Innholdsfortegnelse for January/February 2022 i Discover

Life is resilient. The first living things on Earth appeared as far back as 4 billion years ago, according to some scientists. Throughout Earth’s history, it’s seen all manner of cataclysms. These disparate doomsdays have killed countless life-forms. And at times, those mass extinctions have even eliminated most species on Earth. Yet life has always rebounded. New species emerge. The cycle repeats. So, what would it take to kill off life in full? Here are just a few possible doomsday events that could permanently extinguish all life on Earth — and the last one is likely unavoidable. ASTEROID-IMPACT APOCALYPSE When a city-sized asteroid struck the Gulf of Mexico 66 million years ago, it was game over for the dinosaurs, as well as most other species on Earth at the time.…

AS OUR CALENDARS flipped to 2021, pandemic life didn’t feel particularly different than it had for the past year. Except, by that point, the very first doses of a COVID-19 vaccine had been administered. Over the next few months, as people hit their immunity mark — two weeks after their final dose — those who had been staying home began to venture back into the world. And, on May 13, the CDC announced liberating new guidelines, allowing vaccinated people to “resume activities without wearing a mask or physically distancing.” A return to normal seemed to be on the way. But normal never arrived. The vaccine rollout worldwide was marred by vaccine hesitancy in some areas, and inequities in availability in others. By July 25, two months after children ages 12–15…

IN MARCH, after years of analyzing and confirming data, astrophysicists reported that the IceCube Neutrino Observatory, a detector buried at the South Pole, had picked up an unusual signal in 2016. It suggested that a particle called an antineutrino had crossed space and time — originating far beyond our galaxy — before smashing into Antarctica and releasing a particle shower in the ice. According to the Standard Model of particle physics, every known type of particle has an antimatter counterpart (though there’s hardly any trace of antimatter in the universe today). More than 60 years ago, future Nobel laureate Sheldon Glashow predicted that if an antineutrino — the antimatter answer to the nearly massless neutrino — collided with an electron, it could produce a cascade of other particles. The “Glashow…

TENS OF MILLIONS of years ago, a tiny, milky-white bug known as a whitefly snatched a gene from its host, an ancient plant. Dubbed BtPMaT1, the gene renders a common plant toxin harmless — allowing the pesky insect to become one of today’s most insidious agricultural pests. The discovery of BtPMaT1 in whiteflies marks the first time scientists have identified a gene that’s crossed from a plant to an animal, researchers from China and Europe reported in Cell last March. Horizontal gene transfer, or HGT, occurs when a gene moves from one species into another. It’s common between many species of bacteria, and even occurs between bacteria and plants, or bacteria and animals. Finding a gene from a plant inside an insect, though, was unprecedented. The stolen gene helps explain why…

IF YOU’VE encountered a dead tree in the woods or green algae on a lake, you’ve witnessed fungi at work. Yet scientists are just beginning to grasp the vital role that these worldwide organisms play in carbon sequestration, thanks in part to a couple of breakthrough studies in 2021. Researchers already knew that 300 million years ago, white-rot fungi evolved the unique ability to digest lignin. That’s the natural, tough polymer in the cell walls of trees, making them rigid and woody. This fungal super-skill of digestion ended the Carboniferous Period by decomposing woody debris that would’ve fossilized into coal. But no one really knew what happened to the carbon inside the lignin. Scientists had long thought it simply evaporated into the atmosphere. But that didn’t sit right with Davinia Salvachúa…

THE CENSUS TAKERS set out in the spring of 2021 not in cars, but on a fleet of elephants. More than 300 people, including conservation experts and forestry officials, swept Nepal’s national parks in search of rhinos. Two months later, the team announced that Nepal’s rhino population had risen to 752, a 16.6 percent jump from 2015. After decades of work, this progress demonstrates how local and global efforts can save an animal species from the brink of extinction. One-horned rhinos once roamed the Indus and Ganges river plains in northern and eastern India, southern Nepal, parts of Pakistan and Bhutan, and most of Bangladesh. But hunting and habitat destruction culled the animals to small patches of their former range, mostly in India and Nepal. By the 1970s, Nepal had fewer…

