Starving bacteria (cyan) use a microscopic harpoon—called the Type VI secretion system—to stab and kill neighboring cells (magenta). The prey burst, turning spherical and leaking nutrients, which the killers then use to survive and grow. (Image Credit: Glen D'Souza/ASU/Screen shot from video)NewsletterSign up for our email newsletter for the latest science newsBacteria are bad neighbors. And we’re not talking noisy, never-take-out-the-trash bad neighbors. We’re talking has-a-harpoon-gun-and-points-it-at-you bad neighbors. According to a new study in Science, some bacteria hunt nearby bacterial species when they’re hungry. Using a special weapon system called the Type VI Secretion System (T6SS), these bacteria shoot, spill, and then absorb the nutrients from the microbes they harpoon. “The punchline is: When things get tough, you eat your neighbors,” said Glen D’Souza, a study author and an assistant professor at Arizona State University, according to a press release. “We’ve known bacteria kill each other, that’s textbook. But what we’re seeing is that it’s not just important that the bacteria have weapons to kill, but they are controlling when they use those weapons specifically for situations to eat others where they can’t grow themselves.” According to the study authors, the research doesn’t just have implications for bacterial neighborhoods; it also has implications for human health and medicine. By harnessing these bacterial weapons, it may be possible to build better targeted antibiotics, designed to overcome antibiotic resistance. Ruthless Bacteria Use HarpoonsResearchers have long known that some bacteria can be ruthless, using weapons like the T6SS to clear out their competition. A nasty tool, the T6SS is essentially a tiny harpoon gun with a poison-tipped needle. When a bacterium shoots the weapon into another bacterium from a separate species, the needle pierces the microbe without killing it. Then, it injects toxins into the microbe that cause its internal nutrients to spill out.Up until now, researchers thought that this weapon helped bacteria eliminate their competition for space and for food, but after watching bacteria use the T6SS to attack their neighbors when food was scarce, the study authors concluded that these tiny harpooners use the weapon not only to remove rivals, but also to consume their competitors’ leaked nutrients.“Watching these cells in action really drives home how resourceful bacteria can be,” said Astrid Stubbusch, another study author and a researcher who worked on the study while at ETH Zurich, according to the press release. “By slowly releasing nutrients from their neighbors, they maximize their nutrient harvesting when every molecule counts.” Absorbing Food From NeighborsTo show that the bacteria used this system to eat when there was no food around, the study authors compared their attacks in both nutrient-rich and nutrient-poor environments. When supplied with ample resources, the bacteria used their harpoons to kill their neighbors quickly, with the released nutrients leaking out and dissolving immediately. But when resources were few and far between, they used their harpoons to kill their neighbors slowly, with the nutrients seeping out and sticking around. “This difference in dissolution time could mean that the killer cells load their spears with different toxins,” D’Souza said in another press release. While one toxin could eliminate the competition for space and for food when nutrients are available, another could create a food source, allowing bacteria to “absorb as many nutrients as possible” when sustenance is in short supply.Because of all this, this weapon system is more than ruthless; it’s also smart, and important to some species’ survival. When genetically unedited T6SS bacteria were put in an environment without food, they survived on spilled nutrients. But when genetically edited T6SS bacteria were placed in a similar environment, they died, because their ability to find food in their neighbors had been “turned off.”Harnessing Bacterial HarpoonsAccording to the study authors, the T6SS system is widely used by bacteria, both in and outside the lab. “It’s present in many different environments,” D’Souza said in one of the press releases. “It’s operational and happening in nature, from the oceans to the human gut.” The study authors add that their research could change the way we think about bacteria and could help in our fight against antibiotic resistance. In fact, the T6SS could one day serve as a foundation for targeted drug delivery systems, which could mitigate the development of broader bacterial resistance to antibiotics. But before that can happen, however, researchers have to learn more about bacterial harpoons, and about when and how bacteria use them, both to beat and eat their neighbors.Article SourcesOur writers at Discovermagazine.com use peer-reviewed studies and high-quality sources for our articles, and our editors review for scientific accuracy and editorial standards. Review the sources used below for this article:Sam Walters is a journalist covering archaeology, paleontology, ecology, and evolution for Discover, along with an assortment of other topics. Before joining the Discover team as an assistant editor in 2022, Sam studied journalism at Northwestern University in Evanston, Illinois.1 free article leftWant More? Get unlimited access for as low as $1.99/monthSubscribeAlready a subscriber?Register or Log In1 free articleSubscribeWant more?Keep reading for as low as $1.99!SubscribeAlready a subscriber?Register or Log In

Key Takeaways on Ant PoopDo ants poop? Yes. Any creature that eats will poop and ants are no exception. Because ants live in close quarters, they need to protect the colony from their feces so bacteria and fungus doesn't infect their health. This is why they use toilet chambers. Whether they isolate it in a toilet chamber or kick it to the curb, ants don’t keep their waste around. But some ants find a use for that stuff. One such species is the leafcutter ant that takes little clippings of leaves and uses these leaves to grow a very particular fungus that they then eat.Like urban humans, ants live in close quarters. Ant colonies can be home to thousands, even tens of thousands of individuals, depending on the species. And like any creature that eats, ants poop. When you combine close quarters and loads of feces, you have a recipe for disease, says Jessica Ware, curator and division chair of Invertebrate Zoology at the American Museum of Natural History. “Ant poop can harbor bacteria, and because it contains partly undigested food, it can grow bacteria and fungus that could threaten the health of the colony,” Ware says. But ant colonies aren’t seething beds of disease. That’s because ants are scrupulous about hygiene.Ants Do Poop and Ant Toilets Are RealAnt colony underground with ant chambers. (Image Credit: Lidok_L/Shutterstock)To keep themselves and their nests clean, ants have evolved some interesting housekeeping strategies. Some types of ants actually have toilets — or at least something we might call toilets. Their nests are very complicated, with lots of different tunnels and chambers, explains Ware, and one of those chambers is a toilet chamber. Ants don’t visit the toilet when they feel the call of nature. Instead, worker ants who are on latrine duty collect the poop and carry it to the toilet chamber, which is located far away from other parts of the nest. What Does Ant Poop Look Like? This isn’t as messy a chore as it sounds. Like most insects, ants are water-limited, says Ware, so they try to get as much liquid out of their food as possible. This results in small, hard, usually black or brownish pellets of poop. The poop is dry and hard enough so that for ant species that don’t have indoor toilet chambers, the workers can just kick the poop out of the nest.Ants Use Poop as FertilizerWhether they isolate it in a toilet chamber or kick it to the curb, ants don’t keep their waste around. Well, at least most types of ants don’t. Some ants find a use for that stuff. One such species is the leafcutter ant. “They basically take little clippings of leaves and use these leaves to grow a very particular fungus that they then eat,” says Ware. “They don't eat the leaves, they eat the fungus.” And yep, they use their poop to fertilize their crops. “They’re basically gardeners,” Ware says. If you’d like to see leafcutter ants at work in their gardens and you happen to be in the New York City area, drop by the American Museum of Natural History. They have a large colony of fungus-gardening ants on display.Other Insects That Use ToiletsAnts may have toilets, but termites have even wilder ways of dealing with their wastes. Termites and ants might seem similar at first sight, but they aren’t closely related. Ants are more closely related to bees, while termites are more closely related to cockroaches, explains Aram Mikaelyan, an entomologist at North Carolina State University who studies the co-evolution of insects and their gut microbiomes. So ants’ and termites’ styles of social living evolved independently, and their solutions to the waste problem are quite different.