OK, so what if a giant prehistoric shark, thought to be extinct for about 2.5 million years, is actually still lurking in the depths of the ocean? That’s the premise of the new flick The Meg, which opens August 10 and pits massive Carcharocles megalodon against a grizzled and fearless deep-sea rescue diver, played by Jason Statham, and a handful of resourceful scientists.

The protagonists discover the sharks in a deep oceanic trench about 300 kilometers off the coast of China — a trench, the film suggests, that extends down more than 11,000 meters below the ocean surface. (That depth makes it even deeper than the Mariana Trench’s Challenger Deep, the actual deepest known point in the ocean). Hydrothermal vents down in the trench supposedly keep those dark waters warm enough to support an ecosystem teeming with life. And — spoiler alert! — of course, the scientists’ investigation inadvertently helps megalodons escape from the depths. The giant living fossils head to the surface, where they terrorize shark fishermen and beachgoers a la Jaws.

But could a population of megalodons actually have survived down there? To explore what is and isn’t possible and what we still don’t know about sharks, Science News went to the movies with paleobiologist Meghan Balk of the Smithsonian’s National Museum of Natural History in Washington, D.C., who studies the ancient predators.

Did megalodons ever actually get as big as they are in the movie? Extremely unlikely
The megalodon sharks of The Meg reach sizes of about 20 to 25 meters long, the film says — massive although just a tad smaller than the longest known blue whales. But estimates based on the size of fossil teeth suggest that even the largest known C. megalodon was much smaller, at up to 18 meters — “and that was the absolute largest,” Balk says. On average, C. megalodon tended to be around 10 meters long, she says, which still made them much bigger than the average great white shark, at around 5 to 6 meters long.

Would a megalodon otherwise look like the film version? Yes and no
The movie’s sharks aren’t entirely inaccurate representations, Balk says. These megalodons correctly have six gills — between five and seven is accurate for sharks in general, she says. And the shape of the dorsal fin is, appropriately, modeled after the great white shark, the closest modern relative to the ancient sharks. Also, a male meg in the film even has “claspers,” appendages under the abdomen used to hold a female during mating. “When I looked at it, I was like, oh, they did a pretty good job. They didn’t just create a random shark,” Balk says.
On the other hand, it’s actually a bit odd that the movie’s megalodons wouldn’t have evolved some significant anatomical differences from their prehistoric brethren, Balk says. “Like the eye getting bigger” to see better or becoming blind after a few million or so years living in the darkness of the deep sea, she says. Or you might even expect dwarfism, in which populations restricted by geographic isolation, such as being stuck within a trench, shrink in size.

Would such huge sharks have had enough to eat down there? Extremely unlikely
In general, “there’s just not enough energy in the deep sea” to sustain giant sharks, Balk says. Life does bloom at hydrothermal vents, although the deepest known hydrothermal vents are only about 5,000 meters deep. But even if there were vents in the deepest trenches, it’s not clear there would be enough big species living down there to sustain not just one, but a whole population of massive sharks. In the film, the vent field is populated with many smaller species known to cluster around hydrothermal vents, including shrimps, snails and tube worms. Viewers also see one giant squid, but there would have had to be a whole lot more food of that size. C. megalodon — like modern great whites — ate many different things, from orcas to squid. And the humongous megalodon sharks in the movie “would have eaten a lot of squid,” Balk says, laughing.
Could sharks live at such depths? Unlikely
How deep sharks can live in the ocean is actually still a big unknown (SN Online: 5/7/18). “Quantifying the depth that sharks go to is a big endeavor right now,” Balk says. Few sharks are known to inhabit the abyssal regions of the ocean below about 4,000 meters — let alone the depths of oceanic trenches lying below 6,000 meters. Aside from the scarcity of food, temperature is another limitation to deep-sea living.

