178206846
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sciencehabit writes:
If you’ve ever gotten burned at the beach or swimming pool, you’re no stranger to the Sun bombarding Earth with ultraviolet rays. But the UV light that keeps beachgoers reaching for the sunblock isn’t even the worst the Sun sends our way. Lucky for us, Earth’s ozone layer blocks the Sun’s shortest wave radiation, called UV-C, which is so damaging to cells in high doses that it’s a go-to sterilizer in hospitals.
UV-C is such a killer, in fact, that scientists have questioned whether life can survive on worlds that lack an ozone layer, such as Mars or distant exoplanets. But research published this month in Astrobiology suggests one hardy lichen, a hybrid organism made of algae and fungi, may have cracked the UV-C code with a built-in sunscreen, despite never experiencing these rays in its long evolutionary history.
When scientists brought a sample of the species, the common desert dweller Clavascidium lacinulatum, back to the lab, graduate student Tejinder Singh put the lichen through the wringer. First, Singh dehydrated the lichen, to make sure it couldn’t grow back in real time and mask any UV damage. Then he placed the lichen a few centimeters under a UV lamp and blasted it with radiation. The lichen seemed just fine.
So Singh purchased the most powerful UV-C lamp he could find online, capable of sending out 20 times more radiation than the amount expected on Mars. When he tested the lamp on the most radiation-resistant life form on Earth, the bacterium Deinococcus radiodurans, it died in less than a minute.
After 3 months—likely the highest amount of UV-C radiation ever tested on an organism—Singh pulled the sample so he could finish his master’s thesis in time. About half of the lichen’s algal cells had survived. Then, when the team ground up and cultured part of the surviving lichen, about half of its algal cells sprouted new, green colonies after 2 weeks, showing it maintained the ability to reproduce.
The species may provide a blueprint for surviving on Mars or exoplanets, which don’t have an ozone layer to protect them.
178064691
submission
sciencehabit writes:
The newly discovered microbe provisionally known as Sukunaarchaeum isn’t a virus. But like viruses, it seemingly has one purpose: to make more of itself.
As far as scientists can tell from its genome—the only evidence of its existence so far—it’s a parasite that provides nothing to the single-celled creature it calls home. Most of Sukunaarchaeum’s mere 189 protein-coding genes are focused on replicating its own genome; it must steal everything else it needs from its host Citharistes regius, a dinoflagellate that lives in ocean waters all over the world. Adding to the mystery of the microbe, some of its sequences identify it as archaeon, a lineage of simple cellular organisms more closely related to complex organisms like us than to bacteria like Escherichia coli.
The discovery of Sukunaarchaeum’s bizarrely viruslike way of living, reported last month in a bioRxiv preprint, “challenges the boundaries between cellular life and viruses,” says Kate Adamala, a synthetic biologist at the University of Minnesota Twin Cities who was not involved in the work. “This organism might be a fascinating living fossil—an evolutionary waypoint that managed to hang on.”
Adamala adds that if Sukunaarchaeum really does represent a microbe on its way to becoming a virus, it could teach scientists about how viruses evolved in the first place. “Most of the greatest transitions in evolution didn’t leave a fossil record, making it very difficult to figure out what were the exact steps,” she says. “We can poke at existing biochemistry to try to reconstitute the ancestral forms—or sometimes we get a gift from nature, in the form of a surviving evolutionary intermediate.”
What’s already clear: Sukunaarchaeum is not alone. When team leader Takuro Nakayama, an evolutionary microbiologist at Tsukuba, and his colleagues sifted through publicly available DNA sequences extracted from seawater all over the world, they found many sequences similar to those of Sukunaarchaeum. “That’s when we realized that we had not just found a single strange organism, but had uncovered the first complete genome of a large, previously unknown archaeal lineage,” Nakayama says.
177690643
submission
sciencehabit writes:
Perfumes and lotions do more than soften our skin and give us signature aromas. They can chemically alter the air we breathe, weakening a phenomenon called the human oxidation field, researchers report today in Science Advances.
The new results lend further credence to the idea that the human body can meaningfully alter the chemistry of indoor air, says Nicola Carslaw, an indoor air chemist at the University of York who wasn’t involved with the research. “What’s fascinating about this paper is that it shows what simple bodies in a space can do.” Whether these chemical reactions help—or harm—us, however, remains unclear.