IN 2011, archaeologists digging in a second-century A.D. trash dump near an ancient Red Sea port found the remains of a cancer-ridden hound dog wrapped in a palm leaf mat. The team unearthed 585 cat, dog, monkey and fox skeletons across the roughly 1,000-square-foot area over the next decade. The animals often wore collars and were covered with textiles or pottery pieces. Nearly 2,000 years ago, residents of Berenice, a Roman-ruled trading post in Egypt, created perhaps the world’s oldest pet cemetery. These aren’t the first animal grave finds. At sites dated between 7,000 and 27,000 years old in Eurasia and North America, archaeologists have found burials of canines who likely accompanied hunter-gatherers. Ancient Egyptians mummified cats, crocodiles and other creatures to entomb with dead humans for spiritual purposes. Yet…

UNDER DIFFERENT circumstances, the U.S. Food and Drug Administration’s approval of the medication aducanumab might have been celebrated as one of the great therapeutic advances of 2021. The drug was proclaimed as the first medication to target the underlying pathology of Alzheimer’s disease. The most common form of dementia, Alzheimer’s affects more than 6 million people in the U.S. alone. Although a handful of older drugs can temporarily blunt its symptoms, none can slow the processes behind its devastating onslaught. Yet the FDA’s ruling became one of the year’s biggest scientific controversies. The roots of the brouhaha stretch back to March 2019, when aducanumab’s developers, U.S.-based Biogen and Japan’s Eisai, halted two large clinical trials after an independent monitoring committee determined that the drug showed no clinical benefit. In one…

IN THE LATE 1960s, a serial killer self-identifying as “the Zodiac” killed at least five people in Northern California and claimed to have murdered more. In November 1969, the Zodiac killer sent a card to the San Francisco Chronicle containing a 340-character secret message that for more than 50 years went unsolved by numerous detectives, cryptography experts, amateur sleuths and curious others. Wonder no more, true-crime aficionados. After months of crunching code during the pandemic, three researchers on three different continents announced that they’d finally decoded the message. Further bolstering the claim, experts at the FBI verified the solution (and even tweeted about it). The encrypted message didn’t reveal the identity of the Zodiac killer, but it did bring decades of speculation, conspiracy theories and guesswork about this cipher to…

(“What’s in a Name? More Than You Think,” June 2021) “What’s in a Name?” discusses words that sound like what they mean (e.g.: pop, murmur, whisper). I would like to point out that in English, Spanish, French, and, I suppose, Italian, many words and suffixes that denote the diminutive or feminine use the vowel sounds “i” or “ee”: little, mini, petite, teeny, skimpy, itsy bitsy, bit, pee wee, sissy, -ita, -ina. Even in animals, we have kitty, piggy, filly, chick. These words and suffixes do not sound like what they mean, but somehow, we associate that vowel with being small. Diane Trembly North Fort Myers, Fla. DISHEARTENING HISTORY (“How to Save Planet Earth,” May 2021) Several weeks ago, on the NPR show Planet Money (I think), they had an interview with…

If you’ve ever learned a new language — or tried to — you know how difficult it can be. Native languages seem almost built-in. We soak them up naturally when we’re very young. But learning a new language, especially after early childhood, can be a huge task, burdened by long vocabulary lists and genders to memorize, complex cases and troublesome tenses to master. Of course, it’s worth the effort. In today’s interconnected world, learning a new language can change your life. It will certainly change your brain. ALTERNATE ROUTES Learning anything changes your brain, at least a little bit. But learning a language does it in high gear. John Grundy, a neuroscientist at Iowa State University who specializes in bilingualism and the brain, explains that learning a new language causes…

The quiet of my night on call was interrupted by the familiar chime of my pager. The message on the screen requested I come to the emergency room to evaluate a patient with chest pain. For a gastroenterologist, “chest pain” is a bit of an uncommon symptom; usually, such concerns go to cardiology. But sometimes people with chest pain have a GI cause for their troubles. When I arrived in the ER, the patient was sitting up in bed, leaning forward, and gently rocking back and forth in what was clearly a state of significant distress. Still, Matt, a 60-year-old salesman, was able to tell me what was going on. As part of his job, he occasionally had to take potential clients out to business dinners — lavish affairs at…

