Alison Snyder
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Quick note: The newsletter is taking next week off for Thanksgiving. To those of you celebrating, I hope you have a happy one.

1. Stem cells advance — in unexpected ways

Illustration: Rebecca Zisser / Axios

Axios' Erin Ross writes: New advances in stem cell research have the potential to save lives – but not necessarily for the reasons people think. In the late 90s and early 2000s, scientists and the press heralded the promise of these cells that appeared to have the ability to become whatever type of cell was needed to replace or fix damaged tissues. But major advances were slow to come, and the hype faded.

What's happening now: Instead of flashy, morphing cells, the stem cell therapies of today are much more subtle, work in unexpected ways, and it's not always clear why. Still, these advances are promising, so much so that today the FDA released a newly restructured framework for regenerative medicine, including stem cells, to help expedite applications for new therapies.

How they're being used: Small advances have accumulated, and there are currently several active human clinical trials using various types of stem cells to treat diseases.

  • ALS patients: With this neuromuscular disease, also called Lou Gehrig's disease, the brain cells called glia degrade. Stem cells injected into rats seem to protect these glia. Cedars-Sinai Medical Center has begun recruiting human patients for a phase 1 clinical trial.
  • Stroke patients: Bone marrow stem cells injected into the blood helped reduce movement difficulties in a trial of 31 recent stroke patients conducted by the University of Grenoble in France and the University of Baltimore in Maryland. The findings were presented in a poster at the Society for Neuroscience's annual meeting on Monday, and plans for a 400-patient study are underway.
  • Patients with spinal injuries: In a clinical trial of six patients with recent spinal injuries, all regained some motor function after receiving oligodendrocyte progenitor cells, a type of stem cell.
  • Traumatic brain injury. Research conducted by Shyam Gajavelli, a neurologist at the University of Miami, suggests human neuronal stem cells can prevent the immune system in a rat's brain from turning on itself and attacking neurons after it is injured.

Read Erin's full piece here.

2. AI researchers revisit an old muse

Illustration: Lazaro Gamio / Axios

Deep learning — the artificial intelligence technique that allowed a computer to beat a world champion Go player — has become very good at recognizing patterns in images and games. But it's loosely based on ideas we've had about the human brain for decades. Researchers now have more insights from neuroscience and ever-better technologies, both of which they are trying to use to make more intelligent machines.

What's new: On Tuesday, DeepMind co-founder Demis Hassabis presented new work from the company that indicates a move into different territory. Researchers gave an AI system pictures of a 3D scene, along with the coordinates of the camera angles, and it was able to output a new scene from an angle it had never seen. Being able to build models of the world like this — and then use them to react and respond to new situations never encountered before — is considered key to intelligence.

Read more about the fields of AI and neuroscience reconnecting.

3. Axios stories to spark your brain

4. What we're reading elsewhere

The Open Notebook asked me and four other science editors to take part in a conversation about launching a science news outlet. I'll share the link when the roundtable discussion comes out but in the meantime I thought I'd highlight some stories from the other outlets involved:

  • Undark: Jesse Emspak on the problems — ethical and technical — of research saying AI can link facial features to behavior.
  • BuzzFeed Science: Peter Aldhous on the relationship between domestic violence and mass shootings.
  • STAT: Scientists creating human brain organoids are in "uncharted ethical waters," reports Sharon Begley.
  • Hakai: A dam project in Turkey is threatening Mesopotamian Marshes, writes Emilienne Malfatto. "If that happens, the so-called Marsh Arabs will become refugees — but refugees cast away from a peaceful enclave and into a war-torn zone."

5. Something wondrous

Three main neurons involved in the bee's waggle dance. Photo: Thomas Wachtler / Ludwig Maximilian University of Munich

Bees tell each other how to find pollen-laden flowers using the "waggle dance." It's incredibly precise, and can pinpoint a flower miles away. A bee stomps, vibrates her wings, and waggles her abdomen while walking in a straight line, then circles back to the start and does it again. The angle she moves says which way to go. The amount of time she wags tells the distance. Other bees follow the waggle map.

