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<p>Urban infants who spend their first year of life around microbes like those found on farms are less likely to develop asthma.</p>

‘Farm-like’ dust microbes may protect kids from asthma, even in the city

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<p>A nine-year dataset shows that, in the world of dating, people tend to pair up with partners who share personality traits.</p>

Yes, you really <i>do</i> have a ‘type,’ study finds

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<p>A slab of limestone might hold a snapshot of collective behavior in an ancient species.</p>

A swimming school of 50-million-year-old fish, caught in the act

Koch Foundation

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<p>NOVA Next is NOVA’s award-winning digital publication that provides answers from the cutting edge of science and technology.</p>

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      <div class="rich-text"><p>Someday, in the very distant future, athletes might be able to boost their performance by tapping into a precious, albeit unconventional, resource: the poop of elite runners.</p><p>That possibility is still a long way off. But scientists may now have a few clues on which gut microbes give marathoners the runs (no, not that kind).</p></div>
  

  
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      <div class="rich-text"><p>According to a <a href="https://www.nature.com/articles/s41591-019-0485-4">study</a> published today in the journal <i>Nature Medicine,</i> bacterial “probiotics” extracted from marathoners’ feces can boost the endurance of mice on tiny treadmills. The microbial magic appears to rely on the ability of these bacteria to do what mammalian cells can’t: convert a common byproduct of muscle metabolism into a performance-enhancing compound.</p><p>The treatment has yet to be tested in humans, and there’s nothing to suggest that bacteria alone could make or break an athletic career. But if the findings pan out, future studies of athletes’ fleet-footed feces might just contain a whiff of speedy success.</p><p>“This study presents a really fascinating hypothesis on the ways in which the microbiome can contribute to [human] physiology,” says <a href="http://fischbachgroup.org/people.html">Ariel Brumbaugh</a>, a microbiologist at Stanford University who was not involved in the study. “That said...this alone shouldn’t encourage people to immediately start a round of probiotics.”</p>
            <figure class="richtext-image full-width"><img alt="iStock-506979575.jpg" class="richtext-image full-width" height="430" width="800"
            src="/wgbh/nova/media/images/iStock-506979575.width-800.jpg"/><figcaption><p>Ready, set, poop! Image Credit: ZamoraA, iStock</p><div class="credit"><p></p></div></figcaption>
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            <p>Nowadays, there are few trendier topics in the world of biomedical research than the <a href="https://www.pbs.org/wgbh/nova/video/nova-wonders-whats-living-in-you/">gut microbiome</a>—the diverse, teeming population of single-celled organisms that inhabits the large intestine. Though they’re physically restricted to the colon, these industrious critters, which number in the trillions, are capable of performing a variety of functions that nourish and protect human cells, affecting just about every vital organ system in the body.</p><p>Years of research have shown that perturbing the gut microbiome can accelerate the onset of ailments ranging from <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4290017/">inflammatory bowel disease to certain types of cancer</a>. But in a departure from the disease-centric approach of many microbiome researchers, study author <a href="https://www.fitbiomics.com/">Jonathan Scheiman</a>, then a researcher at Harvard University, decided to test how gut microbes could <i>enhance</i> wellbeing in already healthy individuals—and, perhaps, push the limits of human performance.</p></div>
  

  
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      <div class="rich-text"><p>Scheiman and his colleagues began their study by investigating how the gut microbiome responded to intense exercise. For this team of Boston-based scientists, that meant leveraging the city’s low-hanging fitness fruit: long-distance runners, competing in the <a href="https://www.pbs.org/wgbh/nova/video/marathon-challenge">annual marathon</a>.</p><p>It was a task that required a lot of poop—and a lot of patience. In weeks bookending the 2015 Boston Marathon, Scheiman spent close to 90 hours battling Boston traffic, ferrying samples on dry ice after 15 elite runners and 10 more-sedentary controls dropped their daily deuce.</p><p>But the work paid off. An analysis of the runners’ pre- and post-marathon feces suggested the event had spurred an uptick in a bacterial genus called <i>Veillonella—</i>a group that also seemed to be more prevalent in the average runner than in their non-racing counterparts.</p><p>It’s hard to know which came first, the microbes or the athleticism, says study author <a href="http://www.kosticlab.org/team/#">Aleksander Kostic</a>, a microbiologist and immunologist at Harvard University’s Joslin Diabetes Center. But these associations hinted that something about the runners’ bodies might make them especially good homes for these bacteria.</p><p>That something turns out to be lactate, one of the major byproducts of the reactions that take place in hardworking muscles—and a main source of energy for <i>Veillonella</i>.</p><p>A quick aside: The word “lactate” (often erroneously referred to as “lactic acid”) may sound familiar, as it’s still commonly cited as the culprit behind sore, fatigued muscles. But <a href="https://www.nytimes.com/2006/05/16/health/nutrition/16run.html">that myth was busted long ago</a>, explains <a href="http://nep.missouri.edu/faculty_vieira.html">Victoria Vieira-Potter</a>, an exercise physiologist at the University of Missouri who was not involved in the study. Instead of <i>causing</i> aches, this molecular scapegoat is actually an important source of fuel that cells can use to push <i>through</i> the pain.</p><p>What lactate <i>does</i> do is build up as muscles tire out. And if that’s a common occurrence, that’s probably good news for lactate-loving <i>Veillonella</i>. In return, <i>Veillonella</i> pumps out a molecule called propionate—a compound thought to have a bevy of beneficial effects on the mammalian body, including <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4063845/">regulating</a> <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3600440/">blood pressure</a> and <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5873405/">revving up metabolism</a>.</p><p>To see if this microbial pathway had any performance-enhancing effects, the researchers orally injected two groups of 16 mice with either a strain of <i>Veillonella</i> isolated from one of the marathoners’ fecal samples, or <i>Lactobacillus,</i> another innocuous microbe that’s commonly found in yogurt. Five hours later, the researchers had the rodents hop onto a set of miniature treadmills and run until they were too exhausted to keep going.</p><p>It took around 16 or 17 minutes for the <i>Lactobacillus</i> mice to crap out. The <i>Veillonella</i> mice, on the other hand, lasted closer to 19 minutes—a 13 percent increase in endurance. Even when the researchers leapfrogged the <i>Veillonella</i> and administered propionate directly, the mice maintained a comparable edge over others who received only squirts of salt water.</p><p>Thirteen percent might not sound like much, Kostic says. But for an athlete in the midst of training, even the smallest gains in performance can make an enormous difference. Besides, he adds, this whole pathway constitutes a metabolic bonus: During exercise, there’s often lactate to spare—but if there’s <i>Veillonella</i> around, it might just get recycled into something more useful.</p><p>This symbiotic feedback loop, in which human and microbe alike benefit from repurposing each other’s byproducts, is “the coolest thing about this paper,” says <a href="https://carolina.tropini.org/">Carolina Tropini</a>, a microbiologist at the University of British Columbia who was not involved in the study. It’s also an outside-of-the-box way to think about what these bacteria are sensitive to, she adds. “We always think about <a href="https://www.pbs.org/wgbh/nova/article/gut-microbiome-nutrition-food-groups/">influencing our gut microbes</a> <a href="https://www.pbs.org/wgbh/nova/article/sugar-keeps-good-microbes-at-bay/">through diet</a>,” she says. “But this is a way of shaping the microbiome that has nothing to do with what we’re eating.”</p><p>Figuring out how propionate improves performance is the clear next step, but Kostic’s gut feeling is that the perks of harboring <i>Veillonella</i> go beyond having an in-house propionate factory. Scheiman, who has since left Harvard, and several of the paper’s other authors now run the sports biotechnology company FitBiomics, which they hope will eventually pioneer a line of fitness-enhancing probiotics (this time for humans) that may include <i>Veillonella</i> and similar strains.</p>
            <figure class="richtext-image full-width"><img alt="shutterstock_240595447.jpg" class="richtext-image full-width" height="332" width="800"
            src="/wgbh/nova/media/images/shutterstock_240595447.width-800.jpg"/><figcaption><p>Gut microbes can make a world of difference. But even the best probiotic won’t turn a couch potato into an Olympic runner—and, conversely, a dose of microbiome-altering antibiotics isn’t necessarily going to bench a top-performing athlete. Image Credit: lzf, Shutterstock</p><div class="credit"><p></p></div></figcaption>
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            <p>A lot will need to happen before then, Brumbaugh says. The data so far is intriguing, she adds, but because several of the findings rely on behavioral data in mice, they may be difficult to reproduce in humans. Additionally, larger studies in more diverse populations are needed to figure out how generalizable these results are to other types of exercise, as well as people with different levels of fitness, Vieira-Potter says. Tropini advises caution as well, noting that a human probiotic could have unexpected side effects, or simply no effect at all—especially in the long term.</p><p>Even if a human probiotic passes muster, things could easily get murky if microbes begin to venture into the realm of performance-enhancing drugs. Bacterial “doping” may eventually become something humankind has to grapple with, and “this is an area in which we should tread with caution,” Vieira-Potter says.</p><p>For now, it’s worth keeping in mind that plenty more goes into athleticism than what’s living in your gut. Even in the study, <i>Veillonella</i> was by no means universal among athletes, and not every mouse that received it responded to its effects.</p><p>But we humans still have a lot to learn about the bacterial cells that share our bodies. If the past several decades of research have taught us anything, it’s that our gut microbes are full of surprises.</p><p>Who knows? Someday, going that extra mile may truly come down to going with your gut.</p></div>
  

