Category: 7. Science

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Here’s what you’ll learn when you read this story:

• A remarkable fossilized larva has been discovered by scientists with its brain and guts still intact.

• The fossilized creature is one of the earliest ancestors of a group known as arthropods, which includes insects, crabs, and lobsters.

• A unique window into the past, the ancient critter has allowed experts a chance to better understand evolutionary links between the arthropods of the past and those of the present day.

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We know what fossils look like. For example, typical dinosaur fossils are bones turned to stone and preserved from the passage of time located, if we’re particularly lucky, in large collections that can be reassembled to represent the beast they used to prop up in their entirety.

Now, not all fossils are like that. Some are just impressions of small creatures or animals left in rocks, but most have something in common—it’s just the hard stuff left behind. With the exception of those found in environments particularly adept at preservation, the soft tissues degrade over time and all we’re left with is stony bone.

But not always. Sometimes we get lucky—like a team did when it located a fossil of a 520-million-year-old worm larva that still had its brain and guts intact.

“It’s always interesting to see what’s inside a sample using 3D imaging,” Katherine Dobson, one of the co-authors of a study centered on this remarkable find, said in a press release, “but in this incredible tiny larva, natural fossilization has achieved almost perfect preservation.”

That “almost perfect preservation” made the specimen an absolute gold mine for evolutionary biologists.

According to the press release, the structures observed within the creature—which were studied via 3D images generated from scans made using a technique known as synchrotron X-ray tomography—include a brain, “digestive glands, a primitive circulatory system and even traces of the nerves supplying the larva’s simple legs and eyes.” The incredible amount of detail preserved in this ancient fossil showed scientists that we had previously dramatically underestimated the complexity of early arthropods—a group that came into being during the Cambrian Explosion and includes creatures like crabs, lobsters, insects, and millipedes.

That detail also allowed scientists to draw evolutionary connections between the critters of the ancient past and those scuttling around today. For example, preserved in the larva was a region of the brain known as the protocerebrum. Now that scientists have seen it, they can see that it evolved into the “nub” of arthropod heads that has allowed them to thrive in such a wide variety of environments—from the depths of the ocean to every single continent on Earth (yes, including Antarctica).

“When I used to daydream about the one fossil I’d most like to discover,” Martin Smith, the lead researcher on the study, said in a press release, “I’d always be thinking of an arthropod larva, because developmental data are just so central to understanding their evolution. But larvae are so tiny and fragile, the chances of finding one fossilized are practically zero—or so I thought! I already knew that this simple worm-like fossil was something special, but when I saw the amazing structures preserved under its skin, my jaw just dropped—how could these intricate features have avoided decay and still be here to see half a billion years later?”

Right now, the scientists are happily counting themselves lucky that the creature was preserved at all, giving us a unique window into what life looked like in our distant past.

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The outer planets: Jupiter, Saturn, Uranus, and Neptune, have long fascinated astronomers and the public alike. These gas and ice giants, orbiting far beyond the asteroid belt, were once invisible worlds, discernible only through telescopes. Since the 1970s, humanity has extended its reach into this distant region of the Solar System, sending robotic explorers to unlock the mysteries of these massive planets. The journey has been painstaking, requiring decades of planning, gravity assists, and innovative spacecraft engineering.

Rivers generally come in two styles: braided, where multiple channels flow around sandy bars, and meandering, where a single channel cuts S-curves across a landscape. Geologists have long thought that before vegetation, rivers predominantly ran in braided patterns, only forming meandering shapes after plant life took root and stabilized riverbanks.

The new study, which was published online by the journal Science on Aug. 21, 2025, suggests the theory that braided rivers dominated the first 4 billion years of Earth’s history is based on a misinterpretation of the geological record. The research demonstrates that unvegetated meandering rivers can leave sedimentary deposits that look deceptively similar to those of braided rivers. This distinction is crucial for our understanding of Earth’s early ecology and climate, as a river’s type determines how long sediment, carbon, and nutrients are stored in floodplains.

“With our study, we’re pushing back on the widely accepted story of what landscapes looked like when plant life first evolved on land,” said lead author Michael Hasson, a PhD student in Mathieu Lapôtre’s lab at the Stanford Doerr School of Sustainability. “We’re rewriting the story of the intertwined relationship between plants and rivers, which is a significant revision to our understanding of the history of the Earth.”

