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<p>Scientists are using artificial cervices and 3D models of the uterus to better understand pregnancy and childbirth.</p>

How mechanical engineering could revolutionize the study of preterm birth

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<p>Leonardo da Vinci dissected some 30 cadavers in his lifetime, leaving behind a trove of beautiful—and accurate—anatomical drawings.</p>

Anatomy professor uses 500-year-old da Vinci drawings to guide cadaver dissection

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<p>A glimpse into the lives of the MOSAiC mission’s polar bear guards—and the powerful predators they watch for.</p>

How polar bear guards protect the largest Arctic expedition ever

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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. Launched in 2012, we feature in-depth articles and commentaries from some of the most respected journalists, scientists, and engineers. NOVA Next explores the ideas that are changing the future, from the frontiers of synthetic biology to the politics of personalized medicine.</p><p>Let us know what you think. We’re listening on <a href="http://www.facebook.com/NOVAonline">Facebook</a>, <a href="http://twitter.com/novapbs">Twitter</a>, and email.</p><p>If you’re a journalist and have an idea for a story, send it our way.</p>

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

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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"><h3>10. FDA approves first major new depression treatment in decades</h3><p>In March, the U.S. Food and Drug Administration approved a drug called esketamine, the first major new depression treatment to hit the market in decades. The drug is designed specifically for people suffering from the most extreme forms of treatment-resistant depression and is administered only in certified treatment centers via a nasal spray (rather than an oral pill). Esketamine is specifically for patients who have tried two other antidepressants with no success. </p><p>Janssen Research &amp; Development, the developer of the drug, hopes that by targeting the neurotransmitter glutamate, esketamine can offer rapid antidepressant effects, much like its cousin ketamine does. Experts’ opinions on the new drug, however, are split.</p><p><a href="https://www.pbs.org/wgbh/nova/article/fda-approves-first-major-new-depression-treatment-in-decades/">Read the full article</a>.</p><p></p>
            <figure class="richtext-image full-width"><img alt="warp-edge-on3.png" class="richtext-image full-width" height="450" width="800"
            src="/wgbh/nova/media/images/warp-edge-on3.width-800.png"/><figcaption><p>The Milky Way&#x27;s population of Cepheid stars suggests that our galaxy is a twisted disk. Image Credit: J. Skowron / OGLE / Astronomical Observatory, University of Warsaw</p><div class="credit"><p></p></div></figcaption>
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            <h3>9. A new 3D map of the Milky Way flaunts our galaxy’s warped shape</h3><p>If you ever thought the Milky Way was a flat, featureless pancake, think again. This summer, we learned that the Milky Way is bent out of shape. In fact, it seems to be warped into a wave much like a beach towel being shaken free of sand.</p><p>Finding definitive proof of the Milky Way’s warp was no simple task. While astronomers have gotten pretty good at snapshotting galaxies in more distant regions of the universe, here on Earth we don’t have the best vantage point to get a birds-eye view of the celestial structure that surrounds us: Just imagine trying to map a forest by being dropped down into its center.</p><p><a href="https://www.pbs.org/wgbh/nova/article/milky-way-3d-map-cepheids/?linkid=71919590">Read the full article.</a></p><p></p>
            <figure class="richtext-image full-width"><img alt="192854.jpg" class="richtext-image full-width" height="450" width="800"
            src="/wgbh/nova/media/images/GrapePlamsa-1-3.width-800.jpg"/><figcaption><p>Microwaving grapes is a surefire way to get your hands on some plasma—and an elevated risk of burning down your apartment. Image Credit: Hamza K. Khattak, Trent University; PNAS</p><div class="credit"><p></p></div></figcaption>
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            <h3>8. How does microwaving grapes create plumes of plasma?</h3><p>If you’ve been tempted ever to create some plasma—and potentially burn down your home in the process—we learned this year that grapes and a microwave are the ticket. </p><p>Or, alternatively, you can turn to YouTube and (safely) watch researchers as they puzzle out the physics behind DIY plasma. Spoiler: The result is a swarm of subatomic particles that clash and collide, often emitting roiling blobs of light and heat that can resemble molten fire.</p><p><a href="https://www.pbs.org/wgbh/nova/article/how-does-microwaving-grapes-create-plumes-plasma/">Read the full article</a>. </p><p></p>
            <figure class="richtext-image full-width"><img alt="33158147074_18622a1e57_o.jpg" class="richtext-image full-width" height="450" width="800"
            src="/wgbh/nova/media/images/33158147074_18622a1e57_o.width-800.jpg"/><figcaption><p>European robins make harrowing, cross-continental migrations to escape harsh winters. To guide their way, these birds and others may use quantum entanglement to &quot;read&quot; Earth&#x27;s magnetic field. Image Credit: Frank Vassen, flickr</p><div class="credit"><p></p></div></figcaption>
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            <h3>7. A bird’s eye view of quantum entanglement</h3><p>Every year, billions of birds make harrowing, cross-continental migrations. But how do they know where to go?</p><p>Scientists have known for a while that Earth’s magnetic field lends a helping hand. But this year, some researchers gleaned insight into how, suggesting that at some point in history, avian evolution tapped into quantum mechanics.</p><p><a href="https://www.pbs.org/wgbh/nova/article/birds-quantum-entanglement/?linkid=69249680">Read the full article</a>.</p><p></p>
            <figure class="richtext-image full-width"><img alt="kaiser4HR 2.jpg" class="richtext-image full-width" height="449" width="800"
            src="/wgbh/nova/media/images/kaiser4HR_2.width-800.jpg"/><figcaption><p>An artistic three-dimensional representation cyclo[18]carbon, a ring of 18 carbon molecules. Image Credit: IBM Research</p><div class="credit"><p></p></div></figcaption>
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            <h3>6. A new form of carbon is born—on a bed of salt</h3><p>In August, a new molecule called cyclo[18]carbon officially joined the carbon club. The creation, imaging, and analysis of cyclo[18]carbon helped settle decades of debate on the structure and properties of the molecule, which some researchers doubted could even be stably made in a laboratory setting.</p><p>Historically, researchers’ attempts to generate cyclocarbons in the lab resulted in volatile gas, too ephemeral to rigorously study. But the recent breakthrough shows that cyclocarbons can be generated by pruning carbon and oxygen atoms off a more complex molecule at extremely cold temperatures. Starting with a molecule made up of 24 carbons linked to six oxygens, researchers at IBM Research and Oxford University were able to generate a final structure of 18 carbons—the smallest possible ring of carbons predicted to be stable by theoretical models. </p><p><a href="https://www.pbs.org/wgbh/nova/article/cyclo18carbon/">Read the full article</a>.</p></div>
  