Sharks that do inhabit deeper parts of the ocean, such as goblin sharks and the Greenland shark (SN 9/17/16, p. 13), tend to have low metabolic rates. That means they move much more slowly than the energetic predators of the movie, Balk says. C. megalodon, although it lived around the globe, tended to prefer warmer, shallower waters and used coastal regions as nursing grounds.
So, could megalodons have survived to modern times without humans knowing about it? Extremely unlikely
Sharks shed a lot of teeth throughout their lives, and those teeth are the main fossil evidence of the life and times of prehistoric sharks (SN Online: 8/2/18). Fossilized C. megalodon teeth found in sediments around the world suggest that the creatures lived between about 14 million and 2.6 million years ago — or perhaps up until 1.5 million years ago at the latest, Balk says. It’s not clear why they went extinct. But there are a handful of hypotheses: competition for food with other creatures like orcas; ocean circulation changes about 3 million years ago when the Isthmus of Panama formed (SN: 9/17/16, p. 12); nearshore nursery sites vanished; or possibly a loss of prey sources stemming from a marine mammal extinction about 2.6 million years ago.

Bottom line: The sheer abundance of shed teeth — as many as 20,000 per shark in its lifetime — is one of the strongest arguments against megalodon surviving into modern times, Balk says. “That’s one of the reasons why we know megalodon’s definitely extinct. We would have found a tooth.”

Whales may have made their mark on the seafloor in a part of the Pacific Ocean designated for future deep-sea mining.

Thousands of grooves found carved into the seabed could be the first evidence that large marine mammals visit this little-explored region, researchers report August 22 in Royal Society Open Science. If deep-diving whales are indeed using the region for foraging or other activities, scientists say, authorities must take that into account when planning how to manage future mining activities.
The Clarion-Clipperton Fracture Zone, or CCZ, is a vast plain on the deep seafloor that spans about 4.5 million square kilometers between Hawaii and Mexico. The region is littered with trillions of small but potentially valuable rocky nodules containing manganese, copper, cobalt and rare earth elements.

Little is known of the seafloor ecosystems in this region that might be disturbed by mining of the nodules. So several research cruises have visited the area since 2013 to conduct baseline assessments of what creatures might live on or near the seafloor.
A 2015 cruise led by Daniel Jones of the National Oceanography Centre Southampton in England is the first to find evidence that suggests that live whales may have dived down to visit the seafloor in the region. Using an autonomous underwater vehicle to scan the seafloor at depths from 3,999 meters to 4,258 meters, Jones’ team found 3,539 grooves in all. These depressions tended to be arranged into sequences of as many as 21 grooves, spaced six to 13 meters apart.
It’s difficult to determine exactly when the marks were made, because sediment settles very slowly through the deep water to fill in seafloor depressions. The oldest marks were made within the last 28,000 years, the team estimates. But some newer tracks appear to overlap older tracks.

No known geologic mechanism could produce the grooves, report Jones and his National Oceanography Centre colleagues, deep-sea ecologist Leigh Marsh and marine geoscientist Veerle Huvenne. But living creatures might: Some scientists, including biologist Les Watling of the University of Hawaii at Manoa and marine ecologist Peter Auster of the University of Connecticut at Avery Point, previously suggested that certain deep-diving whales, known as beaked whales, can make such markings as they use their beaks to forage for food hiding in the seafloor.

The new research is intriguing, Watling says, but adds that the biggest question mark is whether a beaked whale could really dive so deep. “When we published our paper, we were extending the probable depth of diving of the whale by several hundred meters,” he says. “These authors are doubling the depth that we talked about.” But, he adds, the new paper also points out that some anatomical studies suggest that a Cuvier’s beaked whale (Ziphius cavirostris), at least, may be able to survive a 5,000-meter dive.

Auster adds that the researchers were careful to consider other possibilities for what might have made the markings and systematically eliminate those options, leaving only the whales. And that’s definitely a matter that prospective miners will have to pay attention to, he says. Before mining proceeds, he says, future seafloors studies in the region should include efforts to detect whales, using passive acoustic monitoring, for instance.
“This is a huge finding,” says Diva Amon, a deep-sea biologist at the Natural History Museum in London. She has previously cataloged a wealth of seafloor life in the CCZ, including new genera of jellyfish, starfish and sponges. That abundance may be attributable to the variety of sediment types in the region, she adds: Soft seafloor sediment and hard rocky nodules offer numerous places for life to get a foothold.