“Termites have found a way to not distance themselves from the feces,” says Mikaelyan. “Instead, they use the feces itself as building material.” They’re able to do this because they feed on wood, Mikaelyan explains. When wood passes through the termites’ digestive systems into the poop, it enables a type of bacteria called Actinobacteria. These bacteria are the source of many antibiotics that humans use. (Leafcutter ants also use Actinobacteria to keep their fungus gardens free of parasites.) So that unusual building material acts as a disinfectant. Mikaelyan describes it as “a living disinfectant wall, like a Clorox wall, almost.”Insect HygieneIt may seem surprising that ants and termites are so tidy and concerned with hygiene, but it’s really not uncommon. “Insects in general are cleaner than we think,” says Ware. “We often think of insects as being really gross, but most insects don’t want to lie in their own filth.”Article SourcesOur writers at Discovermagazine.com use peer-reviewed studies and high-quality sources for our articles, and our editors review for scientific accuracy and editorial standards. Review the sources used below for this article:The American Society of Microbiology. The Leaf-cutter Ant’s 50 Million Years of FarmingAvery Hurt is a freelance science journalist. In addition to writing for Discover, she writes regularly for a variety of outlets, both print and online, including National Geographic, Science News Explores, Medscape, and WebMD. She’s the author of Bullet With Your Name on It: What You Will Probably Die From and What You Can Do About It, Clerisy Press 2007, as well as several books for young readers. Avery got her start in journalism while attending university, writing for the school newspaper and editing the student non-fiction magazine. Though she writes about all areas of science, she is particularly interested in neuroscience, the science of consciousness, and AI–interests she developed while earning a degree in philosophy.

The epidermis (skin) is the body’s largest organ, so it would make sense that toxins found in fabrics that sit on the skin’s surface could be absorbed by the skin and make their way into the bloodstream. And polyester has been considered a particularly suspect fabric because it’s made from a chemical called polyethylene terephthalate, a plastic polymer used in various products.One study published in 1993 followed 24 dogs who were divided into two equal groups, one group wore cotton underpants and the other polyester. At the end of the study period, there was a significant decrease in sperm count and an increase in sperm abnormalities in the dogs who wore the polyester pants. But that said, this study is three decades old, done on dogs, and has had little additional research to show for it since.So, the jury is certainly still out as to whether fabrics decrease fertility, but there are some things that we do know. Chemicals Found in PolyesterAccording to Audrey Gaskins, an associate professor of environmental health at Emory University, most studies are focused on specific chemicals that might be found in fabrics rather than the fabrics themselves, and those chemicals are usually measured in blood or urine. But fabrics like polyester can contain a number of chemicals that might impact fertility. PFAS, short for per- and polyfluoroalkyl substances, are a group of chemicals found in thousands of products, and they’re difficult for the body to eliminate.“PFAS are commonly found in water-resistant clothing,” says Gaskins. However, drinking water is likely the most common avenue of exposure, as well as non-stick cookware, and many others.Research has shown that PFAS can reduce fertility in women by some 40 percent. According to NIH’s National Institute for Environmental Health Sciences, high levels of PFAS found in the blood were linked to a reduced chance of pregnancy and live birth. Other research has shown that PFAS are linked to increased instances of endometriosis and polycystic ovary syndrome (PCOS), both of which reduce fertility.Poor Pregnancy OutcomesPolyester (when combined with spandex) may also contain bisphenol A (BPA), another chemical compound that has been shown to potentially impact fertility. A December 2022 study published in the Journal of Clinical Medicine found a higher prevalence of PCOS in women with high amounts of BPA in their blood.Finally, polyester can contain phthalates, a chemical commonly used in things like sports bras and other pieces of clothing. These, too, have been shown to have a negative impact on fertility. A study published in the September 2021 issue of the journal Best Practice & Research Clinical Endocrinology & Metabolism found that higher concentrations of the chemical have been associated with decreased rates of pregnancy, increased incidences of miscarriage, and other pregnancy complications.“We’ve found suggestive associations between higher concentrations of bisphenol and phthalate metabolites and worse markers of reproductive health like poor success with IVF,” says Gaskins. “What we don’t know is where the source of exposure is coming from.”Exposure to Fertility-Decreasing ChemicalsStill, the obvious implication if you’re trying to get pregnant is to try to decrease your exposure to any of these chemicals through any route possible, especially when you have control over exposure. If we know there are chemicals in these fabrics, decreasing use of them would be more achievable for many people compared to, say, changing your drinking water, says Gaskins.There’s definitely no downside to decreasing your exposure to these chemicals, and while clothing is likely not the largest means of exposure to things like PFAs, phthalates, and BPA, if you’re trying to get pregnant, they’re certainly a good place to start.This article is not offering medical advice and should be used for informational purposes only.Article SourcesOur writers at Discovermagazine.com use peer-reviewed studies and high-quality sources for our articles, and our editors review for scientific accuracy and editorial standards. Review the sources used below for this article:National Institute of Environmental Health Sciences. PFAS Exposure Linked to Reduced Fertility in Women Center for Environmental Health. What You Need to Know About BPA in ClothingJournal of Clinical Medicine. Bisphenol-A and Female Fertility: An Update of Existing Epidemiological StudiesBest Practice & Research Clinical Endocrinology & Metabolism. Phthalates, ovarian function and fertility in adulthoodSara Novak is a science journalist based in South Carolina. In addition to writing for Discover, her work appears in Scientific American, Popular Science, New Scientist, Sierra Magazine, Astronomy Magazine, and many more. She graduated with a bachelor’s degree in Journalism from the Grady School of Journalism at the University of Georgia. She's also a candidate for a master’s degree in science writing from Johns Hopkins University (expected graduation 2023).