  
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            <figure class="richtext-image full-width"><img alt="ncs015__ct015__2018-05-19__16-03-59(5)__Silver backed chevrotain.JPG" class="richtext-image full-width" height="450" width="800"
            src="/wgbh/nova/media/images/Camera-trap_photo_of_silver-backed_chevrotain_.width-800.jpg"/><figcaption><p>A wild silver-backed chevrotain appeared! Image Credit: SIE/GWC/Leibniz-IZW/NCNP Copyright holder: Andrew Tilker</p><div class="credit"><p></p></div></figcaption>
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            <h3>5. Feast your eyes on the first-ever photos of a silver-backed chevrotain in the wild</h3><p>Once upon a time, there was a fanged, cat-sized deer-like creature with a glossy silver back. Then, like many legendary beasts, it was “lost to science.”</p><p>Until this November, that is. Though Western researchers have known about the skittish silver-backed chevrotain for more than a century, they’ve only managed to collect five specimens, all corpses obtained from hunters in Vietnam. The last of these appeared nearly three decades ago. But this year, with the help of local knowledge and a cluster of well-placed camera traps, Global Wildlife Conservation biologist Andrew Tilker and his team snapped the first-ever photos and videos of the silver-backed chevrotain in the wild.</p><p><a href="https://www.pbs.org/wgbh/nova/article/silver-backed-chevrotain-rediscovered-vietnam/?linkid=76835332">Read the full article</a>.</p><p></p><p></p>
            <figure class="richtext-image full-width"><img alt="38730047881_fdb7d67e94_o.png" class="richtext-image full-width" height="450" width="800"
            src="/wgbh/nova/media/images/38730047881_fdb7d67e94_o.width-800.png"/><figcaption><p>As Alzheimer&#x27;s disease progresses, communication between brain cells breaks down. New research suggests that one possible cause for this deterioration may be a brain infection by <i>Porphyromonas gingivalis, </i>a bacterium known for causing gum disease. Image Credit: National Institute on Aging/NIH, flickr</p><div class="credit"><p></p></div></figcaption>
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            <h3>4. Could Alzheimer’s begin with bacteria that cause gum disease?</h3><p>In individuals affected by Alzheimer’s disease, communication between brain cells breaks down over time. Early this year, a study suggested one peculiar potential cause for this deterioration: a brain infection by a bacterium known for causing gum disease.</p><p>In January, researchers reported that the bacterium, <i>Porphyromonas gingivalis</i>, might be capable of traversing the path from mouth to brain, where it can trigger chemical changes that damage cognitive function. These findings suggest that some cases of Alzheimer’s might have an infectious cause—and a new drug that blocks this process is now in clinical trials.</p><p><a href="https://www.pbs.org/wgbh/nova/article/alzheimers-bacteria-gum-disease/?no-cache=&amp;linkid=62727014">Read the full article</a>.</p><p></p><p></p>
            <figure class="richtext-image full-width"><img alt="iStock-500746894.jpg" class="richtext-image full-width" height="449" width="800"
            src="/wgbh/nova/media/images/iStock-500746894.width-800.jpg"/><figcaption><p>A complex tangle of social factors may encourage girls to prioritize verbal skills from a young age. But being excellent at reading doesn’t make a person bad at math—no matter their gender. Image Credit: Imgorthand, iStock</p><div class="credit"><p></p></div></figcaption>
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            <h3>3. Girls’ superb verbal skills may contribute to the gender gap in math</h3><p>Being excellent at reading doesn’t make a person bad at math—no matter their gender.</p><p>According to previous studies, including <a href="https://psycnet.apa.org/doiLanding?doi=10.1037%2Fa0021276">a meta-analysis</a> that probed gender differences in recent studies of mathematics performance, girls are just as good at math as boys are. But a complex amalgam of social factors may encourage girls to prioritize verbal skills from a young age, a study published in July suggests.</p><p>Drawing on data from more than 300,000 high school students from 64 countries, the study found that because girls’ verbal skills outshine their already high marks in math, many who do every bit as well as their male peers in mathematics still choose more humanities-centric careers.</p><p><a href="https://www.pbs.org/wgbh/nova/article/gender-gap-math-comparative-advantage/">Read the full article</a>.</p><p></p><h3>2. Six stupendous reasons to appreciate the heck out of squirrels</h3><p>Beady eyes, bushy tails, can’t lose: We’re talking squirrels. And whether you love these nut-crazed rodents or not, there’s no denying that despite being zany, squirrels are also aerodynamic and brainy.</p><p>On January 21, for Squirrel Appreciation Day, <i>NOVA</i> published a roundup of six squirrel facts—and it quickly became a fan favorite. So if you’re still in the dark about squirrel-induced electrical power outages, squirrels eating spring rolls, the power of squirrel memory, and how squirrels can give investment bankers a run for their money, here’s your ticket out.</p><p><a href="https://www.pbs.org/wgbh/nova/article/six-snippets-squirrel-science/">Read the full article</a>.</p><p></p><p></p>
            <figure class="richtext-image full-width"><img alt="iStock-878222138.jpg" class="richtext-image full-width" height="450" width="800"
            src="/wgbh/nova/media/images/iStock-878222138.width-800.jpg"/><figcaption><p>Now that&#x27;s a purrfect pair. Image Credit: AkilinaWinner, iStock</p><div class="credit"><p></p></div></figcaption>
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            <h3>1. Study finds kittens bond with their human caregivers like babies do</h3><p>Sorry, dogs: You may not be humans’ only faithful companions. Though cats have their critics, it turns out that they can be extremely social with other felines and humans alike.</p><p>In September, researchers revealed that much like human infants, cats are “attached” to their caretakers (and like babies, felines have different ways of expressing their attachment). When analyzing humans, dogs, and cats, the research team found that roughly 60 percent of infants or pets are “secure,” meaning they appear to use their caregivers as a safe base from which to explore their surroundings. Of the felines that seemed, well, insecure, fewer acted aloof or avoidant than one might expect.</p><p><a href="https://www.pbs.org/wgbh/nova/article/cats-secure-attachment/">Read the full article</a>.</p></div>
  

  
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<p>We’ve counted down our ten most-read articles of 2019 and found that health and medicine, physics—and of course animals—were fan-favorite topics this year.</p>

The 10 most popular NOVA stories of 2019





  
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      <div class="rich-text"><p>Have you ever wondered why the first cold day of fall feels so much colder than a day the exact same temperature at the end of the winter? It’s not just a matter of perspective: Your body really is more prepared for cold conditions at certain times of the year—thanks to a mysterious form of fat.</p><p>When you experience cold, your body responds in a few noticeable ways. Your blood vessels constrict—a process called vasoconstriction—taking blood away from your extremities and keeping it near your core. And you shiver, meaning certain muscles start shaking to produce heat. But shivering also triggers the release of a hormone called irisin, which jump-starts a lesser-known cold weather response: the activation and buildup of brown fat.</p><p>Brown adipose tissue, or brown fat, is different from the white fat we might think of when discussing diet or weight loss. White fat lines our skin and muscles, cushioning our organs and bones. But brown fat appears only in specific areas around the neck, spine, aorta, and kidneys. It builds up in clumps around major blood vessels, warming the blood as it passes through the body. “If vasoconstriction is closing the window, brown fat is turning on the heater,” says Yossi Rathner, a physiologist at the University of Melbourne.</p><p>We don’t create enough brown fat to cause noticeable weight gain, but the small deposits are still powerful thanks to their high concentration of energy-creating mitochondria. Instead of burning calories to produce energy to power the body, the mitochondria in brown fat burn calories to produce heat. By acting like little heating stations for blood vessels, these soft clumps of insulation help us deal with the cold more efficiently than shivering, which expends a lot of energy, and vasoconstriction, which puts us at risk of frostbite.</p></div>
  

  
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      <div class="rich-text"><p>“Your body goes from a rickety radiator to a smooth central heating system by the end of the winter,” says Francesco S. Celi, a professor of medicine at Virginia Commonwealth University.</p><p>But the effect only lasts for as long as we need it. When the temperature warms up, brown fat fades away. “If we are not exposed to the cold, the brown fat will atrophy,” says Barbara Cannon, a physiologist at Stockholm University. “There may be a few stem cells left in the area for later regeneration, but it will nearly disappear,” Cannon says.</p><p>Even a one-month tropical vacation is enough to deplete one’s brown fat reserves, Celi says, creating that “extra cold” sensation a traveler might feel upon returning to a cold climate.</p><p>You could say brown fat is winter&#x27;s undercover hero, dropping in when we need it most, and disappearing once the job is done. So, the next time a chilly day leaves you shivering, just remember help is on the way.</p></div>
  

  
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<p>Shivering can activate a series of “heating stations” for your blood vessels—but they take a little while to get up and running.</p>

How “brown fat” helps you cope with cold weather





  
      <div class="rich-text"><h3>1. <i>New Horizons</i> nails the most distant flyby in history</h3><p>Just 33 minutes after ringing in the New Year, scientists at the Johns Hopkins University Applied Physics Laboratory cheered and threw confetti a second time. The<a href="https://www.pbs.org/wgbh/nova/article/new-horizons-ultima-thule-preview/"> <i>New Horizons</i></a> spacecraft had just conducted a flyby of a Kuiper Belt object 4 billion miles from Earth. And as the sun rose on January 1, <i>New Horizons</i> beamed back its first close-up images of the 19-mile-long peanut-shaped space rock, officially named 2014 MU69.</p></div>
  

