Science Signaling Podcast

Meta-analyses—structured analyses of many studies on the same topic—were once seen as objective and definitive projects that helped sort out conflicts amongst smaller studies. These days, thousands of meta-analyses are published every year—many either redundant or contrary to earlier metaworks. Host Sarah Crespi talks to freelance science journalist Jop de Vrieze about ongoing meta-analysis wars in which opposing research teams churn out conflicting metastudies around important public health questions such as links between violent video games and school shootings and the effects of antidepressants. They also talk about what clues to look for when trying to evaluate the quality of a meta-analysis. Sarah also talked with three other contributors to our “Research on Research” special issue. Pierre Azoulay of the Massachusetts Institute of Technology (MIT) in Cambridge, Ben Jones of Northwestern University in Evanston, Illinois, and MIT’s Heidi Williams discuss the evidence for some hoary old scientific home tru

Strawberries had both male and female parts, like most plants, until several million years ago. This may seem like a long time ago, but it actually means strawberries have some of the youngest sex chromosomes around. What are the advantages of splitting a species into two sexes? Host Sarah Crespi interviews freelance journalist Carol Cruzan Morton about her story on scientists’ journey to understanding the strawberry’s sexual awakening. In 2016, experimental Zika vaccines were swiftly developed in response to the emergence of serious birth defects in the babies of infected woman. Two years after the height of Zika cases, there’s so little spread of the virus in the Americas that it has stymied vaccine trials. Researchers hope to overcome this hurdle with “human challenge experiments”—vaccinating people, then intentionally infecting them with Zika to see whether they’re protected from the virus. Meagan Cantwell talks with staff writer Jon Cohen about his news story that highlights the risks and rewards of hum

We are in the middle of what some scientists are calling the sixth mass extinction and not all at-risk species can be saved. That’s causing some conservationists to say we need to start thinking about “species triage.” Meagan Cantwell interviews freelance journalist Warren Cornwall about his story on weighing the costs of saving Canada’s endangered caribou and the debate among conservationists on new approaches to conservation. And host Sarah Crespi interviews Hope Michelsen, a staff scientist at Sandia National Laboratories in Livermore, California, about mysterious origins of soot. The black dust has been around since fire itself, but researchers never knew how the high-energy environment of a flame can produce it—until now. Michelsen walks Sarah through the radical chemistry of soot formation—including its formation of free radicals—and discusses soot’s many roles in industry, the environment, and even interstellar space. Check out this useful graphic describing the soot inception process in the related

A new project out of the Center for Open Science in Charlottesville, Virginia, found that of all the experimental social science papers published in Science and Nature from 2010–15, 62% successfully replicated, even when larger sample sizes were used. What does this say about peer review? Host Sarah Crespi talks with Staff Writer Kelly Servick about how this project stacks up against similar replication efforts, and whether we can achieve similar results by merely asking people to guess whether a study can be replicated. Podcast producer Meagan Cantwell interviews Emily Brodsky of the University of California, Santa Cruz, about her research report examining why earthquakes occur as far as 10 kilometers from wastewater injection and fracking sites. Emily discusses why the well-established mechanism for human-induced earthquakes doesn’t explain this distance, and how these findings may influence where we place injection wells in the future. In this month’s book podcast, Jen Golbeck interviews Judea Pearl and

Small satellites—about the size of a briefcase—have been hitching rides on rockets to lower Earth orbit for decades. Now, because of their low cost and ease of launching, governments and private companies are looking to expand the range of these “sate-lites” deeper into space. Host Sarah Crespi talks with Deputy News Editor Eric Hand about the mods and missions in store for so-called CubeSats. And our newest podcast producer Meagan Cantwell interviews Quentin Grafton of Australian National University in Canberra and Brad Udall of Colorado State University in Fort Collins about something called the “irrigation efficiency paradox.” As freshwater supplies dry up around the world, policymakers and farmers have been quick to try to make up the difference by improving irrigation, a notorious water waster. It turns out that both human behavior and the difficulty of water measurement are plaguing water conservation efforts in agriculture. For example, when farms find they are using less water, they tend to plant eve