Scientists coined the term “human oxidation field” in 2022. A study published in Science found that when oils in our skin are exposed to ozone—an oxidant that can creep in from the outdoors or from some air purifiers—they can spawn highly reactive molecules called hydroxyl radicals. These in turn can break down other gases in the air around us, creating a haze of radicals—the human oxidation field.
The researchers are still figuring out exactly what fewer hydroxyl radicals mean for everyday life. If the radicals react with other molecules to form toxic substances, wearing personal care products could be a safeguard; if they are breaking down dangerous gases, then the same products could leave someone more vulnerable. But there’s such a wide variety of compounds in indoor air—created by everything from cooking to cleaning—that researchers don’t have any easy answers.
“We can’t give any public advice on whether this means you should wear a lot of lotion,” says study author, Manabu Shiraiwa, a chemist at the University of California, Irvine.
177690613
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sciencehabit writes:
Hummingbird feeders are a beloved pastime for millions of backyard birders and a convenient dining spot for the birds. But for the Anna’s hummingbird, a common species in the western United States, feeders have become a major evolutionary force. According to research published this week in Global Change Biology, artificial feeders have allowed the birds to expand their range out of Southern California up to the state’s northern end. They have also driven a transformation of the birds themselves. Over just a few generations, their beaks have dramatically changed in size and shape.
As feeders proliferated, Anna’s hummingbird beaks got longer and larger, which may reflect an adaptation to slurp up far more nectar than flowers can naturally provide. Developing a bigger beak to access feeders “is like having a large spoon to eat with,” says study author, Alejandro Rico-Guevara.
This change was more pronounced in areas where feeders were dense. But in birds that lived in colder regions north of the species’ historical range, the researchers spotted the opposite trend: Their beaks became shorter and smaller. This finding also makes sense: The researchers used an infrared camera to show for the first time that hummingbirds use their beaks to thermoregulate, by dissipating heat while they are perched. A smaller beak has less surface area—and would therefore help conserve heat.
It wasn’t just the size and shape of beaks that changed. In areas where feeders are dense, male hummingbirds have also developed beaks that are pointier and sharper than usual. Pointy beaks in hummingbird species often indicate aggressiveness, and the researchers think male skirmishes over feeder control may have made these birds feistier. “Anyone who has a feeder knows that hummingbirds fight like crazy,” Rico-Guevara says.
The most surprising finding, though, was how quickly these changes took place. By the 1950s, hummingbirds were noticeably different from those of the 1930s: a time span of only about 10 generations of birds.
Carleton University animal behaviorist Roslyn Dakin, who wasn’t involved with the study, adds that the new paper beautifully shows “evolution in action.”
177675019
submission
sciencehabit writes:
It’s a truism almost as old as modern weather prediction: Any forecast beyond 2 weeks will fall apart because of the way tiny perturbations compound in the atmosphere. The 2-week limit, grounded in chaos theory and notions of the “butterfly effect” from the 1960s, has been handed down from generation to generation, says Peter Dueben, head of earth system modeling at the European Centre for Medium-Range Weather Forecasts, the world’s leading forecaster. “It’s basically a God-given rule.”
But even the gods can be wrong.
Using an artificial intelligence (AI) weather model developed by Google, atmospheric scientists have found that forecasts of 1 month or more into the future might be possible. “We haven’t found a limit to how far you can go out,” says Trent Vonich, a doctoral student at the University of Washington (UW) who led the work, released late last month as a preprint on arXiv. “We ran out of memory first.”
The result has caused a stir ever since Vonich and Gregory Hakim, his adviser, spoke this year at the annual meeting of the American Meteorological Society, says Amy McGovern, a computer scientist and meteorologist at the University of Oklahoma. Using powerful computer models, researchers have already pushed meaningful forecasts out to about 10 days, coming ever closer to the 2-week limit. Showing this limit can in principle be broken “means that AI will be able to do this someday, which is really exciting,” she says.
177556861
submission
sciencehabit writes:
Can a robot arm wave hello to a cuttlefish—and get a hello back? Could a dolphin’s whistle actually mean “Where are you?” And are monkeys quietly naming each other while we fail to notice?