  
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      <div class="rich-text"><p>Images eventually revealed 2014 MU69 (initially nicknamed “Ultima Thule”), to be a <a href="https://www.pbs.org/wgbh/nova/article/so-long-snowman-ultima-thule-flatter-we-thought/">surprisingly flat</a> “<a href="https://www.pbs.org/wgbh/nova/article/ultima-thule-is-a-kiss-between-two-rocky-lobes/">contact binary</a>,” a body composed of two once-separated rocks that slowly gravitated toward each other until they lightly touched and fused. Scientists believe the flyby data could offer insight into how planets formed in our solar system billions of years ago.</p><p>In November, NASA changed the rock’s nickname from Ultima Thule, a term <a href="https://www.newscientist.com/article/2223176-distant-space-rock-known-as-ultima-thule-renamed-to-avoid-nazi-links/">with links to</a> the Nazi party, to “Arrokoth,” which means “sky” in the Powhatan/Algonquian language.</p>
            <figure class="richtext-image full-width"><img alt="Ultima Thule Comes Into Focus as New Images Reveal Secrets Hero" class="richtext-image full-width" height="450" width="800"
            src="/wgbh/nova/media/images/ultima-thule-comes-into-focus-as-new-images-re.width-800.jpg"/><figcaption><p>2014 MU69 is revealed to be a two-tiered snowman. According to the New Horizons team, this image supports the idea that planets in our system formed as bits of raw planetary matter coalesced over time. Image Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute</p><div class="credit"></div></figcaption>
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            <h3>2.    A second HIV patient enters long-term remission</h3><p>Twelve years after a first patient was declared to be rid of HIV, another person achieved a similar milestone this year. In March, with the help of a stem cell transplant from a virus-resistant donor, the anonymous individual entered long-term<a href="https://www.pbs.org/wgbh/nova/article/second-patient-has-entered-long-term-remission-hiv/"> remission from HIV</a>.</p><p>In both cases, remission followed a transplant of bone marrow from a person with a mutation in the gene that encodes the protein CCR5, which many HIV strains use to infiltrate cells. Neither treatment was originally intended to eliminate the infection itself, but to treat blood cancers that had spread in both individuals.</p><p>While the intervention is likely to be effective in only a small fraction of HIV-positive individuals, the 2019 case shows that its efficacy was more than a one-time event.</p><p></p><h3>3. Scientists reveal the first-ever black hole image</h3><p>In April, we were able to feast our eyes on the <a href="https://www.pbs.org/wgbh/nova/article/first-black-hole-image/">first-ever image</a> of a black hole. The black hole, whose image was generated from data captured by a network of eight radio observatories that make up the Event Horizon Telescope, dwells in the center of a galaxy some 55 million light-years away from Earth.</p><p>As popular as the black hole image was, another aspect of the story that quickly unfolded online: the contribution of 29-year-old MIT scientist Katie Bouman, who crafted an algorithm to help translate the telescope data into the black hole image. Bouman, captured in a photo with a laptop, beaming behind her folded hands,<a href="https://www.pbs.org/newshour/science/katie-bouman-hardly-knew-what-a-black-hole-was-her-algorithm-helped-us-see-one"> quickly became a symbol</a> for women’s accomplishment in astronomy and computer science. But, Marina Koren writes for<a href="https://www.theatlantic.com/science/archive/2019/04/katie-bouman-black-hole/587137/"> <i>The Atlantic</i></a>, “This one image tapped into a multitude of questions about the role of women in science, the myth of the lone genius, and the pressure scientists have to promote themselves and their work on social media.”</p><p>“No one algorithm or person made this image,” Bouman later wrote, referring to the black hole picture, in a Facebook post. “It required the amazing talent of a team of scientists from around the globe and years of hard work to develop the instrument, data processing, imaging methods, and analysis techniques that were necessary to pull off this seemingly impossible feat.” </p><p></p><h3>4. First CRISPR clinical trials in the U.S. take place</h3><p></p>
            <figure class="richtext-image full-width"><img alt="CRISPR-large.jpg" class="richtext-image full-width" height="449" width="800"
            src="/wgbh/nova/media/images/CRISPR-large.width-800.jpg"/><figcaption><p>CRISPR-Cas9 is a tool that lets scientists cut and insert small pieces of DNA at precise areas along a DNA strand. | Photo credit: Public Domain</p><div class="credit"><p></p></div></figcaption>
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            <p>In April, researchers began the first CRISPR-Cas9 gene-editing clinical trials in people in the United States. In the trials, scientists used<a href="https://www.pbs.org/wgbh/nova/video/what-is-crispr-gene-editing/"> CRISPR</a>, a powerful gene-editing technique derived from an ancient bacterial immune system, to combat cancer and blood disorders. That month, two cancer patients—one with myeloma and one with sarcoma—were <a href="https://www.npr.org/sections/health-shots/2019/04/16/712402435/first-u-s-patients-treated-with-crispr-as-gene-editing-human-trials-get-underway">treated using CRISPR</a>.</p><p>In the cancer and blood disorder trials, researchers remove some cells from a patient’s body, edit the cells’ DNA using CRISPR, and inject the cells back in, “now hopefully armed to fight disease,” Tina Hesman Saey writes for<a href="https://www.sciencenews.org/article/crispr-gene-editor-first-human-clinical-trials"> <i>Science News</i></a>. But in another trial, conducted by Editas Medicine in Cambridge, Mass., researchers are using CRISPR to edit DNA directly in the human body by “snipping a small piece of DNA out of cells in the eyes of people with an inherited form of blindness,” Saey writes.</p><p>The trials come on the heels of Chinese scientist He Jiankui’s gene-editing on twin girls born in November 2018, which was widely criticized as premature and<a href="https://www.pbs.org/wgbh/nova/article/crispr-gene-editing-live-births/"> highly unethical</a>. . </p><p></p><h3>5. New fossils capture the day the dinosaurs died—and the million years after</h3><p></p>
            <figure class="richtext-image full-width"><img alt="Mammal Fossils Fill in Missing Piece of the Timeline of Life Hero" class="richtext-image full-width" height="450" width="800"
            src="/wgbh/nova/media/images/mammal-fossils-fill-in-missing-piece-of-the-ti.width-800.jpg"/><figcaption><p>Mammal fossils like this one, discovered by a team of paleontologists and paleobotanists led by Tyler Lyson in Corral Bluffs, Colorado, fill in a missing piece of the timeline of life. Image Credit: HHMI Tangled Bank Studios </p><div class="credit"></div></figcaption>
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            <p>This year, scientists gleaned new insight into the day the dinosaur-killing asteroid crashed into Earth 66 million years ago, and the first million years after the impact.</p><p>In April, paleontologist and graduate student Robert DePalma claimed to unveil an<a href="https://www.pbs.org/wgbh/nova/article/new-fossils-mass-extinction-wiped-out-dinosaurs/"> unprecedented time capsule</a> of the asteroid-induced catastrophe. He reported finding scorched tree trunks and hundreds of well-preserved fossil fish beneath sediment at a site in North Dakota, forming a snapshot of the <a href="https://www.pbs.org/wgbh/nova/video/fossil-discovery-could-offer-glimpse-into-day-the-dinos-died/">first minutes and hours</a> after impact. (Some experts remain cautious about the finding, due in part to the fact that DePalma’s discovery was first announced in a <i>New Yorker</i> article before publication of the peer-reviewed paper.)</p><p>Then, in October,<a href="https://www.pbs.org/wgbh/nova/article/fossils-million-years-after-dinosaurs-died/"> new fossils</a> that capture the million-year timeline of life after the dinosaurs died were revealed. Discovered in Colorado’s Corral Bluffs by paleontologist Tyler Lyson and his team, the fossils showcase the extraordinary resilience of life in the wake of disaster and help reveal the evolutionary journey of<a href="https://www.pbs.org/wgbh/nova/video/rise-of-the-mammals/"> the mammals</a> that survived the asteroid.</p></div>
  