Image of the Archbishop of Canterbury's letters to the Bishop of Winchester on the subject of Ela Fitzpayne, from the register of John de Stratford. Reproduced with permission of Hampshire Archives and Hampshire County Council. (Image Credit: Register of John de Stratford. Reproduced with permission of Hampshire Archives and Hampshire County Council.)NewsletterSign up for our email newsletter for the latest science newsEspionage, sex, public humiliation, murder — these may sound like tropes straight out of Game of Thrones, but they’re actually all elements of a nearly 700-year-old cold case in England. After analyzing Medieval letters and records, a research team from the Cambridge University Institute of Criminology’s Medieval Murder Maps project may have found the killer of a priest. However, this priest may not have been so innocent. A new paper published in Criminal Law Forum takes a deeper look at this 14th-century cold case.Tracing a Medieval MurderThe Medieval Murder Maps project uses interactive maps of three English cities, London, Oxford, and York, during the Medieval period. Throughout the cities are the locations of various deaths and murders. Each location has a story associated with it, directly from written records and coroners' reports at the time. Some of these stories are full of intriguing twists and turns.The Cambridge research team analyzed over 100 murders from texts, translated from Latin, from that period, and used a coding method to separate the deaths into different categories, including time (day, week, month), motivation, weapon used, victim, and location. From this information, one of the deaths the team found most interesting was the murder of John Forde in 1337.A Medieval Lover to Murderer From the letters and texts the team analyzed, they pieced together the events that led up to Forde’s death. Forde was a priest living in London when he was murdered on a busy street. But what possible reason would someone have to want to murder a priest? The motive, according to the research team, was likely revenge. According to Manuel Eisner, one of the study’s authors, the murder may have been an act of revenge by noblewoman Ela Fitzpayne. According to the records, the Archbishop of Canterbury, Simon Mepham, had enacted penance on Fitzpayne after it was discovered that Forde had been her lover. A letter written by Archbishop Mepham accused Fitzpayne of adultery with Forde and possibly others. Her penance was to take a barefoot walk of shame across Salisbury Cathedral. Eisner also found a document that suggested Fitzpayne, her husband, and John Forde sent a gang to rob a church priory and took the livestock for ransom. It’s possible that during this time, Forde found himself in bed with Fitzpayne, before betraying her to the Archbishop Mepham. Commissioned Murder Possibly betrayed by her former lover and sentenced to walks of shame that were to take place once a year for seven years,  Fitzpayne would have none of it. On an early evening on a busy London street, near St. Paul’s Cathedral, three men attacked Forde. One slit his throat while the others stabbed him in the gut. Witnesses claim that the murderers were Fitzpayne’s brother and two of her former servants. “We are looking at a murder commissioned by a leading figure of the English aristocracy. It is planned and cold-blooded, with a family member and close associates carrying it out, all of which suggests a revenge motive,” said Eisner in a press release.Cold Case RevealedAccording to letters from Archbishop Mepham, Fitzpayne was led by the devil and a “spirit of pride.”“The archbishop imposed heavy, shameful public penance on Ela, which she seems not to have complied with, but may have sparked a thirst for vengeance,” said Eisner in a press release. “Not least as John Forde appears to have escaped punishment by the church.” When Archbishop Mepham died in 1333, Fitzpayne waited four years before enacting her revenge, and in 1337, Forde was killed. Article SourcesOur writers at Discovermagazine.com use peer-reviewed studies and high-quality sources for our articles, and our editors review for scientific accuracy and editorial standards. Review the sources used below for this article:A graduate of UW-Whitewater, Monica Cull wrote for several organizations, including one that focused on bees and the natural world, before coming to Discover Magazine. Her current work also appears on her travel blog and Common State Magazine. Her love of science came from watching PBS shows as a kid with her mom and spending too much time binging Doctor Who.1 free article leftWant More? Get unlimited access for as low as $1.99/monthSubscribeAlready a subscriber?Register or Log In1 free articleSubscribeWant more?Keep reading for as low as $1.99!SubscribeAlready a subscriber?Register or Log In

Bacteria wouldn’t be so bad if we could tell them what to do. “Stop spreading! Stop sticking together! Stop fending off our antibiotics!” A new method is starting to allow scientists to do just that, letting them use light to control certain functions of bacteria. Introduced in a paper published in The European Physical Journal Plus, the preliminary approach could have several potential applications, including a possible avenue for combating antibiotic resistance.The Problem of Antibacterial Resistance Bacteria are behind a variety of diseases, from strep to staph to pneumonia and meningitis, and they attack our bodies in a variety of ways, as well, including through the production of toxins that damage and disrupt our cells. Some of these infections stop on their own, but others are too stubborn, or too serious, to leave untreated. These are the infections that we target with antibiotics — that is, as long as our antibiotics are working.But, because bacteria are constantly changing, they can develop defenses against the antibiotics that we use to stave them off, making these treatments much less effective. That’s the gist of the growing threat posed by antibiotic resistance, which has contributed to millions of deaths since 1990 and is anticipated to contribute to millions more by 2050. Setting out to find a new solution to this growing problem, scientists from the Italian Institute of Technology and the Polytechnic University of Milan embarked on the Engineering of Bacteria to See Light (EOS) project. The project aims to use light to control bacteria, primarily for the fight against antibiotic resistance. And the new method pushes the project closer to achieving that aim. Using light and light-sensitive molecules to adjust the electrical signals that are transmitted across the bacterial membrane, the method impacts the biological activity of bacteria without any alterations to their genetic makeup.