These are just a few of the questions tackled by the finalists for this year’s Dolittle prize, a $100,000 award recognizing early breakthroughs in artificial intelligence (AI)-powered interspecies communication. The winning project—announced today—explores how dolphins use shared, learned whistles that may carry specific meanings—possibly even warning each other about danger, or just expressing confusion. The other contending teams—working with marmosets, cuttlefish, and nightingales—are also pushing the boundaries of what human-animal communication might look like.
The prize marks an important milestone in the Coller Dolittle Challenge, a 5-year competition offering up to $10 million to the first team that can achieve genuine two-way communication with animals. “Part of how this initiative was born came from my skepticism,” says Yossi Yovel, a neuroecologist at Tel Aviv University and one of the prize’s organizers. “But we really have much better tools now. So this is the time to revisit a lot of our previous assumptions about two-way communication within the animal’s own world.”
Science caught up with the four finalists to hear how close we really are to cracking the animal code. One amusing exerpt:
"Male [dolphins] form pairs and call each other’s [signature] whistles if they get separated. But once, we were just testing our equipment and played one of those whistles while the pair was still together. They responded with a totally different whistle—one we hadn’t documented before. We’ve since heard it in other confusing situations. We call it the 'WTF whistle,' because it really did seem like that’s what they were asking."
177392655
submission
sciencehabit writes:
Habemus papam! Minutes ago, the Vatican announced that U.S. Cardinal Robert Prevost would be the next pope. Artificial intelligence (AI) made its own prediction earlier this week—but Prevost was not on the shortlist. In a paper posted on the preprint site arXiv, a machine learning algorithm that analyzed the ideological positions of the 133 high-ranking Catholic Church officials who made this decision predicted that Italian Cardinal Pietro Parolin would be the next head of the Catholic Church. Though the program was off this time, experts say its approach could eventually be useful in predicting other types of electoral contests.
AI algorithms that analyze text, such as social media posts and candidates’ speeches, can be very accurate at predicting political election outcomes. But papal conclaves present a unique challenge. The election process, which takes place over multiple rounds until one person receives two-thirds of the vote, has remained the same for centuries. There are no polls or primary elections to analyze, and the papabili are sworn to secrecy about their votes.
So with the help of Michele Re Fiorentin, a physicist at the Polytechnic University of Turin, and University of Madrid mathematician Alberto Antonioni, Valdano set out to develop a way to predict papal elections. When it was announced in February that Pope Francis was ill, this group was already studying the emergence of political and ideological factions within the church, using an algorithm the researchers had trained on five centuries of meticulous “genealogical” records of bishops and the successors they appointed. The researchers’ logic is that a bishop’s or pope’s decision to appoint a new bishop or to elevate one to a cardinal may be partly determined by shared ideology. And when the time comes to appoint a new pope, the thinking goes, each elector is more likely to vote for a colleague who shares his own stances.
To model how these dynamics could play out in the current conclave, the researchers chose four broad topics likely to be important to this year’s papabili: attitudes toward same-sex couples, international migration and poverty, the Catholic Church’s ongoing dialogues with other religions, and synodality—the degree of autonomy and authority enjoyed by local church leaders relative to the pope. Using data from a website that compiles cardinals’ public statements, the researchers trained an AI model to determine how progressive or conservative each elector’s stance on each issue is. The model then categorized the 135 eligible electors (two cardinals didn’t attend the conclave)—and Pope Francis—by their ideological similarity to other candidates.
Next, the scientists simulated the conclave election process among their virtual cardinals. After eight or nine rounds of voting, the electors typically converged on one candidate: Parolin, currently the Vatican’s secretary of state. As the Vatican’s top diplomat and second-in-command to Pope Francis, Parolin is widely considered a front-runner and has the best odds on online betting sites.
The authors’ analysis had put Prevost’s views near the center on all four ideological topics, meaning he was likely elected as a compromise candidate. Electing a U.S. pope could also help shore up support from Catholic communities there.
Re Fiorentin says the model probably missed Prevost as a likely pope because it didn’t consider political and geographical factors that played a role in the election. Lacking that information, he says, “is a major shortcoming of our model.”
