Biodiversity in Antarctic soils may be greatly underestimated after surprising discovery

New methods reveal unsuspected biodiversity in Antarctica, enabled by symbiosis

Frontiers

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The researchers arriving in the Larsemann Hills of East Antarctica by helicopter

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Credit: Dirk Wagner, GFZ

Two important concepts in evolutionary biology, mutualism and altruism, were first made famous by the colorful anarchist prince Peter Kropotkin. He argued that cooperation could be an equally powerful driver of evolution as competition. Crucially, he was inspired by his youth as a geographer in the Russian Far East, where he observed how in particular the harsh climate favored cooperation, both within and between species.

Now, researchers have shown that previously unknown apparent mutualisms allow biodiversity to flourish to an unexpected degree in an even more extreme habitat: weathered debris in front of a glacier in Antarctica. The study is published in Frontiers in Microbiology.

“Here we reveal unexpectedly abundant and diverse microbial community even in these driest, coldest, and nutrient-poorest of soils, which suggest that biodiversity estimates in Antarctic soils may be greatly underestimated,” said Dr Dirk Wagner, a professor at the GFZ Helmholtz Centre for Geosciences and the University of Potsdam in Germany, and the corresponding author.

“Furthermore, it provides important initial insights into the range of interactions between bacteria and eukaryotes in these harsh environments.”

Harsh environment

Some of the team of authors participated in the ‘ANT-XXIII/9’ expedition of the German research vessel ‘Polarstern’ to Antarctica. They took 26 soil samples – at five distances between zero and 80 meters, and at three depths between zero and 30 cm – in front of a slowly retreating glacier in the Larsemann Hills, on the southern shore of Prydz Bay. They used high-throughput DNA barcoding to measure bacterial and eukaryotic biodiversity. The further the distance from the glacier, the more time for ecological succession since the ground was left exposed.

“By distinguishing between intracellular iDNA from living organisms and extracellular eDNA from dead organisms, we could reveal colonizers and locally extinct species preserved in soils. This allowed us to understand the relationships between prokaryotic and eukaryotic microorganisms and gain insights into their interactions over time,” said Wagner.

The researchers found a total of 2,829 genetically defined species, of which 40% in the form of eDNA, while overall species richness was 10.3 times greater for bacteria than for eukaryotes. Every distance from the glacier had its own unique range of species. Typically, the diversity of iDNA was greatest in the top layer.

Strength in unity

Closest to the glacier, were so-called ‘cryophilic’ (cold-loving) fungi. These are thought to be pioneers which contribute to the first phase of soil formation, which then allows other species to settle.

The authors used network analysis to determine which species had the same pattern of local presence versus absence across samples. Consistent coexistence may imply shared niches between species, metabolic dependencies, or novel mutualisms.

“We detected previously unrecognized associations between bacteria and eukaryotes, for example between certain green algae and bacteria, which may promote nutrient exchange. We also found consistent co-occurrence of certain fungi and actinobacteria, which suggests that these fungi could provide carbon for the bacteria by degrading organic matter,” said Wagner.

“Our results indicate that microbial survival in extreme Antarctic habitats may be made possible by tightly linked consortia of species that optimize the utilization of resources,” concluded Wagner.

These results mean that current estimates for species richness across Antarctica need to be revised upwards. They also suggest potential novel mutualisms between bacteria and eukaryotes that need to be confirmed experimentally, for example through microcosm experiments under defined environmental conditions.

“By focusing on both current and past lineages of microbes, our study shows how colonization and environmental alteration through ecological succession helped change the extreme habitat of Antarctica’s Larsemann Hills, making them gradually more hospitable to the current considerable diversity of life,” said Wagner.