  
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<p>A bacterial “probiotic” may enhance athletic performance. But it’s a long way from being ready for use in humans.</p>

Microbes from marathoner poop boost endurance in mice





  
      <div class="rich-text"><p>In the world of quantum computing, diamonds might be an engineer’s best friend.</p><p>That’s because a fabled, <a href="https://wired.com/story/these-perfectly-imperfect-diamonds-are-built-for-quantum-physics/">super-pure type of gem</a> mined from the Ural Mountains has quantum properties that could provide a promising model for a stable, scalable quantum computer.</p><p>For several decades, scientists have been working on applying the strange laws of quantum mechanics—which govern the subatomic world—to the field of computing. So-called quantum computers, they say, could theoretically solve many problems much faster than any classical computer could. That’s because the basic unit of quantum information (a qubit) is fundamentally different in nature from the basic unit of classical information (a bit).</p></div>
  

  
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      <div class="rich-text"><p>A qubit is sort of like a person—it contains multitudes. Whereas a bit has a definite value of 0 or 1, a qubit can exist in two states (both 0 and 1) simultaneously. Quantum particles spend their lives in a superposition of states: sometimes 0 and a hint of 1, other times possibly 0 but more likely 1, and so on. When we observe a qubit, or subject it to the influences of the macroscopic world, that mosaic of states “collapses” into a single reality—much like when you interact with or observe a friend, you’re only seeing a snapshot of her personality at any given moment. Qubits’ complexity makes them stronger. Together with lots of other qubits, they’re able to assess all possible solutions to a problem at once, yielding a vast mélange of options in just seconds.</p></div>
  