In the future, he adds, the model could incorporate geographic information about the candidates. “However, we think that other important data about geopolitical influence, lobbying, etc., are much more difficult to obtain and to use.”
177368081
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sciencehabit writes:
Scientists have captured fungal spores cruising in the inhospitable environment of the stratosphere, much higher than commercial aircraft fly. When brought back to the lab, the researchers found that some of the spores—including pathogens of plants and people—had survived intercontinental trips and could be cultured in the lab.
Made possible via a cheap, homespun sampling device dangled from weather balloons, the project could help researchers figure out what traits and conditions allow spores to survive a swing through the stratosphere and how they get up there in the first place. The work could also be a first step towards an atmospheric monitoring system that could nip emerging fungal pathogens in the bud, the study’s authors reported at a conference of the European Geophysical Union.
After five preliminary flights, the team has already learned a lot. Based on DNA sequencing analysis, they identified spores from 235 genera, including fungi that infect blackberries and carrots in the United States and Japan, and one species, Naganishia albida, that can make immunocompromised people sick. In the lab, they were able to revive and culture spores from 15 different fungal species, among them several plant pathogens.
Mostly the results show that their sampler works. Now, the researchers want to set up regular flights to track airborne fungal biodiversity and seasonal variations. They also want to identify how events such as wildfires or volcanic eruptions inject spores into the stratosphere.
177364857
submission
sciencehabit writes:
As John Rick excavated one of the many underground chambers at the ancient Peruvian site of Chavín de Huántar in 2017 his trowel hit something intriguing, and exceedingly delicate. It was a cigarette-size tube made of animal bone and packed full of sediment. The following year, his team found almost two dozen more. Rick, an archaeologist at Stanford University, suspected these bone tubes were pieces of ancient drug paraphernalia.
Now, a chemical analysis of plant material preserved inside the bone tubes confirms ancient people used them to inhale snuffs made of tobacco and a hallucinogenic plant known as vilca. Rick and colleagues say the rituals involving these drugs may have helped the people of Chavín consolidate their power and influence some 2500 years ago, a time when complex social and political hierarchies were first taking shape in Peru.
Although researchers have long suspected rituals at Chavín involved hallucinogenic drugs, “What’s exciting about this paper is that, for first time, we have actual evidence,” says José Capriles, an archaeologist at Pennsylvania State University who wasn’t involved in the research but has studied psychoactive drugs used by ancient people.
Rick thinks Chavín may have been a pilgrimage site for people belonging to a nascent rulership class taking shape all over the Andes. “They’ve been looking for ways to develop authority,” he says. Perhaps the rituals in Chavín’s underground chamber were initiation rites, inducting a chosen few into a higher status within the religion, conferring prestige upon them back home—and ensuring these newly local powerful rulers would stay indebted to Chavín, which could then attract even more tribute and pilgrims. During these rituals, “the idea of social order may be meddled with,” all to Chavín’s benefit, Rick says.
177350855
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sciencehabit writes:
New NIH director Jayanta “Jay” Bhattacharya sat down for an interview with Science about the future of NIH. The encounter was brief, sometimes confrontational, and even personal.
When asked about low morale at NIH following two waves of firings, and about concerns at academic institutions about funding delays and grant cuts, Bhattacharya wanted to know whom the reporter had talked to. After Science mentioned past NIH Director Harold Varmus, he noted that the Nobel Prize winner had “attacked me pretty viciously” in an op-ed. He complained about the Science's reporter's past coverage of a nonprofit group, the EcoHealth Alliance, that used NIH funding for virus studies in China that some scientists and Republican politicians claim caused the COVID-19 pandemic.
Bhattacharya blamed some NIH restrictions since January on “panicked overreaction to directions from above” and decried “panicked reporting” among media covering NIH. He dismissed an article in Nature on the pending policy on foreign collaborators as “rumors”:
“No, that’s false. There’s going to be a policy on tracking subawards. The NIH and the government should be able to see where the money’s going... I’m really uncomfortable with this conversation, because you’re like, actually spreading rumors that you don’t know anything about. Nature also is spreading rumors. Halt foreign collaborations, that’s not true.”
Later that day, NIH released a policy that halted future subawards to foreign scientists and said they will need to apply directly for money under a system still in development.