The catch: Hives are pitch black. The observing bees don't see the dance — they hear and feel it.

Researchers already knew which neurons the bees used to feel vibrations, and they knew about the dance. But no one had looked at how the two interacted.

Thomas Wachtler, a researcher at the Ludwig Maximilian University of Munich, drummed the beat of an artificial waggle dance to a bee, and observed which neurons activated. At the center of the brain's response were three neurons: the first starts or stops the second in response to sound – so that measures the time period of the waggle. The purpose of the third isn't clear yet, but since it receives signals from both of the bee's antennae, Wachtler thinks it helps the observers track where the dancing bee is in space, so they can determine the angle of the waggle.

"We're starting to understand how a fairly simple neural system, like a bee's, can solve a complex task like communication," Wachtler says.

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AI searches for new inspiration

Illustration: Lazaro Gamio / Axios

Deep learning — the AI technique that allowed a computer to beat a world-champion Go player — has become very good at recognizing patterns in images and games. But it's loosely based on ideas we've had about the human brain for decades. Researchers now have more insights from neuroscience and better technologies, both of which they are trying to use to make more intelligent machines.

What's new: On Tuesday, DeepMind co-founder Demis Hassabis presented new work from the company that indicates a move into different territory. Researchers gave an AI system pictures of a 3D scene, along with the coordinates of the camera angles, and it was able to output a new scene from an angle it had never seen. Being able to build models of the world like this — and then use them to react and respond to new situations never encountered before — is considered key to intelligence.

The unpublished work was presented at the Society for Neuroscience's annual meeting in Washington, D.C. It's one example of different kinds of learning that researchers would like to develop in AI — and one based on aspects of human intelligence that computers haven't mastered yet.

The approach is among a few being tried but one that some researchers are excited about because, as Hassabis recently wrote, "[The human brain is] the only existing proof that such an intelligence is even possible."

"A lot of the machine learning people now are turning back to neuroscience and asking what have we learned about the brain over the last few decades, and how we can translate principles of neuroscience in the brain to make better algorithms," says Saket Navlakha, a computer scientist at the Salk Institute for Biological Sciences.

Last week, he and his colleagues published a paper suggesting that incorporating a strategy used by fruit flies to decide whether to avoid an odor it hasn't encountered before can improve a computer's searches for similar images.

Other goals:

  • One-shot learning. Children can learn a new word, task or concept from few examples. For some of the first deep learning algorithms, it required massive amounts of data. Progress has been made in reducing the amount of data needed, but it is still far more than what a two-year-old needs to learn.
  • Attention: In a crowded place, most of us are able to pay attention to what we need to know and filter out the rest. "Trying to include this idea in neural networks and machine learning is something people are paying more attention to," says Navlakha.
  • External memory: Brains have multiple systems for memory that operate at different time scales. Researchers want to see if they can give algorithms the equivalent of working memory or scratch pads. DeepMind combined external memory with deep learning to create an algorithm that can efficiently navigate the London Underground.
  • Intuitive physics. We recognize when something is physically off — an airplane balancing on its wing on a highway is clearly not right to us. But when a computer puts a caption to just that image, it reads "an airplane is parked on a tarmac at the airport." NYU's Brenden Lake says, "We don't know how the brain has those abilities."
  • Lifelong learning. Humans are built to constantly integrate new and perhaps sometimes conflicting information, resolve it and maybe even at times have to revise our entire understanding of something. "This constant change over time is something machine learning and AI has been struggling with," says Navlakha.

The big question for all AI approaches: What problem is a particular algorithm best suited to solve, and will it be better than other AI techniques? For neuroscience-inspired AI, there has been early progress but "the jury is still out," says Oren Etzioni, who heads the Allen Institute for Artificial Intelligence.

