Archaeologist Peter Bellwood’s academic odyssey wended from England to teaching posts halfway around the world, first in New Zealand and then in Australia. For more than 50 years, he has studied how humans settled islands from Southeast Asia to Polynesia.
So it’s fitting that his new book, a plain-English summary of what’s known and what’s not about the evolution of humans and our ancestors, emphasizes movement. In The Five-Million-Year Odyssey, Bellwood examines a parade of species in the human evolutionary family — he collectively refers to them as hominins, whereas some others (including Science News) use the term hominids (SN: 9/15/21) — and tracks their migrations across land and sea. He marshals evidence indicating that hominids in motion continually shifted the direction of biological and cultural evolution. Throughout his tour, Bellwood presents his own take on contested topics. But when available evidence leaves a debate unresolved, he says so. Consider the earliest hominids. Species from at least 4.4 million years ago or more whose hominid status is controversial, such as Ardipithecus ramidus, get a brief mention. Bellwood renders no verdict on whether those finds come from early hominids or ancient apes. He focuses instead on African australopithecines, a set of upright but partly apelike species thought to have included populations that evolved into members of our own genus, Homo, around 2.5 million to 3 million years ago. Bellwood hammers home the point that stone-tool making by the last australopithecines, the first Homo groups or both contributed to the evolution of bigger brains in our ancestors.
The action speeds up when Homo erectus becomes the first known hominid to leave Africa, roughly 2 million years ago. Questions remain, Bellwood writes, about how many such migrations occurred and whether this humanlike species reached distant islands such as Flores in Indonesia, perhaps giving rise to small hominids called hobbits, or Homo floresiensis (SN: 3/30/16). What’s clear is that H. erectus groups journeyed across mainland Asia and at least as far as the Indonesian island of Java.
Intercontinental migrations flourished after Homo sapiens debuted, around 300,000 years ago in Africa. Bellwood regards H. sapiens, Neandertals and Denisovans as distinct species that interbred in certain parts of Asia and Europe. He suggests that Neandertals disappeared around 40,000 years ago as they mated with members of more numerous H. sapiens populations, leaving a genetic legacy in people today. But he does not address an opposing argument that different Homo populations at this time, including Neandertals, were too closely related to have been separate species and that it was intermittent mating among these mobile groups that drove the evolution of present-day humans (SN: 6/5/21).
Bellwood gives considerable attention to the rise of food production and domestication in Europe and Asia after around 9,000 years ago. He builds on an argument, derived from his 2004 book First Farmers, that expanding populations of early cultivators migrated to new lands in such great numbers that they spread major language families with them. For instance, farmers in what’s now Turkey spread Indo-European languages into much of Europe sometime after roughly 8,000 years ago, Bellwood contends.
He rejects a recent alternative proposal, based on ancient DNA evidence, that horse-riding herders of Central Asia’s Yamnaya culture brought their traditions and Indo-European tongues to Europe around 5,000 years ago (SN: 11/15/17). Too few Yamnaya immigrated to impose a new language on European communities, Bellwood says. Similarly, he argues, ancient Eurasian conquerors, from Alexander the Great to Roman emperors, couldn’t get speakers of regional languages to adopt new ones spoken by their outnumbered military masters.
Bellwood rounds out his evolutionary odyssey with a reconstruction of how early agricultural populations expanded through East Asia and beyond, to Australia, a string of Pacific islands and the Americas. Between about 4,000 and 750 years ago, for instance, sea-faring farmers spread Austronesian languages from southern China and Taiwan to Madagascar in the west and Polynesia in the east. Precisely how they accomplished that remarkable feat remains a puzzle.
Disappointingly, Bellwood doesn’t weigh in on a recent archaeological argument that ancient societies were more flexible and complex than long assumed (SN: 11/9/21). On the plus side, his evolutionary odyssey moves along at a brisk pace and, like our ancestors, covers a lot of ground.
Sometimes a photo is literally a matter of life, death — and zombies.
This haunting image, winner of the 2022 BMC Ecology and Evolution photography competition, certainly fits that description. It captures the fruiting bodies of a parasitic fungus, emerging from the lifeless body of an infected fly in the Peruvian rainforest.
The fungus-infested fly was one of many images submitted to the contest from all over the world, aiming to showcase the beauty of the natural world and the challenges it faces. The journal revealed the winners August 18. Roberto García-Roa, a conservation photographer and evolutionary biologist at the University of Valencia in Spain, took the winning photo while visiting the Tambopata National Reserve, a protected habitat in the Amazon.
The fungus erupting from the fly belongs to the genus Ophiocordyceps, a diverse collection of parasitic fungi known as “zombie fungi,” due to their ability to infect insects and control their minds (SN: 7/17/19).
“There is still much to unravel about the diversity of these fungi as it is likely that each insect species infected succumbs to its own, specialized fungus,” says Charissa de Bekker, an expert in parasitic fungi at Utrecht University in the Netherlands.
First, spores of the fungus land on the ill-fated fly. So begins the manipulative endgame. The spores infiltrate the fly’s exoskeleton before infecting its body and eventually hijacking its mind. Once in control, the fungus uses its new powers of locomotion to relocate to a microclimate more suitable to its own growth — somewhere with the right temperature, light and moisture.
Fungus and fly then bide their time until the fly dies, becoming a food source for the fungus to consume. Fruiting bodies work their way out of the fly, filled with spores that are released into the air to continue the macabre cycle in a new, unsuspecting host. It is a “conquest shaped by thousands of years of evolution,” García-Roa said in a statement announcing the winners.
Research into the molecular aspects of fungal mind control is under way, De Bekker says, including in her own lab. “These fungi harbor all sorts of bioactive chemicals that we have yet to characterize and that could have novel medicinal and pest control applications.”
This is the first picture of an exoplanet from the James Webb Space Telescope.
“We’re actually measuring photons from the atmosphere of the planet itself,” says astronomer Sasha Hinkley of the University of Exeter in England. Seeing those particles of light, “to me, that’s very exciting.”
The planet is about seven times the mass of Jupiter and lies more than 100 times farther from its star than Earth sits from the sun, direct observations of exoplanet HIP 65426 b show. It’s also young, about 10 million or 20 million years old, compared with the more than 4-billion-year-old Earth, Hinkley and colleagues report in a study submitted August 31 at arXiv.org. Those three features — size, distance and youth — made HIP 65426 b relatively easy to see, and so a good planet to test JWST’s observing abilities. And the telescope has once again surpassed astronomers’ expectations (SN: 7/11/22).
