Latest news with #Quirks&Quarks
CBC
19-04-2025
- Science
- CBC
Apr 19: What the dinos did, and more...
On this week's episode of Quirks & Quarks with Bob McDonald: There's not a more vulnerable creature in nature than a baby bird. Tiny and immobile, they're easy pickings for predators. But the chicks of the white-necked jacobin hummingbird have evolved a unique defence. They disguise themselves as poisonous caterpillars to discourage those that might eat them. Jay Falk, an NSF postdoctoral fellow at the University of Colorado and Scott Taylor, director of the Mountain Research Station and associate professor at the University of Colorado, studied these birds in Panama. Their research was published in the journal Ecology. Seals can dive at length to tremendous depth thanks to some remarkable adaptations, like the ability to collapse their lungs, and radically lower their heart rate. Chris McKnight, a senior research fellow at the University of St Andrews Sea Mammal Research Unit in Scotland, led a study looking to see if tweaking oxygen and C02 levels changed the seals' dive times. The researchers discovered that the seals have the unique ability to measure the oxygen levels in their tissues, so they can anticipate when they need to return to the surface before they get into trouble. The research was published in the journal Science. As the joke goes, time flies like an arrow, fruit flies like a banana. Researchers recently demonstrated that fruit flies enjoy more than just aged produce. Using a custom carousel built to fly scale, scientists found that some, but not all, of their fruit flies would play on it, enjoying an activity that had nothing to do with the necessities of life. This brings up the possibility of variability in personality for fruit flies. Wolf Hütteroth is an associate professor at Northumbria University, Newcastle and was part of the team, whose research was published in the journal Current Biology. Krill, the small, shrimp-like creatures that swarm the world's oceans and are particularly abundant in southern oceans, play a big role in marine food webs, connecting microscopic organisms with many of the oceans' larger animal species. Researchers in Australia investigated how krill respond to predator cues, like the smell of their feces. Nicole Hellessey, from the University of Tasmania, said the mere whiff of penguin feces affects the Antarctic krills' feeding behaviour and causes them to take frantic evasive action. The study is published in the journal Frontiers in Marine Science. Dinosaur bones can tell amazing stories about these prehistoric beasts, but how do we piece together how they behaved? A new book dives into the many lines of evidence that can shed light on the behaviour of these extinct creatures. From fossils, to tracks they left behind, to their modern day descendents, paleontologist David Hone from Queen Mary University of London explores how scientists develop robust theories about how dinosaurs lived in his new book, Uncovering Dinosaur Behavior: What They Did and How We Know.
CBC
11-04-2025
- Science
- CBC
De-extinction or pre-extinction? Biotech company's resurrected 'dire wolves' raise questions
American biotech company Colossal Biosciences has announced they have created the "world's first successfully de-extincted animal," using ancient DNA and gene-editing technology to create hybrid puppies that they are calling resurrected dire wolves. So far, three snow white pups have been born — two males and a female — and they're being kept in an undisclosed location in the northern U.S., a region where ancient dire wolves likely roamed before going extinct 13,000 years ago. This is controversial for a number of reasons. First, the new animals are not real dire wolves, they are hybrids that resemble the extinct animals. The company made 20 edits on 14 grey wolf genes to create traits specific to dire wolves, like white coats, bigger heads and longer fur. But grey wolves have more than 20,000 genes, so the newcomers are still mostly grey wolves. It is not known whether these animals will be able to breed with each other. The company also has plans to bring back the woolly mammoth using modern elephants as a template. They have already created a woolly mouse by editing mouse genes with known woolly mammoth mutations. The company has also said it's exploring reviving the dodo, using a chicken as a template. If successful, these so-called de-extinct animals will be unique in the world. However, while it would be an amazing experience to see a living woolly mammoth — or an elephant that resembles one — that animal could end up as an oddity in a zoo, captive and alone for the rest of its life. Colossal Biosciences chief scientist Beth Shapiro told Quirks & Quarks via email that is not their intention. "While there's something poignant about a lone mammoth facing an altered planet, Colossal's vision is decidedly not that. Our approach focuses on establishing viable populations over time, not just individual animals," she wrote. "For these social groups to thrive, they need a place to live to which they are adapted. Ultimately, we need not only to recreate lost species, but also actively restore aspects of their original ecosystems — bridging conservation and restoration." One problem is that the ice age environment these animals lived in no longer exists. The Arctic and the rest of the planet has warmed a great deal since they inhabited it, and the trend continues today. That means the animals will have to adapt to a new environment, or special habitats created to care for