THE DEVELOPMENT of the mRNA vaccine — a break-through in its field, instructing cells to produce their own protection without the risk of giving someone the virus — was fast and furious, made possible through rapid genome sequencing. But its origins go back to the late 1980s, when Kati Kariko, a researcher at the University of Pennsylvania, began experimenting with placing mRNA (m stands for “messenger”) into cells to instruct them to produce new proteins, even if those cells had been previously unable to do so. Eventually, Kariko also discovered that pseudouridine, a molecule of human tRNA (t stands for “transfer”), could help a vaccine evade an immune response when added to the mRNA. It laid the groundwork for a first-of-its-kind antidote that helped save hundreds of thousands of lives,…

THERE’S NO SUCH thing as being alone in the cosmos. Physicists have known for decades that particles and antiparticles pop in and out of existence all the time, some of which we know about and many of which likely remain undiscovered. Physicists search for signs of new particles beyond the Standard Model — the theory that describes how elementary particles and fundamental forces interact — to push physics into new realms. In April, an international collaboration of more than 200 scientists, based at the Fermilab National Accelerator Laboratory in Batavia, Illinois, reported findings that may open a door to physics that transcends the Standard Model. The experiment centered on muons, which are positively- or negatively-charged short-lived subatomic particles with about 200 times as much mass as electrons. Like electrons, muons…

CONCERNS ABOUT microplastics are not new. They’ve been growing for more than a decade. Over the past two years, however, many creative solutions have emerged to address the problem on a local level, ranging from hoovering beaches to shooting bubbles up from river bottoms. Still, experts say there’s a need for a huge, coordinated effort if we want to curb the global issue: The world produces 400 million tons of plastic annually, and much of that material breaks down into tiny pieces that now litter our planet. The term microplastics was coined in 2004 by marine ecologist Richard Thompson after he discovered tiny bits of plastic littering British beaches. Since then, scientists have found microplastics — fragments less than 5 millimeters wide — nearly everywhere: in the deep sea, in…

ABOUT 600 MILES northwest of Honolulu, in the middle of the Pacific Ocean, two small pinnacles poke out of the sea. To an observer, the 5 acres of rock known as Pūhāhonu might seem insignificant, except as a landing pad for weary seabirds. But their presence suggests the existence of something much bigger beneath the surface: what many experts are now calling the largest single volcano on Earth. New seafloor mapping of the Papahānaumokuākea Marine National Monument revealed Pūhāhonu’s full size. Michael Garcia, a volcanologist at University of Hawai’i at Mānoa, and his colleagues found that the mostly submerged volcano contains at least 35 cubic miles of rock, according to a study published in 2020 in Earth & Planetary Science Letters. That’s roughly double the volume of Hawaii’s Mauna Loa, the…

IN LATE 2017, paleontologist Qiang Ji showed his anthropologist colleague Xijun Ni photos of a human skull with a hefty browridge. Besides missing all but one tooth, the cranium appeared remarkably intact — making it one of the best-preserved skulls from any human ancestor or relative. “I was shocked,” recalls Ni. “I said, ‘This is the most important discovery, [more] than any of your dinosaurs.’” Ji, a dinosaur expert at Hebei GEO University in China, didn’t excavate the specimen. It reportedly surfaced in 1933, when a contractor was building a bridge near Harbin City in northeast China. After encountering the fossil, he stashed it in a well to protect it from Japanese occupiers. The noggin remained there for 85 years, until the dying man divulged its location. His grandchildren retrieved the…

ONE HUNDRED thousand years ago, Neanderthals gathered in a cave perched 3,000 feet up in presentday Spain’s Atapuerca Mountains. While cooking and watching youngsters wrestle, they littered the floor with DNA in shed skin, spit and other bodily debris. Dirt accumulated and protected the genetic material for millennia, even as humans and animals sheltered there. At the site, known as Estatuas, archaeologists have uncovered abundant stone tools and animal bones since 2008. The sole Neanderthal bone found — a toe tip with Swiss cheese consistency — seemed too precious to crush for DNA analysis. The scientists therefore couldn’t elucidate the inhabitants’ genetic traits and ties with other Neanderthal clans. Instead, they searched the dirt for loose DNA. In 2018, researchers dropped into pits at Estatuas and collected sediment from layers…

AT LONG LAST, scientists have declared “mission accomplished” on the complete sequencing of the human genome — one of the most ambitious research undertakings of the past few decades. The news may trigger déjà vu: Scientists with the Human Genome Project first announced they had sequenced the human genome in 2003. That initial effort came with some notable omissions, though. A sizable chunk of the genome remained inaccessible, the era’s technology unable to parse more complex DNA regions. Though additional work added more clarity, around 8 percent of the human genome remained a mystery — until this year, when an international collaboration called the Telomere-to-Telomere (T2T) Consortium filled the gaps. Many of these tricky regions include long stretches of highly repetitive DNA sequences. Though they often don’t code for proteins, the…