“We’ve demonstrated really how powerful JWST is as an instrument for the direct imaging of exoplanets,” says exoplanet astronomer and coauthor Aarynn Carter of the University of California, Santa Cruz.
Astronomers have found more than 5,000 planets orbiting other stars (SN: 3/22/22). But almost all of those planets were detected indirectly, either by the planets tugging on the stars with their gravity or blocking starlight as they cross between the star and a telescope’s view.
To see a planet directly, astronomers have to block out the light from its star and let the planet’s own light shine, a tricky process. It’s been done before, but for only about 20 planets total (SN: 11/13/08; SN: 3/14/13; SN: 7/22/20).
“In every area of exoplanet discovery, nature has been very generous,” says MIT astrophysicist Sara Seager, who was not involved in the JWST discovery. “This is the one area where nature didn’t really come through.”
In 2017, astronomers discovered HIP 65426 b and took a direct image of it using an instrument on the Very Large Telescope in Chile. But because that telescope is on the ground, it can’t see all the light coming from the exoplanet. Earth’s atmosphere absorbs a lot of the planet’s infrared wavelengths — exactly the wavelengths JWST excels at observing. The space telescope observed the planet on July 17 and July 30, capturing its glow in four different infrared wavelengths.
“These are wavelengths of light that we’ve never ever seen exoplanets in before,” Hinkley says. “I’ve literally been waiting for this day for six years. It feels amazing.”
Pictures in these wavelengths will help reveal how planets formed and what their atmospheres are made of.
“Direct imaging is our future,” Seager says. “It’s amazing to see the Webb performing so well.”
While the team has not yet studied the atmosphere of HIP 65426 b in detail, it did report the first spectrum — a measurement of light in a range of wavelengths — of an object orbiting a different star. The spectrum allows a deeper look into the object’s chemistry and atmosphere, astronomer Brittany Miles of UC Santa Cruz and colleagues reported September 1 at arXiv.org.
That object is called VHS 1256 b. It’s as heavy as 20 Jupiters, so it may be more like a transition object between a planet and a star, called a brown dwarf, than a giant planet. JWST found evidence that the amounts of carbon monoxide and methane in the atmosphere of the orb are out of equilibrium. That means the atmosphere is getting mixed up, with winds or currents pulling molecules from lower depths to its top and vice versa. The telescope also saw signs of sand clouds, a common feature in brown dwarf atmospheres (SN: 7/8/22).
“This is probably a violent and turbulent atmosphere that is filled with clouds,” Hinkley says.
HIP 65426 b and VHS 1256 b are unlike anything we see in our solar system. They’re more than three times the distance of Uranus from their stars, which suggests they formed in a totally different way from more familiar planets. In future work, astronomers hope to use JWST to image smaller planets that sit closer to their stars.
“What we’d like to do is get down to study Earths, wouldn’t we? We’d really like to get that first image of an Earth orbiting another star,” Hinkley says. That’s probably out of JWST’s reach — Earth-sized planets are still too small see. But a Saturn? That may be something JWST could focus its sights on. Those three features — size, distance and youth — made HIP 65426 b relatively easy to see, and so a good planet to test JWST’s observing abilities. And the telescope has once again surpassed astronomers’ expectations (SN: 7/11/22).
“We’ve demonstrated really how powerful JWST is as an instrument for the direct imaging of exoplanets,” says exoplanet astronomer and coauthor Aarynn Carter of the University of California, Santa Cruz.
Astronomers have found more than 5,000 planets orbiting other stars (SN: 3/22/22). But almost all of those planets were detected indirectly, either by the planets tugging on the stars with their gravity or blocking starlight as they cross between the star and a telescope’s view.
To see a planet directly, astronomers have to block out the light from its star and let the planet’s own light shine, a tricky process. It’s been done before, but for only about 20 planets total (SN: 11/13/08; SN: 3/14/13; SN: 7/22/20).
“In every area of exoplanet discovery, nature has been very generous,” says MIT astrophysicist Sara Seager, who was not involved in the JWST discovery. “This is the one area where nature didn’t really come through.”
In 2017, astronomers discovered HIP 65426 b and took a direct image of it using an instrument on the Very Large Telescope in Chile. But because that telescope is on the ground, it can’t see all the light coming from the exoplanet. Earth’s atmosphere absorbs a lot of the planet’s infrared wavelengths — exactly the wavelengths JWST excels at observing. The space telescope observed the planet on July 17 and July 30, capturing its glow in four different infrared wavelengths.
“These are wavelengths of light that we’ve never ever seen exoplanets in before,” Hinkley says. “I’ve literally been waiting for this day for six years. It feels amazing.”
Pictures in these wavelengths will help reveal how planets formed and what their atmospheres are made of.
“Direct imaging is our future,” Seager says. “It’s amazing to see the Webb performing so well.”
While the team has not yet studied the atmosphere of HIP 65426 b in detail, it did report the first spectrum — a measurement of light in a range of wavelengths — of an object orbiting a different star. The spectrum allows a deeper look into the object’s chemistry and atmosphere, astronomer Brittany Miles of UC Santa Cruz and colleagues reported September 1 at arXiv.org.
That object is called VHS 1256 b. It’s as heavy as 20 Jupiters, so it may be more like a transition object between a planet and a star, called a brown dwarf, than a giant planet. JWST found evidence that the amounts of carbon monoxide and methane in the atmosphere of the orb are out of equilibrium. That means the atmosphere is getting mixed up, with winds or currents pulling molecules from lower depths to its top and vice versa. The telescope also saw signs of sand clouds, a common feature in brown dwarf atmospheres (SN: 7/8/22).
“This is probably a violent and turbulent atmosphere that is filled with clouds,” Hinkley says.
HIP 65426 b and VHS 1256 b are unlike anything we see in our solar system. They’re more than three times the distance of Uranus from their stars, which suggests they formed in a totally different way from more familiar planets. In future work, astronomers hope to use JWST to image smaller planets that sit closer to their stars.