  
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      <div class="rich-text"><p>Quantum computing, then, is <a href="http://iontrap.umd.edu/wp-content/uploads/2016/06/SciAm_May2016.pdf">extremely exciting</a>. This sophisticated technology could enhance privacy and security, help build more accurate clocks, improve machine learning, and even assist in the creation of new materials. And yet, a major barrier to realizing these advances is qubits’ strength. Along with superposition, “entanglement,” which allows two particles to exert an instantaneous influence on each other, is a key element of quantum computing. But scientists haven’t figured out how to entangle a huge bundle of qubits at once, nor how to increase their coherence times (the amount of time a particle is locked in a state of superposition before collapsing into a single state). Until engineers can transcend these limitations, we likely won’t see a large-scale quantum computer available for commercial use.</p><p>“I think it’s going to be just a few years until we see quantum computers that are offering real value on the first initial [math] problem sets, which will maybe be more scientific in nature,” says Robert Schoelkopf, a professor of physics at Yale University and a director of the Yale Quantum Institute. “But then I think we’ll rapidly see an expansion of the kinds of problems these quantum computers can address as we get better and better at engineering them.”</p><p>To get there, Schoelkopf and others are trying to make qubits into Olympic athletes: strong, resilient, and cooperative in team settings. And they’re looking to the tiniest and purest objects in the universe for the most elite qubit prototypes, since any Schrödinger’s cat-like object that both <i>is</i> and <i>isn’t</i> in a particular state could be the basis for a viable qubit. Three major contenders for the gold medal in qubit-ing are nitrogen-vacancy (NV) centers in diamond lattices, trapped ions, and superconducting qubits—but they all have distinct advantages and disadvantages.</p><h2><b>Qubits need to be isolated from their surrounding environment</b></h2><p>The most amateur qubit, the isolated single atom, obeys one of the most important laws of quantum computing: that qubits need to be completely isolated from the outside world. This is the most basic form a qubit can take. When separated from the outside world in a vacuum, its energy states (sometimes called spin states) store quantum information in a way that is durable and long-lasting.</p><p>Too many interactions with the surrounding environment can deflate the integrity of the quantum system and cause it to collapse into a single reality, a process called decoherence. This is why experimentalists cool most quantum computers to very low temperatures: large copper-colored cylinders refrigerate so-called superconducting qubits (which companies like IBM and Google are investing in) so that they move more slowly and are less suited to interact with undesirable particles. Laser beams can also cool single atoms until they are nearly at rest by transferring momentum from the atom to the scattered laser light.</p><p>The problem with the isolated single atom, though, is that its neutral charge means it’s harder to entangle them because they’re not as reactive. And to build real quantum machines capable of super-powered mathematical acrobatics, engineers need to entangle lots of qubits.</p><p>“There’s a fundamental tension of trying to keep the isolation from the outside world while simultaneously controlling the quantum bits and making them talk to each other,” Schoelkopf says.</p><h2><b>Qubits need to communicate effectively with other qubits</b></h2><p>Take away one electron from a neutral atom and you have an ion—a positively charged particle. Ions interact strongly with one another, but scientists have played around with “trapping” ions in an electromagnetic field and then deep-freezing them with lasers to form a crystal of ions. Additional lasers can help nudge the crystals’ ions into a state of entanglement, and multiple crystals linked together subsequently become the building blocks of a larger quantum network.</p><p>The benefit of trapped-ion systems is that the ions are inherently going to affect one another. “When you physically shake one of them, all of the other ions feel it,” says Michael Goldman, a postdoctoral researcher at the Joint Quantum Institute in Maryland. Systems like this that are scalable (meaning engineers can make them bigger) and malleable are promising models for quantum computers—they can do very fast operations, Schoelkopf says.</p><p></p>
            <figure class="richtext-image full-width"><img alt="razoriontrap-001.jpg" class="richtext-image full-width" height="800" width="800"
            src="/wgbh/nova/media/images/razoriontrap-001.width-800.jpg"/><figcaption><p>Segmented razor blade trap used to trap ions | Photo credit: E. Edwards/Joint Quantum Institute</p><div class="credit"><p></p></div></figcaption>
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            <p></p><p>Trapped-ion qubits can do a lot. They’re easily entangled, plus scientists can turn that interactivity on and off easily so that individual qubits don’t engage with unwanted thermal fluctuations, or heat that would cause the system to decohere. And they’re becoming popular enough that companies like IonQ and Honeywell are investing in technologies that incorporate them.</p><p>“Nature makes [the ions] identical,” Goldman says. “They’re clean and have a long coherence time. As a system, they are really mature. Every system does have a problem with scaling past a certain point, but I think right now ion trapping has a viable path.”</p><h2><b>Qubits need to be cheap and future-proof</b></h2><p>Whereas the trapped-ion method requires elaborate tools—an electromagnetic field and lasers—to trap the ions, scientists are finding that Russian “magic diamonds” can hold qubits in place and thus act the same way that a trapped-ion rig does. By replacing a single carbon atom in a diamond’s atomic lattice with a nitrogen atom and leaving a neighboring lattice node empty, engineers can create what’s called a nitrogen-vacancy (NV) center. This is generally inexpensive since it’s derived from nature. The NV center is a flaw, or blemish, in an otherwise super-pure atomic structure.</p><p>“I like to think of the NV center as an inside-out atom, in a way,” Goldman says. In a typical atom, electrons surround the nucleus in orbitals; in this case, electrons occupy orbitals inside the vacancy of the NV center (they come from the valence, or outer-ring, electrons of the nitrogen atom) while the NV center’s electronic spins react with the nuclear spin of some of the carbon atoms nearby. In this case, both the NV center and the adjacent carbon atoms function as qubits, and the diamond lattice keeps them stationary and entangled.</p><p>These qubits—called solid-state spin qubits—are limited, though, since the system can only have as many qubits as there are neighboring carbon atoms (just three in the immediate vicinity). And NV centers are difficult to control, which means they might not be as scalable as other options. Nature, too, is fundamentally variable, and NV centers can be influenced by the nuclear spins of other atoms in the lattice—which means one diamond lattice is undoubtedly going to be slightly different from the next.</p><p>“In terms of being a general, perfect qubit, ions may be better suited… just because they’re cleaner,” Goldman says.</p><p>NV centers can operate at room temperature (trapped ions can, too), which is a massive bonus, depending on what scientists want to use them for. For example, we may need to experiment with types of quantum machines that aren’t large enough to maintain cool temperatures, or that need to accomplish tasks that wouldn’t be allowed in a standard ultra-cold arrangement.</p><p>Researchers at the Delft University of Technology in the Netherlands have entangled an NV center’s electronic spin with the spins of nine nearby nuclei, an impressive start to this burgeoning technology, which is being developed by a Harvard-bred start-up called Quantum Diamond Technologies.</p></div>
  

  
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      <div class="rich-text"><p>Nicole Yunger Halpern, a theoretical physicist and quantum computing expert at Harvard University, says that NV centers are promising, but that the scientific community shouldn’t rule out other uses of solid-state qubits (qubits contained in solid objects). Ultimately, a mixture of qubit types in one system could be the best way to build a scalable quantum computer.</p><p>“Over the past decade or two, there have been revolutions in the way people have been using different types of platforms to build qubits,” she says. If scientists could figure out how to transfer information from one type of qubit to another, she says, they might be able to knit together a robust fabric of top-tier qubits.</p><h2><b>Qubits need long coherence times</b></h2><p>A popular type of qubit is the superconducting qubit, which has a decent coherence time, meaning it can endure in a state of quantum superposition for a relatively long time. These qubits take the form of superconducting (that is, zero electrical resistance) circuits that maintain a state of both 0 and 1 as a photon both does and doesn’t zoom through them. Though trapped ions have a better track record when it comes to coherence time, superconducting qubits (and NV centers) are close behind.</p><p>Some scientists, like Schoelkopf and the University of Chicago’s David Schuster, are trying to build a twist into this model that will help coherence times and improve this type of system. “When you’re using superconducting qubits in a quantum computer, you’re also using light that interacts with the superconducting qubits,” Yunger Halpern says. “Some of these groups are reversing the roles of the superconducting qubits and the light.” In other words, they’re storing quantum information in the light as opposed to the superconducting qubits.</p><p>Schoelkopf says this kind of information carrier can live longer than qubits created by conventional methods by a factor of 30 or 50. “Not just the rate but the number or type of errors that it can experience are smaller,” he says.</p><h2><b>Qubits need to be flexible</b></h2><p>Above all, the most refined and athletic qubits are the ones that are going to be more flexible. The ability to operate quantum computers at room temperature, for example, is a particularly enticing possibility that would give qubits more flexibility. And the more receptive qubits are to being guided by lasers, the more amenable they’ll be to entanglement.</p><p>“You want the qubits to be docile and go where they are led,” Yunger Halpern says. “This is maybe more of a characteristic of a show dog than an Olympic athlete.”</p><p>Techniques for adding flexibility to these systems vary tremendously: From understanding the relationship between entropy and information (which could affect how engineers understand thermodynamic processes in quantum situations) to using different methods of entanglement, scientists are training qubits to reach and surpass their expected limits.</p><p></p>
            <figure class="richtext-image full-width"><img alt="Qubit2.JPG" class="richtext-image full-width" height="533" width="800"
            src="/wgbh/nova/media/images/Qubit2.width-800.jpg"/><figcaption><p>This cat’s name is Qubit. He may not be an Olympic athlete, but the author thinks he’s a pretty Great Qubit. | Photo courtesy Amanda Gefter and Justin Smith</p><div class="credit"><p></p></div></figcaption>
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            <p></p><p>“There are always going to be physical challenges with a quantum computer,” says Ashley Montanaro, a quantum computation researcher at the University of Bristol. “But when you scale up, as long as the noise [that the qubits] have to contend with doesn’t increase too much, you’ll be able to have a system that’s a thousand or one million qubits.”</p><p>Scientists are slowly, incrementally making their way toward that goal. And in the process, these little qubits could help solve some universal puzzles.</p><p>“The transition from truly quantum behavior to behavior that can be described as classical mechanics has been mysterious for a long time,” Yunger Halpern says. “I hope that as our quantum systems grow, we’ll be able to use them more and more to probe the crossover.”</p></div>
  