  
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      <div class="rich-text"><h3>6. Racism persists in medicine and science</h3><p>With the use of artificial intelligence on the rise, one serious flaw continued to make headlines in 2019: <a href="https://www.vice.com/en_us/article/8xzwgx/racial-bias-in-ai-isnt-getting-better-and-neither-are-researchers-excuses">racial bias</a>. In October, researchers announced that a particular algorithm, which predicts who might benefit from follow-up care and affects 100 million Americans, underestimates black patients’ need for additional treatment. The algorithm <a href="https://www.pbs.org/wgbh/nova/article/racial-bias-medical-algorithm-black-patients/">underestimates the health needs</a> of black patients even when they’re sicker than their white counterparts.</p><p>Additionally, the U.S. remains one of the most dangerous developed nations in which to be pregnant and give birth, particularly for minorities. “Pregnancy-related deaths are rising in the United States and the main risk factor is being black,” Mike Stobbe and Marilynn Marchione write for <a href="https://apnews.com/4907da5c58c84a708a548c4ea18fc5c7"><i>AP News</i></a>. A CDC report concludes “black women, along with Native Americans and Alaska natives, are three times more likely to die before, during or after having a baby, and more than half of these deaths are preventable,” Stobbe and Marchione write.</p><p>Also this year, researchers further investigated why black scientists are less likely to receive funding from the National Institutes of Health (NIH) than their white counterparts. A study published in October illustrated that topic choice contributes to the lower rates of NIH awards going to black scientists. “Specifically,” Jeffrey Mervis writes for <a href="https://www.sciencemag.org/news/2019/10/study-identifies-key-reason-black-scientists-are-less-likely-receive-nih-funding"><i>Science Magazine</i></a>, “black applicants are more likely to propose approaches, such as community interventions, and topics, such as health disparities, adolescent health, and fertility, that receive less competitive scores from reviewers.” </p><p></p><h3>7. A new link is drawn between humans and Denisovans</h3><p></p>
            <figure class="richtext-image full-width"><img alt="Denisova_Phalanx_distalis.jpg" class="richtext-image full-width" height="449" width="800"
            src="/wgbh/nova/media/images/Denisova_Phalanx_distalis_9gGhHID.width-800.jpg"/><figcaption><p>A replica of a fragment of a Denisovan finger found in Denisova Cave, Siberia, in 2008. Image Credit: Thilo Parg, Wikimedia Commons</p><div class="credit"><p></p></div></figcaption>
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            <p>New findings in 2019 added to anthropologists’ understanding of Denisovans, a species of early human that likely shared the planet with <i>Homo sapiens</i> as recently as 50,000 years ago.</p><p>This fall, scientists learned that although Denisovans’ DNA ties them more closely to Neanderthals, their fingers may have looked<a href="https://www.pbs.org/wgbh/nova/article/denisovan-finger/"> more like ours</a>, suggesting Neanderthals’ broader digits evolved after their lineage split off from the Denisovans around 410,000 years ago. “A few more fossils,” Bruce Bower writes for<a href="https://www.sciencenews.org/article/mysterious-denisovan-hominid-fossils-dna-top-science-stories-2019-yir"> <i>Science News</i></a>, “plus genetic analyses indicated Denisovans were close relatives and occasional mating partners of Neanderthals and <i>Homo sapiens</i> tens of thousands of years ago. But there was too little evidence to say what Denisovans looked like or how they behaved.”</p><p></p><h3>8. Google claims quantum supremacy</h3><p>Physicists reached a milestone in <a href="https://www.pbs.org/wgbh/nova/video/six-ways-quantum-computers-could-change-the-world/">quantum computing</a> this year, a method of computing that uses quantum physics to solve complex problems quickly. </p><p>In October, Google said it had achieved “<a href="https://www.pbs.org/wgbh/nova/article/google-quantum-supremacy/">quantum supremacy</a>.” Its AI Quantum Team presented evidence that it had built a quantum computer that needs only 200 seconds to solve a problem that would have taken IBM’s Summit, the world’s most powerful supercomputer, 10,000 years to crack. Though IBM disputed the claim, others in the computing community are tentatively optimistic about the breakthrough’s promise. If validated, it may bring us closer to a future of ultra-efficient computing.</p><p></p><h3>9. Saturn now has the most moons in the solar system</h3><p></p>
            <figure class="richtext-image full-width"><img alt="saturns-rings" class="richtext-image full-width" height="450" width="800"
            src="/wgbh/nova/media/images/saturns-rings.width-800.jpg"/><figcaption>
  Saturn, as viewed from NASA’s Cassini spacecraft during its 2009 equinox.
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            <p>Just when you thought Saturn couldn’t get <a href="https://www.pbs.org/wgbh/nova/video/saturn-facts-ringed-gas-giant-planet/">any more awesome</a>, it secured yet another claim to fame: <a href="https://www.pbs.org/wgbh/nova/article/saturn-20-new-moons/">the most known moons</a> of any planet in our solar system (sorry, Jupiter). </p><p>On October 7, the International Astronomical Union’s Minor Planet Center announced that researchers discovered an additional 20 moons orbiting Saturn, bringing its grand total to a whopping 82. Jupiter, the <a href="https://www.pbs.org/wgbh/nova/video/jupiter-facts-biggest-planet-solar-system/">largest and oldest planet</a> in our solar system, has 79.</p><p>The latest discoveries were made possible by Hawaii’s Subaru telescope. A team led by Carnegie Science’s Scott S. Sheppard <a href="https://sites.google.com/carnegiescience.edu/sheppard/home/newjupitermoons2018?authuser=0">first eyed them</a> in the spring of 2017, but because faraway moons are dim and tough to spot, researchers used Subaru to scan the skies periodically throughout the following years to confirm their finding. Then, they used a computer algorithm to link the data through time and confirm that the moons were indeed reliably orbiting Saturn.</p><p></p><h3>10. Climate change intensifies, and youth fight back </h3><p></p>
            <figure class="richtext-image full-width"><img alt="glacier_2048x1152" class="richtext-image full-width" height="450" width="800"
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  Retreating glaciers are slowly raising Earth's sea levels.
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            <p>Less than a week after the U.N. climate talks came to a close in Madrid this month, Australia recorded its <a href="https://www.theguardian.com/australia-news/2019/dec/19/419c-australia-records-hottest-ever-day-one-day-after-previous-record?utm_source=dlvr.it&amp;utm_medium=facebook">hottest day ever</a>, one day after its previous record. Just a few months ago, wildfires raged across not only the <a href="https://www.nationalgeographic.com/science/2019/12/how-will-california-prevent-more-mega-wildfire-disasters/">American West</a> and Australian Outback but also <a href="https://www.nationalgeographic.com/science/2019/12/how-to-live-with-mega-fires-portugal-forests-may-hold-secret/">Europe</a> and the <a href="https://www.usatoday.com/story/news/nation/2019/10/18/amazon-rainforest-still-burning-more-fires-future/4011238002/">Amazon</a>, an occurrence that many climatologists believe may have been exacerbated by <a href="https://grist.org/justice/wildfires-are-getting-worse-and-so-is-the-deadly-smoke-they-bring-with-them/">climate change</a>-induced drought and high temperatures. And in May, a United Nations report claimed that one million plant and animal species are on the verge of extinction—more than in any other period in human history—with alarming implications for human survival. The warming climate, which heightens the effects of overfishing, pesticide use, pollution, and urban expansion is <a href="https://www.washingtonpost.com/climate-environment/2019/05/06/one-million-species-face-extinction-un-panel-says-humans-will-suffer-result/">a major driver</a>, the report concludes. </p><p>Three weeks ago, a “bleak” climate report, also from the U.N., predicted that global carbon emissions will climb “despite promises from almost 200 nations to address climate change, propelling temperatures upward and threatening to shatter the threshold of 2°C that scientists say would invite dramatic changes to ecology and the economy,” Nathaniel Gronewald writes for <a href="https://www.sciencemag.org/news/2019/11/new-un-climate-report-offers-bleak-emissions-forecast"><i>Science Magazine</i></a>. And many declared this month’s COP25 climate talks to be <a href="https://earther.gizmodo.com/how-to-fix-the-biggest-issue-plaguing-un-climate-talks-1840480211">a massive failure</a>.</p><p>But climate activists, particularly teens, have seized the spotlight this year. Greta Thunberg, a 16-year-old Swedish climate activist, was just named <a href="https://www.nytimes.com/2019/12/11/business/media/time-person-of-the-year-greta-thunberg.html"><i>TIME’s</i> Person of the Year</a>. And at COP25, official youth constituency representatives expressed their disappointment to leaders and officials, Kartik Chandramouli writes for <a href="https://india.mongabay.com/2019/12/youth-rising-at-cop25-they-came-they-protested-they-negotiated/"><i>Mongabay</i></a>. “Do you want to be remembered as the ones who had the chance to act but decided not to as betrayers of our generation, of indigenous people and communities desperately fighting on the ground?” Youth representatives said. “We are rising, we are fighting and we will win.”</p></div>
  

  
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<p>Black holes, gene editing, and quantum computing wowed us—while new climate findings and racial bias in medicine brought renewed urgency.</p>

The top 10 science stories of 2019





  
      <div class="rich-text"><p>Having already staked its claim in our solar system as the largest planet, Jupiter now stands out from its planetary kin for another reason: its shape-shifting magnetic field. </p><p>In a <a href="https://www.nature.com/articles/s41550-019-0772-5">recent study</a>, researchers compared observations of Jupiter’s magnetic field from NASA’s Juno spacecraft with those taken by Pioneer 10, Pioneer 11, Voyager 1, and Ulysses. They found that Jupiter’s field had changed in just a few short decades—a phenomenon known as secular variation. </p></div>
  

  
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      <div class="rich-text"><p>One theory for the variation over time points to zonal winds—large storm systems in Jupiter’s atmosphere that extend to over 1,800 miles deep. At this depth, the <a href="https://www.pbs.org/wgbh/nova/article/jupiter-core-collision/">hydrogen inside Jupiter</a> is under so much pressure and at such high temperatures that it behaves like the molten iron in Earth’s core to produce a magnetic field. </p><p>“If the [zonal] winds are that deep, they would distort the magnetic field,” says Eli Galanti, a planetary scientist at the Weizmann Institute of Science, who was not involved in the study but researches these disturbances using gravity measurements. Galanti says Moore’s research shows that changes in flow could explain the historical movements of the magnetic field.</p><p>If these storms interfere with the flow of hydrogen, they could also explain why Jupiter’s magnetic field has such a peculiar “shape.” </p><p>Earth’s magnetic field is often represented with a simple bar magnet, but Jupiter’s field, according to <a href="https://www.nature.com/articles/s41586-018-0468-5">data compiled</a> from Juno in 2018, seems to be much more complex. </p><p>Magnetic field visualizations typically use a range of colors to represent the nature of a planet’s field: Shades from red to yellow illustrate where the field emerges, and shades from green to blue show where it reenters. Using this convention, Earth’s South Pole is painted red and the North Pole is blue. </p><p>Jupiter’s magnetic field is not as demarcated. It resembles a bruised peach with two distinct, deep blue blotches against swaths of red and yellow. </p>
            <figure class="richtext-image full-width"><img alt="PIA23229_modest.jpg" class="richtext-image full-width" height="433" width="769"
            src="/wgbh/nova/media/images/PIA23229_modest.width-800.jpg"/><figcaption><p>How Jupiter&#x27;s magnetic field appears at a single moment in time. Image Credit: NASA/JPL-Caltech/Harvard/Moore et al.</p><div class="credit"></div></figcaption>
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            <p>Rather than originating from Jupiter’s true north, the Jovian magnetic field springs from a broader band lower in the northern hemisphere. Arguably more intriguing is Jupiter’s southern hemisphere. Juno’s data suggest the planet’s magnetic field arcs out from magnetic north and returns through two different points, one near the south pole and another just below the equator. Researchers affectionately name this concentrated southerly zone the Great Blue Spot, an homage to Jupiter’s famous <a href="https://www.missionjuno.swri.edu/jupiter/great-red-spot/">Great Red Spot</a>.</p><p>Before Juno, astronomers had a limited view of Jupiter. Kimberly Moore, a graduate student at Harvard University who led both the recent study and last year’s data compilation, says that Earth’s magnetic field is like that produced by a tilted dipole, or an axis with opposite magnetic polarity on each end. “But (for Jupiter) we are learning you can’t use such a simple picture,” Moore says.</p><p>“We are looking at a completely different Jupiter than the one that was anticipated a few years ago,” says Mohamed Zaghoo, a research scientist at the Laboratory for Laser Energetics at the University of Rochester who was not involved in the study. </p><p>“The amazing thing about Jupiter is that because it’s a gaseous planet there is no crust to obscure our measurements of the planet’s dynamo (the engine that drives the magnetic field),” Zaghoo says. In Earth—about two-thirds of the way into the planet’s interior at the core-mantle boundary—molten iron constantly moves and creates electric currents that generate the magnetic field we observe at the surface.</p></div>
  