“What we’d like to do is get down to study Earths, wouldn’t we? We’d really like to get that first image of an Earth orbiting another star,” Hinkley says. That’s probably out of JWST’s reach — Earth-sized planets are still too small see. But a Saturn? That may be something JWST could focus its sights on.
For some ant queens, the secret to long life might be a self-produced insulin blocker.
Ant queens are famously long-lived, even though they shouldn’t be. Generally, animals that put lots of energy into reproduction sacrifice some time off their life. But ant queens produce millions of eggs and live an extraordinarily long time compared with worker ants that don’t reproduce.
Now, researchers have shown how one ant species pulls off this anti-aging feat. When queens and wannabe queens of the species Harpegnathos saltator gear up to reproduce, a part of what’s called the insulin signaling pathway gets blocked, slowing aging, the researchers report in the Sept. 2 Science. That molecular pathway has long been implicated in aging in mammals, including humans. “There’s been a need to understand why queens, or reproductives, in social insects can live for so amazingly long,” says Marc Tatar, a biologist at Brown University in Providence, R.I., who was not involved with the study. Some ant species have queens that survive 30 times as long as their workers. Other social insects such as bees and termites also have long-lived queens.
In a rare behavior for ants, when a queen H. saltator dies, some female workers begin competing in duels for the chance to replace her (SN: 1/17/14). These hopeful royals develop ovaries, start laying eggs and transition into queenlike forms called gamergates. When a worker transitions to a gamergate, her life span becomes five times as long as it was. But if she doesn’t end up becoming queen and reverts back to a worker, her life span shortens again.
The researchers exploited this behavior to investigate the molecular underpinnings of anti-aging in these ants. H. saltator gamergates, it turns out, extend their life spans by taking advantage of a split in the insulin signaling pathway, the chain of chemical reactions that drive insulin’s effects on the body. One branch of this pathway is involved with reproduction, while the other is implicated in aging.
“Insulin comes with our life — [after] we eat, we have high insulin,” says Hua Yan, a biologist at the University of Florida in Gainesville. “But a constant high level of insulin is bad for longevity.”
Examining patterns of gene activity, Yan and colleagues found that gamergates have more active insulin genes than regular worker ants and, as a result, have increased metabolic activity and ovary development. But the secret sauce protecting the ants from the insulin’s aging effects appears to be a molecule called Imp-L2, which blocks the branch of the insulin pathway linked to aging, experiments showed. The branch involved in reproduction, however, remains active.
“What we don’t understand is how Imp-L2 can act on one aspect of the pathway and not on the other,” says study coauthor Claude Desplan, a developmental biologist at New York University.
These results represent a leap forward in our understanding of extreme social insect longevity, the researchers say, while also showcasing an anti-aging evolutionary adaptation that hasn’t been seen in the wild before.
For some ant queens, the secret to long life might be a self-produced insulin blocker.
Ant queens are famously long-lived, even though they shouldn’t be. Generally, animals that put lots of energy into reproduction sacrifice some time off their life. But ant queens produce millions of eggs and live an extraordinarily long time compared with worker ants that don’t reproduce.
Now, researchers have shown how one ant species pulls off this anti-aging feat. When queens and wannabe queens of the species Harpegnathos saltator gear up to reproduce, a part of what’s called the insulin signaling pathway gets blocked, slowing aging, the researchers report in the Sept. 2 Science. That molecular pathway has long been implicated in aging in mammals, including humans. “There’s been a need to understand why queens, or reproductives, in social insects can live for so amazingly long,” says Marc Tatar, a biologist at Brown University in Providence, R.I., who was not involved with the study. Some ant species have queens that survive 30 times as long as their workers. Other social insects such as bees and termites also have long-lived queens.
In a rare behavior for ants, when a queen H. saltator dies, some female workers begin competing in duels for the chance to replace her (SN: 1/17/14). These hopeful royals develop ovaries, start laying eggs and transition into queenlike forms called gamergates. When a worker transitions to a gamergate, her life span becomes five times as long as it was. But if she doesn’t end up becoming queen and reverts back to a worker, her life span shortens again.
The researchers exploited this behavior to investigate the molecular underpinnings of anti-aging in these ants. H. saltator gamergates, it turns out, extend their life spans by taking advantage of a split in the insulin signaling pathway, the chain of chemical reactions that drive insulin’s effects on the body. One branch of this pathway is involved with reproduction, while the other is implicated in aging.
“Insulin comes with our life — [after] we eat, we have high insulin,” says Hua Yan, a biologist at the University of Florida in Gainesville. “But a constant high level of insulin is bad for longevity.”
Examining patterns of gene activity, Yan and colleagues found that gamergates have more active insulin genes than regular worker ants and, as a result, have increased metabolic activity and ovary development. But the secret sauce protecting the ants from the insulin’s aging effects appears to be a molecule called Imp-L2, which blocks the branch of the insulin pathway linked to aging, experiments showed. The branch involved in reproduction, however, remains active.
“What we don’t understand is how Imp-L2 can act on one aspect of the pathway and not on the other,” says study coauthor Claude Desplan, a developmental biologist at New York University.
These results represent a leap forward in our understanding of extreme social insect longevity, the researchers say, while also showcasing an anti-aging evolutionary adaptation that hasn’t been seen in the wild before.
The Milky Way: An Autobiography of Our Galaxy takes a tour of our home in the cosmos from an unexpected perspective. Astrophysicist and folklorist Moiya McTier presents herself not as the author, but as the lucky human vessel through which the Milky Way has chosen to tell its story. Then she lets the galaxy take it away, with humor, heart and a huge dose of snark.
The book alternates chapters between science and mythology, reflecting McTier’s dual specialties (her bio says she was the first student in Harvard University’s history to study both). “Many of you don’t realize this, but myths were some of your species’ first attempt at scientific inquiry,” the Milky Way tells us.
The Milky Way is telling its story now because it’s sick of being ignored. Once upon a time, humans looked to the glittering smudge of stars in the sky for insight into when to plant crops or avoid floods. We told stories about the Milky Way’s importance in the origin and fate of the world.