them. While the production of genetically modified animals that resemble extinct species is a novel demonstration of the power of modern gene-editing techniques, it would require a tremendous effort, including significant technological breakthroughs and millions — if not billions — of dollars to bring back thundering herds of woolly mammoths or sky-darkening flocks of passenger pigeons. There are also ethical considerations, considering cloned animals have a low survival rate and there are serious risks to the surrogate mothers. It invites the question of whether those resources would be better used to halt the extinction of current species, which humans are driving at an alarming rate. A 2017 study found that, given limited conservation resources, the cost of just protecting animals that had been brought back from extinction would mean the decline and potential loss of more species that might currently be on the brink, leading to net biodiversity loss. These considerations are something we've talked about on Quirks & Quarks many times, including with Beth Shapiro herself. Many scientists have suggested that we are now in what is known as the sixth great extinction in the history of our planet — the previous one being the catastrophe that ended the reign of the dinosaurs. Species are being driven out of existence by human activity, including the loss of their natural habitat, and climate change. Some estimate that the current rate of extinction is somewhere between 1,000 and 10,000 times above the natural extinction rate. Colossal says that their work will help with conservation efforts by bringing back creatures whose ecosystem functions are now missing on the planet. But bringing the current extinction event to a halt will have more far reaching effects than a few wildlife refuges for rare beasts. Working at the pre-extinction side of the process could solve many other environmental problems that are affecting the human species as well. After all, if we can just stop destroying the environment and driving these animals to extinction, we won't have to worry about the ethics or controversies surrounding bringing them back from the dead.
CBC
05-04-2025
- Science
- CBC
Apr 5: Our bodies and brains fight weight loss, and more...
On this week's episode of Quirks & Quarks with Bob McDonald: A Canadian team is developing minimally-invasive micro-tools for brain surgery that can be operated by magnetic fields from outside of the skull. The tools, including scalpels and forceps, will enter the cranium through small incisions, and then be controlled by focused and precise magnetic fields. Eric Diller is associate professor of mechanical and industrial engineering at the University of Toronto and his team's research was published in the journal Science Robotics. In recent decades scientists have discovered animals from primates to birds and marine mammals can use tools — a capacity once thought to be exclusive to humans. Now scientists have discovered fish using hard surfaces to crack open hard-shelled prey and get at the meaty meal inside. The research, led by Juliette Tariel-Adam from Macquarie University, included recruiting divers and scientists from around the world to report any sightings of tool use, which led to 16 reports across five species of wrasses. The results were published in the journal Coral Reefs. WATCH: Tool use by a yellowhead wrasse in South Caicos Island: For a hardy few, soaking in cold water has long been held out as being healthful and invigorating. Well, unfortunately, the latest research suggests that they're right. Volunteers who soaked in cold water for an hour a day for a week showed improvements in autophagy, an important cellular clean-up function that typically declines with age. Kelli King is a postdoctoral researcher at the University of Ottawa and was co-lead on this study, published in the journal Advanced Biology. The narwhal is a small whale distinguished by its long spiral horn — an elongated tooth. Researchers have long speculated about what the ostentatious bit of dentition is actually for, but the elusive narwhal has, until now, been hard to study. Now scientists, including Cortney Watt from Fisheries and Oceans Canada, have used drones to learn that the horn is used in several ways: to play, explore and forage. The research was published in the journal Frontiers in Marine Science. New research is revealing why it's so difficult to keep weight off after you've lost it. One study in Nature found that genes in the fat cells of people who lost a significant amount of weight through bariatric surgery largely continued to behave as if they were still obese. Ferdinand von Meyenn, from ETH Zurich, said that despite these individuals becoming, in many respects, much more healthy, genes that became active during obesity remained active, and genes that were turned off, remained turned off, predisposing them to regain lost weight. In formerly obese mice, their fat cells remained much better at taking up sugars and fats. In addition, another study revealed that neurons in a primitive part of the brain hold onto memories of fat and sugar that can drive our cravings, according to a study on mice in Nature Metabolism. Guillaume de Lartigue, from the Monell Chemical Senses Center and the University of Pennsylvania, said specific neural circuits in the brain light up, depending on whether the gut received sugar or fat. Removing these neurons protected the mice from diet-induced weight gain, something de Lartigue is hoping to translate to humans to dial down impulsive eating behaviour.