The big picture: It isn't about replicating the brain in a computer, but building a mathematical theory of learning, says Terrence Sejnowski who is also at the Salk Institute. "Eventually we will get to a point where theory in the machine learning world will illuminate neuroscience in a way unlike we've seen so far."

The back story: Deep learning algorithms only started to work in recent years as more data became available to train them and more processing power could be dedicated to them. In that sense, Sejnowski and others say what we've seen so far is really an "engineering achievement."

The field's pioneer, Geoffrey Hinton, recently said it needs new ideas.

The recent advances have reignited a bit of a debate among AI researchers about how best to actually do this. One way is to find principles of how the brain works and translate them into machine learning and other applications.

There's the "build it like the brain" approach — and to that end, efforts to map how neurons communicate with one another. And then there is the strategy of hard-wiring rules gleaned from models of how humans learn. MIT's Joshua Tenenbaum, Lake and their colleagues suggest the latter is needed to get beyond the accomplishments of pattern recognition. It's very likely advances will come from combining both.

"A more productive way to think about it is that there are some core things that infants, children, and adults use to learn new concepts and perform new tasks," says Lake. He suggests these principles of development and cognition should be seen as milestones and targets for machine learning algorithms to capture, however they get there.

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Opioid addiction treatments are equally effective, study finds

Vivitrol packaging. Photo: Carla K. Johnson / AP

The first study in the U.S. to directly compare two medications to treat opioid addiction — one injected monthly, one given daily as a film placed under the tongue — found the treatments are equally effective, according to research published in the Lancet on Tuesday.

Yes but: Naltrexone (or Vivitrol) injections can't begin until someone has detoxed, typically after a few days. In the study, 28 percent of the participants who were to receive naltrexone didn't detox and couldn't begin the treatment.

What it means: Increasing access to medications for treating opioid addiction was a top recommendation from President Trump's opioid crisis commission. One potential advantage of naltrexone for some patients is that it is a monthly shot versus a daily treatment. Until now, there was limited data about the medication's effectiveness. "We need as many evidence-based options as possible because opioid abuse disorder is more deadly and affecting more people," says Alex Walley, a physician and researcher at Boston Medical Center's Grayken Center for Addiction, who was not involved in the study. He says detox programs should be offering both treatments and allowing patients and their physicians to choose.

What they did: 570 people who had used illegal opioids, mostly heroin, were recruited from inpatient treatment clinics in eight different locations across the U.S. Roughly half of the people in the study received monthly shots of Vivitrol, and the other half took buprenorphine and naloxone (Suboxone) at home each day.

The researchers then tracked any relapses, overdoses, and deaths in the groups over the following 24 weeks. 52 percent of the people that were able to detox and receive naltrexone relapsed during the next six months versus 56 percent of the group that received Suboxone. "We need to think of staying on medication as an important outcome," says Walley.

The big question: What happens long-term? Nora Volkow, director of the National Institute on Drug Abuse, which funded the trial, says they want to understand the characteristics of patients that determine if they will respond better to one treatment versus another. They also want to know how protocols used by centers to initiate treatments might be standardized and improved.

Editor's note: This story has been corrected. In the study, Suboxone was administered daily as a film placed under the tongue, not a pill.

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The human story of cholera started in Asia

Cholera patients in a clinic in Harare, Zimbabwe, in January 2009. Photo: Tsvangirayi Mukwazhi / AP

The planet is in the midst of its seventh cholera pandemic — one that affects about 3 million people each year and, unlike past pandemics that faded away, persists. Stopping its spread hinges on tracking its movements.

By analyzing the genomes of bacteria isolated from samples collected during cholera outbreaks over the past half-century, scientists have now determined that outbreaks in Africa and the Americas were sparked by strains that arrived from Asia. Tracing the paths into and around these regions offers new targets for efforts to control the disease.

The back story: The seventh pandemic began in Indonesia in 1961, then spread to South Asia (1963), Africa (1970), Latin America (1991) and then Haiti (2010). A current outbreak in Yemen just surpassed that in Haiti, and is nearing 1 million cases in the war-torn country.