<p>At the core of quantum computing is the qubit. The best ones have a few defining traits, and scientists are looking to everything from lasers to Russian diamonds to help refine the best qubits for the next generation of quantum computing.</p>

What makes a great qubit? Diamonds and ions could hold the answer





  
      <div class="rich-text"><p>Take a quick flight over Peru’s Nazca (Nasca) Desert, and you’ll find yourself ogling an enormous, sprawling tapestry of ancient geoglyphs: a series of swirls, zigzags, and lines carved through sand and stone, some running many miles long. Perhaps most curious of all are the portraits of animals sprinkled among the geometric designs—creatures that range from commonplace to mythical, with little to explain their purpose or creation.</p><p>Now, new research may be pulling back the veil on these enigmatic etchings. In a <a href="https://www.sciencedirect.com/science/article/pii/S2352409X18307430?via%3Dihub">study</a> published yesterday in the <i>Journal of Archaeological Science,</i> a team of archaeologists reports the identification of four of the Nazca Lines’ 16 carvings of birds. Curiously, none of the four, which include a rainforest-dwelling hermit, a tropical parrot, and two coastal pelicans, are native to the arid landscape where their depictions are found.</p></div>
  

  
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      <div class="rich-text"><p>Researchers may never know for sure what significance these foreign species had: Some of the Nazca Lines are thought to be up to 2,000 years old, and the pre-Incan peoples who likely forged this geographic Etch-A-Sketch are long gone. But identifying the winged members of this ancient menagerie could help researchers home in on what once inspired these painstakingly rendered formations—and better understand the artists who immortalized them centuries ago.</p></div>
  

  
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      <div class="rich-text"><p>The new study isn’t the first to attempt to break the anonymity of the Nazca Lines’ birds, which appear to outnumber other animals in the glyphs. But before now, most researchers had based their designations on just a handful of traits, study author Masaki Eda, a zooarchaeologist at the Hokkaido University Museum in Japan, <a href="https://eurekalert.org/pub_releases/2019-06/hu-fl061719.php">said in a statement</a>. Instead, Eda and his team took an ornithological approach, analyzing the bills, necks, tails, wings, and feet of each bird and comparing their shapes and relative lengths to those of species known to frequent Peruvian skies.</p><p>Though several of the etchings bore at least a passing resemblance to a modern species, the researchers assigned names to just four. Two seem to be pelicans (in the Pelecanidae family), which are native to the Peruvian coasts; one is a probable hermit (in the Phaethornithinae subfamily), a type of tropical hummingbird found in northern and eastern Peru; and another appears to be a juvenile in the parrot family, like those that found in the country’s rainforests. Though none of these birds would have had much business pecking around a desert, the regions they’re found in were all likely Pre-Incan travel destinations.</p><p>It’s still unclear <i>why</i> the Nazca Lines were drawn, though <a href="https://www.nationalgeographic.com/archaeology-and-history/archaeology/nasca-lines/">purposes ranging from astronomical to agricultural have been proposed</a>. No matter the impetus, researchers are confident that the design and execution of these extraordinary etchings were no small feats. Ancient Peruvians would have had to haul away layers of rocks and Earth to reveal the light-colored sands below. These birds—wherever they hailed from—must have signified something pretty special to warrant that much effort, <a href="https://www.newsweek.com/nazca-lines-exotic-birds-peru-1444804">Eda told Hannah Osborne at <i>Newsweek</i></a>.</p><p>Untangling that part of the puzzle will require more work. Already, Eda and his team are hard at work studying how the bird glyphs stack up against similar depictions in temples and on ceramics, <a href="https://www.livescience.com/65755-mysterious-nazca-lines-birds-identified.html">reports Stephanie Pappas at <i>Live Science</i></a>.</p><p>There’s no telling what these new analyses will reveal. Until then, we’ll need to be satisfied with the little we do know of the Nazca Lines—still best appreciated, it seems, from a bird’s eye view.</p></div>
  

  
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<p>The famous desert geoglyphs appear to show birds that occur in Peru’s forests and coastal areas.</p>

Peru’s Nazca Line etchings depict bird species not native to the area





  
      <div class="rich-text"><p>Ah, the lost wallet. Few inanimate objects are capable of sowing more internal conflict.</p><p>Stumble upon a forsaken folio, and your brain will quickly find itself on an ethical seesaw: While keeping the wallet comes with a clear payoff, there’s also a serious moral cost to pocketing the prize.</p><p>It’s hard to predict what someone will do when these two impulses clash, and countless extenuating circumstances can sway the outcome. But what happens when the amount of money in the wallet increases? You might think that the average human would be more tempted to keep a fatter pocketbook.</p><p>If that’s what your gut is telling you, congratulations: You’d be in agreement with the majority of people, including most professional economists.</p><p>You’d also be wrong.</p><p>At least, that’s what a new <a href="https://science.sciencemag.org/lookup/doi/10.1126/science.aau8712">study</a> suggests. In an unprecedented global experiment, a team of international researchers has discovered that as the amount of cash in a lost wallet increases, so does a person’s likelihood of contacting the owner. The findings, published today in the journal <i>Science</i>, fly in the face of economic theories that predict the predominance of self-interest, and contradict the assumptions of researchers and non-researchers alike. Nonetheless, they hold true in 38 out of 40 countries tested around the world, capturing what appears to be a nearly universal, albeit unexpected, trend.</p><p>“What this study [found]...is delightfully counterintuitive,” says <a href="https://www.human.cornell.edu/people/vr53">Valerie Reyna</a>, a psychologist and expert in human decision making at Cornell University who was not involved in the study. “It goes against what many would assume, and the logic of...many powerful economic theories. Whenever you have something like that, it’s exciting for science.”</p></div>
  

