From the timing of black hole eruptions to the quiet retreat of wolverines from ski trails, science this week has been in the business of revising certainty. Researchers across disciplines have uncovered formulas where there was once only waiting, found disruption where we assumed harmony, and heard sounds from 165 million years ago that no living ear has ever known. Perhaps most unsettling of all, the very categories we use to judge what belongs in nature—native, invasive, good, harmful—are proving far less stable than we once believed.
Black holes' timing mystery solved; wolverines face human pressure
The old certainties about what belongs are dissolving
Mark
So astronomers have figured out when black holes are going to burp? How does that actually help them?
Mimi
It means they can point their telescopes at the right time instead of just hoping. These jets are rare and powerful, and telescope time is expensive. If you know when to look, you catch the event.
Luke
But the study just identifies the formula—it doesn't say how far in advance you can predict. Can they see it coming days ahead, or hours?
Mimi
That's a fair question. The source doesn't specify the prediction window.
Mark
And the wolverine study—they found fewer wolverines where people ski and hike. Is that because the animals are avoiding those areas, or because they're dying?
Mimi
The study shows correlation, not mechanism. Fewer wolverines in overlapping zones. Whether they're being displaced or killed or just avoiding people, the paper doesn't say.
Luke
Three hundred wolverines across an area the size of Austria. That's a density figure, but we don't know if that's healthy or declining compared to historical numbers.
Mark
The spiny water flea thing is wild—it's been here centuries longer than we thought. Does that change whether we try to get rid of it?
Mimi
That's exactly what Tanentzap's work raises. If it's been here that long, calling it invasive starts to feel arbitrary.
Luke
But the source doesn't say whether the flea's presence has actually changed. It could have been here for centuries at low numbers and only recently exploded. Timing alone doesn't tell you impact.
Il Polso
- Astronomers have long wasted precious telescope hours waiting for black hole jets that may never come during their watch—a new predictive formula could end that guesswork entirely.
- Wolverines are quietly disappearing from mountain corridors not because of industry or poaching, but because of hikers and skiers who believe they are leaving nature undisturbed.
- A 165-million-year-old katydid was producing ultrasonic calls long before scientists thought such biological sophistication was possible, rewriting the acoustic history of life on Earth.
- The spiny water flea, North America's notorious aquatic invader, may have arrived centuries before the ship ballast water story we've been telling—raising the question of whether 'invasive' still means anything.
- A sweeping meta-analysis finds no reliable link between a species being native and an ecosystem being healthy, threatening one of conservation biology's most foundational assumptions.
From the timing of black hole eruptions to the quiet retreat of wolverines from ski trails, science this week has been in the business of revising certainty. Researchers across disciplines have uncovered formulas where there was once only waiting, found disruption where we assumed harmony, and heard sounds from 165 million years ago that no living ear has ever known. Perhaps most unsettling of all, the very categories we use to judge what belongs in nature—native, invasive, good, harmful—are proving far less stable than we once believed.
When a black hole consumes a star, it doesn't simply absorb the material—it launches violent jets of high-energy particles outward into space. For astronomers, witnessing these events has been largely a matter of luck, with vast telescope time spent in fruitless waiting. Astrophysicist Adelle Goodwin and colleagues have now published a formula in Nature Astronomy that predicts when these bursts will occur, potentially transforming how observation resources are allocated worldwide.
On the ground in Canada's mountain ranges, wolverines are declining in ways that implicate an unlikely culprit. A three-year study tracking 300 wolverines across a region the size of Austria found that populations were consistently lower wherever backcountry skiing and hiking overlapped with wolverine habitat. Published in Biological Conservation, the research suggests that even recreation we consider low-impact is quietly redrawing the boundaries of where these fierce, territorial animals can survive.
Deeper in time, researchers at the University of Lincoln reconstructed the sounds of a Jurassic forest by studying the fossilized wings of ancient katydids and crickets, some 165 million years old. By modeling how those wing structures would have vibrated, they recreated calls that haven't been heard since the age of dinosaurs—and discovered that at least one species was already producing ultrasonic frequencies far earlier than anyone had imagined.