Our galaxy ate it up: For an entity that spends most of its time ripping up smaller galaxies and watching its own stars die, “your stories made me feel loved and needed and, perhaps for the first time in my long existence, more helpful than I was ruinous.” But in the last few centuries, technology and light pollution have pulled humankind away. “At first, I thought it was just a phase,” the Milky Way says. “Then I remembered … that several hundred years is actually a long time for humans.” So the Milky Way decided to remind us why it’s so important. Its autobiography covers big-picture scientific questions about galaxies, like where they come from (“When a gas cloud loves itself very much,” the Milky Way explains, “it hugs itself extra tight, and after a few hundred million years, a baby galaxy is born. Leave the storks out of it, please.”). It also gets into what galaxies are made of, how they interact with other galaxies, and how they live and die. The book then zooms out to cover the origins and possible ends of the universe, mysteries like dark matter and dark energy, and even humankind’s search for other intelligent life (SN: 8/4/20).
The author takes pains to explain scientific jargon and the technical tools that astronomers use to study the sky. A lot of popular astronomy writing glosses over how astronomers think about cosmic distance or exactly what a spectrum is, but not this book. If you’ve ever been curious about these insider details, The Milky Way has you covered.
McTier’s version of our home galaxy is heavily anthropomorphized. The Milky Way is brash, vain and arrogant in a way that may hide a secret insecurity. Its central black hole is characterized as the physical embodiment of the galaxy’s shame and regrets, a source of deep existential angst. And its relationship with the Andromeda galaxy is like a long-term, long-distance romance, with each galaxy sending stars back and forth as love notes until the two can eventually merge (SN: 3/05/21).
This could have felt gimmicky. But McTier’s efforts to make the metaphors work while keeping the science accurate and up-to-date made the premise endearing and entertaining.
I laughed twice on Page 1. I learned a new word on Page 2. I dog-eared the endnotes early on because it became instantly clear I would want to read every one. I read this book while traveling in rural upstate New York, where the sky is much clearer than at my home outside of Boston. The Milky Way reminded me to look up and appreciate my home in the universe, just like its narrator wanted.
For millions of people, COVID-19 doesn’t end with a negative test. Weeks or months after traces of the virus disappear from noses and throats, symptoms can persist or come back. New ones might pop up and stick around for months. People suffering from long COVID are unwillingly in it for the long haul — and it’s still unclear who’s at the highest risk for the condition.
Researchers don’t yet have an official definition for long COVID, and its symptoms are wide-ranging (SN: 7/29/22). Some people struggle with extreme fatigue that interferes with their daily lives. Others can’t concentrate or struggle with memory amid thick brain fog. Still others have organ damage or a persistent cough and difficulty breathing. “There are a variety of different kinds of ways that people can have long COVID. It’s not just the one thing,” says Leora Horwitz, an internal medicine physician at New York University Langone Health. “That’s what makes it so hard to study.”
This spectrum of symptoms makes pinning down who’s at high risk for long-term health problems from the disease especially hard. Some post-COVID conditions may stem from virus-induced damage or from the stress of being hospitalized with severe disease. In other cases, the body’s own immune response to the virus could drive the damage. Or the virus may be hiding somewhere in the body, possibly the gut, helping symptoms to persist (SN: 11/24/20). Different causes may have different risk groups, says Hannah Davis, cofounder of the Patient-Led Research Collaborative, a research and advocacy group studying long COVID.
There are some broad hints about who’s at risk. Studies suggest that women are more likely than men to have lingering symptoms. COVID-19 patients with more than five symptoms in the first week of infection or preexisting health conditions such as asthma may be more likely to develop long COVID. Age also appears to be a risk factor, though results are mixed regarding whether the burden falls on older people or middle-aged people. Populations that were disproportionally hit by COVID-19 overall — including Black and Hispanic people — may similarly face disparities for long COVID. And while vaccination seems to protect people from developing long COVID, Horwitz says, it’s still unclear by how much.
Age is a risk factor for severe COVID-19, and the U.S. Centers for Disease Control and Prevention lists more than 30 health problems, including cancer and lung disease, that also raise the risk. “So many researchers assume that those [risk factors] will be the same for long COVID and there’s no scientific basis for that,” Davis says. There are many more that researchers could be missing when it comes to long COVID.
Using health records and exams, and knowledge of ailments with symptoms similar to long COVID, experts are on the hunt for those risk factors.
Examining health When it comes to getting a better handle on who’s at risk for long COVID — which also goes by the wonky alias Post-Acute Sequelae of SARS-CoV-2 infection — electronic health records may hold important clues.
Horwitz is part of the U.S. National Institutes of Health’s RECOVER initiative that aims to understand the long-term impacts of COVID-19. One arm of the study involves mining millions of electronic health records to find potential patterns.
Studying millions of these records should pinpoint potential risk factors that are rare in the population overall but perhaps more common for people with long COVID, Horwitz says. “That’s hard even in a cohort study of thousands.”
But health records aren’t perfect: They depend on physicians logging that patients are having trouble sleeping or focusing, or that they’re exhausted. “The things people are complaining about, we’re really bad at writing down those diagnoses on the record,” Horwitz says. “So we miss that.” To account for health records’ deficiencies, Horwitz and colleagues are also directly studying thousands of people. Participants answer a questionnaire every three months so that the team can identify what kinds of symptoms people have and whether they’re getting better or worse.
Then blood, urine, stool and saliva samples can reveal what’s happening in the body. Tests on those samples can uncover if the coronavirus is still around and causing trouble, or if the immune system has learned to attack the body itself. Participants with abnormal test results will undergo additional, targeted testing.
“Unlike electronic health records where it’s hit or miss, like somebody might have had a CAT scan or might not, here we say, ‘OK, you have trouble breathing. We will take a look at your lungs,’” Horwitz says.
The study includes a range of participants: adults and kids, pregnant people, those currently with COVID-19 and people who died after having the disease.
Some of the potential risk factors that the team is looking for include autoimmune diseases and other viral infections. The list may grow as more people join the study. “We’re trying to balance the fishing versus making sure that we’re at least fishing for things that could be in the water,” Horwitz says.
Among short supply, though, are people who never caught the virus — important “controls” to highlight what’s different about people who got COVID-19.
So far, more than 7,000 people have signed up, and the group plans to recruit around 10,000 more. It’s a lot of data, but early results may soon start coming in.
“We’ll probably try to do an interim peek at those data this fall,” Horwitz says. “It’s tricky because we deliberately wanted to enroll 18,000 people so we would have enough power to really look at the things we care about. I don’t want to cheat and look too early, but we also know that there’s a lot of interest.”