Several thousand years ago the volcano under Santorini in Greece—known as Thera—erupted in a tremendous explosion, dusting the nearby Mediterranean civilizations of Crete and Egypt in a layer of white ash. This geological marker could be used to tie together many ancient historical events, but the estimated date could be off by a century. Contributing Correspondent Lizzie Wade joins host Sarah Crespi to talk about a new study that used tree rings to calibrate radiocarbon readings—and get closer to pinning down a date. The findings also suggest that scientists may need to change their standard radiocarbon dating calibration curve. Sarah also talks to Tony Belpaeme of Ghent University in Belgium and Plymouth University in the United Kingdom about his Science Robotics paper that explored whether people are susceptible to peer pressure from robots. Using a classic psychological measure of peer influence, the team found that kids from ages 7 to 9 occasionally gave in to social pressure from robot peers, but adult

We now live in the Meghalayan age—the last age of the Holocene epoch. Did you get the memo? A July decision by the International Commission on Stratigraphy, which is responsible for naming geological time periods, divided the Holocene into three ages: the Greenlandian, the Northgrippian, and the Meghalayan. The one we live in—the Meghalayan age (pronounced “megalion”)—is pegged to a global drought thought to have happened some 4200 years ago. But many critics question the timing of this latest age and the global expanse of the drought. Staff writer Paul Voosen talks with host Sarah Crespi about the evidence for and against the global drought—and what it means if it’s wrong. Sarah also talks to staff writer Kelly Servick about her feature story on what happens when biocontrol goes out of control. Here’s the setup: U.S. Department of Agriculture researchers wanted to know whether brown marmorated stink bugs that have invaded the United States could be controlled—aka killed—by importing their natural predators,

Yes, humans are the only species with language, but how did we acquire it? New research suggests our linguistic prowess might arise from the same process that brought domesticated dogs big eyes and bonobos the power to read others’ intent. Online News Editor Catherine Matacic joins host Sarah Crespi to talk about how humans might have self-domesticated themselves, leading to physical and behavioral changes that gave us a “language-ready” brain. Sarah also talks with Micah Edelson of the University of Zurich in Switzerland about his group’s research into the role that “responsibility aversion”—the reluctance to make decisions for a group—might play when people decide to lead or defer in a group setting. In their experiments, the team found that some people adjusted how much risk they would take on, depending on whether they were deciding for themselves alone or for the entire group. The ones who didn’t—those who stuck to the same plan whether others were involved or not—tended to score higher on standardized

Billions of years ago, Mars probably hosted many water features: streams, rivers, gullies, etc. But until recently, water detected on the Red Planet was either locked up in ice or flitting about as a gas in the atmosphere. Now, researchers analyzing radar data from the Mars Express mission have found evidence for an enormous salty lake under the southern polar ice cap of Mars. Daniel Clery joins host Sarah Crespi to discuss how the water was found and how it can still be liquid—despite temperatures and pressures typically inhospitable to water in its liquid form. Read the research. Sarah also talks with science journalist Katherine Kornei about her story on changing athletic performance after gender transition. The feature profiles researcher Joanna Harper on the work she has done to understand the impacts of hormone replacement therapy and testosterone levels in transgender women involved in running and other sports. It turns out within a year of beginning hormone replacement therapy, transgender women pla

Suckling mothers milk is a pretty basic feature of being a mammal. Humans do it. Possums do it. But monotremes such as the platypus and echidna—although still mammals—gave up suckling long ago. Instead, they lap at milky patches on their mothers’ skin to get early sustenance. Science News Writer Gretchen Vogel talks with host Sarah Crespi about the newest suckling science—it turns out monotremes probably had suckling ancestors, but gave it up for the ability to grind up tasty, hard-shelled, river-dwelling creatures. Sarah also talks with Sandra Yuter of North Carolina State University in Raleigh about her work on fast-clearing clouds off the southwest coast of Africa. These immense marine layers appear to be exiting the coastal regions under the influence of gravity waves (not to be confused with gravitational waves). This finding can help scientists better model cloud behavior, particularly with respect to their influence on global temperatures. This week’s episode was edited by Podigy. Download a transcr