  
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      <div class="rich-text"><p>In the study, a globetrotting team of economists, psychologists, and 13 very intrepid research assistants planted 17,303 “lost” wallets in 355 metropolitan hubs around the world. In each case, an undercover scientist approached an employee at a bank, theatre, police station, post office, hotel, or other public institution and hurriedly handed over a wallet, claiming to have found it on the street. The researcher then hastily exited stage left, saddling their unwitting study subject with a difficult choice.</p><p>Every wallet in the study was transparent, and was stuffed with a key, a grocery list, and three business cards with a (fictitious) male name and email address, giving the employee ample opportunity to return the wallet. Some wallets came with each country’s equivalent of $13.45 in United States currency, while others had no money at all. In the United States, United Kingdom, and Poland, the researchers also distributed a third set of wallets containing $94.15—a hefty sum they nicknamed “Big Money.”</p>
            <figure class="richtext-image full-width"><img alt="wallet_all.jpg" class="richtext-image full-width" height="568" width="800"
            src="/wgbh/nova/media/images/wallet_all.width-800.jpg"/><figcaption><p>An example wallet. Each wallet belonged to a (fictitious) male software developer with a country-specific name (in this case, the United States), listed on a business card with an email address. Also in the wallet were a key, a grocery list, and cash and coins. Image Credit: Courtesy of Alain Cohn, University of Michigan</p><div class="credit"><p></p></div></figcaption>
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            <p>When the team looked at how often people in each country tried to reach out to the wallets’ rightful “owners” over email, stark differences emerged: While only 10 or 15 percent of wallet recipients came clean in China and Morocco, for instance, the numbers jumped close to 70 percent in Switzerland and several Nordic countries. (In the United States, citizens landed in the absolute middle of the pack, contacting the researchers about 50 percent of the time.)</p><p>While it’s not completely clear what underlies these differences, there were a few hints of what kinds of societies might encourage or discourage financial integrity. A country’s tendency to keep mum about a lost wallet is actually a decent proxy for other measures of nationwide “dishonesty,” like public corruption, smuggling, and even filing inaccurate tax forms, says study author <a href="https://michelmarechal.com/">Michel Maréchal</a>, an economist at the University of Zürich in Switzerland.</p><p>On the other hand, people in countries that were wealthier, educated, and more politically egalitarian—as well as those that placed more cultural emphasis on individual culpability—were more likely to speak up about the wallet.</p><p>From the outset, however, the researchers were more interested in a related, but separate, question probing the data <i>within</i> each country: whether or not a larger sum of cash would deter people from emailing the wallet’s owner.</p></div>
  

  
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      <div class="rich-text"><p>In situations like these, economic dogma dictates that there’s a certain point at which greed wins out. In other words, guilt has a probable price tag—and from a self-interested perspective, the more money the wallet contains, the less likely someone should be to speak up.</p><p>That’s what Cohn and his economist colleagues went in thinking. And when surveyed, most people in a pool of 279 experts and 299 members of the general public predicted the same.</p><p>But the exact opposite turned out to be true. The sweeter the pot, the <i>more</i> likely recipients were to try to contact the owner, topping out at an attempted return rate of 72 percent in the “Big Money” condition. This trend, which bucked economic expectation, was observed in 38 out of 40 countries tested.</p><p>“We were really surprised by how robust the effect was across countries,” says study author <a href="https://www.si.umich.edu/people/alain-cohn">Alain Cohn</a>, an economist at the University of Michigan. “It’s remarkable to observe such a consistent result.”</p><p>Of course, not all wallets were homeward bound. Post office employees, for instance, were particularly unlikely to reach out, possibly because of the demands of their hectic schedules, says study author <a href="https://davetannenbaum.github.io/">David Tannenbaum</a>, a behavioral scientist at the University of Utah. Wallets turned into the Vatican and a couple anti-corruption bureaus also mysteriously went off the grid.</p><p>There were also two countries—Mexico and Peru—in which cash didn’t boost wallet reporting. But even here, the patterns didn’t completely reverse: Money or no, people attempted to return the wallets at roughly the same rate.</p><p>Explaining the trend was another matter entirely. The trend couldn’t be chalked up to self-consciousness, fear of penalty, or even the expectation of a bigger finder’s fee. It was even clear that participants weren’t returning the wallets after skimming off some of the cash: In the Czech Republic and Switzerland, research assistants kept up the ruse long enough to reunite with nearly 200 wallets, and found 98 to 99 percent of the money intact. (In all other cases, after being contacted over email, the researchers—still impersonating the wallet’s owner—thanked the study’s good Samaritans and told them they didn’t need the contents.)</p>
            <figure class="richtext-image full-width"><img alt="aau8712_Figure_fig1_seq7_v2.jpg" class="richtext-image full-width" height="566" width="800"
            src="/wgbh/nova/media/images/aau8712_Figure_fig1_seq7_v2.width-800.jpg"/><figcaption><p>The share of wallets in each country reported to their &quot;owners&quot; in each of two conditions: US $0 (No Money, orange) and US $13.45 (Money, red). Image Credit: Cohn <i>et al. Science, </i>2019</p><div class="credit"><p></p></div></figcaption>
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            <p>One thing that <i>did</i> seem to make a difference, however, was pure and simple altruism. When the researchers repeated their experiment in a subset of countries with some of the wallets’ contents removed, they noticed that the presence of a key upped the number of concerned emails they received. Taking a key from a lost wallet is pointless. Returning it to the owner, however, benefits the other party exclusively—a hint that the bump in reporting reflected magnanimity.</p><p>“People are surprisingly caring about others,” Reyna says. “More caring than you would think when there’s nothing in it for them.”</p><p>It’s also noteworthy, Tannenbaum says, that this tendency toward benevolence transcended so many cultural and geographical boundaries. “This might suggest that this [impulse] is just a very basic human motivation,” he says. “We may come into this world with a prepackaged moral psychology.”</p><p>The inclination to rehome a lost wallet, however, wasn’t entirely charitable. Through a series of follow-up surveys, the team discovered another major motivation behind this seemingly selfless act: a strong aversion to coming off as a thief—one that increased with the amount of money packed into the wallet.</p><p>There’s a little bit of irony in this, Reyna points out. Strictly speaking, she says, “a thief is a thief for $10, and a thief for $1000.” Nonetheless, the more money the wallet contained, the more crooked people felt about pocketing it.</p>
            <figure class="richtext-image full-width"><img alt="iStock-843522736.jpg" class="richtext-image full-width" height="600" width="800"
            src="/wgbh/nova/media/images/iStock-843522736.width-800.jpg"/><figcaption><p>To test the limits of human integrity, researchers planted more than 17,000 &quot;lost&quot; wallets in 40 countries around the world. Image Credit: spukkato, iStock</p><div class="credit"><p></p></div></figcaption>
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            <p>Compared to altruism, preserving a positive self-image is probably a more subtle driving force—one that might not often occur to people when they’re attributing intention to others, explains <a href="https://sites.google.com/view/ukarma">Uma Karmarkar</a>, a decision neuroscientist at the University of California San Diego who was not involved in the study. “It’s easier to focus on other people’s desires...and more difficult to imagine the social pressures they might face,” she says. This, she adds, could help explain why the predictions made by study participants were so off base.</p><p>Not wanting to sully your identity doesn’t sound quite as noble as worrying about someone else’s wellbeing. But the study’s findings aren’t necessarily cynical, Tannenbaum says. “It feels more positive if it’s all driven by altruism...But if we still have these concerns where we don’t want to see ourselves as bad people, that’s still a positive. We’re better off with people having those motivations than not.”</p><p>There’s no guarantee the implications of these results will translate into other ethically fraught scenarios—or even to a slightly altered (and more experimentally challenging) situation in which wallets were dropped on sidewalks, rather than entrusted to employees in a professional setting, Karmarkar points out. But there’s no denying the importance of a field study, conducted outside the artificial environment of a research laboratory. It is, after all, a unique opportunity to observe humans in the wild, behaving as they otherwise would. Even if vanity sneaks its way in, when push comes to shove, people often <i>will</i> do the right thing. And sometimes, that’s enough.</p><p>“I think there’s a lot of room for optimism,” Karmarkar says. “The study shows that the social norms we have decided are important for our society hold up reasonably well under duress. And that’s reassuring.”</p></div>
  