  
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      <div class="rich-text"><p>In contrast, Jupiter doesn’t have a firm surface and is largely composed of hydrogen, which does not ordinarily conduct electricity as a gas. However, under the planet’s extreme pressure, liquid metallic hydrogen forms, named for its ability to conduct electric currents like metals do. </p><p>Metallic hydrogen circulates inside Jupiter due to the convection currents created by the difference between high internal temperatures and lower outer temperatures. This constant churning is believed to generate electric currents inside Jupiter, which in turn produce the magnetic field measured by Juno.</p><p>The irregular pattern of the magnetic field might be explained by the changing properties of metallic hydrogen as it descends deeper inside the planet. “You can think of it like you’re diving down an ocean, where different layers have different densities and conductivities,” says Zaghoo. In his work, Zaghoo recreates the conditions of hydrogen at different depths in Jupiter and compares how observations here on Earth line up with models made from the space mission.  </p><p>But studying the flow of metallic hydrogen might not tell the whole story. Other, more stable layers of fluid deep inside Jupiter could also be responsible for the magnetic field, Moore and her colleagues suggest. If these layers contain heavier elements like helium, they might divert the flow of electric currents and consequently alter the magnetic fields that radiate from within. </p><p>“So far Juno has provided more questions than answers.” says Zaghoo. “The biggest lesson we’ve learned from Juno is humility.”</p><p>As the space probe continues orbiting Jupiter, it might offer more clues to its magnetic mystery. Juno will keep gathering information until July 2021, when it will plunge toward Jupiter and disintegrate in the planet’s atmosphere. </p><p>In the meantime, scientists like Moore hope to glean as much information as they can about Jupiter’s magnetic field.</p><p>“The magnetic field is much stronger and generated much closer to the surface on Jupiter than on Earth,” Moore says. “The insights we are getting into how these fields are generated on Jupiter might help us understand how they are generated here on Earth.”</p></div>
  

  
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<p>In 2018 and 2019, data from NASA’s Juno mission revealed new discoveries about Jupiter’s bizarre magnetic field.</p>

What’s up with Jupiter’s wandering magnetic field?





  
      <div class="rich-text"><p>When Keith Rose joined the Occupy St. Louis movement in 2011, he didn&#x27;t heed the advice of a fellow demonstrator to wear bandanas to cover his face. The police had cameras out, but Rose didn&#x27;t think they were doing much with the photos they were taking.</p><p>When he joined the Ferguson protests a few years later, it seemed to him that law enforcement had indeed started to put together a file on him. He had not been arrested at that point, but after a few run-ins with police where they knew things like where he had been, who he had been with, or what he had said, he thought it seemed pretty clear that they were monitoring him.</p></div>
  

  
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      <div class="rich-text"><p>&quot;It really upset me and got me more concerned with surveillance,&quot; Rose says.</p><p>During the protests, the St. Louis Metropolitan Police Department opened a surveillance hub called the Real Time Crime Center (RTCC). This data center aggregates information gathered through technologies like license plate readers, sensors that can detect and locate gunfire, and cameras spread across the city. Most of RTCC, as well as much of the technology that powers it, was not funded by the city, but through grants and public-private partnerships with companies like Motorola. That approach, according to the American Civil Liberties Union (ACLU), allowed the police department to <a href="https://www.aclu.org/blog/privacy-technology/surveillance-technologies/how-shift-power-police-people">sidestep going to the city&#x27;s elected Board of Aldermen</a> for approval and city funds.</p><p>&quot;It&#x27;s really disturbing what this says about the future of big tech being able to expand its own power,&quot; Rose says.</p><p>But with an effort called <a href="https://www.aclu.org/issues/privacy-technology/surveillance-technologies/community-control-over-police-surveillance?redirect=feature/community-control-over-police-surveillance">Community Control Over Police Surveillance</a> (CCOPS), the ACLU is attempting to give citizens more control over the technology that police could use to monitor them. Launched in 2016, CCOPS aims to help local communities draft and pass laws giving them oversight of any surveillance technology that law enforcement agencies or the government want to deploy.</p><p>The ACLU works with local lawmakers to craft each law, changing it to meet the community&#x27;s specific needs. A dozen cities, plus San Francisco&#x27;s BART system, have passed CCOPS laws. In addition to St. Louis, at least another dozen cities, plus the state of Maine, are in the process of adopting their own versions of the law.</p><p>St. Louis Alderman John Collins-Muhammad helped <a href="https://www.stlouis-mo.gov/government/city-laws/board-bills/boardbill.cfm?bbDetail=true&amp;BBId=10831&amp;fbclid=IwAR2dISUYbLnHGl-n7Tys97ijbIKg8rbMMWR9xdxZZI24kjj1o0bZZoFWTPU">introduce CCOPS legislation</a> in 2017 and 2018, and recently <a href="https://www.stlouis-mo.gov/government/city-laws/board-bills/boardbill.cfm?bbDetail=true&amp;BBId=13371">reintroduced</a> an updated version. Collins-Muhammad said that he and the rest of the Board got community input and updated each iteration. He thinks the latest version of the bill will pass this year. The law would create a process for board approval of any new surveillance technology, require annual reports for equipment purchases, strengthen sunshine laws around law enforcement data, and call for publishing crime reduction statistics. The bill tries to balance the concerns of both the public and the police, Collins-Muhammad says.</p><p>&quot;We don&#x27;t want to invade privacy,&quot; he says. &quot;But we also don&#x27;t want to limit the police in doing their jobs.&quot;</p><p>The St. Louis Metropolitan Police Department has also contributed comments on the bill and has been supportive of it in general, Collins-Muhammad says. In a statement, Keith Barrett, a sergeant with ‎the Department, said that civil liberties and surveillance technology can coexist if used in a responsible manner while still helping police do their job.</p><p>“The advancement of technological resources continues to allow our department to deter, document, and reduce crime,” Barrett says. “The technology that is deployed continues to aid our efforts to prevent crime and apprehend criminals. We look forward to working with all our community partners in ensuring transparency and accountability.”</p><p>Privacy Watch, a group of nonprofits in St. Louis, took part in the discussion around the bill. It wanted the law to address issues related to bias with the technology, privacy, freedom of speech, and the cost to taxpayers.</p><p>&quot;There are so many layers of concern,&quot; says Kendra Tatum, a St. Louis resident and an organizer for the Organization for Black Struggle, a member group of Privacy Watch. &quot;People refer to the phrase ‘Big Brother’ jokingly a lot, but we all know that this type of stuff happens.&quot;</p><p>Collins-Muhammad says he knows the threat personally, having experienced surveillance when he was an activist during the Ferguson protests. He said it was “scary” and got him interested in creating policy that could limit that experience for others in the future.</p><p>&quot;This is something very important to me,&quot; he says.</p><h3><b>An AI Panopticon</b></h3><p>While the Real Time Crime Center doesn&#x27;t use AI-powered tools yet, it is technically easy to overlay face recognition software after cameras are in use. The proposed CCOPS legislation in St. Louis wouldn&#x27;t outlaw the technology, but would require law enforcement to go through the Board of Aldermen if they want to use it.</p><p>AI-powered surveillance technology has <a href="https://carnegieendowment.org/publications/interactive/ai-surveillance">spread across the world quickly</a>. ACLU&#x27;S <a href="https://www.aclu.org/report/dawn-robot-surveillance">Dawn of Robot Surveillance</a> report points out that this is occurring as camera technology is improving with higher resolution and night-vision capabilities. At the same time, more cities are installing centralized surveillance systems, with about <a href="https://www.sdmmag.com/articles/92407-rise-of-surveillance-camera-installed-base-slows">350 million surveillance cameras</a> across the world in 2016.</p>
            <figure class="richtext-image full-width"><img alt="surveillance2.jpg" class="richtext-image full-width" height="450" width="800"
            src="/wgbh/nova/media/images/surveillance2.width-800.jpg"/><figcaption><p>With artificial intelligence, a lot of surveillance work can be automated, making AI game-changing technology. Image Credit: iStock, andreusK</p><div class="credit"></div></figcaption>
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            <p>The potential of facial recognition technology is perhaps most prominently on display in China. The government not only uses it to give out traffic tickets, and has passed laws mandating face scans for those signing up for internet or a new phone number, but has put it to work <a href="https://www.nytimes.com/2019/04/14/technology/china-surveillance-artificial-intelligence-racial-profiling.html">monitoring and imprisoning the Uighur minority</a>. By 2020, China plans to have more than <a href="https://www.cbsnews.com/news/china-social-credit-system-surveillance-cameras/">600 million cameras operating</a>.</p><p>Beyond concerns over increased surveillance, facial recognition software has been shown to perform less well on dark skin. In a 2018 report called &quot;<a href="http://gendershades.org/">Gender Shades</a>,&quot; researchers Joy Buolamwini and Timnit Gebru found that three commercially available systems performed no better than chance at identifying women with darker skin tones.</p><p>The ACLU did its own study showing that Rekognition, Amazon&#x27;s face recognition software, <a href="https://www.aclu.org/blog/privacy-technology/surveillance-technologies/amazons-face-recognition-falsely-matched-28">misidentified 28 members of Congress</a>. Forty percent of the algorithm’s mistakes were made in attempting to identify people of color, even though they make up only 20 percent of Congress. Amazon disputed the study and showed that with the recommended higher confidence threshold, which only lets the algorithm offer up matches if it is very sure it is right, the misidentifications disappear. However, one of the police departments<a href="https://gizmodo.com/defense-of-amazons-face-recognition-tool-undermined-by-1832238149">testing the software admitted</a> to not setting any confidence threshold.</p><p>That isn&#x27;t the only case of police departments using software in a way that the developers didn&#x27;t intend. A study by Georgetown Law Center on Privacy and Technology <a href="https://www.flawedfacedata.com/">found that police fed celebrity photos</a> into face recognition software, along with sketches and photoshopped images.</p><p>There is a long history of surveillance in the U.S. according to Matt Cagle, an attorney at the ACLU of Northern California. Public and civil rights groups like the ACLU have fought against much of it, with varying levels of success. With AI, however, a lot of surveillance work can be automated, making AI game-changing technology.</p><p>&quot;If they can watch us, they can control us,&quot; Cagle says.</p><p>In fact, the face recognition conversation can be part of the larger conversation about government surveillance according to Chad Marlow, a senior advocacy and policy counsel at the ACLU, who is also overseeing CCOPS. The proliferation of technology like surveillance cameras and Stingrays—which mimic cell phone towers and send out signals that trick nearby phones into transmitting identifying information and data about their locations—can be reevaluated. Also, anything new developed, with or without AI capabilities, can be integrated in a way that the community is aware of and has some control over.</p><p>“In that way, we aren’t playing whack-a-mole,” Marlow says.</p></div>
  