Striking similarities Some long COVID symptoms — brain fog, fatigue and trouble sleeping — mirror another illness: myalgic encephalomyelitis/chronic fatigue syndrome, or ME/CFS. Other long COVID symptoms, such as rapid heartbeat and dizziness, fall in the category of nervous system disorders called dysautonomia. Similar symptoms could belie similar risk factors.
Yet potential risk factors for those conditions are largely missing from long COVID research, says Davis, who has had long COVID since March 2020. Among the possibilities that scientists are considering are things like Epstein-Barr virus, migraines and some autoimmune diseases.
Epstein-Barr virus could be a big one, Davis says. Infections last a lifetime because the virus can go into hiding in the body and possibly reemerge. That virus has been linked to ME/CFS for decades, though its role in the disease remains unclear, Davis says. Some early hints of a link between Epstein-Barr virus and long COVID already exist. Multiple studies have found evidence in blood samples from some long COVID patients that the immune system recently battled with Epstein-Barr virus, which can cause infectious mononucleosis, a disease characterized by extreme fatigue. Other studies have found signs of the virus itself. And in 2021, Davis and colleagues found that 40 out of 580 people with symptoms of long COVID who responded to an online survey reported having a current or recent Epstein-Barr virus infection.
With ME/CFS, it’s possible that another illness caused by a different virus triggers the Epstein-Barr virus, which then causes the fatigue syndrome. Given the parallels between that condition and long COVID, some scientists are wondering if the two are actually the same disease, with the coronavirus now known as one trigger.
Examining health conditions that raise the chances of long COVID could provide answers for both diseases, says Nancy Klimas, an immunologist at Nova Southeastern University in Fort Lauderdale, Fla. That’s in part because researchers can more easily identify people who developed lingering symptoms after a bout of COVID-19 compared with unknown infections that may precede ME/CFS.
Also, “there’s a huge difference in these two fields and it’s money,” Klimas says. She now has funding from the CDC to compare long COVID patients with people who have ME/CFS. The team hopes that physical exams and specialized tests will reveal whether the two diseases are indeed the same and be a step toward understanding the mechanisms behind the lingering symptoms.
Still, since long COVID as a whole encompasses such a wide range of symptoms, it will take time to uncover who is at risk of what.
If COVID-19 were just one disease impacting the lungs, heart or brain, the research might be easier, Horwitz says. “But we have to test everything.”
Mother’s Day is on my mind, and I’ve been thinking about the ways I’m connected to my mom and my two little daughters. Every so often I see flickers of my mom in my girls — they share the lines around their smiles and a mutual adoration of wildflowers. Of course, I’m biased. I know that I’m seeing what I’m looking for. But biologically speaking, mothers and their children are connected in a way that may surprise you.
Way back when you and your mom shared a body, your cells mingled. Her cells slipped into your body and your cells circled back into her. This process, called fetal-maternal microchimerism, turns both mother and child into chimeras harboring little pieces of each other.
Cells from my daughters are knitted into my body and bones and brain. I also carry cells from my mom, and quite possibly from my grandma. I may even harbor cells from my older brother, who may have given some cells to my mom, who then gave them to me. It means my younger brother just might have cells from all of us, poor guy. This boundary blurring invites some serious existential wonder, not least of which might involve you wondering if this means your family members really are in your head.
These cellular threads tie families together in ways that scientists are just starting to discover. Here are a few of my favorite instances of how cells from a child have woven themselves into a mother’s body: Fetal cells are probably sprinkled throughout a mother’s brain. A study of women who had died in their 70s found that over half of the women had male DNA (a snippet from the Y chromosome) in their brains, presumably from when their sons were in the womb. Scientists often look for male DNA in women because it’s easier than distinguishing a daughter’s DNA from her mother’s. If DNA from daughters were included, the number of women with children’s cells in their brains would probably be even higher.
When the heart is injured, fetal cells seem to flock to the site of injury and turn into several different types of specialized heart cells. Some of these cells may even start beating, a mouse study found. So technically, those icky-sweet Mother’s Day cards may be right: A mother really does hold her children in her heart.
Fetal cells circulate in a mother’s blood. Male DNA turned up in blood samples from women who were potential stem cell donors. That result may have implications for stem cell transplants. This cell swapping may make parents better donor candidates for their children than strangers, for instance. Other studies have found fetal cells in a mother’s bones, liver, lungs and other organs, suggesting that these cells have made homes for themselves throughout a mother’s body. Maybe this is a way for a child to give back to the mother, in a sense. Growing fetuses slurp nutrients and energy out of a mother’s body during pregnancy (not to mention the morning sickness, heartburn and body aches). In return, fetuses offer up these young, potentially helpful cells. Perhaps these fetal cells, which may possess the ability to turn into lots of different kinds of cells, can help repair a damaged heart, liver or thyroid, as some studies have hinted.
Before I get carried away, a caveat: these cells may also make mischief. They may have a role in autoimmune disorders, for instance.
Microchimerism also has implications here for women who have lost pregnancies, an extremely common situation hidden by the taboo of talking about miscarriages. Fetal cells seem to migrate early in pregnancy, meaning that even brief pregnancies may leave a cellular mark on a woman.
Scientists are just starting to discover how this cellular heritage works, and how it might influence health. The scientist in me can’t wait to see how this story unfolds. But for now, I’m content to marvel at the mother and daughters in me.
Monkeypox is not yet a global public health emergency, the World Health Organization said June 25.
The decision comes as the outbreak of the disease related to smallpox continues to spread, affecting at least 4,100 people in 46 countries as of June 24. That includes at least 201 cases in the United States. Those cases have been found in 25 states and the District of Columbia, according to the U.S. Centers for Disease Control and Prevention. “Controlling the further spread of outbreak requires intense response efforts,” and the situation should be reevaluated in a few weeks, the WHO committee evaluating the outbreak said in an announcement.
The declaration of a public health emergency would have potentially made it easier to get treatments and vaccines to people infected with or exposed to the virus. Some medications and vaccines that could help fend off monkeypox are approved for use against smallpox, and can be used against monkeypox only with special authorization.