  
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<p>Altruism is alive and well. So is the desire to protect one’s self-image.</p>

Humans are surprisingly honest when it comes to returning lost wallets





  
      <div class="rich-text"><p>During the Cold War, there was a heck of a lot more frost—and I’m not just referring to the geopolitical tensions between the United States and the former Soviet Union. Back then, the Himalayas, too, were feeling the chill.</p><p>But that’s long since changed. According to a <a href="https://advances.sciencemag.org/content/5/6/eaav7266">study</a> published today in the journal <i>Science Advances, </i>rising temperatures in the Himalayas have melted nearly 30 percent of the region’s total ice mass since 1975. Once nicknamed Earth’s ‘Third Pole’ for its impressive cache of snow and ice, the Himalayas may now have a bleak future ahead. Four decades of satellite data, including recently declassified Cold War-era spy film, suggest these glaciers are currently receding twice as fast as they were at the end of the 20th century. </p></div>
  

  
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      <div class="rich-text"><p>The findings underscore the persistent and increasing dangers of global warming in the Himalayas, where disappearing glaciers stand to imperil the water supply of up to a billion people throughout Asia.</p><p>“It’s the climate crisis you haven’t heard of,” Philippus Wester, a researcher at the International Centre for Integrated Mountain Development who was not involved in the study, <a href="https://www.theguardian.com/environment/2019/jun/19/himalayan-glacier-melting-doubled-since-2000-scientists-reveal">told Damian Carrington at <i>The Guardian</i></a>. </p></div>
  

  
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      <div class="rich-text"><p>The study’s sobering findings come as the result of a massive compilation of data across time and space. While previous studies have documented the trajectories of individual glaciers in the Himalayas, the new findings track 650 glaciers that span a staggering 1,250-mile-wide range across Nepal, Bhutan, India, and China. They also draw on some 40 years of satellite imagery, which the scientists stitched together to reconstruct a digital, three-dimensional portrait of the glacier’s changing surfaces—almost like an ultra-enhanced panorama.</p><p>When a team of climatologists analyzed the time series, they found a stark surge in glacier shrinkage. Between 1975 and 2000, an average of about 10 inches of ice were shed from the glaciers each year. Post-Y2K, however, the net loss doubled to around 20 inches per year—a finding in keeping with accelerated rates of warming around the globe. </p><p>While previous studies have had difficulty disentangling the relative contributions of rising temperatures, ice-melting pollutants, and reduced rainfall to the boost in glacier melt, the latter two simply aren’t enough to explain the alarming drop in ice mass in recent years, study author Josh Maurer, a researcher at Columbia University’s Lamont-Doherty Earth Observatory, <a href="https://www.wired.com/story/cold-war-spy-photos-show-how-fast-himalaya-glaciers-are-melting/">told Eric Niiler at <i>Wired</i></a>.</p><p>“It is really the doubling of the speed of glacier melt that is most concerning,” study Joerg Schaefer told Carrington at <i>The Guardian. </i>“There is no doubt in my mind, not a single grain of doubt, that [the impact of the climate crisis] is what we are seeing.”</p>
            <figure class="richtext-image full-width"><img alt="iStock-1029820810.jpg" class="richtext-image full-width" height="533" width="800"
            src="/wgbh/nova/media/images/iStock-1029820810.width-800.jpg"/><figcaption><p>A new study leveraged Cold War-era satellite images to construct a series of portraits of the Himalayas over time and space, allowing researchers to track declines in ice mass. Image Credit: gagarych, iStock</p><div class="credit"><p></p></div></figcaption>
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            <p>As things stand, several billion tons of ice are sloughing off the Himalayas each year without being replaced by snow. That spells serious trouble for the peoples of South Asia, who depend on seasonal Himalayan runoff for agriculture, hydropower, drinking water, and more. Melting glaciers could also prompt destructive floods and threaten local ecosystems, generating a ripple effect that may extend well beyond the boundaries of the mountain’s warming peaks.</p><p>This study and others hint that, without serious and drastic interventions, the planet’s forecast <a href="https://link.springer.com/book/10.1007%2F978-3-319-92288-1">looks grim</a>. “We have to prepare the societies living there with realistic predictions of what this landscape will look like in 10 or 20 years,” Schaefer told Niiler.</p></div>
  

  
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<p>Accelerating ice melt in the Himalayas may imperil up to a billion people in South Asia who rely on glacier runoff for drinking water and more.</p>

Declassified spy images show Earth’s ‘Third Pole’ is melting fast





  
      <div class="rich-text"><p>When Meena Sankaran was a child growing up in Mumbai, India, her family didn’t have consistent access to water in their home, and what they did have wasn’t always safe to drink. She was often sick—with typhoid, malaria, jaundice, mumps, and pneumonia, all before she was 17. If these illnesses weren’t directly water-related, the lack of clean water didn’t help her recovery.</p><p>“My immune system just got used to it,” Sankaran says.</p><p>Sankaran is one of the lucky ones. The <a href="http://documents.worldbank.org/curated/en/586371495104964514/pdf/115133-WP-P152203-PUBLIC-17-5-2017-12-28-1-WaterlifeCaseApril.pdf">World Bank estimates</a> that almost a quarter of all communicable diseases in India are due to unsafe water and the lack of safe hygiene practices, with more than 500 children under the age of five dying each day from diarrhea.</p><p>Sankaran spent 20 years getting an engineering degree in the U.S. and working in the tech industry before using her personal experiences to launch a startup in 2016 called KETOS, a water management company that uses AI to monitor and test quality.</p></div>
  