  
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      <div class="rich-text"><h3><b>Drawbacks of Bans</b></h3><p>Four cities have gone further than community oversight with their CCOPS laws: Berkeley, Oakland, San Francisco, and Somerville, Massachusetts have outright banned face recognition by the government. Earlier this year, the ACLU, along with another 60 groups, <a href="https://www.aclu.org/letter/coalition-letter-calling-federal-moratorium-face-recognition">sent a letter to Congress</a> asking for a federal moratorium on the use of facial recognition for law enforcement and immigration enforcement until Congress fully debates which practices should be allowed.</p><p>“This capability threatens to create a world where people are watched and identified as they attend a protest, congregate outside a place of worship, visit a medical provider, or simply go about their daily lives,” the letter said.</p><p>But Daniel Castro, vice president of the Information Technology and Innovation Foundation and director of the Center for Data Innovation, says cities could also end up blocking better potential uses of face recognition tools out of fear of a surveillance state.</p><p>&quot;We&#x27;re not there yet,&quot; he says. &quot;A lot of the concerns there are premature.&quot;</p><p>Other law enforcement applications of the technology, like finding suspects or missing children, can be made safer with laws that create guardrails, like establishing accuracy rates for any software used. The areas that do matter get conflated with broader issues, like whether the police should be surveilling protestors at all, Castro said.</p><p>&quot;We can separate some of these issues without banning the technology,&quot; he says.</p><p>CCOPS laws only regulate government use of technology, and don&#x27;t stop private companies from using it. St. Louis has a handful of businesses, like corner stores, using cameras run by a local company called Blue Line Technology that says it <a href="https://www.kmov.com/news/local-former-cops-create-facial-recognition-technology-to-fight-crime/article_e7694d3a-7689-11e9-ab41-939fb5bbfa86.html">uses face recognition</a>. Another company called Persistent Surveillance Systems (PSS) <a href="https://fox2now.com/2019/07/31/surveillance-company-offers-st-louis-6-6-million-crimefighting-tools-for-free/">offered millions of dollars in crime-fighting technology</a> to St. Louis for free.</p><p>But if the police wanted to plug AI-powered cameras from private property into their Real Time Crime Center or take PSS up on their offer, CCOPS would kick in, forcing the police to bring the project to the Board of Aldermen, points out Marlow. Then the community and its elected officials would decide the future they want to see in their city.</p><p>&quot;CCOPS sets up the conversation; it isn&#x27;t the conversation itself,&quot; he says.</p></div>
  

  
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<p>As law enforcement agencies deploy AI-powered facial recognition systems, some communities are pushing back, insisting on having a say in how they’re used.</p>

Communities come face-to-face with the growing power of facial recognition technology





  
      <div class="rich-text"><p>Though often hidden behind closed lips, teeth do a lot of heavy lifting in daily life. They’re the pearly whites flashed for smiles, the sharp powerhouses that grind our food.</p><p>Our teeth can also take the place of tools, removing pen caps, tearing open bags of chips, and snipping tags off new clothes. Dentists <a href="https://www.deltadental.com/us/en/protect-my-smile/overall-health/oral-habits---safety/your-teeth-are-not-tools.html">decry the practice</a>, but it really comes in handy—literally: Sharp-edged and stable, teeth often function as well as fingers, earning the mouth the moniker of “<a href="https://www.nature.com/articles/sj.bdj.2012.902">third hand</a>.”</p><p>“I use my mouth all the time when both my [actual] hands are tied up,” says biological anthropologist <a href="https://www.luc.edu/anthropology/faculty/drkristinlkrueger/">Kristin Krueger</a> of Loyola University Chicago. “Sometimes, it’s the only way to get things done.”</p><p>Krueger’s not alone. Plenty of modern humans join her in this convenient form of dental dexterity—and that’s apparently been the case for tens of thousands of years.</p></div>
  

  
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      <div class="rich-text"><p><a href="https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0224573">Reporting today</a> in the journal <i>PLOS ONE,</i> Krueger and her colleagues have found that our early modern human ancestors also treated their teeth as tools, perhaps using them to support their hands in grasping objects, softening wood or fibers, or preparing animal hides for clothing.</p><p>Though this strategy has long been known in Neanderthals, it’s often been dismissed as a “primitive” behavior in the fossil record, restricted to lineages without the sophistication to fashion external tools. But the new study, which shows similar wear patterns on Neanderthal and early modern human canines and incisors (teeth at the front of the jaw) takes a big bite out of that antiquated idea.</p><p>“In many cases...using teeth as tools was likely a clever, expedient thing to do,” says <a href="https://anthropology.osu.edu/people/guatelli-steinbe.1">Debbie Guatelli-Steinberg</a>, an anthropologist at Ohio State University who wasn’t involved in the study.</p><p>The findings also add to the growing list of traits shared by Neanderthals and our early modern human ancestors—two groups that, despite their radically different evolutionary fates, appear to have interacted with their surroundings in very similar ways.</p><p>“We’re still caught up with this idea of the behavioral revolution: that anatomically modern humans are so much better [than other lineages that died out],” says <a href="https://www.kenyon.edu/directories/campus-directory/biography/bruce-hardy/">Bruce Hardy</a>, a paleoanthropologist and Neanderthal expert at Kenyon College who wasn’t involved in the study. “But it’s becoming increasingly difficult to stick with that line.”</p>
            <figure class="richtext-image full-width"><img alt="Sapiens_neanderthal_comparison_en_blackbackground.png" class="richtext-image full-width" height="416" width="800"
            src="/wgbh/nova/media/images/Sapiens_neanderthal_comparison_en_blackbackgro.width-800.png"/><figcaption><p>Modern humans (left) and Neanderthals (right) had their fair share of anatomical differences (including the size, shape, and features of their skulls). But years of research have shown that, contrary to prior belief, they had many behavioral similarities. Image Credit: hairymuseummatt, DrMikeBaxter, Wikimedia Commons</p><div class="credit"><p></p></div></figcaption>
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            <p>Neanderthals first became known to researchers in the mid-1800s, after a partial, stocky skeleton bearing a thick brow ridge on its skull was unearthed in Germany’s Neander Valley. Scientists were quick to describe the newly dubbed <i>Homo neanderthalensis</i> as a species of hunched, barbaric beasts—a “lesser” lineage that had been quashed in the evolutionary race against the well-postured, intellectually savvy <i>Homo sapiens</i>.</p><p>The Neanderthal narrative <a href="https://www.pbs.org/wgbh/nova/article/neanderthal-rib-cage-moved-breathed/">has since evolved</a>. In recent years, a deluge of studies have shown that Neanderthals weren’t the boorish brutes they were once thought to be. Like early modern humans, they <a href="https://www.amnh.org/exhibitions/permanent/human-origins/neanderthal-tools">crafted stone tools</a> and harnessed fire to <a href="https://www.nationalgeographic.com/news/2014/5/140430-neanderthals-cook-food-evolution-science/">cook complex meals</a>. They <a href="https://www.theatlantic.com/health/archive/2018/10/neanderthal-medicine/573028/">concocted medicines</a> to treat the injured and sick, and may have even gone to great lengths to <a href="https://www.scientificamerican.com/article/new-evidence-suggest-neandertals-buried-their-dead/">bury their dead</a>.</p><p>Some researchers even believe Neanderthals and modern humans <a href="https://www.pbs.org/wgbh/nova/article/are-neanderthals-human/">aren’t separate species at all</a>. Whatever their differences, the two groups were certainly close enough to interact, and <a href="https://www.pbs.org/wgbh/nova/article/ancient-dna-neanderthal-complex/">even interbreed</a>—ancient rendezvous that can still be <a href="https://ghr.nlm.nih.gov/primer/dtcgenetictesting/neanderthaldna">detected in the DNA</a> of people living today.</p></div>
  