“This interplay between light and electrical [signaling] allows us to control key biological processes such as movement, biofilm formation, and antibiotic sensitivity,” said Giuseppe Maria Paternò, a study author and a professor at the Polytechnic University of Milan, according to a press release. “We can influence antibiotic uptake and restore or even enhance the effectiveness of treatments against resistant strains.”Coating Bacteria to Curb Antibiotic ResistanceTo control bacteria, the method takes advantage of a light-sensitive molecule called Ziapin2, which sticks to the bacterial surface. By covering bacteria with this light-sensitive molecule and by subjecting the covered bacteria to light, the scientists were able to modify the electrical signals that were transmitted across their bacterial membranes, transforming the bacteria’s basic functioning. Testing their method on one of the most studied bacterial species, the scientists changed the electrical signaling across the membranes of Bacillus subtilis, a popular model organism that’s often used as a stand-in for Staphylococcus aureus, the bacterium that causes staphylococcus, or staph, infections.When tested, the method modulated the bacteria’s susceptibility to Kanamycin, an intracellular antibiotic that’s frequently used as a treatment for severe bacterial infections after other treatments fail. “Under blue light,” Paternò said in the release, “the effectiveness of Kanamycin was significantly reduced,” indicating that the electrical signaling on the bacterial membrane “plays a crucial role in the drug’s uptake.”Additional research is required to tailor the method to increase the effectiveness of Kanamycin and other antibiotics against bacteria. But for now, it seems that such an outcome could be possible. “This initial assessment […] represents a first step in a completely new field of study,” the scientists state in their paper. “This proof-of-concept study underscores the potential of non-genetic, light-based interventions to modulate bacterial susceptibility in real time. Future work will expand this approach […] ultimately advancing our understanding of bacterial bioelectric regulation and its applications in antimicrobial therapies.”This article is not offering medical advice and should be used for informational purposes only.Article SourcesOur writers at Discovermagazine.com use peer-reviewed studies and high-quality sources for our articles, and our editors review for scientific accuracy and editorial standards. Review the sources used below for this article:The European Physical Journal Plus. Photocontrol of Bacterial Membrane Potential Regulates Antibiotic Persistence in B. SubtilisSam Walters is a journalist covering archaeology, paleontology, ecology, and evolution for Discover, along with an assortment of other topics. Before joining the Discover team as an assistant editor in 2022, Sam studied journalism at Northwestern University in Evanston, Illinois.

If you’ve ever wondered whether the food on your plate could shape your brain’s future, the science is starting to say: yes, it might. While healthy eating has long been linked to better brain health, new research is getting more specific about which diets help, and when you should start following them.At this year’s annual Nutrition conference in Orlando, Florida, researchers presented findings that add weight to the growing link between diet and dementia. According to a news release, study author Song-Yi Park of the University of Hawaii at Manoa said, “Our study findings confirm that healthy dietary patterns in mid to late life and their improvement over time may prevent Alzheimer’s and related dementias. This suggests that it is never too late to adopt a healthy diet to prevent dementia.”The research focused on nearly 93,000 U.S. adults from the long-running Multiethnic Cohort Study. Participants were between 45 years and 75 years old when they entered the study in the 1990s. Over time, more than 21,000 developed Alzheimer’s disease or related dementias — but those who closely followed a specific eating plan, the MIND diet, were significantly less likely to be among them.Combining the Mediterranean Diet and DASH DietThe MIND diet (short for Mediterranean-DASH Intervention for Neurodegenerative Delay) blends the best elements of two established eating plans: the Mediterranean diet and the DASH diet.The Mediterranean diet is inspired by the traditional cuisines of countries like Greece, Italy, and Spain. It focuses on plant-based foods (fruits, vegetables, legumes, nuts, seeds, and whole grains), healthy fats like olive oil, and moderate amounts of fish, poultry, and dairy, with red meat eaten sparingly. It’s been linked to a lower risk of heart disease and is also environmentally friendly.The DASH diet, originally designed to lower blood pressure, shares many similarities but puts extra emphasis on limiting sodium and increasing intake of nutrients like potassium, magnesium, and calcium. It includes low-fat dairy and lean protein sources and doesn’t rely on any hard-to-find foods.The MIND diet specifically promotes brain-healthy foods like leafy greens, berries, nuts, and olive oil, combining benefits of both approaches with a focus on protecting cognitive health.Read More: Is the Mediterranean Diet Healthy?The MIND Diet Over TimeAccording to Park and her team, people who scored highest in MIND diet adherence at the study’s start had a 9 percent lower risk of developing dementia. That number was even higher with around 13 percent for African American, Latino, and White participants. Looking at those who improved their adherence to the MIND diet over time, showed a 25 percent reduction in dementia risk compared to those whose dietary habits declined, which was consistent no matter the age or racial background.“We found that the protective relationship between a healthy diet and dementia was more pronounced among African Americans, Latinos, and Whites, while it was not as apparent among Asian Americans and showed a weaker trend in Native Hawaiians,” Park said in the press release. “A tailored approach may be needed when evaluating different subpopulations’ diet quality.”Interestingly, Asian Americans also tend to have lower dementia rates overall, which researchers believe could mean other cultural eating patterns might offer similar protection than the MIND diet for that group.The Best Time to Start Is NowOne of the most encouraging findings was that starting late still helped. Participants who began following the MIND diet more closely over a 10-year period, regardless of how old they were when they began, saw benefits. This suggests that even if you didn’t grow up eating brain-boosting foods, it’s not too late to change course.It’s worth noting that the study is observational, so, by itself, it can’t prove this specific diet causes better brain health. Study author Park notes that the next step is conducting interventional studies to verify these promising results.Still, the evidence is mounting. Whether you're 45 or 75, choosing greens over greasy snacks could make a real difference when it comes to aging with or without dementia.This article is not offering medical advice and should be used for informational purposes only.Article SourcesOur writers at Discovermagazine.com use peer-reviewed studies and high-quality sources for our articles, and our editors review for scientific accuracy and editorial standards. Review the sources used below for this article:National Institute of Aging. What Do We Know About Diet and Prevention of Alzheimer’s Disease?Harvard Health Publishing. A practical guide to the Mediterranean dietNational Heart, Lung, and Blood Institute. Following the DASH Eating PlanHaving worked as a biomedical research assistant in labs across three countries, Jenny excels at translating complex scientific concepts – ranging from medical breakthroughs and pharmacological discoveries to the latest in nutrition – into engaging, accessible content. Her interests extend to topics such as human evolution, psychology, and quirky animal stories. When she’s not immersed in a popular science book, you’ll find her catching waves or cruising around Vancouver Island on her longboard.