  
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      <div class="rich-text"><p>The company has two products: KETOS Wave, a device that sits in a water pipe and can detect more than 20 parameters like flow, pressure, usage, and volume that feed into a machine learning algorithm that can identify possible leaks and track use. So if water volume goes down in a way that the algorithm parsing the data doesn’t expect, Wave can notify the user of the likely leak with a mobile app, which also has the ability to remotely shut the water off.</p><p>The company’s other product is KETOS Shield, which can measure and detect 20 different dangerous contaminants like lead, copper, nitrates, arsenic, and chlorine. Measuring these toxins doesn’t utilize AI, but Shield combines routine chemical testing with factors that can contribute to fluctuations—such as the time of year, or the temperature—in a machine learning algorithm that predicts chemical spikes before they happen.</p><p>While the 140 deployments to date are mainly with municipal and agricultural clients in the U.S. and Mexico, Sankaran also wants to do something for her homeland. That led KETOS to offer water solutions across India as part of the government’s <a href="https://www.smartvillagesinitiative.org/">Smart Village Initiative</a>. In 2017, the company deployed its technology in 25 villages. None of the villages had a way to monitor quality, and several could go days without getting water at all. Sankaran said they were able to improve that supply by up to two hours a day in most cases.</p>
            <figure class="richtext-image full-width"><img alt="IMG_7090.jpg" class="richtext-image full-width" height="600" width="800"
            src="/wgbh/nova/media/images/IMG_7090.width-800.jpg"/><figcaption><p>Meena Sankaran (second from left), is the founder of the tech startup KETOS, a water management company that uses AI. In 2017, KETOS deployed its technology to 25 villages in Sankaran&#x27;s homeland, India. Image credit: KETOS</p><div class="credit"><p></p></div></figcaption>
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            <p>Not that there haven’t been hiccups. Saravana Sarru is a resident of Kuppam, the first village in the State of Andhra Pradesh that KETOS worked in, and ended up working as a liaison on the ground for many of the other villages. In some of them, the rainy season interfered with the devices sending information back to those monitoring the water, a problem that was solved by relying on a mesh network, a type of network that made internet connectivity more reliable. Even with the initial issues, Sarru said that all the communities have been excited by the potential to have more control over their water source.</p><p>“It’s very new to India,” Sarru says.</p><p>KETOS is planning a project in Majuli, the world’s largest river island, which has major problems with arsenic contamination. They are actively partnering with an Indian NGO to recruit local women as field support personnel, giving them jobs that are also empowering villagers to take care of their own water. Thousands of other villages have expressed interest, but the recent elections have halted the project.</p><p>“We are slowly but surely pressing forward,” Sankaran says. “India takes time.”</p><p>But the country has no time to spare in finding new ways to better monitor and improve water management. More <a href="https://washmatters.wateraid.org/publications/the-water-gap-state-of-the-worlds-water">than 163 million Indians</a> don’t have access to clean water, the highest number of any country in the world, and more than 600 million face acute water shortages. Nearly two dozen cities could run out of groundwater by next year, including megacities like Bangalore and New Delhi.</p></div>
  

  
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      <div class="rich-text"><h2><b>A Global Problem</b></h2><p>Across the rest of the world, over 2 billion people are living in areas of water scarcity, <a href="http://www.unwater.org/water-facts/scarcity/">according to the United Nations</a>, and that number could grow to <a href="https://www.theguardian.com/environment/2018/mar/19/water-shortages-could-affect-5bn-people-by-2050-un-report-warns">5 billion by 2050</a>. Nearly a million people die each year from water, sanitation, and hygiene-related diseases that would be reduced with access to clean water.</p><p>The U.S. has one of the safest overall systems but still has serious issues to contend with in the coming decades. America’s drinking water is delivered through more than a million miles of pipes, most of which were laid in the early to the mid-20th century with a lifespan of 75 to 100 years. This past-retirement age system contributes to an estimated 240,000 water main breaks each year—and some two trillion gallons of water lost annually. The government will need to spend a trillion dollars maintaining and expanding services for a growing population over the next 25 years, according to the American Water Works Association.</p><p>These old pipes also create water quality problems. While the bigger public drinking water systems have the ability to test water frequently, smaller municipal systems that still serve millions of Americans in more rural areas don’t necessarily have the budget or expertise to do the same amount of testing. AI-powered tools like KETOS could help bridge the gap, and identify problems that otherwise might remain invisible for years.</p><p>“We are desperately in need of better monitoring,” says Peter Gleick, a climate and water scientist who co-founded the Pacific Institute. “It’s a problem, even here in the U.S.”</p><p>By far the most public water crisis has been unfolding in Flint, Michigan, where over 100,000 citizens have been exposed to dangerous levels of lead leaching from their pipes due to insufficient treatment. The state has struggled for five years to make it right. AI might be part of the solution to finally helping Flint: Volunteer researchers <a href="https://www.theatlantic.com/technology/archive/2019/01/how-machine-learning-found-flints-lead-pipes/578692/">developed a machine learning algorithm</a> to predict which homes are most likely to have lead pipes that need to be changed out.</p><p>Implementing this inspection system has proven difficult, however. Some residents whose pipes were not prioritized by the algorithm have complained, feeding into the general atmosphere of <a href="http://bit.ly/2IPETgm">distrust in politicians and policymakers</a> that still simmers in Flint five years after the crisis started. Roughly one-quarter of the water pipes in the city have yet to be inspected, and even when that’s done and any remaining lead pipes have been replaced, an unknown number of damaged pipes <i>within</i> homes will remain, ensuring that Flint’s struggle for safe drinking water will drag on for years to come.</p>
            <figure class="richtext-image full-width"><img alt="Sequence 01.00_38_26_19.Still001.jpg" class="richtext-image full-width" height="450" width="800"
            src="/wgbh/nova/media/images/Sequence_01.00_38_26_19.Still001.width-800.jpg"/><figcaption><p>Activists and residents gather at a water treatment plant in Flint, Mich. to commemorate the 5-year anniversary of the Flint water crisis. Image credit: Jason Vlahos, WKAR</p><div class="credit"><p></p></div></figcaption>
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            <p>The problem isn’t unique to Flint, however. There are an estimated <a href="https://www.cbsnews.com/news/lead-in-americas-water-systems-is-a-national-problem/">6.1 million lead pipes across the country</a>. Flint is the only city that has so far been able to prove a causal link between its water and elevated lead levels, but a <a href="https://www.reuters.com/investigates/special-report/usa-lead-testing/">Reuters’ investigation</a> found 3,000 areas in the U.S. with lead poisoning rates that were at least double those that were seen in Flint during the height of that crisis. Most spots have what the report calls a “lead legacy” made up of old pipes, abandoned industrial waste, and peeling paint that could all be contributing to elevated lead levels.</p><p>“We’ve known for a long time that there are certain water problems that require a lot of data and observations to get a hand on,” Gleick says. “If AI can help sort through that data, it would be enormous step forward in better management of our limited water resources.&quot;</p><p>Sankaran’s work in India got KETOS more business but she said that’s not the point. She wants to see a focus on using new tools, like the ones she’s developed, to make the world a better place.</p><p>“You have to question yourself about what’s the benefit of all these advancements in technology if you can’t improve the quality life at a basic level,” Sankaran says.</p></div>
  

  
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<p>Around the world, aging and inadequate water systems are a huge public health problem. Now, researchers are using artificial intelligence to help conserve and monitor the quality of drinking water.</p>

