It’s possible that I shall make an ass of myself. But in that case one can always get out of it with a little dialectic. I have, of course, so worded my proposition as to be right either way (K.Marx, Letter to F.Engels on the Indian Mutiny)
Tuesday, October 14, 2025
Outfoxed: New research reveals Australia’s rapid red fox invasion
One of Australia’s most devastating invasive predators took just 60 years to colonise the whole continent, according to new Curtin-led research that offers vital clues to help prevent future extinctions of native animals from foxes. Reconstructing the invasion patterns of foxes using new statistical simulation tools, the new paper has uncovered critical data needed to disentangle the role of foxes in the demise of Australia’s native animals. Lead author Dr Sean Tomlinson, from Curtin’s School of Molecular and Life Sciences, said researchers used hundreds of first sighting records, and thousands of model simulations, to reconstruct the arrival and spread of the fast and fierce hunters. “European red foxes and domestic cats brought to Australia by European colonists kill about 300 million native animals in Australia every year and remain the major driver of past and current extinctions,” Dr Tomlinson said. “Our detailed reconstructions show that foxes filled their potential distribution in Australia in just 60 years, providing new biogeographic data needed to quantify past losses of fauna and help avert future extinctions.” Australia’s fox population is about 1.7 million and the Invasive Species Council estimates as many as 16 mammals have become extinct mainly or partly because of foxes. Dr Tomlinson said foxes were deliberately introduced to multiple locations across the country following their initial arrival in 1870. “Our modelling indicates that foxes quickly expanded their distribution throughout the southeastern corner of Australia between 1870 and 1895, before rapidly spreading in northerly and westerly directions. By 1900, it is likely that foxes had occupied all available habitat in the south-eastern region of Australia,” Dr Tomlinson said. “Fox colonisation across the northwest of Australia was the final phase of colonisation, with the distribution of foxes being completely infilled in 1940.” Researchers hope the findings will offer a useful framework for mapping the spread of other invasive species including cats, potentially helping curb Australia's worrying decline in native wildlife. The research was a collaboration with the University of Adelaide and the University of Copenhagen’s GLOBE Institute as part of an Australian Research Council Discovery Project. The full paper, titled ‘Reconstructing fox invasion of Australia: A process-based approach using historical sightings’, has been published in Diversity and Distributions and can be viewed online here.
Irvine, Calif., Oct. 14, 2025 –Children living near the Salton Sea, in Southern California’s desert region of Imperial County, are experiencing poorer lung function than children exposed to less wind-blown dust, according to a new study led by researchers at the University of California, Irvine’s Joe C. Wen School of Population & Public Health.
They found that higher dust exposure – measured in hours per year – was linked to lower lung function, with the negative effects most pronounced among children living closest to the lake. The work, published in the American Journal of Respiratory and Critical Care Medicine, marks one of the first investigations to directly link dust events from a drying saline lake to measurable declines in children’s respiratory health.
A federal grant from the National Institute of Environmental Health Sciences and the Southern California Environmental Health Sciences Center funded the research in partnership with the Imperial Valley community-based organization Comite Civico del Valle.
From 2019 to 2022, investigators used spirometry on nearly 500 children, all around 10 years of age, to measure lung function. The test evaluates lung size and strength by gauging how much air a person can exhale, as well as how fast they can do so.
Team members collected nearly 1,300 lung function assessments, alongside health questionnaires and in-person clinical examinations. Using data from 12 air monitors maintained by the California Air Resources Board, they estimated participants’ exposure to particulate matter during dust events – defined as hours in which particulate matter concentrations exceeded regulatory thresholds. For each child, the researchers calculated cumulative dust event exposure during the three months preceding each lung function test.
The analysis revealed a clear association: Children living near the Salton Sea experienced worse lung function due to their exposure to dust events. The study builds on growing evidence that the high particulate matter levels around the shrinking Salton Sea contribute to elevated rates of asthma, wheezing and other respiratory conditions – echoing health disasters such as “Dust Bowl pneumonia” in the 1930s, when widespread dust exposure led to severe and often fatal respiratory illness.
“The drying of the Salton Sea is not only an environmental crisis but also a public health crisis,” said corresponding author Jill Johnston, associate professor of environmental and occupational health at Wen Public Health. “Our study provides concrete evidence that children in surrounding communities are facing measurable harm to their lungs as a result of increased dust exposure.”
California’s largest inland lake, the Salton Sea has been receding for decades, exposing large stretches of dried lakebed that release dust into the air when disturbed by wind. This dust can carry contaminants including pesticides, metals and other toxic substances. Communities near the lake, predominantly low-income and Latino, are disproportionately bearing the health burden.
In the article, the researchers emphasize the urgent need for continued monitoring and intervention to mitigate air pollution in the region. “Protecting the health of children in the Salton Sea communities requires immediate attention through targeted public health strategies,” Johnston said.