But whales can be a game changer, because large, charismatic marine mammals can garner public attention in a way that smaller seafloor-dwellers don’t, she says. Although the new study can’t pinpoint when the grooves were made, she says, “this is why more work needs to be done.” Even if the observed grooves were made by whales thousands of years ago, the whales’ behavior may not have changed significantly in the ensuing years, given the stability of the deep-sea environment.

“I would expect that if they were [making the depressions] a couple of thousand years ago, they’re probably still doing it now,” she says.

To date, the International Seabed Authority, the organization that oversees both mining licenses in international waters and environmental regulation of those regions, has issued 16 exploration contracts within the CCZ. Contractors working in the area must record marine mammal sightings within surface waters, as well as sightings of migratory birds, Amon says.

But, she adds, “the fact that these whales may be diving about a thousand meters deeper than was previously known” — and using seafloor that could be irreparably altered [by mining] — has the potential to change the way we manage the CCZ.”

Scientists are one step closer to a long-sought way to store carbon dioxide in rocks.

A new technique speeds up the formation of a mineral called magnesite that, in nature, captures and stores large amounts of the greenhouse gas CO2. And the process can be done at room temperature in the lab, researchers reported August 14 at the Goldschmidt geochemistry conference, held in Boston. If the mineral can be produced in large quantities, the method could one day help fight climate change.
“A lot of carbon on Earth is already stored within carbonate minerals, such as limestone,” says environmental geoscientist Ian Power of Trent University in Peterborough, Canada, who presented the research. “Earth knows how to store carbon naturally and does this over geologic time. But we’re emitting so much CO2 now that Earth can’t keep up.”

Researchers have been seeking ways to boost the planet’s capacity for CO2 storage (SN: 6/5/10, p. 16). One possible technique: Sequester the CO2 gas by converting it to carbonate minerals. Magnesite, or magnesium carbonate, is a stable mineral that can hold a lot of CO2 naturally: A metric ton of magnesite can contain about half a metric ton of the greenhouse gas.

But magnesite isn’t quick to make — at least, not at Earth’s surface. Previous researchers have considered pumping CO2 deep into Earth’s interior, where high temperatures and pressures can speed up the gas’s reaction with a magnesium-bearing upper mantle rock called olivine. But many barriers remain to making this idea commercial, including finding the right locations to insert the CO2 to produce large amounts of magnesite and the costs of transportation and storage for the gas.

Another option is to try to make magnesite in the laboratory — but at room temperature, that can take a very long time. One place where magnesite forms naturally at Earth’s surface is in arid basins called playas in northern British Columbia. From previous work at such sites, Power and his colleagues determined that groundwater circulating through former mantle rocks such as olivine in the region becomes enriched in magnesium and carbonate ions. The ions eventually react to form magnesite, which settles out of the water. In British Columbia, the process began as far back as 11,000 years ago, Power says. “We knew it was slow, but no one had ever measured the rate.”
Under very high temperatures, scientists can quickly create magnesite in the lab, using olivine as a feedstock. But that process uses a lot of energy, Power says, and could be very costly.

The problem with making magnesite quickly, Power’s team found, is that water gets in the way. To make the rock in the lab, Power and colleagues put magnesium ions into water. When the magnesium ions — atoms that have a charge due to a gain or loss of electrons — are put into water to create the magnesite, the water molecules themselves tend to surround the ions. That “shell” of water molecules hinders the magnesium’s ability to bond with carbonate ions to form magnesite. “It’s difficult to strip away those water molecules,” Power says. “That’s one of the reasons why magnesite forms very slowly.”

To get around this problem, Power and his colleagues used thousands of tiny polystyrene microspheres, each about 20 micrometers in diameter, as catalysts to speed up the reaction. The microspheres were coated with carboxyl, molecules with a negative charge that can pull the water molecules away from the magnesium, freeing it up to bond with the carbonate ions. Thanks to these microspheres, Power says, the researchers managed to make magnesite in just about 72 days. Theoretically, he adds, the microspheres would also be reusable, as the spheres weren’t used up by the experiments.