  
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      <div class="rich-text"><p>But old stigmas die hard. Part of the longstanding stereotype of Neanderthals is their “uncouth” practice of grasping and clamping objects with their teeth, evidenced by the severe amount of wear and tear on their fossilized canines and incisors. “They had tools, but the idea was that they weren’t sophisticated enough to not use their teeth, too,” Krueger says. Because we’re still around and they’re not, she says, many researchers assumed that early modern humans—our direct ancestors—must have been doing “something better.”</p><p>Until now, though, little had been done to actually check if that was true. So Krueger and her colleagues put the theory to the test.</p>
            <figure class="richtext-image full-width"><img alt="Smith_Figure_Intro-2.jpg" class="richtext-image full-width" height="475" width="800"
            src="/wgbh/nova/media/images/Smith_Figure_Intro-2.width-800.jpg"/><figcaption><p>The upper jaw and teeth of an infant Neanderthal, unearthed from the Schmerling Cave in Belgium. Image Credit: Tanya Smith, Griffith University</p><div class="credit"><p></p></div></figcaption>
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            <p>When she and her team compared casts from 45 Neanderthal and 30 early modern human teeth under a microscope, they found that the two groups’ dental wear patterns were pretty much identical. Both sets of chompers carried haphazard scratch marks: some vertical, from the up-and-down motion of biting into food, but also some horizontal, likely from grasping objects that were tugged back and forth.</p><p>On average, the two sets of teeth also bore similarly sized grooves and divots. The depth of these pockmarks, Krueger says, is a proxy for bite force, which increases as teeth take on more heavy-duty functions.</p><p>All told, this suggests that on a day-to-day basis early modern humans and Neanderthals were doing comparable things with their teeth—results that came as a surprise to Krueger. “I was expecting to see that early modern humans <i>weren’t</i> [doing this],” she says. “But when I ran the numbers...I really had to shift my frame of reference.”</p><p>Actually nailing down <i>what</i> our predecessors were sinking their teeth into, however, is a bit complicated. Animal hides and plant fibers don’t have the same staying power as skeletal fossils—which means the nature of these materials, and how they were treated, has to be inferred from only the marks they left behind.</p><p>But Krueger and her team found that the marks on the ancient teeth resembled those from the dentition of the Tigara, an indigenous Arctic population that inhabited what’s now Point Hope, Alaska, between 750 and 250 years ago. The Tigara are one of many modern groups known to have frequently employed the “third hand,” using their teeth while processing animal hides or softening sinew threads for weaving. Though it’ll be tough to confirm, it’s possible that Neanderthals and early modern humans engaged in similar practices long ago—or at least close analogs befitting of the time and place they lived in, Krueger says.</p>
            <figure class="richtext-image full-width"><img alt="20080319_0261.JPG" class="richtext-image full-width" height="430" width="800"
            src="/wgbh/nova/media/images/20080319_0261.width-800.jpg"/><figcaption><p>A set of recent modern human teeth from Amarna, Egypt. Image Credit: Courtesy of Kristin Krueger, Loyola University Chicago</p><div class="credit"><p></p></div></figcaption>
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            <p>Though these behaviors are well-documented in ethnographic records of the Tigara and several other populations from around the globe, these people—and the innovative things they did with their teeth—haven’t typically been considered representative of modern humans. This oversight is perhaps indicative of scientific racism, the failure of anthropologists to be culturally sensitive and inclusive to non-Western practices, Krueger says.</p><p>“We’re educated to not put [non-food] items in our mouths and bite down on them,” says <a href="http://www.drtanyamsmith.com/">Tanya Smith</a>, a biological anthropologist and teeth expert at Griffith University in Australia who wasn’t involved in the study. “Doing that contradicts what we think of as hygienic...we imagine it as a verboten behavior.”</p><p>As such, the findings might be viewed as progressive, rather than regressive, and elevate the idea of teeth as tools, Krueger suggests. (As of the afternoon of November 27, representatives of Alaska’s North Slope Borough could not be reached for comment.)</p><p>Uncovering and analyzing more dental samples will continue to build upon the picture that’s emerging, Smith says. While the Neanderthal teeth used in the study come from all over western Eurasia, spanning a period of roughly 200,000 to 40,000 years ago, the early modern human dental set is sparser, clustering mostly within European sites from the last 40,000 years. It would be fascinating, Smith says, to get a glimpse of the teeth of early modern humans before they left Africa—a time more contemporary with Neanderthals.</p><p>It’s still unclear why the Neanderthal lineage fizzled out while ours persisted. And the use of teeth might not have had anything to do with it. “There may be many other behavioral differences [between us and Neanderthals],” Guatelli-Steinberg says, “but this wasn’t one of them.”</p></div>
  

  
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<p>New findings bolster the argument that the two groups of early humans had a lot of behavioral similarities.</p>

Like Neanderthals, early modern humans used their teeth as tools





  
      <div class="rich-text"><p>It’s hard to imagine an animal with “giant” in its name going unnoticed for decades. But two such species make our list of near misses—creatures once believed to be gone forever. (Most species considered extinct aren’t so lucky.)</p><p>Here are the tales of eight underdogs that clawed, buzzed, and scampered their way back onto the radar:</p></div>
  

  
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      <div class="rich-text"><h3><b>Black-footed ferret (</b><b><i>Mustela nigripes</i></b><b>)</b></h3><p></p><p>With rounded ears, a short muzzle, and big, dark eyes, the black-footed ferret is the only ferret species native to North America—and it’s downright adorable. Perhaps surprisingly, this once-presumed-extinct animal owes its recovery to a dog named Shep, an unlikely ally that helped saved the species by killing one of its members.</p><p>In the early 1900s, black-footed ferret numbers plummeted when grassland habitats in the western U.S. were converted to farmland. In addition to habitat loss, this change led to severe declines in the ferrets’ favorite food: prairie dogs. Several infectious diseases, including sylvatic (bubonic) plague, which ferrets contract from infected prairie dog prey, also hit the species hard. Because black-footed ferrets are found only in North America, declines in the U.S. meant the dwindling of the entire global population.</p><p>By 1979, these fuzzy carnivores were considered extinct.</p><p>But just two years later, in 1981, Shep brought a dead black-footed ferret home to her owners, Lucille and John Hogg, a pair of Wyoming cattle ranchers. The Hoggs then took the ferret to their local taxidermist, who confirmed its identity.</p><p>Conservationists soon found the remnant population on a nearby ranch and brought the 18 survivors into captivity to help increase their numbers. Today, thanks to <a href="https://www.vox.com/future-perfect/2018/11/21/18103851/future-perfect-podcast-endangered-species-ferret-crispr">careful captive breeding</a> and strategic releases, about 300 to 400 black-footed ferrets scamper about North America.</p><h3><b>New Zealand storm-petrel (</b><b><i>Fregetta maoriana</i></b><b>)</b></h3><p></p>
            <figure class="richtext-image full-width"><img alt="Oceanites_maorianus.jpg" class="richtext-image full-width" height="400" width="600"
            src="/wgbh/nova/media/images/Oceanites_maorianus.width-800.jpg"/><figcaption><p>A New Zealand storm-petrel sails over the sea. Image Credit: Wikimedia Commons, Aviceda</p><div class="credit"><p></p></div></figcaption>
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            <p>With nearly 100 different species of seabirds breeding on its shores and islands, New Zealand is sometimes called the Seabird Capital of the World. But habitat loss and predation by invasive mammals have caused the nation’s seabird numbers to plummet.</p><p>For the entire twentieth century, there was not a single recorded observation of a New Zealand storm-petrel—a species only known to science because of three specimens collected in the nineteenth century—and so it was presumed extinct. (The New Zealand storm-petrel is one of about two-dozen storm-petrel species.) The situation shifted in 2003, when birders photographed a member of the long-lost storm-petrel species. Two years later, one of these sparrow-sized birds flew onto the boat of a conservation ranger-turned-fisher who was able to identify the species.</p><p>With these two encounters assuring scientists that the storm-petrels were out there, Chris Gaskin, a founding member of the Northern New Zealand Seabird Trust, and his collaborators spent years trying to find more of them and figure out where they nest.</p><p>The birds are small, nocturnal, and spend most of their lives at sea—all of which made them difficult to track down. They largely eluded the scientists until 2013, when Gaskin and his team finally found a nesting site. They’ve since captured 400 birds, but Gaskin believes there could be a few thousand alive. Still, the storm-petrel’s situation remains precarious, Gaskin says, since the team only knows of a single site where they breed and nest. “Chances are they’re on other islands,” Gaskin says. “We just haven’t discovered them.”</p><h3><b>Wallace’s giant bee (</b><b><i>Megachile pluto</i></b><b>)</b></h3><p></p><p>The world’s biggest bee seems like it would be hard to overlook. But following heavy deforestation in its native habitat—the North Molucca Islands in Indonesia—Wallace’s giant bee went missing for nearly 40 years.</p><p>Dwarfing your average honeybee, Wallace’s giant bee has enormous mandibles (jaws) and a 2.5-inch wingspan—about the width of a tennis ball. The species was named for its discoverer, Alfred Russel Wallace, a British naturalist and entomologist, who published a joint paper with Charles Darwin in 1858 arguing the theory of evolution through natural selection. Aside from Wallace’s first identification, the only other recorded sighting of this outsize insect occurred in 1981 when entomologist Adam Messer collected a few specimens. Wallace’s giant bee then went MIA until earlier this year.</p><p>In January 2019, a search team found a single female. The team’s photographs and videos are the <a href="https://www.nationalgeographic.com/animals/2019/02/worlds-largest-bee-rediscovered-not-extinct/">first-ever documentation</a> of a live specimen of Wallace&#x27;s giant bee.</p><p>Because species this rare can become targets for collectors, Simon Robinson, an Australian biologist on the trip, <a href="https://www.nytimes.com/2019/02/21/science/giant-bee-wallace.html">told Douglas Quenqua at <i>The New York Times</i></a> that he and his team are keeping the exact location of their discovery quiet. They hope they can learn more about this ultra-rare species and how to help its numbers buzz back.</p><h3></h3><h3><b>Fernandina giant tortoise (</b><b><i>Chelonoidis phantasticus</i></b><b>)</b></h3><p></p><p>The Fernandina giant tortoise was “extinct” for more than 100 years. But on February 17, 2019, <a href="https://www.vice.com/en_us/article/xwb4xa/giant-tortoise-feared-extinct-reappears-after-113-years">researchers found one</a>. Washington Tapia, director of the Galápagos Conservancy’s Giant Tortoise Restoration Initiative, and his team discovered the female tortoise on the island of Fernandina in the Galapagos, the first of her kind spotted since 1906.</p><p>The team <i>had</i> found a clue suggesting the species still roamed Fernandina Island several years prior. In 2015, Galápagos National Park ranger Jeffreys Malaga and Charles Darwin Foundation researcher Patricia Jaramillo spotted feces they believed belonged to the species. Because Fernandina Island is an active volcano, its terrain is challenging to navigate, so it took Tapia years to finally track down the poo-producing (or so he presumes) tortoise. She is now the only known survivor of her kind.</p><p>But, based on tracks found it the area, it looks like there may be more Fernandina giant tortoises out there. “It created hope for people to know conservation is possible and that changing human activities is necessary for it to continue,” <a href="https://www.nationalgeographic.com/animals/2019/02/extinct-fernandina-giant-tortoise-found/">Tapia told <i>National Geographic</i></a>. This female is estimated to be 100 years old, but she could live to be 200. If more tortoises are found, she could have another century to breed and help her species rebound.</p><h3></h3><h3><b>Crested gecko (</b><b><i>Correlophus ciliatus</i></b><b>)</b></h3><p></p>
            <figure class="richtext-image full-width"><img alt="Izzy.jpg" class="richtext-image full-width" height="450" width="800"
            src="/wgbh/nova/media/images/Izzy.width-800.jpg"/><figcaption><p>The crested gecko is now one of the most popular species of lizard in the reptile pet trade. Image Credit: Sukee Bennett, WGBH</p><div class="credit"><p></p></div></figcaption>
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            <p>The crested gecko is unique in many ways. It can lick its own eyeballs and <a href="https://www.livescience.com/47307-how-geckos-stick-and-unstick-feet.html">use electromagnetism to stick to walls</a>. Its coloration and scale patterns vary wildly between individuals, and it has a spiky fringe that fans out above its eyes, earning it the nickname “eyelash gecko.” It also has the distinction of going unseen by humans longer than any other species on this list.</p><p>After its identification in 1866 by a French zoologist named Alphone Guichenot, the crested gecko was not seen again for nearly 130 years. In 1994, this little reptile, which at around 35 grams weighs about the same as 7 nickels, was rediscovered. During an expedition led by German herpetologist Robert Seipp, scientists found the crested gecko on its native islands of New Caledonia, a French territory in the South Pacific.</p><p>Soon after the crested gecko’s reemergence, several live specimens were collected on the islands and brought to Europe and the United States for research. Some specimens were also bred in captivity. While the export of crested geckos from the wild is now prohibited, captive breeding has been very successful: This species is now one of the most commonly owned pet lizards in the world.</p></div>
  