177268743
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sciencehabit writes:
Before the silver or gold in your favorite piece of jewelry made its way to Earth, it first had to spawn during one of the universe’s most energetic explosions. At first, astronomers knew of only one cosmic scenario that fit the bill for this violent formation of “jewelry shop” elements: the collision of two ultra-dense stellar corpses called neutron stars. Now, a second has stepped onto the scene.
As they report this week in The Astrophysical Journal Letters, researchers have discovered signatures of this heavy element formation — called the r-process — in a giant flare first detected from a highly magnetic neutron star in 2004.
The flare, which released more energy than our Sun does in a million years as it spewed electrically charged material, has remained shrouded in mystery since its discovery 20 years ago. Researchers quickly traced the outburst to a nearby magnetar, a special breed of neutron star whose magnetic fields are trillions times stronger than Earth’s. But ten minutes after the massive flare, a second, fainter signal inexplicably came from the same star.
More r-process sources may still be looming in the dark. The new study accounts for about 10% of the Milky Way’s heavy elements, suggesting that astronomers will have to scour the cosmos for even more places where the r-process is hiding. One potential spot is a rare type of supernova that births rapidly rotating neutron stars, says says Anirudh Patel, the new study’s lead author and an astronomer at Columbia University. He
hopes that with more observations, astronomers will be able to sharpen that picture. But for now, he says it’s exciting enough to find a new birthplace for what makes up so much of our world: “These heavy elements pervade our lives — we make use of them every day. It’s humbling to realize that these were made in such extreme astrophysical environments.”
177236075
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sciencehabit writes:
On a cool, sunny, mid-April day, the cheerful redbuds and other flowering trees amid the sprawling labs on the National Institutes of Health (NIH) main campus belied the pervasive gloom. Nearly 3 months into President Donald Trump’s administration, NIH in-house scientists and other workers were reeling from mass layoffs of colleagues; the removal of leaders; and limits on travel, communication, and purchasing that have shut the agency off from the outside world, hamstrung experiments, and crushed the community’s spirits.
On that spring day in Bethesda, Maryland, one senior scientist lamented that two star colleagues in his institute were heading back to their native China from NIH, abandoning a destination that had always drawn talent from around the world. “I want to cry,” he said. Another pointed to the abrupt retirement the previous day of a noted NIH nutrition scientist who said the agency had censored his publications and interactions with the media.
The Department of Government Efficiency (DOGE), billionaire Elon Musk’s quasi-official White House enforcer, “pops in and out” of online meetings of senior leaders, the scientists said. Another researcher, who is not a U.S. citizen, mentioned that he has prepared a “deportation plan,” including a company lined up to ship belongings back to his native country, in case he’s fired and loses his work visa.
The atmosphere is one of “chaos and fear and frustration and anger,” said a senior scientist with NIH’s intramural research program who, like others, spoke on condition of anonymity to protect themselves and others from retribution. This scientist added: “It’s this feeling of utter powerlessness and repeated insults.”
A former top NIH official who was forced out believes that’s the intent. “I think the plan is to sow as much chaos as possible. I think they want a dispirited workforce at NIH so people will just say ‘to hell with it’ and leave.”
It’s working. Hundreds of NIH employees took voluntary buyouts offered by the Trump administration. And at least 25 of the roughly 320 physician-researchers who lead trials of drugs, cell therapies, and vaccines at NIH’s massive Clinical Center are leaving, as are consulting physicians, a researcher there told Science.
176995035
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sciencehabit writes:
In 2001, archaeologists made a discovery that promised to rewrite the history of cat domestication. Scientists had long believed cats became our friends in ancient Egypt, where they’ve been immortalized in mummies and art. But when researchers dug beneath a 9500-year-old home in a farming village on the Mediterranean island of Cyprus, they discovered what appeared to be a pet cat buried with a human—more than 4000 years before ancient Egypt even existed.
And so a new story began to take shape. The discovery of other ancient cat bones across Europe persuaded many scientists that domestication began when wildcats slunk into the villages of early farmers—perhaps in what is now Turkey—and eventually evolved into the housecats we know today. As these farmers migrated to new parts of Europe, they brought their feline companions with them.