CBC
21-03-2025
- Health
- CBC
Beyond long COVID — how reinfections could be causing silent long-term organ damage
COVID may no longer be considered an official global emergency, but mounting scientific evidence suggests every COVID infection a person gets increases their risk of developing long-term health issues. "There is no such thing as a COVID infection without consequence," says long COVID researcher, David Putrino, from the Icahn School of Medicine at Mount Sinai in New York. The long-term effects can show up as long COVID, with symptoms such as shortness of breath, digestive problems, fast or irregular heartbeats, extreme fatigue and brain fog, or as silently accumulating cellular or organ damage. Putrino has been studying the lingering effects of COVID since early in the pandemic five years ago. Here is part of his conversation with Quirks & Quarks host Bob McDonald. What kind of cumulative, silent damage can a COVID infection cause, beyond long COVID? There is more and more literature emerging to show that, beyond long COVID, there are also effects that SARS-CoV-2 infections are having on the bodies of the general public that manifest in a way that might be viewed as silent. So what I mean by that is no one's going to their doctor and saying "I feel different" or "I feel as though my functional status has changed," but what's happening is, silently in the background, things are changing. For the longest time in the field of immunology, there was the sort of adage that your immune system needs to be tested every now and again to stay strong. That's an old-fashioned idea. A good example of that is the effect that SARS-CoV-2 infections can have on cognition. There was a recent 2024 study that showed us that individuals who survive an acute COVID-19 infection — these are not individuals who are getting diagnosed with long COVID — on average will lose somewhere in the neighbourhood of two to six IQ points per infection. Really, with each infection? According to the most recent study, yes. So there is a cumulative effect that can be occurring with each infection. Early in the pandemic, we actually published a paper where we showed that, even in animal models — when we infected mice with a very, very mild case of SARS-CoV-2 infection — which only caused lung inflammation, we still saw these inflammatory chemicals called chemokines emerging from the infected lungs and starting to attack central nervous system structures such as the spinal cord and the brain. Wow. So in other words, COVID is doing more than just infecting the lungs; it's going to other parts of the body. Exactly. You know, this is a virus that, once it enters the body, is very capable of entering the bloodstream, creating immune responses that travel all over the body. COVID is largely known as a respiratory disease. Can you walk me through the range of other body systems that might be vulnerable to long-term damage? Well, in all of the peer-reviewed literature that has emerged on long COVID, we've seen that it is a very diffuse clinical syndrome where every single organ system can be affected. And at last count, over 200 symptoms have been catalogued as potential symptoms of long COVID. When we actually dig into the science of why long COVID is causing the symptoms that it's causing, we see that there are problems such as what we call " viral persistence." Meaning the SARS-CoV-2 virus is not being effectively cleared by the body and it's sticking around. It's hiding out in different areas of the body in what we typically call "immune privileged sites," which mean that immune cells don't actually go there and can't sort of seek out and destroy the virus. So that can happen in a number of different locations in the body, which leads to a wide array of symptoms. We also see that the virus can cause prolonged chronic inflammation that can be whole-body wide. So it can affect every single organ and so often, many of the symptoms that people are experiencing are more related to which organ is most susceptible to them given their past medical history. So we see things that are quite insidious. People who were pre-diabetic are suddenly diabetic. People who were having a few issues with gallbladder, suddenly can't digest fat anymore. Well, what is it about the coronavirus that enables it to spread throughout the body like that? In 2021, two colleagues of mine published a really wonderful paper that I think is very prescient and it spoke about why SARS-CoV-2 presents such an increased threat to cause persistent symptoms. The reality of that situation is that this virus has a lot of very unique qualities that specifically cause immune damage to the host. So it's not just about infecting you and causing respiratory illness and fever and all of the things that we usually get with the viral infection. This virus also specifically causes your immune system to become weaker. It disrupts what we call "interferon signalling," which is part of the immune system that helps you to fight off infections or latent infections, such as Epstein Barr virus. Typically our immune system can keep these things suppressed, but when SARS-CoV-2 enters the picture, it starts to cause altered interferon signalling. It causes immune damage and dysregulation. Although your immune system can take on [a COVID] infection, you want to avoid testing it as much as possible because your body is sustaining damage with each infection that it survives. And suddenly, not only does your body have trouble clearing the SARS-CoV-2 virus itself, but it