Scientists camping at the research site in East Antarctica

Panorama of the landscape in the Larsemann Hills, East Antarctica

Credit

Dirk Wagner, GFZ

Journal

Frontiers in Microbiology

DOI

10.3389/fmicb.2025.1576898 

Method of Research

Experimental study

Subject of Research

Not applicable

Article Title

From single pioneers to complex pro-and eukaryotic microbial networks in soils along a glacier forefield chronosequence in continental Antarctica (Larsemann Hills, East Antarctica)

Article Publication Date

21-May-2025

 

Taking the guesswork out  of birdsong evolution

Biologists from UMass Amherst are the first to comprehensively link bird songs’ pitch and volume, providing insight into bird evolution

University of Massachusetts Amherst

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Chipping sparrow

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Credit: UMass Amherst

 

AMHERST, Mass. — Biologists at the University of Massachusetts Amherst recently announced that they have released the first broad scale, comparative, fine-grained analysis linking the amplitude, or volume, of a birds’ song to its vocal frequency, or pitch. Though biologists have long wondered whether birds are able to control their pitch as they get louder or if their vocal abilities are mechanically limited, until now there has been no wide-ranging data with which to probe this aspect of the evolutionary history of birdsong. The study, published recently in Proceedings B, is a large step forward in the goal of understanding how communication and evolution have influenced each other.

If you’ve ever been at an outdoor concert and had to yell across a few rows to your friends, you’ve probably noticed that as your voice gets louder, increasing in amplitude, it also increases in frequency by getting higher pitched.

However, you’ve also probably noticed that you can hear the low bass frequencies from a concert at a far greater distance than you can hear the higher, trebly voices and instruments.

It would make sense, then, that if you wanted to be heard at a greater distance, your voice would drop in pitch while rising in volume—but it doesn’t. The physiology of our own vocal apparatus cannot do both low and loud. We’re mechanically constrained, and that’s why screams are ear-piercingly high and not rumblingly low.

“The difference is between what you can do and what you want to do,” says João C. T. Menezes, graduate student in the Organismic and Evolutionary Biology Program at UMass Amherst and lead author of the new paper.

But what about birds?

“There have been two main arguments over the decades,” says Jeffrey Podos, professor of biology at UMass Amherst and the paper’s senior author. “One camp holds that if birds sing loudly, their pitch should increase because they are mechanically constrained.” This is the textbook prediction, Podos says, but there’s another camp, which makes the opposite argument and points to evolution. “Since lower sounds carry farther and therefore should increase a singer’s chance of being heard, it would make sense that birds should be both loud and deep at the same time.”

So, which camp is right?

Until now, the two main camps have remained speculative largely because it has been challenging to measure with any precision the volume of a wild bird’s song in its natural setting. “It’s only been in the last 10 years or so that devices capable of measuring amplitude precisely enough, in the millisecond bursts that birds sing and with the durability and portability to take out into the field, have been available,” says Podos.

But now that the technology exists, Menezes and Podos intensively sampled the amplitude and frequency of hundreds of songs and calls from 53 species of birds, ranging from the Canada goose to the elusive black-and-gold cotinga from Brazil.

What they discovered was a mix.

“There’s considerable variation across species,” says Menezes. Of the 53 species the team sampled, 27 species’ calls got higher pitched as they got louder, 12 species’ calls got lower and louder, and 14 species showed no consistent pattern in the linkage between volume and pitch at all. What this means is that we can’t simply point our finger at either physiology or evolution as an explanation for how birds’ calls work.

But the team did find that songbirds, in particular, tended to narrow the range of frequencies they used as their volume increased. Some songbirds were able to focus their loudest calls on the higher frequencies, some at the lower. But nearly all of them were able to narrow their range.

“One of the specializations that songbirds have developed,” says Podos, “is an ability to control the tension of their vocal apparatus as they ramp up and down in volume. Most birds don’t have this. It means that songbirds could, in theory, have more evolutionary freedom in evolving their songs.”

Or as Menezes puts it, “this might be a hint that songbirds are like opera singers and can actively control their frequencies to the ones that are most amplified by their bodies for the best projection.”