MALARIA KILLS over 400,000 people a year around the world, most of them children. That toll, though grim, is a little under half what it was in 2000, thanks to campaigns to distribute mosquito nets, conduct indoor pesticide spraying and administer preventive medications. Since 2015, however, factors ranging from funding shortfalls to increased drug and insecticide resistance have caused the numbers of deaths and overall cases — more than 200 million annually — to plateau. Two breakthroughs could make a difference. One came in October, when the World Health Organization approved the first vaccine against the disease. Mosquirix, manufactured by GlaxoSmithKline, is only moderately effective: In clinical trials, it reduced cases by about 56 percent over 12 months, dropping to 36 percent over four years. Still, as Pedro Alonso, director…

IN A DREAM, fluorescent lights flicker over your head. Short, short, long … short, long. It’s Morse code, sent from a scientist in the waking world who’s watching you sleep under a light they’re controlling. After receiving the full message, you shift your closed eyes left then right, four times, to signal your reply. During a lucid dream, people are aware they’re dreaming. Skilled lucid dreamers not only have these dreams often, but they can remember instructions given to them before falling asleep. This allows dreamers in a lab setting to respond — often with strategic eye movements — to onlooking researchers who send prompts to the sleeping subjects. In April, researchers reported that they talked to lucid dreamers, and the dreamers talked back. “When I first saw it happening,…

SNUGGLE STRESS This hibernating Arctic ground squirrel may look serene, but it’s under significant stress — at least, its body is. To survive the brutal winter, these critters slip into a deep sleep that can last for weeks at a time. Burrowed safely, they alternate between periods of low oxygen consumption and brief rewarming periods of normal consumption. The sudden surges can kick off a chain reaction in the body that produces hydrogen peroxide, resulting in excessive inflammation. According to a report in Critical Care Explorations, researchers last year identified a hidden hero that evolved to combat the stress: iodide, a form of iodine released by thyroid hormones. Increased levels of iodide in the blood convert harmful hydrogen peroxide into plain old oxygen and water. The discovery could someday lead…

HUMANS HAVE wondered if there’s ever been life on Mars for as long as we’ve known it’s a planet. We could soon have an answer. In February, NASA landed its Mars Perseverance rover, along with a companion helicopter, the intrepid Ingenuity, in an ancient river delta called Jezero Crater. The NASA mission, dubbed Mars2020, was designed to search for signs of ancient life and collect drilling samples to return to Earth for deeper analysis. “For the first time, we are actually going to bring back cores from Mars to Earth,” says Vandi Verma, chief engineer of robotic operations for the mission. Along the way, Perseverance will also lay the groundwork for future human missions by studying environmental conditions, identifying resources like water and testing a method for making oxygen. Perseverance wasn’t…

FROM BRUTAL heat in North America and Siberia to devastating flooding in China and Europe, 2021 delivered worsening climate extremes of the kind long predicted by scientists. Streetcar cables melted in Portland. A raging river swept away entire homes in Germany’s lush Ahr Valley wine region. And wildfires have set records across the globe in the past two years. For many people, recent disasters have transformed human-caused climate change from a theoretical, far-off risk to an undeniable reality. And this summer, the United Nations dropped a landmark climate report, emphasizing that avoiding even worse impacts will require deep, rapid cuts in greenhouse gas pollution. But does that mean 2021 will be remembered as the year denial of climate change all but died? At least one renowned environmental scientist believes so.…

JUST HALFWAY through the summer of 2021, a startling record was set: By one measure, almost 100 percent of the Western U.S. was in drought. In 122 years of observation, never had that much land been that dry west of the Continental Divide. Lack of precipitation was a factor. But even more significant were high temperatures. In June alone, 202 all-time record highs were set in the West. For the Southwest, these extremes amplified a 20-year megadrought that’s been drying out the region and, most notably, the Colorado River Basin. In the effort to meet rising water demands in the basin, the two largest reservoirs in the U.S. — lakes Mead and Powell along the Colorado River — both shriveled to historic lows this summer. “It’s a ticking time bomb,” says…