The challenge: "When cholera was imported into Africa in 1970, it was easy to spot introduction routes and propagation routes because it was a new disease. At some point, the signal was lost because it was everywhere and you weren't able to link the outbreaks to each other," says Francois-Xavier Weill from the Institut Pasteur in Paris, who was involved in both studies.

The bacteria responsible for cholera, Vibrio cholerae, doesn't change much over time, so differences in the DNA of one strain compared to another are hard to spot. So the researchers turned to whole genome sequencing to analyze 714 samples collected on the three continents.

What they found: In Africa, cholera epidemics were traced to at least 11 different introductions from Asia since 1970. (The last five were multi-drug resistant strains.) And, it tended to enter through East/Southern Africa and West Africa.

"All the action should be taken there first," Weill says of public health surveillance efforts. Knowing the genetic fingerprint of the pandemic-producing strain could also inform decisions about when and where to use a global stockpile of cholera vaccine.

The researchers also found that one strain caused an outbreak in Africa that lasted 28 years. Both papers indicate that there's no local reservoir for cholera, meaning if a strain disappears at some point and another isn't introduced, cholera could be eliminated from the region, says Weill.

What's next: Until now, models of cholera's pathways were based on tens of samples. "Not only does the analysis provide more insight into how cholera moves but it also adds samples for others to make inferences so more researchers will be able to study its movement," says Andrew Azman from Johns Hopkins University, who was not involved in the research but studies cholera's epidemiology in East Africa. He says by adding the whole genome sequences of hundreds of strains to the public domain researchers can further understand the dynamics of how cholera is transmitted. Azman plans to pair Weill's results with detailed analysis of cases of cholera in Africa.

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1. The power of news

Illustration: Rebecca Zisser / Axios

News stories have a measurable impact on Americans taking to Twitter to talk about policy issues, according to a study published today in Science. Researchers found people — regardless of their gender or political affiliation — discussed race, immigration and other topics more often after stories were published than if news outlets weren't covering the issues.

The bottom line: If a few small outlets can have an effect on the national conversation as the study suggests, study author Gary King says bad actors may also be able to have a big impact. "And so we all have this responsibility to make some kinds of decisions about the entire ecosystem since it seems to be highly influential," according to King, who's a social scientist at Harvard University.

Read the rest of the story here.

2. Decolonizing science

Photo illustration: Axios Visuals

Axios' Erin Ross writes: In classrooms in the U.S. and around the world, science is often taught as an idea that began with the Greeks. Now there is a growing movement calling for science to be decolonized, and to acknowledge the contributions and ideas of non-Western peoples.

At the World Conference of Science Journalists last month, South African science writer Sibusiso Biyela spoke about how language inequality can keep people — and ideas — out of science. Axios followed up with Biyela to ask whether colonization still influences science in South Africa today.

"Do you really understand something if you don't understand it in your own language?" Biyela asks.

Read the interview here.

3. Axios stories to spark your brain

  • Regeneration: A young boy with a rare disease lost 80% of his skin. Scientists used stem cell and gene therapy to grow him a new one, per Eileen O'Reilly.
  • Taxing: Steve LeVine on how the GOP's proposed tax bill could affect U.S. graduate students.
  • Click: A coconut crab has been caught eating a bird, reports Erin Ross. The behavior could have an impact on the distribution of birds on islands in the Pacific and Indian oceans.
  • ICYMI: Mike Allen interviewed Vice President and Dr. Biden and Sean Parker at an Axios event about cancer research and care yesterday in Philadelphia.

4. What we're reading elsewhere

  • Sheepish: Ben Guarino from The Washington Post writes about a study in which sheep learn to recognize celebrity faces. No pulling the wool over their eyes.
  • Mistakes: Erik Vance writes that the effort to save Mexico's vaquitas was doomed from the beginning because poaching that led to the porpoise being endangered wasn't addressed. "In fact, this whole effort has been one long lesson in throwing the porpoise out with the bathwater."
  • For the weekend: China has built the world's largest radio observatory to scan the skies for signals from extraterrestrial life. The Atlantic's Ross Andersen visited and wrote this sweeping story on what might happen if researchers there make first contact with another civilization.