Whatever the ultimate answer to the argument may be, we now know much more about how birdsong pitch and volume relate—next time you’re listening to the birds, see if you can hear the dynamic relationship between pitch and volume.

A media kit with sound clips of bird calls, photos and all caption and credit information is available here.

Chipping sparrow song (AUDIO)

Song by a chipping sparrow. Though it’s hard to perceive because chipping sparrows trill so fast, louder, lower notes are interspersed with softer, higher notes, denoting a negative relationship between amplitude and frequency as found for about one quarter of our species.

Credit

UMass Amherst

Usage Restriction

DOI

10.1098/rspb.2025.0781 

Article Title

Diverse relationships between amplitude and frequency in bird vocalizations

Article Publication Date

21-May-2025

 

More than half of US workers say job insecurity causing stress

US workforce grapples with government policy changes, economic concerns

American Psychological Association

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A majority of U.S. workers (54%) said job insecurity has had a significant impact on their stress levels at work, and more than a third (39%) said they are concerned they may lose their job in the next 12 months due to changes in government policies, according to the American Psychological Association’s 2025 Work in America™ survey.

Two-thirds of employed adults (65%) said their company or organization has been affected by recent government policy changes. The survey found that for some, these changes, as well as growing economic uncertainty, are related to intensifying workplace stress and mental health concerns. The Harris Poll conducted the survey on behalf of APA from March 26-April 4, 2025, among more than 2,000 working U.S. adults ages 18 and older.

“When people feel their jobs are at risk, it creates a sense of uncertainty that can affect every aspect of their lives,” said Arthur C. Evans Jr., PhD, APA’s chief executive officer. “This cultural moment is threatening workers’ sense of stability, control and ability to meet their basic needs. And feelings of insecurity at work and poor mental health can amplify each other in a vicious cycle.”

Government policy changes, economic concerns and general stress over job security may have had a ripple effect on the psychological and emotional standing of employees, according to the survey findings. Those whose company or organization had been affected by recent government policy changes were more likely than others to report experiencing negative outcomes at work over the last month. These workers most commonly reported experiencing a lack of interest, motivation or energy (28% whose company experienced drastic/significant impacts and 31% whose company experienced moderate/minor impacts vs. 16% whose company experienced no impacts), emotional exhaustion (27% and 30% vs. 18%) and difficulty focusing (23% and 24% vs. 13%).

Other highlights include:

• Workers who said government policy changes had significantly or drastically affected their company or organization — to the point of fundamental changes to their operation or strategy — were more likely than people who had not experienced any changes due to government policies to say job insecurity had a significant impact on their stress at work (70% vs. 39%).
• Among local, state or federal government workers, 53% said they anticipate changes happening in their company or organization due to government policy changes that may happen in the future.
• Around half of workers (51%) said it would take them a significant amount of time to find a new job if they lost theirs, and two in three workers who said they are concerned about losing their job in the next 12 months due to changes in government policies (66%) said the same.
• More than two in five (44%) said that if they lost their job, they would need to move to a different field or industry to find a new job.

Economic uncertainty appeared to have played a major role in workers’ concerns about job security. More than two in five employed adults (44%) said they were concerned that an economic slump, downturn or recession could lead to being laid off, furloughed or having their job eliminated within the year. This represented a notable increase from 2024, when only 36% expressed the same concern.

These worries appeared to take a toll on both quality of sleep and personal relationships. Among those concerned about job security due to an economic slump, downturn or recession, 42% said work-related stress makes it difficult to sleep, while 36% reported that their personal relationships had recently been suffering due to stress experienced at work.

“In recent years, awareness has grown around the profound impact the workplace has on people’s mental health,” Evans said “This year’s survey makes one thing clear: unmanaged stress is not just a personal health issue—it’s a critical organizational risk, contributing to lower productivity and higher turnover. Employers have a responsibility to go beyond awareness and invest in evidence-based strategies that promote workers’ psychological well-being. At the same time, employees must recognize the importance of prioritizing their mental health and be empowered with the skills and support to do so.”