The muddy floodplains of meandering rivers – dynamic ecosystems created over thousands of years by river overflow – are among the planet’s most abundant non-marine carbon reservoirs. Carbon levels in the atmosphere, in the form of carbon dioxide, act as Earth’s thermostat, regulating temperature over vast timescales. Accurately budgeting for the carbon caches created by meandering rivers could help scientists build more comprehensive models of Earth’s ancient and future climate.

“Floodplains play an important role in determining how, when, and whether carbon is buried or released back into the atmosphere,” Hasson said. “Based on this work, we argue carbon storage in floodplains would have been common for much longer than the classic paradigm that assumes meandering rivers only occurred over the last several hundred million years.”

Where the river flows

To gauge vegetation’s impact on river channel patterns, the researchers examined satellite imagery of about 4,500 bends in 49 current-day meandering rivers. About half of the rivers were unvegetated and half were densely or partly vegetated.

The researchers keyed in on point bars – the sandy landforms that develop on the inside bends of meandering rivers as water flow deposits sediments. Unlike the sandy bars that form in the middle of braided rivers, point bars tend to migrate laterally away from the centers of rivers. Over time, this migration contributes to meandering rivers’ characteristically sinuous channel shapes.

Recognizing that these sandy bars form in different places based on river style, geologists for decades have measured the trajectory of bars in the rock record to reveal ancient river paths. The rocks, typically of sandstones and mudstones, provide evidence for divergent river styles because each deposits different kinds of and amounts of rock-forming sediment, giving geologists clues for reconstructing long-ago river geometries. If sandstones showed little variation in the angle of bar migration, geologists interpreted the bars as moving downstream, and thus that a braided river created the deposits.

Using this technique, geologists had noticed that rivers changed the way they behaved around the time that plants first evolved on Earth. This observation led to the conclusion that land plants made river meandering possible, for instance by trapping sediment and stabilizing riverbanks.

“In our paper, we show that this conclusion – which is taught in all geology curricula to this day – is most likely incorrect,” said Lapôtre, the paper’s senior author and an assistant professor of earth and planetary sciences at the Doerr School of Sustainability.

By looking at modern rivers with a wide range of vegetation cover, the researchers showed that plants consistently change the direction of point bar migration. Specifically, in the absence of vegetation, point bars tend to migrate downstream – like mid-channel bars do in braided rivers.

“In other words, we show that, if one were to use the same criterion geologists use in ancient rocks on modern rivers, meandering rivers would be miscategorized as braided rivers,” Lapôtre said.

Rivers over time

The findings offer a provocative new window into Earth’s past eons, upending the conventional picture of how rivers have sculpted continents. If indeed carbon-loaded floodplains were laid down far more extensively over history, scientists may need to revise models of major natural climate swings over time, with implications for our understanding of ongoing climate change.

“Understanding how our planet is going to respond to human-induced climate change hinges on having an accurate baseline for how it has responded to past perturbations,” Hasson said. “The rock record provides that baseline, but it’s only useful if we interpret it accurately.”

“We’re suggesting that an important control on carbon cycling – where carbon is stored, and for how long, due to river type and floodplain creation – hasn’t been fully understood,” he said. “Our study now points the way to better assessments.”

Additional co-authors are from the University of Padova and the University of British Columbia.

NASA’s Juno spacecraft has been orbiting Jupiter since 2016, peeling back layers of mystery around the Solar System’s largest planet. From colossal storms at the poles to a surprisingly diffuse ‘fuzzy’ core, Juno’s data is rewriting our understanding of Jupiter’s structure and violent history. The mission is revealing a world far more dynamic and complex than previously imagined, challenging decades of scientific assumptions and offering clues about how gas giants, and possibly other planetary systems, form and evolve. Each discovery pushes the boundaries of planetary science, bringing us closer to understanding the giant at the heart of our solar system.

The team members went through a process of incrementally determining what elements and molecules the bacterial strain could grow on. They already knew it could use oxygen, so they tested other combinations in the lab. When oxygen was absent, RSW1 could process hydrogen gas and elemental sulfur—chemicals it would find spewing from a volcanic vent—and create hydrogen sulfide as a product. Yet while the cells were technically alive in this state, they didn’t grow or replicate. They were making a small amount of energy—just enough to stay alive, nothing more. “The cell was just sitting there spinning its wheels without getting any real metabolic or biomass gain out of it,” Boyd said.