The virus that causes monkeypox, named for its discovery in monkeys in 1958 though it is probably a virus that mainly infects rodents, is not a new threat. Countries in central Africa, where monkeypox is endemic, have had sporadic outbreaks since researchers found the first human case in 1970. Places in western Africa had few cases until 2017. But most cases outside the continent were travel-related, with limited spread to others (SN: 5/26/22).
“Monkeypox has been circulating in a number of African countries for decades and has been neglected in terms of research, attention and funding,” WHO director-general Tedros Ghebreyesus said in a statement announcing the decision. “This must change not just for monkeypox but for other neglected diseases in low-income countries as the world is reminded yet again that health is an interconnected proposition.”
Monkeypox typically kills fewer than 10 percent of people who contract it. At least one person has died in the global outbreak.
As case numbers climb, researchers are working to decipher the genetic blueprint of the virus, in hopes of uncovering whether some viral mutations might explain why the virus has quickly gained a foothold in new places.
Tracing the mutations The closest known relative of the versions of the virus behind the global outbreak comes from Nigeria, hinting that the outbreak may have got its start there.
In the newest surge in cases, scientists have uncovered more viral changes than anticipated — a sign that the virus may have been circulating undetected among people for a while, perhaps since Nigeria’s 2017–2018 monkeypox outbreak, new research suggests. What’s more, a group of enzymes known for their virus-fighting abilities in the body may be to blame for many of those mutations.
A genetic analysis of monkeypox viruses involved in the global outbreak from 15 people across seven countries shows that these viruses have an average of 50 more genetic tweaks than versions circulating in 2018 and 2019, researchers report June 24 in Nature Medicine. That’s roughly six to 12 times as many mutations as scientists would have expected the virus to develop over that time. Unlike some other types of viruses, poxviruses, which include smallpox and monkeypox viruses, typically mutate fairly slowly.
The changes have a pattern that is a hallmark of an enzyme family called APOBEC3, the researchers say. These enzymes edit DNA’s building blocks — represented by the letters G, C, A and T — in a specific way: Gs change to As and Cs to Ts. The analysis found that particular pattern in the viral sequences, suggesting that APOBEC3s are responsible for the mutations.
Ideally, so many DNA building blocks are swapped for another that a virus is effectively destroyed and can’t infect more cells. But, sometimes, APOBEC3 enzymes don’t make enough changes to knock out the virus. Such mutated, though still functional, viruses can go on to infect additional cells, and possibly another person.
A big question, though, is whether the genetic tweaks seen in the monkeypox virus are helpful, harmful or have no effect at all on the virus.
While it’s still unknown whether the enzymes are directly responsible for the changes in the monkeypox virus, similar mutations are still popping up, the team found. So, APOBEC3s may still be helping the virus change as it continues to spread. One member of the enzyme family is found in skin cells, where people with monkeypox can develop infectious pox lesions. Different symptoms Symptoms reported in the global outbreak have been generally milder than those reported in previous outbreaks, perhaps allowing the disease to spread before a person knows they’re infected.
It is not clear whether those differences in symptoms are related to changes in the virus, Inger Damon, director of the CDC’s Division of High-Consequence Pathogens and Pathology, said June 21 in a news briefing hosted by SciLine, a service for journalists and scientists sponsored by the American Association for the Advancement of Science.
Typically, in previous outbreaks, people would develop flu-like symptoms, including fever, headaches, muscle aches and exhaustion about a week or two after exposure to the virus. Then, one to three days after those symptoms start, a rash including large pus-filled lesions pops up generally starting on the face and limbs, particularly the hands, and spreads over the body. Though generally milder, those symptoms are similar to smallpox, but people with monkeypox also tend to develop swollen lymph nodes.
All patients in the U.S. outbreak have gotten rashes, Damon said, “but the lesions have been scattered or localized to a specific body site, rather than diffuse, and have not generally involved the face or the … palms of the hand or the soles of the feet.” Instead, rashes may start in the genital or anal area where they can be mistaken for sexually transmitted diseases, such as syphilis or herpes, she said.
In many cases, the rashes have not spread to other parts of the body. And the classical early symptoms such as fever have been “mild and sometimes nonexistent before a rash appears,” Damon said.
Monkeypox is transmitted from person to person through close skin-to-skin contact or by contact with contaminated towels, clothes or bedding. It may also be spread by droplets of saliva exchanged during kissing or other intimate contact. The CDC is investigating whether the virus might be spread by semen as well as skin-to-skin contact during sex, Agam Rao, a captain in the U.S. Public Health Service, said June 23 at a meeting of the CDC’s Advisory Committee on Immunization Practices.
“We don’t have any reason to suspect it is spread any other way,” such as through the air, Rao said.
In Nigeria, more monkeypox cases have been recorded among women, while the global outbreak has affected mainly men, particularly men who have sex with men. Experts warn that anyone can be infected with monkeypox, and some people face an increased risk of severe disease. Those at increased risk include children, people who are immunocompromised, pregnant people and people with eczema.
The risk of catching monkeypox through casual contact is still low in the United States, Rao said. But data she presented show that while people in the country have contracted monkeypox while traveling abroad, cases have also spread locally.
A flexible sensor applied to the back of the neck could help researchers detect whiplash-induced concussions in athletes.
The sensor, described June 23 in Scientific Reports, is about the size of a bandage and is sleeker and more accurate than some instruments currently in use, says electrical engineer Nelson Sepúlveda of Michigan State University in East Lansing. “My hope is that it will lead to earlier diagnosis of concussions.”
Bulky accelerometers in helmets are sometimes used to monitor for concussion in football players. But since the devices are not attached directly to athletes’ bodies, the sensors are prone to false readings from sliding helmets. Sepúlveda and colleagues’ patch adheres to the nape. It is made of two electrodes on an almost paper-thin piece of piezoelectric film, which generates an electric charge when stretched or compressed. When the head and neck move, the patch transmits electrical pulses to a computer. Researchers can analyze those signals to assess sudden movements that can cause concussion.
The team tried out the patch on the neck of a human test dummy, dropping the figure from a height of about 60 centimeters. Researchers also packed the dummy’s head with different sensors to provide a baseline level of neck strain. Data from the patch aligned with data gathered by the internal sensors more than 90 percent of the time, Sepúlveda and colleagues found.
The researchers are now working on incorporating a wireless transmitter into the patch for an even more streamlined design.