Co-lead author Ravneet Sidhu examines an ancient human tooth at the McMaster Ancient DNA Centre. (Image Credit: McMaster University)NewsletterSign up for our email newsletter for the latest science newsA new study in Science suggests that changes in a gene in Yersinia pestis, the bacterium that causes plague, could’ve added to the length of two plague pandemics, including the pandemic that started with the “Black Death.” “Ours is one of the first research studies to directly examine changes in an ancient pathogen, one we still see today, in an attempt to understand what drives the virulence, persistence, and eventual extinction of pandemics,” said Hendrik Poinar, a study author and the director of the McMaster Ancient DNA Centre, according to a press release.The study suggests that less virulent plague bacteria could’ve caused longer plague pandemics — thanks to the fact that infected rodents lived (and spread plague) for longer periods of time before dying from their infections. Read More: Scientists Reveal the Black Death’s Origin StoryThe Three Plague PandemicsThe bacterium Y. pestis infects rodents and humans alike and has caused three main plague pandemics in humans, all of which continued for centuries after their initial outbreaks. The first began in the 500s; the second began in the 1300s; and the third started in the 1800s (and still continues in certain areas in Asia, Africa, and the Americas today). Although all three pandemics were devastating at their outset, the second pandemic was by far the most severe. The Black Death, its initial outburst, killed around 30 to 50 percent of the population of Europe between 1347 and 1352 and — to this day — represents the deadliest disease wave in recorded history.To learn more about how these plague pandemics changed over time, scientists at McMaster University in Canada and the Institut Pasteur in France turned to a Y. pestis virulence gene known as pla. This gene is repeated many times throughout the Y. pestis genome, and it allows the bacterium to spread undetected throughout the bodies of infected individuals. A Gene and the PlagueTo investigate this gene, the scientists studied historical strains of Y. pestis from human remains and found that the number of repetitions of pla decreased over the course of the first and second plague pandemics. Then, the scientists tested Y. pestis bacteria from the third pandemic, infecting mice with three strains that had reduced repetitions of pla. “These three samples enabled us to analyze the biological impact of these pla gene deletions,” said Javier Pizarro-Cerdá, another study author and the director of the Yersinia Research Unit at the Institut Pasteur, according to the release.The results revealed that pla depletion decreases the virulence and increases the length of plague infections in mice. According to the study authors, these changes could have caused rodents to live longer in the later stages of the first and second pandemics, allowing them to spread their infections for a longer period. “It’s important to remember that plague was an epidemic of rats, which were the drivers of epidemics and pandemics. Humans were accidental victims. ” Poinar added in another press release.The Continued Threat of Y. PestisThough the pla depletion occurred around 100 years after the first and second pandemics began, the scientists stress that both changes were random and unrelated.“Our research sheds light on an interesting pattern in the evolutionary history of the plague. However, it is important to note that the majority of strains which continue to circulate today in Africa, the Americas, and Asia are highly virulent strains,” said Ravneet Sidhu, another study author and a Ph.D. student at the McMaster Ancient DNA Centre.Though still a threat to current populations, Y. pestis infections are much more manageable now as a result of modern diagnostics and treatments.“Today, the plague is a rare disease, but one that remains a public health concern and serves as a model for gaining a broad understanding of how pandemics emerge and become extinct. This example illustrates the balance of virulence a pathogen can adopt in order to spread effectively,” Pizarro-Cerdá said in the press release.Article SourcesOur writers at Discovermagazine.com use peer-reviewed studies and high-quality sources for our articles, and our editors review for scientific accuracy and editorial standards. Review the sources used below for this article:Science. Sam Walters is a journalist covering archaeology, paleontology, ecology, and evolution for Discover, along with an assortment of other topics. Before joining the Discover team as an assistant editor in 2022, Sam studied journalism at Northwestern University in Evanston, Illinois.1 free article leftWant More? Get unlimited access for as low as $1.99/monthSubscribeAlready a subscriber?Register or Log In1 free articleSubscribeWant more?Keep reading for as low as $1.99!SubscribeAlready a subscriber?Register or Log In

From August 23rd - September 14th, 2023 (Kodiak, Alaska to Seward, Alaska), NOAA Ocean Exploration conducted Seascape Alaska 5: Gulf of Alaska Remotely Operated Vehicle Exploration and Mapping (EX2306), a remotely operated vehicle (ROV) and mapping expedition to the Gulf of Alaska on NOAA Ship Okeanos Explorer. Operations during this 23-day expedition included the completion of 19 successful remotely operated vehicle (ROV) dives, which were conducted in water depths ranging from 253.1 m to 4261.5 m for approximately 87 hours of bottom time and resulted in the collection of 383 samples. EX2306 also collected more than 28,000 sq. km of seafloor bathymetry and associated water column data using an EM 304 multibeam sonar. These images were captured on dives that were included in the source data for the How Little We’ve Seen: A Visual Coverage Estimate of the Deep Seafloor paper. They are good general reference imagery for the type of deep ocean observations captured by ROVs.