That result doesn’t mean the technique is ready for prime time, Power says. So far, the scientists have made only a very small amount of magnesite in the lab — about a microgram or so. “We’re very far away from upscaling,” or making the technology commercially viable.

“What we’ve shown is that it’s possible to form this at room temperatures,” Powers says. Now, having demonstrated the proof of concept, the team can explore next steps. “We want to better understand some of the fundamental science” involved in magnesite formation, he adds.

“The result really surprised me,” says Patricia Dove, a geochemist at Virginia Tech in Blacksburg. Many questions remain about how cost-effective and energy-efficient the process might be, she says, but it’s “certainly very intriguing.”

Talk about blended families. A 13-year-old girl who died about 50,000 years ago was the child of a Neandertal and a Denisovan.

Researchers already knew that the two extinct human cousins interbred (SN Online 3/14/16). But the girl, known as Denisova 11 from a bone fragment previously found in Siberia’s Denisova Cave, is the only first-generation hybrid ever found.

Genetic analyses revealed that the girl inherited 38.6 percent of her DNA and her mitochondrial DNA from a Neandertal, meaning that her mother was Neandertal. Her dad was Denisovan, and contributed 42.3 percent of the girl’s DNA, Viviane Slon of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, and colleagues report online August 22 in Nature. The girl’s father had Neandertal ancestry, too, but way back in his lineage, about 300 to 600 generations before his birth.

Although the girl’s remains were found in Siberia, her Neandertal DNA more closely matches a western European Neandertal from Vindija Cave in Croatia — thousands of kilometers to the west — than an older Neandertal from the same cave as the girl. That finding may mean that eastern Neandertals spread into western Europe sometime after 90,000 years ago, or that western Neandertals beat them to the punch, invading eastward into Siberia before 90,000 years ago and partially replacing the Neandertals living there. Researchers need to test more DNA from western European Neandertals to determine which scenario is correct.

New Horizons has its next destination in sight.

The spacecraft, which buzzed Pluto in 2015, captured its first images on August 16 of the remote icy world nicknamed Ultima Thule, confirming that New Horizons is on track for its January 1 flyby. With about 160 million kilometers to go — roughly the same distance as Earth is from the sun — the tiny world appears as no more than a faint speck in the probe’s camera.

The pictures also barely set a new record: At roughly 6 billion kilometers from Earth, they are the farthest images ever taken. For decades, that honor was held by the Voyager 1 spacecraft, which in 1990 snapped pictures of Earth and many of our neighboring planets from nearly the same distance.

Officially dubbed 2014 MU69, Ultima Thule is part of the Kuiper Belt, a field of frozen detritus left over from the formation of the planets 4.6 billion years ago. By sending New Horizons to take pictures and measure the chemical makeup of Ultima’s surface, researchers hope to unearth clues about the origin of our solar system.

A draft of the poppy’s genetic instruction book is providing clues to how the plant evolved to produce molecules such as morphine.

Scientists pieced together the genome of the opium poppy (Papaver somniferum). Then, they identified a cluster of 15 close-together genes that help the plant synthesize a group of chemically related compounds that includes powerful painkillers like morphine as well as other molecules with potential medical properties (SN: 6/10/17, p. 22).

A group of genes that help poppy plants produce some of these molecules, collectively known as benzylisoquinoline alkaloids, have been clustered together for tens of millions of years, researchers report online August 30 in Science. But the plant’s morphine production evolved more recently. Around 7.8 million years ago, the plant copied its entire genome. Some of the resulting surplus genes evolved new roles helping poppies produce morphine, because the plant already had at least one other copy of those genes carrying out their original jobs.

It wasn’t a one-step process, though. An even earlier gene duplication event caused two genes to fuse into one. That hybrid gene is responsible for a key shape-shift in alkaloid precursors, directing those molecules down the chemical pathway toward morphinelike compounds instead of other benzylisoquinoline alkaloids (SN Online: 6/25/15).