Javier Duarte kicked off his scientific career by witnessing the biggest particle physics event in decades. On July 4, 2012, scientists at the laboratory CERN near Geneva announced the discovery of the Higgs boson, the long-sought subatomic particle that reveals the origins of mass. Duarte was an eager graduate student who’d just arrived at CERN.
“I was physically there maybe a week before the announcement,” Duarte says. As buzzing throngs of physicists crowded together to watch the announcement at CERN, Duarte didn’t make it to the main auditorium. That space was for VIPs — and those determined enough to wait in line all night to snag a seat. Instead, he says, he found himself in the basement, in an overflow room of an overflow room.
But the enthusiasm was still palpable. “It was a very exciting time to be getting immersed into that world,” he says. Since then, he and thousands of other physicists from around the world working on CERN experiments have gone all out exploring the particle’s properties.
Scientists predicted the existence of the Higgs boson back in 1964, as a hallmark of the process that gives elementary particles mass. But finding the particle had to wait for CERN’s Large Hadron Collider, or LHC. In 2010, the LHC began smashing protons together at extremely high energies, while two large experiments, ATLAS and CMS, used massive detectors to look through the debris. The particle’s discovery filled in the missing keystone of the standard model of particle physics. That theory explains the known elementary particles and their interactions. Those particles and interactions are behind just about everything we know. The particles serve as building blocks of atoms and transmit crucial forces of nature, such as electromagnetism. And the mass of those particles is key to their behavior. If electrons were massless, for example, atoms wouldn’t form. Without the Higgs boson, then, one of scientists’ most successful theories would collapse.
The Higgs boson discovery dominated headlines around the globe. About half a million people tuned in to watch the livestreamed announcement, and footage from the event appeared on more than 5,000 news programs. Even oddball minutiae made it into the press, with a few articles analyzing the physicists’ use of the often-scorned font Comic Sans in their presentation. Little more than a year later, the discovery garnered a Nobel Prize for two of the scientists who developed the theory behind the Higgs boson, François Englert and Peter Higgs — for whom the particle is named. Now, as the discovery turns 10 years old, that initial excitement persists for Duarte and many other particle physicists. As a professor at the University of California, San Diego and member of the CMS experiment, Duarte’s research still revolves around the all-important particle. Progress in understanding the Higgs has been “stunning,” he says. “We’ve come so much farther than we expected to.”
Physicists have been working through a checklist of things they want to know about the Higgs boson. They spent the last decade cataloging its properties, including how it interacts with several other particles. Though measurements have so far been in line with the predictions made by the standard model, if a discrepancy turns up in the future, it may mean there are unknown particles yet to be discovered.
And there’s still more on the agenda. An especially important item is the Higgs boson’s interaction with itself. To help pin down this and other Higgs properties, scientists are looking forward to collecting more data. Scientists turned on an upgraded LHC for a new round of work in April. At the time of the Higgs discovery, collisions at the LHC reached an energy of 8 trillion electron volts. Collisions are expected to roll in at a record 13.6 trillion electron volts starting July 5, and data-taking will continue until 2026. These higher energies offer opportunities to spot heavier particles. And the High-Luminosity LHC, a more powerful iteration of the LHC, is expected to start up in 2029.
“Finding a particle, it sounds like the end of something, but it’s really only the beginning,” says experimental particle physicist María Cepeda of CIEMAT in Madrid, a member of the CMS collaboration. Coupling up Studying the Higgs boson is like geocaching, says theoretical particle physicist Gudrun Heinrich of the Karlsruhe Institute of Technology in Germany. Much like hobbyists use a GPS device to uncover a hidden stash of fun trinkets, physicists are using their wits to uncover the treasure trove of the Higgs boson. In 2012, scientists merely located the cache; the next 10 years were devoted to revealing its contents. And that investigation continues. “The hope is that the contents will contain something like a map that is guiding us towards an even bigger treasure,” Heinrich says.
Detailed study of the Higgs boson could help scientists solve mysteries that the standard model fails to explain. “We know that the theory has limitations,” says theoretical particle physicist Laura Reina of Florida State University in Tallahassee. For instance, the standard model has no explanation for dark matter, a shadowy substance that throws its weight around the cosmos, exerting a gravitational pull necessary to explain a variety of astronomical observations. And the theory can’t explain other quandaries, like why the universe is composed mostly of matter rather than its alter ego, antimatter. Many proposed solutions to the standard model’s shortcomings require new particles that would alter how the Higgs interacts with known particles.
The Higgs boson itself isn’t responsible for mass. Instead, that’s the job of the Higgs field. According to quantum physics, all particles are actually blips in invisible fields, like ripples atop a pond. Higgs bosons are swells in the Higgs field, which pervades the entire cosmos. When elementary particles interact with the Higgs field, they gain mass. The more massive the particle, the more strongly it interacts with the Higgs field, and with the Higgs boson. Massless particles, like photons, don’t directly interact with the Higgs field at all.
One of the best ways to hunt for Higgs-related treasure is to measure those interactions, known as “couplings.” The Higgs couplings describe what particles the Higgs boson decays into, what particles can fuse to produce Higgs bosons and how often those processes occur. Scientists gauge these couplings by sifting through and analyzing the showers of particles produced when Higgs bosons pop up in the debris of proton smashups.
Even if unknown particles are too heavy to show up at the LHC, the Higgs couplings could reveal their existence. “Any of these couplings not being what you expect them to be is a very clear sign of incredibly interesting new physics behind it,” says particle physicist Marumi Kado of Sapienza University of Rome and CERN, who is the deputy spokesperson for the ATLAS collaboration. Physicists have already checked the couplings to several elementary particles. These include both major classes of particles in physics: bosons (particles that carry forces) and fermions (particles that make up matter, such as electrons). Scientists have measured the Higgs’ interactions with a heavy relative of the electron called a tau lepton (a fermion) and with the W and Z bosons, particles that transmit the weak force, which is responsible for some types of radioactive decay. Researchers also pegged the Higgs’ couplings to the top quark and bottom quark. Those are two of the six types of quarks, which glom together into larger particles such as protons and neutrons. (The Higgs is responsible for the mass of elementary particles, but the mass of composite particles, including protons and neutrons, instead comes mostly from the energy of the particles jangling around within.)