APA psychologists offer this advice for dealing with toxic or chaotic workplaces.

Methodology

The research was conducted online in the United States by The Harris Poll on behalf of the American Psychological Association among 2,017 employed adults. The survey was conducted March 26-April 4, 2025. Data is weighted where necessary by age, gender, race/ethnicity, region, education, marital status, household size, work status, household income and smoking status to bring it in line with its actual proportions in the population.

 

From tiny worms to giant squid: new global database reveals the hidden power of body size in the ocean

MOBS 1.0 offers the most comprehensive look yet at the sizes of marine life, unlocking critical data for ocean science, conservation, and discovery

University of Louisiana at Lafayette

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The ocean runs on size. Until now, we didn’t have the numbers.

A new open-access resource, the Marine Organismal Body Size (MOBS) Database, is giving scientists, conservationists, and the public an unprecedented look at the true scale of ocean life—literally. Released this month alongside a peer-reviewed publication, MOBS 1.0 catalogs size data for over 85,000 marine animal species, from microscopic zooplankton to massive whales, offering a vital tool for understanding biodiversity and ecosystem function across the world’s oceans.

“Body size isn’t just a number—it’s a key to how life works,” said Dr. Craig R. McClain, Professor at the University of Louisiana at Lafayette and lead creator of the database. “For decades, we’ve had this enormous data gap in marine life. MOBS doesn’t just close that gap—it opens the door to a deeper understanding of the ocean’s biodiversity.”

The MOBS project brings together a global team of researchers including Noel A. Heim (Tufts University), Matthew L. Knope (University of Hawaiʻi at Hilo), Pedro M. Monarrez (Virginia Tech University), Jonathan L. Payne (Stanford University), Isaac Trindade Santos (University of Louisiana at Lafayette), and Thomas J. Webb (University of Sheffield). The database is freely available through GitHub and already covers over 40% of all described marine animal species, with a goal of reaching 75% in the coming years.

Unlike many biological databases that focus on genetics or taxonomy, MOBS focuses on a trait that’s both easy to grasp and incredibly informative: maximum body size. The project standardizes length, width, height, and diameter across marine phyla using data drawn from literature, museum specimens, and online resources. This makes the database immediately useful for scientists studying everything from food webs to climate change.

“Body size is the Rosetta Stone of biology,” said Dr. Craig R. McClain. “It’s the trait that unlocks everything—how a species moves, eats, survives, and evolves. But until now, marine life has been a blank page. With MOBS, we’re finally writing it.”

MOBS is already powering new scientific insights. One recent study revealed how size-related patterns in species descriptions may reflect longstanding biases in how science is done. Current research utilizing MOBS has found that smaller marine species are more likely to be overlooked in biodiversity assessments—a finding with major implications for conservation. It is also enabling new research into how body size responds to climate change—an essential focus given that size influences metabolism, ecological interactions, and species vulnerability in a warming ocean.

By compiling one of the most accessible and scalable marine trait datasets ever created, MOBS elevates the impact of biodiversity research, providing a shared foundation for discovery, education, and environmental decision-making. It invites collaboration, transparency, and exploration—and it’s just getting started.

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Journal

Global Ecology and Biogeography

Article Title

A database of interspecific variation in marine organismal body sizes

 

Thousands of young children worldwide still swallowing magnets despite increased regs

Time to bolster restrictions and use better evidence to inform policy, say researchers

BMJ Group

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Thousands of young children worldwide are still swallowing magnets despite an increase in regulations, finds a review of the available evidence, published online in the journal Injury Prevention.

With US children among those seemingly most at risk, it’s time to bolster restrictions and use better evidence to inform policy, say the researchers. 