5. Something wondrous

The crested pigeon taking off. Video: Murray et al. Current Biology, 2017.

For all the emphasis on language's role in communication, many animals — including us talking humans — communicate non-vocally. We clap and knock on doors. Other unintentional sounds, like our footsteps, communicate our presence.

Other animals do the same. The wing songs of mosquitoes harmonize before they will mate. Rattlesnakes rattle, presumably to signal their presence. Darwin was interested in how these sounds influence our behavior and interactions.

"We're still discovering what animals do this, the biology of how and the relationship between how a sound is made and then how it is used by the animal," says Chris Clark, a biologist at the University of California Riverside.

Australian National University's Trevor Murray tried to address those questions by studying crested pigeons. First, the team synchronized high-speed video of the birds taking off (pictured above) with audio recordings and confirmed that the birds produced a distinct sound with their feathers when fleeing.

They then trimmed some of their feathers — specifically an unusually thin one and those surrounding it. When they played back audio recordings of the sound made without the skinny feather to other birds, the birds did not flee. (When the skinny feather was there, they did.)

The closest relatives of the crested pigeon don't have these unusually shaped feathers. And because the shape produces the sound, it suggests the feathers actually evolved to produce that sound, Murray says. The advantage of these built-in noisemakers? He says by fleeing together the birds may have a smaller chance that a predator will catch them.

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How news can drive our conversations

Illustration: Rebecca Zisser / Axios

News stories have a measurable impact on Americans taking to Twitter to talk about policy issues, according to a study published today in Science. Researchers found people — regardless of their gender or political affiliation — discussed race, immigration and other topics more often after stories were published than if news outlets weren't covering the issues.

The bottom line: If a few small outlets can have an effect on the national conversation as the study suggests, study author Gary King says bad actors may also be able to have a big impact. "And so we all have this responsibility to make some kinds of decisions about the entire ecosystem since it seems to be highly influential," according to King, who's a social scientist at Harvard University.

Be smart: This isn't about the power of fake news but of how media can be used for propaganda. "Most people are missing the fact that propagandists have long followed the rule that they should always tell the truth. The reason is that if they say something false and get found out they lose credibility. A much more effective propaganda strategy is to tell the truth but to amplify the arguments you like," King tells Axios.

What they did: The research team recruited 33 media outlets and advocacy blogs — largely digital and mostly small, ranging from Defending Dissent to The Nation to the Huffington Post. Between October 2014 and March 2016, "packs" of 2–5 outlets wrote and published articles on 11 different policy areas, including race, immigration, climate and education. They asked the groups to choose a specific subject within the area for all members to write about and they then ran the stories at the same time.

The researchers then tracked Twitter discussions on the same topics and reported that, on average, the stories published by a group increased social media posts about a policy area by 10% — or 13,166 additional posts — over the week following publication compared with what was normally being tweeted on the topic. The researchers said most people didn't refer to the story per se but to the larger issue.

One interesting thing: The effect was the same regardless of political party affiliation, geography, gender or how many Twitter followers people had. "Apparently the national conversation really is one conversation, at least among those able to participate in social media; even if they do not interact with each other, the evidence indicates that they are being influenced in similar ways by the news media," the authors wrote.

Keep in mind:

  • The interventions took place during quieter news periods. Major news events could change the effect, the authors noted.
  • Policy pales when compared with entertainment: For example, the team's policy topics generated 1/100th of the tweets circulating when a new episode of Scandal was about to air.
  • Most importantly, the study looked at relatively small news organizations compared to the New York Times or Fox News. The researchers did try to get a handle on the impact of an outlet of that size. They looked at the effect of a NYT article about fracking's impact on drinking water — published when the topic wasn't being widely discussed — and found a 300% increase in people talking about water quality in the day that followed (versus 19% in their experiment).
  • It's also tough to say on an individual level whether someone's focus on a subject is coming from the news or their own interests, says University of Maryland economist Ethan Kaplan, who was not part of this study.