The question of what truly belongs in an ecosystem is proving equally unstable. The spiny water flea, long blamed on 1980s European ship ballast water, turns out to have arrived in North American lakes decades or centuries earlier, according to environmental DNA and radiocarbon dating conducted by Andrew Tanentzap's team at Trent University. And a separate meta-analysis by Erick Lundgren at the University of Alberta found no consistent relationship between a species being native and an ecosystem being healthy. Together, these findings suggest that the categories scientists and conservationists have long relied upon—native, invasive, beneficial, harmful—may be flattening a far more complex and ancient reality.
Black holes have long fascinated astronomers not just for their gravitational pull, but for what happens after they feed. When a black hole consumes a star, it doesn't simply swallow the material whole. Instead, it launches jets of high-energy particles outward into space—a violent release sometimes described as a burp. The problem for researchers has always been timing. These outflows are powerful and rare enough that astronomers spend enormous amounts of telescope time hoping to witness one, often without success. A team of astrophysicists, including Adelle Goodwin, a Forrest Research Foundation Fellow at ICRAR-Curtin University, has now cracked the code. Their work, published in Nature Astronomy, identifies the formula that predicts when these bursts will occur, potentially transforming how scientists allocate their observation resources.
Meanwhile, on the ground in North America's mountain ranges, a different kind of pressure is reshaping wildlife populations. Wolverines—small, fierce carnivores known for their territorial aggression—are declining in parts of Canada, and researchers have begun to understand why. Mirjam Barreuto and colleagues conducted a three-year study across the Rocky Mountain and Columbia Mountain ranges, using frozen beaver carcasses as bait to track wolverine populations. They identified 300 wolverines across an area roughly the size of Austria. What emerged from their work, published in Biological Conservation, was a clear pattern: wolverine numbers were lower in regions where backcountry skiing, hiking, and other human recreational activities overlapped with their habitat. The study suggests that even activities we think of as low-impact are reshaping where these animals can survive.
Further back in time, scientists have reconstructed the soundscape of a Jurassic forest using an unexpected archive: fossilized insect wings. Fernando Montealegre-Zapata and colleagues at the University of Lincoln examined 20 fossils from nine species of ancient katydids and crickets, all roughly 165 million years old, recovered from Inner Mongolia. By studying how the insects' wing structures would have vibrated against each other, the researchers recreated the calls these creatures likely produced. The findings, published in PNAS, revealed something surprising: one species generated calls in the ultrasonic range—frequencies beyond human hearing—far earlier than scientists had believed possible. The discovery pushes back the timeline for when insects developed this sophisticated acoustic capability.
The question of how long a species has actually been present in an ecosystem is reshaping how scientists think about invasive species and environmental health. The spiny water flea, a tiny crustacean, has long been considered one of North America's most destructive aquatic invaders, introduced from Europe via ship ballast water in the 1980s—or so the story went. Andrew Tanentzap, a professor and Canada Research Chair in Climate Change and Northern Ecosystems at Trent University, used environmental DNA and radiocarbon dating to examine hundreds of spiny water flea fossils buried in lake sediments. His team's work, also published in PNAS, revealed that these creatures arrived decades, possibly centuries, earlier than previously documented. The finding raises a fundamental question: if a species has been present far longer than we realized, does calling it invasive still make sense?
This reframing has broader implications for how we understand ecosystem health. The conventional wisdom holds that native species strengthen ecosystems while introduced species damage them. But Erick Lundgren, a postdoctoral researcher at the Centre for Open Science and Research Synthesis at the University of Alberta, has challenged this assumption. His meta-analysis, published in Nature Communications, compared hundreds of studies examining the effects of native African megafauna against introduced megafauna on ecosystem health. The analysis found no clear correlation between an animal's nativeness and the health of the ecosystem it inhabits. The work suggests that our categories—native versus invasive, good versus bad—may be oversimplifying how ecosystems actually function. As researchers continue to uncover the deeper history of species movement and adaptation, the old certainties about what belongs and what doesn't are beginning to dissolve.
Citazioni salienti
Ecosystem health didn't seem to be affected by an animal's nativeness— Erick Lundgren, postdoctoral researcher at the Centre for Open Science and Research Synthesis, University of Alberta
Vuoi la storia completa?
Leggi l'originale su CBC ↗