Jocelyn Bell Burnell first noticed the strange, repeating blip in 1967. A University of Cambridge graduate student at the time, she had been reviewing data from a radio telescope she had helped build near campus. Persistent tracking revealed the signal’s source to be something entirely unknown up to that point — a pulsar, or a rapidly spinning stellar corpse that sweeps beams of radio waves across the sky like a lighthouse.

A half-century later on September 6, Bell Burnell was awarded the $3 million Special Breakthrough Prize in Fundamental Physics. The prize has been given only three times before: to British physicist Stephen Hawking for discovering a type of radiation from black holes in 1974, the CERN team that discovered the Higgs boson in 2012, and the LIGO collaboration that in 2016 found gravitational waves.

But before any of those discoveries, Bell Burnell’s pulsar find was revolutionizing astrophysics. It led to precise tests of Einstein’s theory of gravity, the first observations of exoplanets and the 1974 Nobel Prize in physics — from which Bell Burnell was famously excluded. Now 75 years old, Bell Burnell is giving back, donating her prize to create scholarships for underrepresented minorities in physics and astronomy.

Science News caught up with Bell Burnell to chat about aliens, impostor syndrome and how being an outsider can be a boon in scientific research. The following answers have been edited for length and clarity.
SN: What did the first pulsar data look like to you?
J.B.B.: It was an anomaly, and it was a very small anomaly. Typically it took up about 5 millimeters of my long rolls of chart paper, out of half a kilometer. I was being very, very thorough, very careful. I kept poking at it to try and understand what it was.

SN: You called the first signal LGM-1, for Little Green Man 1. Did you really think it might be a signal from aliens?
J.B.B.: That was a bit of a joke, which I now rather regret. But we did check it out. My advisor Tony [Hewish] argued that, if it were little green men as we nicknamed them, they’d probably be on a planet going round their sun. As their planet moved, we would see what’s called Doppler shift. The spacing between pulses would change as their planet moved. We looked for that, but we couldn’t find any such motion.

SN: At what point did you realize that pulsars were going to be a big deal?
J.B.B.: Quite late in the process. I’d found all four that I was going to find. The first paper announcing the results was to be published a day or two later [on February 24, 1968, in Nature]. My thesis advisor, Tony Hewish, gave a talk in Cambridge, and gave it a very titillating title. Everybody came, and the excitement was palpable.

SN: What have pulsars taught us since then?
J.B.B.: We’ve learned a lot about extreme physics, because pulsars are really, really extreme. They are the remains of stars after the star has expired in a violent explosion. They’re about 10 miles across, but they weigh as much as the sun, a thousand million million million million tons. That’s four millions. Very small, very heavy, very peculiar composition.

We’re using pulsars to test some of Einstein’s theories. His ideas are standing up very well, which is interesting (SN: 2/3/18, p. 7). And we’re developing ideas, looking very far ahead, for using these things as navigation beacons, when we start traveling through the galaxy in spaceships (SN: 2/3/18, p. 7).
SN: What do you wish you’d been told about being a woman in astronomy when you were younger?
J.B.B.: I think it wasn’t what people would tell me, it would be having more women around. Because there were so few women in Cambridge, I rarely got the chance to mix with other women. I would have liked a bit of that.

SN: Do you credit your discovery at all to being in the minority?
J.B.B.: Yes, I do. I was, I reckon, suffering from impostor syndrome in Cambridge, although we didn’t have that name at that time. Cambridge is in the southeast of England, and it’s a very confident, suave type of society. As you may guess from my accent, I don’t come from the southeast of England. I’m from the north and western parts of Britain.

I was both geographically out of place, and as a woman out of place. I thought, wow, they’re all terribly clever. I’m not so bright. They’ve made a mistake. They’re going to find out their mistake, and they’re going to throw me out.

But I said to myself, I’m not going to waste this opportunity. Until they throw me out, I will work my very hardest, so that when they throw me out, I won’t have a guilty conscience…. I think a lot of other people would have overlooked that little anomaly that I chased up.