The big question remains: Just how much of an impact does news media have on what voters or legislators do? One interpretation of the study is that it is a short-lived effect and so politicians don't have to care about reporting on an issue, says Kaplan, who has studied Fox News' influence on voters. "Or, it could be that it is changing someone's view on these issues — they just don't tweet about it as much or they go ahead and vote differently."

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How cancer survival rates have changed since the 70s

More people are surviving a cancer diagnosis today than in the 1970s, according to a report released earlier this year by government agencies and cancer groups. That's the good news facing former Vice President Joe Biden, who's speaking with Mike Allen at an Axios event in Philadelphia today, as he continues his work to speed the progress of cancer research.

But the survival rates are still low for several kinds — including brain cancers like the type that killed his son, Beau Biden.

Data: Journal of the National Cancer Institute; Chart: Chris Canipe / Axios

What's next: Immunotherapies are one promising area of cancer treatment, but there are questions about why checkpoint inhibitors (one class of immunotherapeutic drugs) work in some patients but not others. These treatments, and others known as CAR T-cell therapies that involve changing a patient's own immune cells so they will attack cancerous cells, can also cause serious side effects that researchers are racing to understand.

Dr. Elizabeth Jaffee of Johns Hopkins University, president-elect of the American Association for Cancer Research, says these are the most likely advances in immunotherapy to watch over the next few years:

  • Developing "accelerator" therapies to help the immune system activate more quickly.
  • Activating T-cells that have never been activated before by targeting monocytes, a type of white blood cell.
  • Inhibiting molecules formed when T-cells metabolize so the immune cells can better respond to cancerous ones.

Keep in mind: For breast, prostate and a handful of other cancers, increased screening and early detection may have improved survival rates while masking only minor gains in longevity. Prevention is how we've made the most headway in decreasing actual death rates from cancer — with fewer people smoking, for example — and where more progress can be made.

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Axios Science

Thanks for subscribing to Axios Science. Please let me know what you think about the newsletter or our daily coverage. You can reply to this email, or reach me at alison@axios.com.

Quick note for Philly readers: Vice President and Dr. Biden, along with Sean Parker, will join Axios' Mike Allen on November 8th to discuss cancer research and care, and you're invited. Celgene CEO Mark Alles, cancer survivor and advocate Stefanie Joho, and Elizabeth Jaffee, the deputy director of the Kimmel Cancer Center at Johns Hopkins, will also discuss the topic with Mike. RSVP here.

1. How people came to the Americas

Data: Sites compiled from academic papers and information provided by Braje; Map: Lazaro Gamio / Axios

Axios' Erin Ross writes: We still don't know how humans got to the Americas. Many researchers are arguing we need to ditch the land-first hypothesis of human migration, and look for underwater evidence of a seafaring past. It's an idea that's gaining momentum, though the evidence is complex and the proposal isn't unanimously accepted.

The map above shows some of the oldest archaeological sites in the Americas. Many in South America are either along the coastline or major waterways, supporting the coastal migration hypothesis. But North America looks a lot messier and lacks many coastal sites.

Why it matters: "We're trying to answer one of the most fundamentally important questions in American archaeology," Todd Braje, an author of the paper that appears today in Science, tells Axios. Recent finds have challenged the old, accepted models of a single migration over a single route.

Read the rest of Erin's story here.

2. Axios stories to spark your brain

3. Language, like life, can evolve by chance

Illustration: Rebecca Zisser / Axios

Since Darwin's day, the principles of evolution have been used to try to explain how and why language changes. In a new study, researchers look at changes within the English language over short periods of time and find random chance plays a larger role than previously thought in quickly altering aspects of language.