The study adds critical evidence to the body of research on environmental health risks linked to climate change and ecosystem decline. As similar changes in inland lakes occur globally, these potential impacts demand greater public health attention, underscoring the importance of preventive policies and community-level protections.
Additional authors included Fangqi Guo, Sandrah Eckel and Shohreh Farzan of the University of Southern California’s Department of Population and Public Health Sciences; Elizabeth Kamai of UC Irvine; Luis Olmedo, Esther Bejarano and Christian Torres of Comite Civico del Valle; and Christopher Zuidema and Edmund Seto of the University of Washington’s Department of Environmental & Occupational Health Sciences.
About the University of California, Irvine: Founded in 1965, UC Irvine is a member of the prestigious Association of American Universities and is ranked among the nation’s top 10 public universities by U.S. News & World Report. The campus has produced five Nobel laureates and is known for its academic achievement, premier research, innovation and anteater mascot. Led by Chancellor Howard Gillman, UC Irvine has more than 36,000 students and offers 224 degree programs. It’s located in one of the world’s safest and most economically vibrant communities and is Orange County’s second-largest employer, contributing $7 billion annually to the local economy and $8 billion statewide. For more on UC Irvine, visit www.uci.edu.
Media access: Radio programs/stations may, for a fee, use an on-campus studio with a Comrex IP audio codec to interview UC Irvine faculty and experts, subject to availability and university approval. For more UC Irvine news, visit news.uci.edu. Additional resources for journalists may be found at https://news.uci.edu/media-resources.
Journal
American Journal of Respiratory and Critical Care Medicine
Article Title
Dust Events and Children’s Lung Function Near a Drying Saline Lake
Article Publication Date
8-Oct-2025
Drip by drip: The hidden blueprint for stalagmite growth
Deep inside caves, water dripping from the ceiling creates one of nature’s most iconic formations: stalagmites. These pillars of calcite, ranging from centimeters to many meters in height, rise from the cave floor as drip after drip of mineral-rich water deposits a tiny layer of stone. Beyond their beauty—echoed in fanciful nicknames like the “Minaret” or the “Wedding Cake”—stalagmites are also natural archives, recording ancient climatic changes in their layered growth, much like tree rings.
But what determines the shape of a stalagmite? Why do some grow into slender cones, others into massive columns, and still others into curious flat-topped forms? A new study by researchers from the University of Warsaw, the University of Florida, the Research Center of the Slovenian Academy of Sciences and Arts and University Medical Center Ljubljana, published in the Proceedings of the National Academy of Sciences, provides the first complete mathematical description of stalagmite shapes.
The team succeeded in analytically solving a 60-year-old mathematical model of stalagmite growth, which predicts how an “ideal” stalagmite grows when conditions in the cave remain steady. The mathematics reveals one of nature's hidden blueprints: stalagmites grow into flat-topped pedestals, classical columns, or pointed cones not by chance, but according to a single controlling factor - the Damköhler number - which represents a balance between the rates of calcite precipitation and the flow of water. When dripping is concentrated and steady, a columnar form emerges, while spread-out dripping produces flat tops. When the flow rate is high or when water drips directly onto the stalagmite from the cave roof, conical shapes with sharp pointed tops can emerge.
“It turns out that the rich diversity of stalagmite shapes can be explained by one simple parameter,” says the lead author Piotr Szymczak of the University of Warsaw. “This is a rare case where the beauty we see in nature corresponds directly to a clean mathematical law.”
To test their theory, the scientists used X-ray tomography on stalagmites from Slovenia’s famous Postojna Cave. The scans, performed in Ljubljana University Medical Centre, matched the predicted shapes with striking accuracy. Even delicate details, such as the transition from a flat top to a columnar body, were captured by the equations.
“When we compared our analytic solutions with real cave samples, the match was remarkable,” adds Matej Lipar of the Research Centre of the Slovenian Academy of Sciences and Arts. “It shows that even under natural, messy conditions, the underlying geometry is there.”
The study also shows that shape matters for climate science. Stalagmites are widely used to reconstruct rainfall and temperature records through subtle shifts in the chemical signatures of carbon isotopes trapped inside the stone layers, rather like reading a diary written by ancient rainwater. The new model reveals that flat-topped stalagmites record these isotope signals differently from columnar or conical ones—a finding that could refine how paleoclimate records are interpreted.
“Stalagmites are natural climate archives, but we now see that their geometry leaves its own imprint on the isotopic record,” explains Anthony Ladd of the University of Florida. “Recognizing this effect will allow us to extract more reliable information about past climates.”
So the next time you stand in front of a stalagmite - whether in Poland’s Raj Cave, Kentucky's Mammoth Cave, or Slovenia's Postojna Cave, you may see more than a curious rock formation. Stalagmites are not just stone curiosities; they are natural laboratories where physics, chemistry, and geology meet—and now, with mathematics, their forms can be read like a code written over millennia by dripping water.