A detection of a single neutrino at the 1-square-kilometer IceCube detector in Antarctica may signal the beginning of “neutrino astronomy.” The neutral, almost massless particle left its trail of debris in the ice last September, and its source was picked out of the sky by the Fermi Gamma-ray Space Telescope soon thereafter. Science News Writer Daniel Clery joins host Sarah Crespi to discuss the blazar fingered as the source and how neutrinos from this gigantic matter-gobbling black hole could help astronomers learn more about mysterious high-energy cosmic rays that occasionally shriek toward Earth. Read the research. Sarah also talks with Cornell University’s Susan McCouch about her team’s work on deep-water rice. Rice can survive flooding by fast internodal growth—basically a quick growth spurt that raises its leaves above water. But this growth only occurs in prolonged, deep flooding. How do these plants know they are submerged and how much to grow? Sarah and Susan discuss the mechanisms involved and whe

Wild polio has been hunted to near extinction in a decades-old global eradication program. Now, a vaccine-derived outbreak in the Democratic Republic of the Congo (DRC) is threatening to seriously extend the polio eradication endgame. Deputy News Editor Leslie Roberts joins host Sarah Crespi to talk about the tough choices experts face in the fight against this disease in the DRC. Sarah also talks with Online News Editor David Grimm about when dogs first came to the Americas. New DNA and archaeological evidence suggest these pups did not arise from North American wolves but came over thousands of years after the first people did. Now that we know where they came from, the question is: Where did they go? Read the research. This week’s episode was edited by Podigy. Download a transcript of this episode (PDF) Listen to previous podcasts. About the Science Podcast [Image: Polio virus/David Goodsell/RCSB PDB; Music: Jeffrey Cook]

Public opinion on the morality of animal research is on the downswing in the United States. But some researchers think letting the public know more about how animals are used in experiments might turn things around. Online News Editor David Grimm joins Sarah Crespi to talk about these efforts. Sarah also talks Ken Wachter of the University of California, Berkeley about his group’s careful analysis of data from all living Italians born 105 or more years before the study. It turns out the risk of dying does not continue to accelerate with age, but actually plateaus around the age of 105. What does this mean for attempts to increase human lifespan? In this month’s book segment, Jen Golbeck talks with Simon Winchester about his book The Perfectionists: How Precision Engineers Created the Modern World. Read more book reviews at our books blog, Books et al. This week’s episode was edited by Podigy. Listen to previous podcasts. [Image: Chris Jones/Flickr; Music: Jeffrey Cook]

Since the 2016 reports of a mysterious assault on U.S. embassy staff in Cuba, researchers have struggled to find evidence of injury or weapon. Now, new research has discovered inner-ear damage in some of the personnel complaining of symptoms. Former International News Editor Rich Stone talks to host Sarah Crespi about the case, including new reports of a similar incident in China, and what kind of weapon—if any—might have been involved. Sarah also talks with Staff Writer Gretchen Vogel about the bones of an extinct gibbon found in a 2200- to 2300-year-old tomb in China. Although gibbons were often featured in historical poetry and paintings, these bones confirm their presence and the fact that they were distinct from today’s species.   Read the research. This week’s episode was edited by Podigy. Listen to previous podcasts. [Image: Pedro Szekely; Music: Jeffrey Cook]

Nigeria, Russia, and Florida seem like an odd set, but they all have one thing in common: growing caseloads of HIV. Science Staff Writer Jon Cohen joins host Sarah Crespi to talk about this week’s big read on how the fight against HIV/AIDS is evolving in these diverse locations. Sarah also talks with Armin Raznahan of the National Institute of Mental Health in Bethesda, Maryland, about his group’s work measuring which parts of the human brain are bigger in bigger brains. Adult human brains can vary as much as two times in size—and until now this expansion was thought to be evenly distributed. However, the team found that highly integrative regions are overrepresented in bigger brains, whereas regions related to processing incoming sensory information such as sight and sound tend to be underrepresented.  This week’s episode was edited by Podigy. Listen to previous podcasts. [Image: Misha Friedman; Music: Jeffrey Cook]