Then the team added oxygen back into the mix. As expected, the bacteria grew faster. But, to the researchers’ surprise, RSW1 also still produced hydrogen sulfide gas, as if it were anaerobically respiring. In fact, the bacteria seemed to be breathing both aerobically and anaerobically at once, and benefiting from the energy of both processes. This double respiration went further than the earlier reports: The cell wasn’t just producing sulfide in the presence of oxygen but was also performing both conflicting processes at the same time. Bacteria simply shouldn’t be able to do that.

“That set us down this path of ‘OK, what the heck’s really going on here?’” Boyd said.

Breathing Two Ways

RSW1 appears to have a hybrid metabolism, running an anaerobic sulfur-based mode at the same time it runs an aerobic one using oxygen.

“For an organism to be able to bridge both those metabolisms is very unique,” said Ranjani Murali, an environmental microbiologist at the University of Nevada, Las Vegas, who was not involved in the research. Normally when anaerobic organisms are exposed to oxygen, damaging molecules known as reactive oxygen compounds create stress, she said. “For that not to happen is really interesting.”

Boyd’s team observed that the bacteria grew best when running both metabolisms simultaneously. It may be an advantage in its unique environment: Oxygen isn’t evenly distributed in hot springs like those where RSW1 lives. In constantly changing conditions, where you could be bathed in oxygen one moment only for it to disappear, hedging one’s metabolic bets might be a highly adaptive trait.

Other microbes have been observed breathing two ways at once: anaerobically with nitrate and aerobically with oxygen. But those processes use entirely different chemical pathways, and when paired together, they tend to present an energetic cost to the microbes. In contrast, RSW1’s hybrid sulfur/oxygen metabolism bolsters the cells instead of dragging them down.

This kind of dual respiration may have evaded detection until now because it was considered impossible. “You have really no reason to look” for something like this, Boyd said. Additionally, oxygen and sulfide react with each other quickly; unless you were watching for sulfide as a byproduct, you might miss it entirely, he added.

It’s possible, in fact, that microbes with dual metabolisms are widespread, Murali said. She pointed to the many habitats and organisms that exist at tenuous gradients between oxygen-rich and oxygen-free areas. One example is in submerged sediments, which can harbor cable bacteria. These elongated microbes orient themselves in such a way that one end of their bodies can use aerobic respiration in oxygenated water while the other end is buried deep in anoxic sediment and uses anaerobic respiration. Cable bacteria thrive in their precarious partition by physically separating their aerobic and anaerobic processes. But RSW1 appears to multitask while tumbling around in the roiling spring.

It’s still unknown how RSW1 bacteria manage to protect their anaerobic machinery from oxygen. Murali speculated that the cells might create chemical supercomplexes within themselves that can surround, isolate and “scavenge” oxygen, she said—using it up quickly once they encounter it so there is no chance for the gas to interfere with the sulfur-based breathing.

RSW1 and any other microbes that have dual metabolism make intriguing models for how microbial life may have evolved during the Great Oxygenation Event, Boyd said. “That must have been a quite chaotic time for microbes on the planet,” he said. As a slow drip of oxygen filtered into the atmosphere and sea, any life-form that could handle an occasional brush with the new, poisonous gas—or even use it to its energetic benefit—may have been at an advantage. In that time of transition, two metabolisms may have been better than one.

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Original story reprinted with permission from Quanta Magazine, an editorially independent publication of the Simons Foundation whose mission is to enhance public understanding of science by covering research developments and trends in mathematics and the physical and life sciences.

About 1,000 of a set of 15,000 open access scientific journals appear to exist mainly to extract fees from naive academics.

A trio of computer scientists from the University of Colorado Boulder, Syracuse University, and China’s Eastern Institute of Technology (EIT) arrived at this figure after building a machine learning classier to help identify “questionable” journals and then conducting a human review of the results – because AI falls short on its own.

A questionable journal is one that violates best practices and has low editorial standards, existing mainly to coax academics into paying high fees to have their work appear in a publication that fails to provide expected editorial review.