Now, two studies—both posted late last month on the preprint server bioRxiv—restore the focus on Egypt. Ancient bones and DNA from cats across Europe and the Mediterranean suggest they may have been domesticated in Egypt after all, possibly as recently as 3000 years ago. The process, one of the new papers theorizes, was a gruesome one: Mass sacrifices of cats tied to a religious cult instilled tameness over many generations. “It’s the murder pathway of domestication,” says Greger Larson, an evolutionary biologist at the University of Oxford and author on both studies.
176902105
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sciencehabit writes:
With his little round glasses tucked into his helmet and a less than explosive stride, Mikhail Lukin could never be mistaken for a professional hockey player. A world-renowned physicist and expert in quantum computing at Harvard University, Lukin played hockey growing up in Russia and clearly knows what he’s doing. But, at 53, he doesn’t do anything on skates fast.
And, yet, the lanky lefty still possesses a scorer’s touch, as he showed at a friendly hockey game he helped organize last month at the American Physical Society’s (APS’s) Global Physics Summit. At least four times, Lukin ends up the right place at the right time to drive home a rebound or tip in a cross-ice pass for an easy goal. However, one of Lukin’s own teammates suggests his offense comes at the expense of his defense. “Misha never backchecks,” says Kunal Tiwari, a physicist at the Massachusetts Institute of Technology’s (MIT’s) Lincoln Laboratory. “I don’t want you to attribute that to me.”
Now something of a fixture at APS’s biggest annual meeting, the “quantum hockey” game grew out of a weekly pickup session Lukin organizes for physicists at Harvard and MIT. When APS met in Boston in 2019, he and Andreas Wallraff, a physicist at ETH Zürich, decided to open the skate to meeting attendees. Since then, the two lifelong hockey players have taken the game on the road, when possible. In 2020, “I was standing in front of my house with my hockey gear, ready to go, when the meeting in Denver was canceled because of COVID,” Wallraff recalls.
Nominally, the contest is a grudge match between scientists working on two different basic technologies for quantum computing. Wallraff captains the Superconducting Lightning, which comprises mostly researchers working with quantum bits, or qubits, made of tiny superconducting electrical circuits. Lukin leads the Mighty Atomic Strike, whose roster is filled with researchers working with qubits made of individual atoms. “We’ve got the superior platform, so we’ve got to show it on the ice, too,” says Justin Perron, a Strike member from California State University San Marcos.
Though obviously fun, the game serves a deeper purpose, Lukin says. Quantum computing isn’t just a prestigious scientific field, it’s also a budding industry in which startups can ink deals worth hundreds of millions of dollars. With so much at stake, rivalries can boil over. Just the day before at the meeting, tempers flared over Microsoft’s controversial claim to have fashioned a particular type of qubit. The game helps cut the tension, Lukin notes. “For community building, this is really useful,” he says. “It’s a very competitive field.”
176830741
submission
sciencehabit writes:
Growing up to 55 meters tall in the tropical forests of Panama, the almendro tree is a natural lightning rod. And that appears to be a good thing: The millions of volts that course through this species during a strike electrocute parasitic vines and leap from branches, killing nearby trees that might compete for the almendro’s sunlight, researchers report today in New Phytologist.
In a recent survey of a patch of Panamanian jungle, scientists found that Almendro trees (Dipteryx oleifera) seemed particularly resilient to lightning strikes. All nine that had been struck were practically unscathed, losing only small patches of leaves. In comparison, similarly tall trees of other species took nearly six times as much damage; 40% of their upper branches and leaves were destroyed, on average, and 64% of those trees died within the first 2 years after being struck.
The only thing that died on the almendros were the vines. Called lianas, they grow over a tree's foliage, robbing it of light. These vines are so aggressive they can stunt tree growth and reproduction.
Another benefit of the lightning strikes: smaller trees surrounding the almendros took collateral damage. Within weeks, the shorter trees’ branch tips began to die, presumably because electrical current had sparked across the air, passed through touching leaves, or flowed through shared vines. Over several months, many bystander trees slowly lost leaves and died.
The researchers calculated that living near an almendro increases a given tree’s likelihood of dying during a strike by 48%—so lightning may help eliminate trees that might grow tall enough to compete for an almendro's sunlight, says the lead researcher. "Any tree that gets close essentially gets electrocuted."