The couplings measured so far involve the standard model’s heavier elementary particles. The top quark, for example, is about as heavy as an entire gold atom. Since the Higgs couples more strongly to heavy particles, those interactions tend to be easier to measure. Next up, scientists want to observe the lighter particles’ couplings. ATLAS and CMS have used their giant detectors to see hints of the Higgs decaying to muons, the middleweight sibling in the electron family, lighter than the tau but heavier than the electron. The teams have also begun checking the coupling to charm quarks, which are less massive than top and bottom quarks.
So far, the Higgs has conformed to the standard model. “The big thing we discovered is it looks pretty much like we expected it to. There have been no big surprises,” says theoretical particle physicist Sally Dawson of Brookhaven National Laboratory in Upton, N.Y.
But there might be discrepancies that just haven’t been detected yet. The standard model predictions agree with measured couplings within error bars of around 10 percent or more. But no one knows if they agree to within 5 percent, or 1 percent. The more precisely scientists can measure these couplings, the better they can test for any funny business. One of a kind Before the LHC turned on, scientists had a clear favorite for a physics theory that could solve some of the standard model’s woes: supersymmetry, a class of theories in which every known particle has an undiscovered partner particle. Physicists had hoped such particles would turn up at the LHC. But none have been found yet. Though supersymmetry isn’t fully ruled out, the possibilities for the theory are far more limited.
With no consensus candidate among many other theories for what could be beyond the standard model, a lot of focus rests on the Higgs. Physicists hope studies of the Higgs will reveal something that might point in the right direction to untangle some of the standard model’s snarls. “Measuring [the Higgs boson’s] properties is going to tell us much more about what is beyond the standard model … than anything before,” Reina says.
One question that scientists are investigating in LHC smashups is whether the Higgs is truly unique. All the other known elementary particles have a quantum form of angular momentum, known as spin. But the Higgs has a spin of zero, what’s known as a “scalar.” Other types of particles tend to come in families, so it’s not outlandish to imagine that the Higgs boson could have scalar relatives. “It could be there’s a huge scalar sector somewhere hiding and we just saw the first particle of it,” Heinrich says. Supersymmetry predicts multiple Higgs bosons, but there are plenty of other ideas that envision Higgs accomplices.
It’s also possible that the Higgs is not actually elementary. Combinations of particles, such as quarks, are known to make up larger particles with spins of zero. Perhaps the Higgs, like those other scalars, is made up of yet unknown smaller stuff.
While hunting for these answers, physicists will be watching closely for any connection between the Higgs’ behavior and other recent puzzling results. In 2021, the Muon g−2 experiment at Fermilab in Batavia, Ill., reported hints that muons have magnetic properties that don’t agree with predictions of the standard model. And in April, scientists with the CDF experiment — which studied particle collisions at Fermilab until 2011 — found that the W boson’s mass is heavier than the standard model predicts.
The Higgs boson’s relative newness makes it ripe for discoveries that could help sort out these quandaries. “The Higgs boson is the least explored elementary particle, and it could be a door to the other mysteries we still have to uncover or to shed light on,” Heinrich says. Self-talk To work out thorny puzzles, physicists sometimes talk to themselves. Fittingly, another puzzle atop scientists’ Higgs to-do list is whether the particle, likewise, talks to itself.
This “self-coupling,” how Higgs bosons interact with one another, has never been measured before. But “it turns out to be really just an incredible barometer of new physics,” says theoretical particle physicist Nathaniel Craig of the University of California, Santa Barbara. For example, measuring the Higgs self-coupling could suss out hidden particles that interact only with the Higgs, oblivious to any of the other standard model particles.
The Higgs self-coupling is closely related to the Higgs potential, an undulating, sombrero-shaped surface that describes the energy of the universe-pervading Higgs field. In the early universe, that potential determined how the fundamental particles gained mass, when the Higgs field first turned on.
How, exactly, that transition from massless to massive happened has some big implications for the cosmos. It could help explain how matter gained the upper hand over antimatter in the early universe. If the Higgs field did play that role in the universe’s beginnings, Craig says, “it’s going to leave some fingerprints on the Higgs potential that we measure today.”
Depending on the full shape of the Higgs potential’s sombrero, at some point in the exceedingly distant future, the Higgs field could shift again, as it did in the early universe. Such a jump would change the masses of fundamental particles, creating a universe in which familiar features, including life, are probably obliterated.
To better understand the Higgs potential, scientists will attempt to measure the self-coupling. They’ll do it by looking for Higgs bosons produced in pairs, a sign of the Higgs interacting with itself. That’s thought to happen at less than a thousandth the rate that individual Higgs bosons are produced in the LHC, making it extremely difficult to measure.
Even with the planned High-Luminosity LHC, which will eventually collect about 10 times as much data as the LHC, scientists predict that the self-coupling will be measured with large error bars of about 50 percent, assuming the standard model is correct. That’s not enough to settle the matter.
If scientists just do what they’re on track to do, “we’re going to fall short,” Duarte says. But new techniques could allow physicists to better identify double-Higgs events. Duarte is studying collisions in which two particularly high-energy Higgs bosons each decay into a bottom quark and a bottom antiquark. Using a specialized machine learning technique, Duarte and colleagues put together one of the most sensitive analyses yet of this type of decay.
By improving this technique, and combining results with those from other researchers looking at different types of decays, “we have a good hope that we’ll be able to observe [the self-coupling] definitively,” Duarte says. Waiting game Despite all his passion for the Higgs, Duarte notes that there have been disappointments. After that first rush of the Higgs announcement, “I was hoping for a Higgs-level discovery every year.” That didn’t happen. But he hasn’t lost his optimism. “We expect there to be another twist and turn coming up,” he says. “We’re still hoping it’s around the corner.”
The wait for new physics is no shock to veterans of earlier particle hunts. Meenakshi Narain, a particle physicist at Brown University in Providence, R.I., and a member of the CMS experiment, was an undergraduate student around the time the bottom quark was discovered in the 1970s. After that discovery, Narain joined the search for the top quark. Even though physicists were convinced of the particle’s existence, that hunt still took nearly 20 years, she says. And it took nearly 50 years to uncover the Higgs boson after it was postulated.
The standard model’s flaws make physicists confident that there must be more treasures to unearth. Because of her past experiences with the long-haul process of discovery, Narain says, “I have a lot of faith.”