As detailed in a research paper published in Science Advances, “Estimating the predictability of questionable open-access journals,” scientific journals prior to the 1990s tended to be closed, available only through subscriptions paid for by institutions. 

The open access movement changed that dynamic. It dates back to the 1990s, as the free software movement was gaining momentum, when researchers sought to expand the availability of academic research. One consequence of that transition, however, was that costs associated with peer-review and publication were shifted from subscribing organizations to authors.

“The open access movement was set out to fix this lack of accessibility by changing the payment model,” the paper explains. “Open-access venues ask authors to pay directly rather than ask universities or libraries to subscribe, allowing scientists to retain their copyrights.”

Open access scientific publishing is now widely accepted. For example, a 2022 memorandum from the White House Office of Science and Technology Policy directed US agencies to come up with a plan by the end of 2025 to make taxpayer-supported research publicly available.

But the shift toward open access has led to the proliferation of dubious scientific publications. For more than a decade, researchers have been raising concerns about predatory and hijacked [PDF] journals. 

The authors credit Jeffrey Beall, a librarian at the University of Colorado, with applying the term “predatory publishing” in 2009 to suspect journals that try to extract fees from authors without editorial review services. An archived version of Beall’s List of Potentially Predatory Journals and Publishers can still be found. The problem with a list-based approach is that scam journals can change their names and websites with ease.

In light of these issues, Daniel Acuña (UC Boulder), Han Zhuang (EIT), and Lizheng Liang (Syracuse), set out to see whether an AI model might be able to help separate legitimate publications from the questionable ones using detectable characteristics (e.g. authors that frequently cite their own work).

“Science progresses through relying on the work of others,” Acuña told The Register in an email. “Bad science is polluting the scientific landscape with unusable findings. Questionable journals publish almost anything and therefore the science they have is unreliable. 

“What I hope to accomplish is to help get rid of this bad science by proactively helping flagging suspected journals so that professionals (who are scarce) can focus their efforts on what’s most important.”

Acuña is also the founder of ReviewerZero AI, a service that employs AI to detect research integrity problems.

Winnowing down a data set of nearly 200,000 open access journals, the three computer scientists settled on a set of 15,191 of them.

They trained a classifier model to identify dubious journals and when they ran it on the set of 15,191, the model flagged 1,437 titles. But the model missed the mark about a quarter of the time, based on subsequent human review.

“About 1,092 are expected to be genuinely questionable, ~345 are false positives (24 percent of the flagged set), and ~1,782 problematic journals would remain undetected (false negatives),” the paper says.

“At a broader level, our technique can be adapted,” said Acuña. “If we care a lot about false positives, we can flag more stringently.” He pointed to a passage in the paper that says under a more stringent setting, only five false alarms out of 240 would be expected.

Acuña added that while many AI applications today aim for full automation, “for such delicate matters as the one we are examining here, the AI is not there yet, but it helps a lot.”

The authors are not yet ready to name and shame the dubious journals – doing so could invite a legal challenge.

“We hope to collaborate with indexing services and assist reputable publishers who may be concerned about the degradation of their journals,” said Acuña. “We could make it available in the near future to scientists before they submit to a journal.” ®

Despite centuries of study, Jupiter still hides its deepest secrets. It has no solid surface, only layers of dense gas and possibly a core of rock or metallic hydrogen under immense pressure. Recent missions, particularly NASA’s Juno spacecraft, have revealed that Jupiter’s atmosphere is far more complex than previously thought, with ammonia storms, jet streams running thousands of kilometres deep, and strange ‘cyclone clusters’ circling its poles.

Scientists have suggested that when artificial intelligence (AI) goes rogue and starts to act in ways counter to its intended purpose, it exhibits behaviors that resemble psychopathologies in humans. That’s why they have created a new taxonomy of 32 AI dysfunctions so people in a wide variety of fields can understand the risks of building and deploying AI.

In new research, the scientists set out to categorize the risks of AI in straying from its intended path, drawing analogies with human psychology. The result is “Psychopathia Machinalis” — a framework designed to illuminate the pathologies of AI, as well as how we can counter them. These dysfunctions range from hallucinating answers to a complete misalignment with human values and aims.