What's new: Techniques used by biologists to study genetic changes have been honed, and linguists can now use them to analyze the large amounts of digitized texts. Understanding what causes individual words, sounds and syntax to change within a single language could provide clues about how new languages arise. And, advances in linguistic understanding have led to better speech recognition, predictive text, artificial intelligence and related algorithms.

Bottom line: We are beginning to get a detailed picture of the history of language, much like we have for the history of species.

Read the rest of the story here.

4. What we can learn from a return to the Moon

Illustration: Rebecca Zisser / Axios

At last month's meeting of the National Space Council, Vice President Mike Pence announced plans for the next stages of U.S. space exploration. "We will return American astronauts to the Moon, not only to leave behind footprints and flags, but to build the foundation we need to send Americans to Mars and beyond," he said.

We asked four experts what we might learn by sending astronauts back to the Moon:

5. What we're reading elsewhere

  • Nature: Emma Marris' beautiful tale in Outside of the wolf's return to Oregon and the man who tried to manage it.
  • Math ability: Philip Ball in Aeon about whether culture or biology gave us our sense of numbers.
  • Pest management: The Galapagos Island of Floreana has a rodent problem that one conservationist is proposing be solved by genetically modifying rats and mice. Stephen Hall writes in Scientific American about the complexities of that approach.

6. Something wondrous

Armillaria mellea rhizomorphs grow on a plate. Photo: Zsolt Merényi

Armillaria fungi can spread across thousands of acres of forest for thousands of years, making it one of Earth's largest organisms. Above ground, the fungus is seen as honey mushrooms growing on trees but under the soil it extends a vast network of structures called rhizomorphs (pictured above) that scientists suspect allow the fungus to grow to such large sizes.

How? Researchers looked at the genes expressed in the rhizomorphs and the mushroom fruiting bodies and, surprisingly, found that rather than evolving completely new genes, the rhizomorphs co-opted genes from the mushroom to form multicellular structures below the ground, explains László Nagy from the Hungarian Academy of Sciences. They also found genes responsible for degrading plant cells being expressed in the rhizomorphs, suggesting they aren't just exploring the surrounding soil but taking up nutrients.

Why it matters: Armillaria are forest pathogens that infect and damage trees. They can wipe out forests. Understanding how their rhizomorphs develop, explore the soil and communicate with host trees could lead to more effective strategies for preventing their spread and fighting infection, says the University of Sopron's György Sipos.

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Chance plays a role in how languages change

Illustration: Rebecca Zisser / Axios

Since Darwin's day, the principles of evolution have been used to try to explain how and why language changes. In a new study, researchers look at changes within the English language over short periods of time and find random chance plays a larger role than previously thought in quickly altering aspects of language.

What's new: Techniques used by biologists to study genetic changes have been honed, and linguists can now use them to analyze the large amounts of digitized texts. Understanding what causes individual words, sounds and syntax to change within a single language could provide clues about how new languages arise. And, advances in linguistic understanding have led to better speech recognition, predictive text, artificial intelligence and related algorithms.

Bottom line: We are beginning to get a detailed picture of the history of language, much like we have for the history of species.

"This is a really interesting piece of work that nicely combines large-scale databases with quantitative modeling. These approaches are becoming more common in linguistics, helping to revitalize the field," says Simon Greenhill from the Max Planck Institute for the Science of Human History, who was not involved in the research but recently analyzed 81 Austronesian languages (from islands in Southeast Asia and the Pacific) and found their grammar changed faster than their lexicon.

How evolution works: Selection is when one form of a word is preferred over another — because it sounds better, is popular or more effective, or is easier to say or remember — and therefore perpetuated, whereas drift or neutral evolution is when a version of a word is randomly copied. It just sort of happens.