(Image Courtesy of NOAA Ocean Exploration)NewsletterSign up for our email newsletter for the latest science newsKey Takeaways on Deep Ocean Exploration: We have visually explored less than 0.001 percent of the deep sea floor. To put that in perspective, 66 percent of the planet is deep ocean, and 99.999 percent of that ocean is unknown to us.Like ecosystems on land, the sea has a complex food web. Most of life in the sea depends on detritus, mostly phytoplankton, falling down from the surface, something called “marine snow.”Organisms that live in shallow water absorb carbon dioxide and take that with them when they sink to the bottom, often to be buried in deep-sea sediment. This is known as a carbon sink. It’s important to know the rates at which this happens, because this partially offsets the carbon we’re adding to the atmosphere. It’s been said many times that we know more about the moon than our own ocean. But is it really true that we’ve explored only a tiny portion of the sea?Katy Croff Bell wondered about this, too. Bell is an oceanographer and the founder of the Ocean Discovery League. She knew that Woods Hole Oceanographic Institution and others have been operating deep-sea submersibles like Alvin for decades, and there are facilities in 20 or so places around the world doing deep-sea research. But how much of the sea floor have these projects actually explored visually, not just mapped or sampled?Mapping the Deep OceanBell started looking up dive data and doing some math. “I stayed up way too late and came up with a very, very tiny number,” she recalls. She didn’t believe her own results and got everyone she could think of to double-check her math. But the results held. Over the next four years, she and her team compiled a database of dives from organizations and individuals around the world, and the data support her initial estimate. The number is indeed tiny. It turns out that we have visually explored less than 0.001 percent of the deep sea floor. To put that in perspective, 66 percent of the planet is deep ocean, and 99.999 percent of that ocean is unknown to us. Bell and her team published their findings in May 2025 in the journal Science Advances.Why Deep Sea Exploration MattersFrom July 14 - July 25, 2023, NOAA Ocean Exploration and partners conducted the third in a series of Seascape Alaska expeditions on NOAA Ship Okeanos Explorer. Over the course of 12 days at sea, the team conducted 6 full remotely operated vehicle (ROV) dives, mapped nearly 16,000 square kilometers (6,180 square miles), and collected a variety of biological and geological samples. When combined with numerous biological and geological observations, data from the Seascape Alaska 3: Aleutians Remotely Operated Vehicle Exploration and Mapping expedition will help to establish a baseline assessment of the ocean environment, increase understanding of marine life and habitats to inform management decisions, and increase public awareness of ocean issues. These images were captured on dives that were included in the source data for the How Little We’ve Seen: A Visual Coverage Estimate of the Deep Seafloor paper. They are good general reference imagery for the type of deep ocean observations captured by ROVs. (Image Courtesy of NOAA Ocean Exploration)About 26 percent of the ocean has been mapped with multi-beam sonar, explains Bell, and that gives us an idea of the shape of the ocean floor. But that’s like looking at a topographical map of an area you’re planning to hike. You know where the hills and valleys are, but you have no idea what kind of plants and animals you’re likely to encounter. If you want to understand the deep ocean, you need to get down there and see what kind of rocks and sediment are there, learn about the corals and sponges and other animals living there, she says. Samples of ocean life are helpful, but they do not give anything like a full picture of the life-forms in the deep sea, and more importantly, they tell you little about the complex ecosystems they’re a part of. But when you put mapping and sampling together with visual data, plus data about temperature, depths, and salinity, Bell says, you start to build a picture of what a given ocean habitat is like, and eventually, the role of that habitat in the global ocean system.The Deep-Sea "Snow" That Provides LifeFrom August 23rd - September 14th, 2023 (Kodiak, Alaska to Seward, Alaska), NOAA Ocean Exploration conducted Seascape Alaska 5: Gulf of Alaska Remotely Operated Vehicle Exploration and Mapping (EX2306), a remotely operated vehicle (ROV) and mapping expedition to the Gulf of Alaska on NOAA Ship Okeanos Explorer. Operations during this 23-day expedition included the completion of 19 successful remotely operated vehicle (ROV) dives, which were conducted in water depths ranging from 253.1 m to 4261.5 m for approximately 87 hours of bottom time and resulted in the collection of 383 samples. EX2306 also collected more than 28,000 sq. km of seafloor bathymetry and associated water column data using an EM 304 multibeam sonar. These images were captured on dives that were included in the source data for the How Little We’ve Seen: A Visual Coverage Estimate of the Deep Seafloor paper. They are good general reference imagery for the type of deep ocean observations captured by ROVs. (Image Courtesy of NOAA Ocean Exploration)Like ecosystems on land, the sea has a complex food web. Most of life in the sea depends on detritus, mostly phytoplankton, falling down from the surface, something called “marine snow,” explains James Douglass, an ecologist at Florida Gulf Coast University who studies life on the sea bed. This snow of nutrients is eaten by what are called suspension feeders, including filter feeders, such as sponges and corals, which have tentacles or basket-like appendages to trap the snow. Then other organisms, such as crabs and worms, feed on these creatures. The crabs and worms, in turn, are eaten by fish. Deposit feeders, such as the sea pig, a type of sea cucumber that “trundles across the bottom eating mud all day,” add to the already huge variety of life, Douglass says. The types of organisms you have in the deep sea depend on how deep it is, whether the sea floor is rocky or muddy, how quickly currents bring food, and whether there are underwater hot springs or cold seeps, or other sources of extra energy, says Douglass. So yes, it’s a complicated world down there, and there’s an awful lot we don’t yet know.Deep-Sea Ecosystems and Climate Change From July 14 - July 25, 2023, NOAA Ocean Exploration and partners conducted the third in a series of Seascape Alaska expeditions on NOAA Ship Okeanos Explorer. Over the course of 12 days at sea, the team conducted 6 full remotely operated vehicle (ROV) dives, mapped nearly 16,000 square kilometers (6,180 square miles), and collected a variety of biological and geological samples. When combined with numerous biological and geological observations, data from the Seascape Alaska 3: Aleutians Remotely Operated Vehicle Exploration and Mapping expedition will help to establish a baseline assessment of the ocean environment, increase understanding of marine life and habitats to inform