also starts to have trouble keeping some of these other viruses that have been latent from reactivating and causing problems. In addition to SARS-CoV-2's ability to dysregulate the immune system and suppress the immune system, the spike protein itself is very damaging to blood vessel structures as well as red blood cells and platelets themselves. And so between those two features, the ability to dysregulate the immune system and the ability to cause systemic damage throughout the bloodstream, you have a very dangerous novel virus on your hands. Well, if it has the ability to suppress the immune system, how does that affect our ability to fight off other external pathogens that we might be susceptible to? It's something that we worry about a lot. In 2023, we published a paper in Nature where we showed that individuals with long COVID were much more likely than a cohort of healthy controls to express signs of what we call "T-cell exhaustion." Meaning that their T cells, which are parts of the immune system that are typically used to fight off infections, are starting to present as exhausted — that there has been a persistent stimulation of these T cells for long enough that their responses over time are starting to weaken. As a result, in this study we saw immune dysregulation, we saw hormonal dysregulation, we saw reactivation of herpes viruses that were previously thought to be latent. And as we have made leaps and bounds in our ability to understand the role of these persistent pathogens, these things that we used to think, "Everybody's got Epstein-Barr virus, but don't worry, it sort of just lays dormant in your body and it doesn't cause any trouble." What we're learning is that, well, it very much can cause trouble. If it's mixed with another pathogen and that pathogen causes the reactivation, then people can get very, very sick. For the longest time in the field of immunology, there was the sort of adage that your immune system needs to be tested every now and again to stay strong. That's an old-fashioned idea.
CBC
08-03-2025
- Science
- CBC
Feb 8: The rapidly changing Arctic, and more
On this episode of Quirks & Quarks with Bob McDonald A little bit of scratching can do some good, but too much can hurt Scratching an itch can feel great, so scientists decided to dig into why that is the case since we know too much scratching isn't good for us. Dr. Dan Kaplan, a professor of dermatology and immunology at the University of Pittsburgh, said they found that scratching drives inflammation to the skin, which, in light moderation, helps to fight bacterial skin infections. But he warns that continual or excessive scratching can prolong an itch and potentially damage the skin. Their study is in the journal Science. A wildlife manager in the US has found that drones can be a safe and effective way to discourage problem bears from troubling human habitation and livestock. Wesley Sarmento started working in the prairies of Montana to prevent bear-human conflicts, but found the usual tricks of the trade were not as effective as he wanted them to be. Previously he tried to use noisemakers, dogs, trucks, and firearms, but buzzing bears with flying robots turned out to work much better. Now a PhD student at the University of Montana, he published an article about his hazing research in Frontiers in Conservation Science. Wildlife manager says drones are 'magic tools' to help reduce bear-human conflicts 29 days ago Duration 0:42 Research biologist and former wildlife manager Wesley Sarmento started using drones to chase bears away from people, and found that it was much safer and more precise than traditional methods. Ants can remember and hold grudges against those who trouble them When ants fight with those from another nearby colony, it makes an impression. A new study has found the insects can remember the chemical signature of the aggressors, and will respond more vigorously and violently the next time they cross paths. Volker Nehring, a researcher at the University of Freiburg, Germany, describes the phenomenon as "the nasty neighbour" where ants are most aggressive to ant colonies closest to them, and says this is due to resource protection. Nehring and his team's research was published in the journal Current Biology. Scientists on the front line of permafrost thaw describe changes in the Arctic The acceleration of change in the Arctic due to global warming is transforming the landscape on a year-to-year basis, often in surprising ways. That's according to scientists who've been studying the effects of climate change in the North. One study found that lakes in Western Greenland shifted from pristine blue to dirty brown from one year to the next due to increased permafrost melting and runoff. Jasmine Saros, a lake ecologist from the University of Maine, said they were astonished by the magnitude of change they saw in all 10 lakes they studied and how quickly it happened. That study was published in the journal PNAS. We also speak with William Quinton, a permafrost hydrologist from Wilfrid Laurier University and the director of the Scotty Creek Research Station in southern Northwest Territories, an area he describes as "the frontline of permafrost thaw." Quinton was part of a research team, led by Anna Virkkala from the Woodwell Climate Research Centre, that found that 34 per cent of the Arctic Boreal Zone — a region where carbon was safely locked up in the permafrost for thousands of years — has now become a carbon source. That study is in the journal Nature Climate Change.