What they did: Physicist-turned-biologist Mitchell Newberry and linguist Christopher Ahern along with their colleagues at the University of Pennsylvania ran their statistical models, which borrow from techniques in population genetics, on databases of digitized texts containing more than 400 million words and spanning the 12th to 21st centuries. They tested the models on three known grammatical changes in the English language:

  1. The use of -ed to create past-tense verbs. They found drift accounted for changes in rare verbs that make them more prone to being replaced. And, the preferred form of just six of the 36 verbs they studied arose via selection. Some were irregular, which linguists have hypothesized may be because those forms pleasingly rhyme with other words being used frequently at the time. In the study, the rise of the irregular verb quit was found to coincide with more use of the words hit, split and slit, supporting the hypothesis.
  2. The rise of do as a verb. Random drift seems to have initially brought do into questions beginning in the 1500s and then natural selection took over as do made its way into other contexts like when Say not that! became Don't say that! for "reasons of grammatical consistency or cognitive ease," they wrote.
  3. How negative sentences were formed. In Middle English, the phrase was I not say, then it changed to I not say not, then by Shakespeare's time it was, I say not and, finally, I don't say. This cycle of moving no around to wherever it gives us the most emphasis was known to happen across many languages due to natural selection and the test basically acted as the control for their model.
"One of the crucial things we've added is that at certain time scales — year by year counts as opposed to century by century — the picture is really different. If you look at the data in a fine grain way, you will discover new things," says Ahern.

Yes, but: Some linguists contacted by Axios were skeptical the study's findings were novel and said historical data is incomplete. "The amount of material we have varies a lot from century to century, and that affects the conclusions that can be drawn from the dataset," says Claire Bowern, a linguist at Yale University who was not involved in the study. She also points out that linguists have looked at the role of random drift in language change before.

The response: Ahern says that among linguists, "the level of detail at which these changes are 'well known' is a little bit overstated." And, he says the point is he and his colleagues came up with a way to test long-standing hypotheses for the first time. "We're building in language the intellectual infrastructure that we built in genetics in the 60s," Newberry says.

What's next: Determining whether the patterns occur in other languages and extending and nuancing the models by incorporating other work in linguistics, Greenhill says.

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Jupiter's unusual X-ray auroras

An infrared image of Jupiter's southern aurora from NASA's Juno spacecraft. Photo: NASA / JPL / Caltech / SwRI / ASI / INAF / JIRAM

Scientists report today they've detected X-ray auroras on Jupiter's southern pole that, unlike Earth's synchronized Northern and Southern Lights, behave independently from their northern counterparts. Exactly how the planet's magnetic field produce its powerful auroras is unknown.

The big picture: Aurora-producing magnetic fields protect life on Earth's surface so scientists want to be able to recognize their various features and processes as they search for places that could harbor life, study co-author William Dunn from University of College London told the Verge.

How they saw it: Using data collected in 2007 and 2016 from two space-based observatories that could see both poles at the same, William Dunn and his colleagues at University College London found Jupiter's southern aurora pulsed every 9-11 minutes whereas the northern one was inconsistent — it flared every 12, 26 or 40-45 minutes — and with varying brightness.

On Earth auroras form when charged particles in the solar wind get pushed to the planet's poles by the magnetic field. There, the particles collide with oxygen and nitrogen in the atmosphere and emit photons that we see as the Northern and Southern Lights. (There are also auroras in infrared light, ultraviolet light and X-ray that we can't see.) Earth's auroras brighten and dim together as the charged particles are pushed to each pole. Unexpectedly, Jupiter's auroras aren't in such unison.

Why it happens: Unclear but one possibility the researchers propose is that when the solar wind hits Jupiter's large and strong magnetic field, the lines vibrate and produce waves. Charged particles — some of which come from volcanic eruptions on Jupiter's moon Io and others from the solar wind — may ride those waves to the poles and collide with the atmosphere in X-ray producing pulses.

What's next: NASA's Juno spacecraft is orbiting Jupiter and sending data about the planet's magnetosphere. Researchers plan to combine that with X-ray observations to see how the aurora are connected to what is happening on the planet and whether the behavior they saw is common or an exception.