What book are you taking to the beach or the field this summer? Science’s books editor Valerie Thompson and host Sarah Crespi discuss a selection of science books that will have you catching comets and swimming with the fishes. Sarah also talks with Mira Moufarrej of Stanford University in Palo Alto, California, about her team’s work on a new blood test that analyzes RNA from maternal blood to determine the gestational age of a fetus. This new approach may also help predict the risk of preterm birth. This week’s episode was edited by Podigy. Listen to previous podcasts. [Image: William Warby/Flickr; Music: Jeffrey Cook]

Astronomers have been able to detect supermassive black holes and teeny-weeny black holes but the midsize ones have been elusive. Now, researchers have scanned through archives looking for middle-size galaxies and found traces of these missing middlers. Host Sarah Crespi and Staff Writer Daniel Clery discuss why they were so hard to find in the first place, and what it means for our understanding of black hole formation. Farming animals and plants for human consumption is a massive operation with a big effect on the planet. A new research project that calculated the environmental impact of global food production shows highly variable results for different foods—and for the same foods grown in different locations. Sarah talks with one of the researchers—Joseph Poore of the University of Oxford in the United Kingdom—about how understanding this diversity can help cut down food production’s environmental footprint and help consumers make better choices. This week’s episode was edited by Podigy. Listen to prev

DNA fingerprinting has been used to link people to crimes for decades, by matching DNA from a crime scene to DNA extracted from a suspect. Now, investigators are using other parts of the genome—such as markers for hair and eye color—to help rule people in and out as suspects. Staff Writer Gretchen Vogel talks with Sarah Crespi about whether science supports this approach and how different countries are dealing with this new type of evidence. Sarah also talks with Jill Fernandes of the University of Queensland in Brisbane, Australia, about her Science Advances paper on a light-based technique for detecting Zika in mosquitoes. Instead of grinding up the bug and extracting Zika DNA, her group shines near-infrared light through the body. Mosquitoes carrying Zika transmit this light differently from uninfected ones. If it’s successful in larger trials, this technique could make large-scale surveillance of infected mosquitoes quicker and less expensive. In our monthly books segment, Jen Golbeck talks with author

Two thousand years ago, ancient Romans were pumping lead into the air as they smelted ores to make the silvery coin of the realm. Online News Editor David Grimm talks to Sarah Crespi about how the pollution of ice in Greenland from this process provides a detailed 1900-year record of Roman history. This week is also resistance week at Science—where researchers explore the global challenges of antibiotic resistance, pesticide resistance, herbicide resistance, and fungicide resistance. Sarah talks with Sarah Gurr of the University of Exeter in the United Kingdom about her group’s work on the spread of antifungal resistance and what it means for crops and in the clinic. And in a bonus books segment, staff writer Jennifer Couzin-Frankel talks about medicine and fraud in her review of Bad Blood: Secrets and Lies in a Silicon Valley Startup by John Carreyrou. This week’s episode was edited by Podigy. Listen to previous podcasts. [Image: Wheat rust/Oregon State University; Music: Jeffrey Cook]

Who were the first horse tamers? Online News Editor Catherine Matacic talks to Sarah Crespi about a new study that brings genomics to bear on the question. The hunt for the original equine domesticators has focused on Bronze Age people living on the Eurasian steppe. Now, an ancient DNA analysis bolsters the idea that a small group of hunter-gatherers, called the Botai, were likely the first to harness horses, not the famous Yamnaya pastoralists often thought to be the originators of the Indo-European language family. Sarah also talks with News Intern Katie Langin about her feature story on a single salmon gene that may separate spring- and fall-run salmon. Conservationists, regulators, and citizens are fiercely debating the role such a small bit of DNA plays in defining distinct populations. Is the spring run distinct enough to warrant protection? This week’s episode was edited by Podigy. Listen to previous podcasts. [Image: Jessica Piispanen/USFWS; Music: Jeffrey Cook]