SN: How did you feel about not being included on the 1974 Nobel Prize?
J.B.B.: At that stage, the image people had of science was of a senior man, and it always was a man, with a fleet of younger people working for him. And if the project went well, the man got praise. If the project went badly, the man got the blame. The younger people working under him were isolated from all of that. It seemed to me to be part of that pattern of doing things.

I think the Nobel Prize is still fairly male orientated. The world is now making strenuous efforts to be more inclusive. Prizes like the Nobel tend to go to the most senior people, so that will reflect how the society was when they were young and active. It’s going to be some time until changes percolate to the senior prizes.

SN: How do you feel now, winning the Breakthrough Prize?
J.B.B.: Oh, it’s fantastic, amazing! I was speechless when I was told about it. And as you may guess, I’m not often speechless.

SN: Why did you decide to donate the money to diversity initiatives?
J.B.B.: I’ve been conscious that diverse bodies are often more successful, more flexible, more robust. I’d like to see more diversity in science, and I’d like more people who often don’t get the chance to do research given the chance to do research. That’s my thinking.

SN: What other diversity initiatives have you been involved in?
J.B.B.: This is not the first. I’ve been one of a small group of senior women that set up a project in the United Kingdom called Athena SWAN, that encourages universities to be women-friendly places…. And if they’re women-friendly, they’re probably fair for everybody, not just women.

Bite a mouse in the back of the neck and don’t let go. Now shake your head at a frenzied 11 turns per second, as if saying “No, no, no, no, no!”

You have just imitated a hunting loggerhead shrike (Lanius ludovicianus), already considered one of North America’s more ghoulish songbirds for the way it impales its prey carcasses on thorns and barbed wire.

Once the shrike hoists its prey onto some prong, the bird will tug it downward “so it’s on there to stay,” says vertebrate biologist Diego Sustaita. He has witnessed a shrike, about the size of a mockingbird, steadying a skewered frog like a kabob for the grill. A bird might dig in right away, keep the meal for later or just let it sit around and demonstrate sex appeal (SN Online: 12/13/13).
Shrikes eat a lot of hefty insects, mixing in rodents, lizards, snakes and even small birds. The limit may be close to the shrike’s own weight. A 1987 paper reported on a shrike killing a cardinal not quite two grams lighter than its own weight and then struggling to lift off with its prize. Recently, Sustaita got a rare chance to study how the loggerheads kill their prey to begin with.

Conservation managers breed one loggerhead subspecies on San Clemente Island. That’s about 120 kilometers west of where Sustaita works at California State University San Marcos. Sustaita set up cameras around a caged feeding arena and filmed shrikes, beak open, lunging to catch dinner. “They’re aiming for the prey’s neck,” he says.
That’s a very shrikey thing. Falcons and hawks attack with their talons, but shrikes evolved on the songbird branch of the bird tree — without such powerful grips. Instead, shrikes land on their feet and attack with their hooked bills. “The bite happens at the same time the feet hit the ground,” Sustaita says. If the mouse somehow dodges, the shrike pounces again, “feet first, mouth agape.”

Reading several decades of gruesome shrike papers, Sustaita first believed the real killing power came from the bird’s bill, with bumps on the side, wedging itself between neck vertebrae and biting into the spine. Shrikes definitely bite, but based on videos, he now proposes that shaking may help immobilize, or even kill, prey.

Sustaita and colleagues discovered that the San Clemente shrikes fling their mouse prey with a ferocity that reached six times the acceleration due to Earth’s gravity, or about what a person’s head would feel in a car crash at 2 to 10 miles per hour, the researchers report September 5 in Biology Letters. “Not superfast,” he acknowledges, but enough to give a person whiplash.

In a small mouse, such shaking looks more damaging. Video analysis showed that the mouse’s body and head were twisting at different speeds. “Buckling,” Sustaita calls it. Just how much damage twisting does versus the neck bite remains unclear. But there’s a whole other question: How does a shrike manage not to shake its own brain to mush?

The language we learn growing up seems to leave a lasting, biological imprint on our brains.