A GIANT ASTEROID smashing into our planet sounds singularly catastrophic. But it might have also sparked environmental shifts that define Earth as we know it. New research suggests that the Chicxulub asteroid impact that most likely wiped out the dinosaurs also set the stage for modern neotropical rainforests like the Amazon. Tens of thousands of plant and pollen fossils collected from rocks across Colombia have revealed that the collision — which took place 66 million years ago — led to drastic changes in rainforest plant diversity, according to a Science study published in April. “It’s staggering that the neotropical rainforests we see today are a byproduct of a single historical accident,” says Carlos Jaramillo, a paleopalynologist studying ancient plants at the Smithsonian Tropical Research Institute, and one of the study’s co-authors.…

DINOSAURS KEEP breaking records. Every so often, paleontologists report that another giant, long-necked dinosaur might win the title of “Biggest Yet.” Since 1993, Argentinosaurus had stood as the likely record-holder, only to be supplanted in 2017 by the roughly 120-foot-long, 57-ton Patagotitan. In yet another upset, this year paleontologists working in Argentina’s Neuquén Province announced their finding: another sauropod that may be even larger. The new dinosaur is currently unnamed, but its bones were described in a June Cretaceous Research paper by paleontologist Alejandro Otero of Facultad de Ciencias Naturales y Museo in Buenos Aires. Researchers have uncovered about two dozen vertebrae and hip and shoulder bones from this 98-million-year-old animal. The fossils indicate that the creature was a titanosaur — a long-necked, herbivorous dinosaur related to Argentinosaurus and Patagotitan…

WOOLLY MAMMOTHSare Pleistocene celebrities. These massive, shaggy beasts trod much of the Northern Hemisphere between 700,000 and 10,000 years ago, thriving during cold times when glaciers expanded and vast, cold grasslands spread. But, a study published in 2021 in Nature reported, the traits that allowed woolly mammoths to tolerate the chill were not unique to these furry elephants alone. Woolly mammoths inherited many of their cold-adapted traits from even older mammoth species, according to a new finding revealed by million-year-old DNA. The analysis, led by Sweden’s Science for Life Laboratory bioinformaticianTom van der Valk and colleagues, was based on ancient DNA sampled from three mammoth molars found in northeastern Siberia during the 1970s. Each of the fossils has a nickname — the oldest, called the Krestovka mammoth, is more than…

OBESITY IS A modern scourge, affecting 42 percent of Americans and raising overall risk of cardiovascular disease, diabetes and cancer. It is also notoriously difficult to control; for most people, diet and exercise offer only temporary results, even when combined with medication. Gastric bypass and similar procedures — though more effective — carry significant health risks of their own. In June, however, the U.S. Food and Drug Administration approved a treatment that could transform that outlook for millions of people. Semaglutide, a synthetic version of a gut hormone called glucagon-like peptide-1 (GLP-1), increases insulin production and adjusts the brain’s metabolic settings — helping to regulate appetite rather than suppress it. Developed by Danish company Novo Nordisk, the drug has been used since 2017 to treat Type 2 diabetes. Subsequent clinical…

THE CRISPR-CAS9 gene-editing tool once again ventured into uncharted territory this year — in more ways than one. Most notably, the gene editor — which functions like molecular scissors to snip apart DNA and insert, delete or modify genes — went to work inside human patients. In a landmark trial, a group of scientists from the U.K. and New Zealand showed that CRISPR can be used to successfully edit genes in the human body. Their work involved six patients with a devastating genetic disease called transthyretin amyloidosis, and was published in the New England Journal of Medicine in June. The hereditary form of the disease stems from mutations to the TTR gene, which produces the protein transthyretin. Patients experience progressively debilitating symptoms as misshapen protein clumps called amyloids build up in…

AMERICANS SPEND more than 11 hours a day online, creating and consuming posts, images, tweets and more. And this year we saw more digital media up for sale than ever before — at record prices — in the form of the non-fungible token (NFT). These digital assets, purchased through cryptocurrency, have been around for nearly a decade, but 2021 made them a global phenomenon. Non-fungible essentially means “one of a kind” — unlike, say, a dollar bill. Both real and digital cash are fungible; one dollar or one Bitcoin is always worth the same as another dollar or Bitcoin. An NFT, on the other hand, is a unique digitally encoded asset that someone can own and whose value is determined by what buyers are willing to pay. For instance, this…