management decisions, and increase public awareness of ocean issues. These images were captured on dives that were included in the source data for the How Little We’ve Seen: A Visual Coverage Estimate of the Deep Seafloor paper. They are good general reference imagery for the type of deep ocean observations captured by ROVs. (Image Courtesy of NOAA Ocean Exploration)Learning about ocean ecosystems is extremely valuable as basic science. But it has a more urgent purpose as well. Though we often think of the land and the sea as two completely separate places, they are intertwined in many significant ways. The ocean has absorbed 90 percent of the excess heat and 30 percent of the carbon dioxide released into the atmosphere by humans, says Bell. “But we don’t really have a good understanding of how this is going to impact deep-sea ecosystems, and those ecosystems play a vital role in the process of carbon sequestration,” she says.When it comes to climate change, the deep sea has a lot to teach us. In parts of the deep sea, Douglass explains, nothing disturbs the layers of sediment that are deposited slowly over the course of thousands, even millions of years. Geologists can interpret the layers and study the fossils preserved in them to get an understanding of what the conditions of the planet were like in the distant past, similar to the way climatologists study Antarctic ice cores. “We've learned things about how the ocean ecosystem changes when climate changes. We've learned that some worrying things can happen under certain climate conditions in the deep ocean,” Douglass says. “For example, the ocean can become less oxygenated, which would be a catastrophic threat to deep-sea life.”The Deep Ocean and Climate RegulationAnd, of course, there’s carbon dioxide. “The deep sea is not just a passive record of what happened to the climate; it’s involved in regulating climate,” Douglass says. Organisms that live in shallow water absorb carbon dioxide and take that with them when they sink to the bottom, often to be buried in deep-sea sediment. This is known as a carbon sink. Douglass says it’s very important to know the rates at which this happens, because this partially offsets the carbon we’re adding to the atmosphere. “Deep-sea carbon storage is a huge element in our understanding of the planet's ability to regulate climate,” he adds.If we are to truly understand the way the entire planet works, we need to understand the deep sea and its complex ecosystems as well as life on land and in the shallows. And to do that, Bell says, we need to get down there and look.Article SourcesOur writers at Discovermagazine.com use peer-reviewed studies and high-quality sources for our articles, and our editors review for scientific accuracy and editorial standards. Review the sources used below for this article:Science Advances. How little we’ve seen: A visual coverage estimate of the deep seafloorAvery Hurt is a freelance science journalist. In addition to writing for Discover, she writes regularly for a variety of outlets, both print and online, including National Geographic, Science News Explores, Medscape, and WebMD. She’s the author of Bullet With Your Name on It: What You Will Probably Die From and What You Can Do About It, Clerisy Press 2007, as well as several books for young readers. Avery got her start in journalism while attending university, writing for the school newspaper and editing the student non-fiction magazine. Though she writes about all areas of science, she is particularly interested in neuroscience, the science of consciousness, and AI–interests she developed while earning a degree in philosophy.1 free article leftWant More? Get unlimited access for as low as $1.99/monthSubscribeAlready a subscriber?Register or Log In1 free articleSubscribeWant more?Keep reading for as low as $1.99!SubscribeAlready a subscriber?Register or Log In

Cicadas are back at it again in 2025, already emerging in droves to announce the approach of summer with their screeches. If you live in the Eastern U.S., get ready to meet (and hear) Brood XIV (14), this year’s batch of periodical cicadas. Cicadas in Brood XIV have begun to pop up in multiple states, climbing out of the underground holes that they’ve spent the last 17 years in. Now, they’ll dedicate the entire month of June to mating and laying eggs before dying. Learn more about the lives of these noisy insects and what makes Brood XIV so noteworthy. Cicadas From South to NorthPeriodical cicadas consist of seven species, falling under 15 broods that either emerge every 13 or 17 years. They’re not the same as annual cicadas, which arrive every summer in much smaller numbers and don’t have the same synchronized development.Most years, one brood of periodical cicadas makes an appearance above ground. However, 2024 was an extraordinary year for cicadas because two adjacent broods (XIII and XIX) overlapped. The rare double-brood event was a must-see, since the next double-brood won’t occur until 2037 (IX and XIX will emerge together, but they aren’t adjacent). This year’s Brood XIV — a 17-year brood — won’t bring as much cicada chaos as last year, but its range is undoubtedly impressive. Cicadas will appear mostly in the Midwest and South, with a large swath concentrated from southern Ohio, down through Kentucky, and Tennessee. Their prevalence in Kentucky has led some to designate Brood XIV as the “Bourbon Brood”.Cicadas in Brood XIV will also appear as far south as northern Georgia and as far north as Long Island, New York, and Cape Cod, Massachusetts. Brood XIV is notable for being the second largest brood after XIX, a 13-year brood referred to as “The Great Southern Brood." Brood XIV is also considered to be the ancestral group from which all other 17-year broods have been shaped. This brood holds a special place in history, as its forebears were first recorded by the Pilgrims in the Plymouth Colony in 1634. Understanding the Cicada Lifecycle Cicadas in Brood XIV were last seen above ground in 2008; the ones that lived back then laid the eggs that have now become the fully-fledged cicadas emerging this year. The cicada life cycle starts when eggs that are located underground hatch into nymphs, which eat fluid from the roots of trees. The nymphs undergo five juvenile stages over the course of years, molting with each stage. They eventually crawl out of exit tunnels and find a spot to molt one final time, marking the start of adulthood. Once the adult cicadas’ exoskeleton hardens, they then focus on mating. The males climb up trees and produce their shrill