Falling drops wet a small circular patch rather than a point, keeping the top level as calcium carbonate precipitates.
A 150-million-year-old fossil with a singular adaptation may unlock the origin of quironomids
The finding, led by the Do̱ana Biological Station (EBD-CSIC), represents the oldest known record in the Southern Hemisphere of quironomids Рa family of non-biting insects that play a key role in freshwater ecosystems
An international team of scientists led by the Doñana Biological Station (EBD-CSIC) has described a new species of fossilized insect from the Australian Jurassic period, estimated to be around 151 million years old. It represents the oldest known member in the Southern Hemisphere of the Chironomidae family — non-biting midges that inhabit freshwater environments. The fossil shows a unique evolutionary adaptation: a mechanism, that likely allowing it to firmly anchor to surrounding rocks. Until now, this mechanism was thought to be exclusive to marine species.
An international team of scientists led by the Doñana Biological Station (EBD-CSIC) has described a new species of fossilized insect from the Australian Jurassic period, estimated to be around 151 million years old. It represents the oldest known member in the Southern Hemisphere of the Chironomidae family — non-biting midges that inhabit freshwater environments. The fossil shows a unique evolutionary adaptation: a mechanism, that likely allowing it to firmly anchor to surrounding rocks. Until now, this mechanism was thought to be exclusive to marine species.
The fossilized remains were discovered in the Talbragar fish beds in New South Wales. The research, published in the journal Gondwana Research, included contributions from the Australian Museum Research Institute, the University of New South Wales, the University of Munich, and Massey University, New Zealand.
The fly from the stagnant waters
“This fossil, which is the oldest registered find in the Southern Hemisphere, indicates that this group of freshwater animals might have originated on the southern supercontinent of Gondwana”, explains Viktor Baranov, a researcher at the Doñana Biological Station and first author of the study.
The new species has been named Telmatomyia talbragarica, which translates to "fly from the stagnant waters," reflecting the lacustrine nature of the habitat at Talbragar.
The current research involved analyzing six fossilized specimens —both pupae and eclosing adults— that exhibited a terminal disc. This mechanism, which functions in tide-influenced habitats, was previously thought to be exclusive to marine species. However, sedimentological and paleontological evidence from the Talbragar Fish Beds suggests a freshwater paleoenvironment, highlighting the phenotypic plasticity displayed by chironomids.
New insights on the origin of the family
Podonominae has long been utilized as a model system for biogeographical study, offering an ideal medium to describe and interpret the general patterns governing the distribution and origin of biological diversity.
Initial theories proposed that Podonominae flies originated in Northern Gondwana and later expanded into Laurasia, the supercontinent located in the Northern Hemisphere. However, their fossil record is scarce due to taphonomic biases and the lack of studies focused on fossils from the Southern Hemisphere. Later, the discovery of older fossils in Eurasia, dating from the Jurassic, led to new interpretations suggesting that their origin was in Laurasia.
Now this new study provides compelling evidence that the Podonominae subfamily probably originated in the Southern Hemisphere and later dispersed and expanded globally.
Contemporary Podonominae are found almost entirely in the Southern Hemisphere and their disjunct distribution across South America, Australia, South Africa, and New Zealand represents a classic case of vicariance. This biological phenomenon takes place when a geographical barrier —like a mountain range or a river— divides a species' population, compelling the isolated groups to undergo independent evolution, which results in the creation of new species. According to the hypothesis proposed by Swedish entomologist Lars Brundin in 1966, the Podonominae populations experienced this process after the ancient supercontinent of Gondwana fragmented.
Limitations due to the scarcity of fossils in the Southern Hemisphere
While this discovery addresses a significant gap in the lineage's fossil record, a comprehensive understanding of this group's evolutionary history is still limited by the lack of Southern Hemisphere fossils. The majority of known Podonominae fossils originate from the Northern Hemisphere, with only two prior exceptions documented from the Southern Hemisphere: an Eocene specimen from Australia and a Paleocene record from India.
There is a strong bias towards finding and studying fossils in the Northern Hemisphere. Because of this we end up making incorrect assumptions about where groups originated”, explains Matthew McCurry, palaeontologist from the Australian Museum and The University of New South Wales.
Professor in Massey University Steve Trewick claims, “there are long-standing questions about the way Southern Hemisphere biotas formed and changed through geological time. Fossils species of tiny, delicate freshwater insects like the Talbragar fly are rare and help us interpret the history of life on our planet”.
The analysis of the fossilized specimens, combined with genomics, will help determine whether the dispersal of these insects after the breakup of Gondwana was primarily passive or active. The resulting data will certainly be of value for comprehending and conserving modern-day biodiversity.