Thirsty for solutions, water managers are putting AI-powered tools to work





  
      <div class="rich-text"><p>You know the look. Everyone does. The wide, winsome eyes; the forlorn, furrowed brow. It’s enough to melt your heart—and send your hand reaching for the treat bag.</p><p>But the next time your dog fixes you with that sorrowful stare, take comfort (or chagrin) in the knowledge that she—and the rest of the world’s pet pooches—could owe their expressive eyes entirely to us.</p></div>
  

  
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      <div class="rich-text"><p>According to <a href="https://www.pnas.org/cgi/doi/10.1073/pnas.1820653116">new research</a> published today in the journal <i>PNAS</i>, the allure of puppy dog eyes may be a product of domestication, acquired as a lineage of charismatic canines split off from wolves. While their wild ancestors lack the necessary facial anatomy to raise their inner eyebrows, dogs possess certain muscles that, when put to use, make their mugs resemble ours—something that may have piqued the interest of ancient peoples.</p><p>These brow-raising results hint that, on the road to becoming our closest companions, dogs may have evolved a way to hijack, or at least mimic, a core tenet of human communication: eye contact.</p>
            <figure class="richtext-image full-width"><img alt="iStock-871215928.jpg" class="richtext-image full-width" height="534" width="800"
            src="/wgbh/nova/media/images/iStock-912167862.width-800.jpg"/><figcaption><p>It&#x27;s hard to stay mad at a face like this. Image Credit: RalchevDesign, iStock</p><div class="credit"><p></p></div></figcaption>
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            <p>“Eye contact is central to human communicative skills,” says <a href="https://www.aleahbowie.com/">Aleah Bowie</a>, a conservation psychologist at Duke University who was not involved in the study. “So it makes sense if we’re selecting for non-human animals [like dogs], we’re going to look for the same kind of traits.”</p><p>In other words, the power of puppy dog eyes is rooted not so subtly in a bit of egocentrism: Wide, expressive eyes <a href="https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0082686">remind us of human babies</a>, or a person on the verge of tears—emotive extremes of ourselves.</p></div>
  

  
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      <div class="rich-text"><p>And dogs, it seems, have reaped the benefits of this facial familiarity. There’s even evidence to suggest mutts who raise their inner eyebrows more often even <a href="https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0082686">get adopted more quickly from shelters</a>.</p><p>Of course, shelters didn’t exist tens of thousands of years ago, when people first cozied up with a subset of unusually friendly wolves. But that doesn’t mean a similar process wasn’t happening in the early days of domestication: In gravitating toward friendlier canines, humans might have inadvertently reshaped an entire lineage, altering traits both physical and psychological.</p><p>If that’s the case, then wolves might be expected to show less puppy-eyed prowess—or even lack some of the anatomical accoutrements necessary to maneuver their brows.</p><p>To put this theory to the test, a team of researchers led by <a href="http://www2.port.ac.uk/department-of-psychology/staff/dr-juliane-kaminski.html">Juliane Kaminski</a> and <a href="http://www2.port.ac.uk/department-of-psychology/staff/dr-bridget-waller.html">Bridget Waller</a>, both comparative psychologists at the University of Portsmouth in the United Kingdom, compared the facial muscles of six modern mutts and four gray wolves—a stand-in for domestic dogs’ long-gone wild ancestor. Though the two species’ faces were almost identical, almost all dogs tested possessed two extra muscles around their eyes that helped them raise their brows and pull their eyelids in certain directions—both movements that are, scientifically speaking, adorable.</p><p>“To see this kind of soft tissue change in the timespan of [dog domestication] is remarkable,” Waller says. The wolves, however, weren’t a “completely blank slate,” she adds. While the wolves didn’t have fully developed muscles, a few sparse muscle fibers existed in their place—just enough, she says, for evolution to “grab hold and make bigger, more uniform, and more stable in the dogs.”</p><p>Soft tissue like muscle doesn’t fossilize well, and a face-off between two modern species is just an approximation for gazing backwards in time. But already, the study presents a tantalizing hint of how these muscles may have beefed up over time. Only one dog breed studied lacked one of the two critical eye muscles: the Siberian Husky, which is more closely related to wolves than most other dog breeds. “This is suggestive of [an intermediate stage], but we need to follow up on this with other breeds,” Waller says.</p>
            <figure class="richtext-image full-width"><img alt="203461.jpg" class="richtext-image full-width" height="888" width="800"
            src="/wgbh/nova/media/images/203461.width-800.jpg"/><figcaption><p>Most dogs appear to possess two muscles that wolves lack: the levator anguli oculi medialis muscle (LAOM) and the retractor anguli oculi lateralis muscle (RAOL). The pair help dogs maneuver their eyebrows and eyelids. Image Credit: Juliane Kaminski et al., PNAS, 2019</p><div class="credit"><p></p></div></figcaption>
            </figure>
            <p>To complement their anatomical findings, the researchers next filmed 27 shelter dogs and nine captive wolves for two minutes after a stranger approached them. As expected, dogs came out ahead in this face-off as well: On average, they raised their inner eyebrows more often, and seemed capable of producing more exaggerated movements with their eyes than their wolf cousins—findings in keeping with the team’s dissection.</p><p>“It’s really exciting to see a study exploring the connection between anatomy and behavior,” says <a href="https://dogs.arizona.edu/people/gitanjali-gnanadesikan">Gitanjali Gnanadesikan</a>, a cognitive biologist studying dog domestication at the University of Arizona who was not involved in the study. “In the process of domestication, both have changed in remarkable ways...and many of these changes are intertwined. Trying to understand how these different pieces fit together is extremely important.”</p><p>As eye-opening as the findings are, however, Gnanadesikan cautions that they raise “just as many questions as they answer...we still don’t know if these gazes contain information, or if dogs are intentionally trying to communicate with them.”</p>
            <figure class="richtext-image full-width"><img alt="iStock-871215928.jpg" class="richtext-image full-width" height="533" width="800"
            src="/wgbh/nova/media/images/iStock-871215928.width-800.jpg"/><figcaption><p>Wolves can twitch their brows, but those subtle movements are nothing compared to the heartwrenching stares of dogs. Image Credit: Nastasic, iStock</p><div class="credit"><p></p></div></figcaption>
            </figure>
            <p>Figuring that out, she says, will require more studies on how these heart-wrenching stares are used in different contexts. Dogged gazes may tug on our heartstrings, but it’s important not to attribute <i>too</i> much to our canine comrades.</p><p>Even so, the study underscores the importance of facial expressions in communication, Waller says. That seems obvious. But it’s nonetheless notable, she says, just how much humans’ penchant for emotion has shaped our interactions—with both our own species and others.</p><p>It may not have been intentional on our part, or theirs. Either way, these pooches’ expressive eyes continue to get them out of the doghouse. And for anyone who’s ever fed Fido scraps under the table, or forgiven the massacre of an unlucky shoe, it’s clear that these looks of longing have yet to lose their luster.</p><p>You sly dog, you.</p></div>
  

  
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<p>Wolves lack the facial muscles required to raise their eyebrows—a feature that makes dogs especially endearing to people.</p>

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