent of fog droplets. That doesn't sound like much, but it averages to around 1 million 16S rRNA gene copies – a common marker for estimating bacterial abundance – per milliliter of water.

Concentration of bacterial 16S rRNA gene copies in air samples collected before and after six fog events in 2022. 

(Cao et al., mBio, 2026)



"When you take all of the droplets together, the concentration of bacteria is the same as in the ocean," says Ferran Garcia-Pichel, a microbiologist at ASU.

To answer the question of which bacteria are present, the team conducted genetic analyses. This revealed that those in the Methylobacterium genus dominated the picture.

And they didn't seem to be inert, either.

"If they are growing, then the droplets are a habitat. That's a mindset change," says Ferran Garcia-Pichel.

In a subsample of six fog events, the team found that even after the fog cleared, the air contained around 45 percent more bacteria than at the same location before the fog settled in.

That suggests that something about the foggy atmosphere is actively culturing the bacteria.

"We observed them under the microscope to see that yes, the bacteria are getting bigger and they're dividing, so there is growth," says Cao.

Methylobacteria are known to eat volatile carbon compounds such as formaldehyde, so the team suspected this might be the source of their growth.

To check, the researchers incubated samples of fog water and measured how levels of these compounds changed over time.

Unsurprisingly, these levels dropped – but what was surprising was the speed with which the compounds were consumed.

A foggy Pennsylvania field has a secret: Its droplets are home to 'pollutant-eating' bacteria. 

(Thi Thuong Thuong Cao)

"Existing formaldehyde at the start of the incubation was swiftly consumed to undetectable levels," the researchers write, "roughly 200-fold faster than rates measured elsewhere in cloud water."

That's much too fast to purely be a source of food, the team says. Instead, it's probably for "detoxification purposes" as well, since high levels of formaldehyde can be toxic to the bacteria.

The good news is that these compounds are pollutants for us too, meaning this aerial microbiome may have a cleansing effect. Exactly how beneficial this is in the real world will require more research, though.

"The sky's the limit," Garcia-Pichel says.

The Life of Earth

https://chuckincardinal.blogspot.com/