songs en masse, using muscles to vibrate a rigid part of their exoskeletons called tymbals. After mating, a female cicada lays upwards of 600 eggs that will hatch after six to ten weeks, long after all of the adults have died. The newborn nymphs will then fall out of trees and burrow underground to begin the cycle anew. The Issue with Stragglers Tracking and mapping periodical cicadas of each brood is an ongoing process that needs updating nearly every year. The majority of broods come out on time, but it turns out that not all cicadas are flawless in their timekeeping.One factor that complicates tracking efforts is the existence of stragglers, cicadas that emerge earlier or later than their brood is supposed to. Stragglers that arrive at the wrong time could potentially mix with separate, adjacent broods, causing gene flow. For example, the concern this year is that previous broods could have stragglers that appear late and intermingle with Brood XIV. These stragglers could come from Brood X, which last emerged 4 years ago (and stragglers tend to emerge 1 or 4 years after their parent brood). There usually aren’t many stragglers for any given year, and they’re often picked out quickly by predators. However, some survive and influence nearby broods that emerge on time, which can throw off the data that scientists collect. Beyond the inevitable racket that they’ll create, cicadas are entirely harmless. They don’t bite or sting, but at the very least, be prepared for a loud month ahead. Article SourcesOur writers at Discovermagazine.com use peer-reviewed studies and high-quality sources for our articles, and our editors review for scientific accuracy and editorial standards. Review the sources used below for this article:University of Connecticut. Brood XIVArizona State University. Cicada Life CycleUniversity of Connecticut. Straggling and core 17-year broodsJack Knudson is an assistant editor at Discover with a strong interest in environmental science and history. Before joining Discover in 2023, he studied journalism at the Scripps College of Communication at Ohio University and previously interned at Recycling Today magazine.

For a few months of the year, the Alaskan Arctic becomes flooded with birds. From shorebirds to waterfowl, these avians arrive in the spring to breed, nest, and raise their young, and to take advantage of the ample plants and prey (invertebrates and other animals) that thrive in Alaska’s short summers. They do it today, and they did it around 73 million years ago, too. Documenting the earliest evidence ever discovered of birds breeding and nesting in the Arctic, a new study in Science describes a collection of avian fossils and fossil fragments from around 73 million years ago. The collection comprises dozens of bones and teeth from adult and baby birds, and it shows that avians similar to modern shorebirds and waterfowl reproduced in the Arctic in the Cretaceous period, when dinosaurs still dominated the Alaskan terrain.“Birds have existed for 150 million years,” said Lauren Wilson, a study author and a student at Princeton University, who worked on the study while at the University of Alaska Fairbanks, according to a press release. “For half of the time they have existed, they have been nesting in the Arctic.”An Arctic NurseryA fossil fragment of a beak from a baby bird. (Image Credit: Photo by Pat Druckenmiller)Millions of birds travel to the Arctic, and they’ve been traveling there for millions of years. (In fact, some 250 species of birds migrate to Alaska for the spring and summer breeding and nesting seasons today.) But up until now, the earliest traces of birds reproducing in the Arctic dated back to around 47 million years ago, following the disappearance of the non-avian dinosaurs from the Arctic terrain. Now, the authors of the new study claim that birds and non-avian dinosaurs shared the Alaskan Arctic as far back as the Cretaceous period. Sifting bones and teeth from the sediment of Alaska’s Prince Creek Formation, the authors identified an assortment of Cretaceous fossils and fossil fragments, which resembled the remains of modern gulls, geese, ducks, and loons. That the specimens belonged to adult and baby birds suggests that these species were breeding, nesting, and raising their young in Alaska, more than 20 million years earlier than previously thought. “The Arctic is considered the nursery for modern birds,” said Pat Druckenmiller, another study author and a professor at the University of Alaska Fairbanks, according to a press release. “They have been doing this for 73 million years.”Finding Fossils, From Adult and Baby BirdsStudy authors Joe Keeney, Jim Baichtal, and Patrick Druckenmiller in Alaska. (Image Credit: Photo by Lauren Wilson) According to the authors, the bones and teeth of adult birds are often too fragile to survive in the fossil record, and those from baby birds are even more delicate. “Finding bird bones from the Cretaceous is already a very rare thing,” Wilson said in the release. “To find baby bird bones is almost unheard of. That is why these fossils are significant.” Though the majority of specimens that are taken from the Prince Creek Formation are large, the study authors opted to collect the smaller fossils and fossil fragments that most other studies miss. To do so, they inspected screened sediment with a microscope, which revealed their tiny finds. “We put Alaska on the map for fossil birds,” Druckenmiller said in the release. “It wasn’t on anyone’s radar.”Whether the find includes bones and teeth from the Neornithes — or the modern birds — is yet to be determined, though the authors stress that some of the fossils and fossil fragments feature skeletal and dental traits, such as fused leg bones and toothless jawbones, that are seen only in modern birds. “If they are part of the modern bird group, they would be the oldest such fossils ever found,” Druckenmiller said in the release. “But it would take us finding a partial or full skeleton to say for sure.”Article SourcesOur writers at Discovermagazine.com use peer-reviewed studies and high-quality sources for our articles, and our editors review for scientific accuracy and editorial standards. Review the sources used below for this article:Science. Arctic Bird Nesting Traces Back to the CretaceousSam Walters is a journalist covering archaeology, paleontology, ecology, and evolution for Discover, along with an assortment of other topics. Before joining the Discover team as an assistant editor in 2022, Sam studied journalism at Northwestern University in Evanston, Illinois.