German and Arabic native speakers have different connection strengths in specific parts of the brain’s language circuit, researchers report February 19 in NeuroImage, hinting that the cognitive demands of our native languages physically shape the brain. The new study, based on nearly 100 brain scans, is one of the first in which scientists have identified these kinds of structural wiring differences in a large group of monolingual adults.
“The specific difficulties [of each language] leave distinct traces in the brain,” says neuroscientist Alfred Anwander of the Max Planck Institute for Human Cognitive and Brain Sciences in Leipzig, Germany. “So we are not the same if we learn to speak one language, or if we learn another.”

Every human language expresses itself using a different set of tricks. Some use rich systems of suffixes and prefixes to build enormous, dense words. Others change how words sound or how they are arranged within phrases to create meaning. Our brains process these tricks in a constellation of brain regions connected by white matter. This tissue routes long, cablelike nerve cells from one part of the brain to another and speeds up communication between them. Wiring brain regions together this way is part of how we learn: The more often we use a connection, the more robust it becomes.

Different parts of the brain’s language circuit have different jobs. But while the large-scale structure of this circuit is universal, every language has “its own difficulties,” which might result in different white matter networks, Anwander says.

He and his team recruited 94 healthy volunteers who spoke one of two unrelated native languages — German or Levantine Arabic — for structural MRI brain scans. The Arabic speakers had arrived recently in Germany as refugees and didn’t yet speak German. They tended to have stronger connections across their left and right hemispheres, the scans revealed, whereas the German speakers had a denser network of connections within the left hemisphere.

“This corresponds to the specific difficulties in the respective languages,” Anwander says.
For instance, the complexity of Arabic’s roots — trios of consonants that buddy up with vowel patterns to produce words — might demand extra effort from parts of the brain involved in parsing sounds and words. A common example of this kind of root is k-t-b, which forms words related to writing like kitaab (book), taktub (you or she writes) and maktab (office). Arabic text is also written right to left, which the researchers speculate might demand more communication between the hemispheres.

German, for its part, has a complex and flexible word order that allows the language to create subtle shades of meaning just by shuffling around words within a phrase. While an English speaker can’t rearrange the words woman, ball and dog in the sentence “the woman gave the dog a ball” without garbling the core meaning, it’s possible to do exactly that in German. This could explain the German speakers’ denser white matter networks within parts of the left hemisphere that parse word order.

Still, it’s possible that the Arabic speakers’ recent arrival in Germany could have tweaked their white matter networks too, says Zhenghan Qi, a cognitive neuroscientist at Northeastern University in Boston who was not part of the study.

Just one month of learning a new language, she says, can lead to more engagement of the brain’s right hemisphere and greater interaction between the two hemispheres. Examining MRI scans of Arabic speakers living in their home countries or tracking brain changes as people learn new languages would help separate the effects of language learning from those of native language, Qi says.

While the new study focused just on the language circuit, parts of that circuit handle more than just language, Qi says. And language learning “might also change nonlinguistic regions of the brain,” so it’s possible that people with different language experiences might process nonlanguage information differently too, she says.

It’s still controversial whether language-associated white matter rewiring affects more than just language, Anwander says. But at least within the language circuit, the new results hint that our mother tongues are far more than just the words we happened to grow up with — they are quite literally a part of us.

What pollution does to you — Science News, March 31, 1973

Scientists described the results of their attempts to correlate pollution levels with various complaints of patients…. As expected, when smog increased, so did incidence of eye irritation, pulmonary disorders and nosebleeds…. Finally, for reasons not yet understood, more patients complained of animal bites on days when the air contained more suspended particulate matter.

Update
The harms of air pollution go beyond irritated eyes, lungs and noses. Researchers have linked exposure to dirty air with an increased risk for heart disease, diabetes, and dementia (SN: 9/19/17), and have found associations with violent behavior.

Air pollution appears to lead to more aggressive behavior in other animals too. For example, the risk of dogs biting people goes up on smoggy days, an analysis of nearly 70,000 U.S. cases found. More bites occurred with increasing ground-level ozone, which occurs when pollutants chemically react in sunlight (SN: 12/8/21), scientists reported in December on the preprint server Research Square. The dogs’ aggression may be due to a stress response or brain impacts from the ozone exposure, the researchers suggest.