The swallowing of small high powered magnets is a significant issue worldwide, especially among children under the age of 4, note the researchers, because they are commonly found in household items, such as toys, remotes, and small household appliances, they add.

While swallowing one of these magnets isn’t usually problematic, swallowing several or in combination with a metallic object can cause serious harm, often requiring surgery or other invasive procedures, they point out.

In a bid to build the evidence base and better inform policy, the researchers sought to compare global reports of children’s magnet swallowing and current regulatory policies for countries throughout the world.

They trawled through international research databases looking for relevant studies published between 2002 and 2024 on the frequency and medical outcomes of magnet swallowing among children from birth up to the age of 18.

From an initial haul of 2998 articles, 96 eligible studies were included in the review. Information on case volume, demographics of the affected children, and the interventions required was extracted from each study. 

A comprehensive online search was also made of policies related to magnet production, sales, and use in each country, drawing on information from government websites, news articles, or other descriptions of policies that could be translated into English or Spanish.

Most of the published studies originated from Asia and the Middle East (44 studies), North America, including Mexico (28), and Europe (11), plus a handful from Chile, Australia, Egypt and Tunisia, representative of only 23% of the world’s countries.

The number of incidents reported in any one study ranged from 1 to 23,756. Overall, the US reported the highest number of cases (23,756), possibly as a consequence of the breadth of its reporting systems, suggest the researchers. A total of 47 single case reports came from 23 different countries.

Sequential studies in several countries documented an increase in incidence over time, including China and the US. Boys comprised between 20% to 86% of magnet swallowing cases, while the overall average age ranged between 2 and 8. 

There were more cases in towns/cities than in rural communities, and most children found the magnets or objects containing them at home, daycare, and nursery in toys, and in school and office supplies.

A significant proportion of the children required admission to hospital, surgery, and/or other medical interventions. Magnets were found in all parts of the gut, and documented injuries included obstruction,twisted intestine (volvulus), perforation, fistulas, and abscesses.

A rise in the number of cases over time was reported in several countries. This could indicate a true increase, or improvements in reporting accuracy, say the researchers. Magnet marketing, cost, and availability may all explain the increases, as might changes in industry and government regulations, they add. 

But whatever the reason, it’s clear children swallowing magnets remains a problem worldwide, they emphasise.

Only 10 policies were found online: 2 from Canada and the US; 3 from the European Union, UK, and France; 1 each from the UAE, Taiwan, Japan, Australia and New Zealand.

These policies ranged in their intent and wording, with some banning small magnets altogether (UAE, New Zealand, and the UK). Others limited the strength of magnets, required stricter labelling, or some combination of the two. Bans were associated with fewer cases.

The US, for example, introduced regulations in 2014 which were overturned in 2016, after which the number of new cases rose by 444%. New safety standards were adopted in 2022, but these don’t apply to toys marketed for under 14s, the demographic most at risk, say the researchers.

“Many countries still lack national policies aimed at limiting access to small, ingestible magnets, even countries with published incidence of morbidity and mortality from paediatric magnet ingestions,” note the researchers.

They acknowledge that they were often not comparing like with like and that granular data were often not available. Cases that don’t require medical intervention are likely underreported, so potentially underestimating the true number of cases.

But the researchers nevertheless conclude: “These data demonstrate that paediatric magnet ingestion is an international problem that must be addressed. Every geographic area has different availability of products and types of restrictions in place, yet the problem remains the same: If magnets are accessible to children, some children will inevitably ingest them, leading to a wide range of severe consequences. 

“These data also provide some insight about potential solutions. Removal of magnets from the market is linked to a decreased incidence of injuries related to magnet ingestions and thus, such policies should be proposed, promoted, and enforced.”

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Journal

Injury Prevention

DOI

10.1136/ip-2024-045545 

Method of Research

Systematic review

Subject of Research

People

Article Title

Paediatric magnet ingestion persists worldwide despite increasing regulatory policies

Article Publication Date

20-May-2025