  
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      <div class="rich-text"><h3></h3><h3><b>Wood&#x27;s hau kuahiwi (</b><b><i>Hibiscadelphus woodii</i></b><b>)</b></h3><p></p><p>It’s not just fauna that sometimes reappear on our radar. Some plants only grow in incredibly remote locations, meaning it’s difficult for humans to know if they’re still around.</p><p>One such plant, a hibiscus relative known as <i>Hibiscadelphus woodii</i>, was<a href="https://news.mongabay.com/2019/05/drone-rediscovers-hawaiian-flower-thought-to-be-extinct/">rediscovered in January 2019</a> on a remote cliff in the Kalalau Valley in Kaua‘i, Hawai‘i: It wasn’t spotted by an extreme expeditioner, but rather a drone surveying the cliff face. The found specimen was not flowering, but its species produces bright yellow blooms that transform to purple over time.</p><p>First discovered by botanist Kenneth R. Wood and his colleagues in 1991, this hibiscus relative was listed as “presumed extinct” in 2016 after seven years without a single sighting. Until, that is, a team of researchers flew a drone to scour the hidden ridges deep within the Kalalau Valley. They captured images of a shrub that resembled <i>H. woodii</i> peeking out of the steep rocks that line the Kalalau Valley. This location is home to many threatened plant species, but because they grow so far down on the steep cliff, they are largely inaccessible.</p><p>Though researchers were unable to reach the plant by hiking or rappelling, in February, drones once again helped them confirm the sighting. Now, drones may even be sent back into the valley to collect clippings that scientists could use to learn more about the plant, and potentially help it recover by growing cuttings in a greenhouse.</p><p>Ben Nyberg, who worked with National Tropical Botanical Garden on this rediscovery project, <a href="https://qz.com/1600255/botanists-are-using-drones-to-rediscover-extinct-flowers/">told Zoë Schlanger at <i>Quartz</i></a> this is the first instance he knows of in which a drone was used to rediscover a presumably extinct plant species.</p><h3></h3><h3><b>Takahē (</b><b><i>Porphyrio hochstetteri</i></b><b>)</b></h3><p></p>
            <figure class="richtext-image full-width"><img alt="takahe.jpg" class="richtext-image full-width" height="450" width="800"
            src="/wgbh/nova/media/images/takahe.width-800.jpg"/><figcaption><p>A Takahē sports an antenna so that scientists can monitor its movements. Data like this can better help researchers protect endangered species. Image Credit: Wikimedia Commons, russellstreet</p><div class="credit"><p></p></div></figcaption>
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            <p>Along with its namesake storm-petrel, New Zealand is home to another bird that famously surprised scientists with its reemergence: the takahē. Like most birds in New Zealand, takahē numbers were hit hard when Polynesian voyagers, and then European settlers, introduced rats, stoats, possums, and other predators to a country with no native land mammals.</p><p>Faced with a host of new threats, nearly 60 of New Zealand’s bird species went extinct—and for about 50 years the large, flightless takahē was believed to be among them.</p><p>At the turn of the nineteenth century, its iridescent blue and green feathers were scarcely seen. But in 1948, driven by promising tracks and photographs, an expedition set out to see if any takahē had somehow survived. Physician Geoffrey Orbell and his team <a href="https://thespinoff.co.nz/science/22-11-2018/once-thought-extinct-takahe-have-a-brand-new-home/">uncovered a small population</a> of the birds in the remote Murchison Mountains, to the delight of the nation.</p><p>Scientists still don’t understand how this population escaped predation. But they have since helped takahē numbers increase through captive breeding and release onto pest-free islands and fenced-in sanctuaries cleared of mammalian predators. Today, there are approximately 350 takahē in New Zealand.</p><h3></h3><h3><b>Lord Howe stick insect (</b><b><i>Dryococelus australis</i></b><b>)</b></h3><p></p>
            <figure class="richtext-image full-width"><img alt="Dryococelus_australis_02b_Pengo.jpg" class="richtext-image full-width" height="393" width="800"
            src="/wgbh/nova/media/images/Dryococelus_australis_02b_Pengo.width-800.jpg"/><figcaption><p>A Lord Howe stick insect at the Melbourne Museum in Melbourne, Australia. Image Credit: Wikimedia Commons, Peter Halasz</p><div class="credit"><p></p></div></figcaption>
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            <p>Nicknamed the “tree lobster,” the Lord Howe stick insect is about the size of a human hand. It inhabits Lord Howe Island, about 350 miles off Australia’s east coast. And like many island-dwelling species, the Lord Howe stick insect was no match for rats, which invaded the island when a ship crashed nearby in 1918. Just a few years later, the insects were difficult to find. In 1960, experts declared them extinct.</p><p>Unlike the other species on this list, <a href="https://www.wired.com/story/welcome-back-lord-howe-island-stick-insect/">the reemergence</a> of the Lord Howe stick insect came down to genetics. In 2001, scientists found similar-looking stick insects on nearby islands. They looked different enough, though, that many experts doubted they could be tree lobsters.</p><p>To find out, scientists sequenced the genome of the newly discovered insects (a massive genome about 25 percent larger than <a href="https://www.pbs.org/wgbh/nova/video/cracking-your-genetic-code/">the human genome</a>) and found that the variation was small enough for them to be considered the same species. Scientists have since bred more from this population. They hope to one day reintroduce the tree lobster to Lord Howe Island—if they’re able to reduce or eliminate invasive rat populations.</p><p></p></div>
  

  
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<p>A giant tortoise, a seabird, and a gecko all went undetected by scientists for more than a century.</p>

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