Proceedings of the National Academy of Sciences

In this issue: Domestication of a bacterial strain for botulinum production, the origin of ear canal shape in birds, and the activation of astrocytes during learning and recall. In PNAS: https://ow.ly/YP5h51009Ca

A sudden surge in the abundance of a previously rare hybrid crab in the Bering Sea was an outcome of a marine heatwave that occurred seven years earlier and caused a collapse of the snow crab population, according to a study. In PNAS: https://ow.ly/3A6V51015iJ

Could relying on AI summaries affect how deeply we learn? A Forbes commentary draws on a PNAS Nexus research article finding that LLM-based learning can produce shallower knowledge and less original advice. In Forbes: https://ow.ly/t9iQ51016S1 In PNAS Nexus: https://ow.ly/qI2c51016Sg

How did pitcher plants evolve their insect-trapping abilities? Explore their evolution with LabX Tree of Life series and PNAS Science Sessions. 🎧: https://ow.ly/RAIe510142C ▶️: https://ow.ly/6IWa51013T5

Researchers developed a potential Alzheimer's treatment and discovered the peptide naturally occurs in human blood, at lower levels in people with cognitive impairment. Could it also serve as a biomarker. In PNAS Nexus: https://ow.ly/g5XZ51016NQ

What can ancient DNA reveal about colonial Montréal? Researchers analyzed remains from a 17th–18th century cemetery, finding evidence that challenges historical narratives about the French-Canadian founder population. In Live Science: https://ow.ly/uXfM510155Q In PNAS: https://ow.ly/EsFO51014Yz

Read highlights in this week’s issue of PNAS: We explore the ancestry of individuals in a colonial Montreal cemetery, study maternal investment in offspring social play, and analyze AI-generated language and human communication. https://ow.ly/xbpP51015cU

According to a study, the urban heat island effect is reduced in clusters of similar buildings, due to their regular aerodynamic roughness, efficient ventilation corridors, and ability to release anthropogenic heat on synchronized schedules. In PNAS: https://ow.ly/j0UI51014nM

Explore the unusual side of science in a classic PNAS Science Sessions episode. 🦇✨ What can mysterious swamp lights and bats’ vision teach us about the natural world? Revisit two unusual research stories this spooky season. 🎧Listen now: https://ow.ly/UBmb5100mxQ

🥧 The secret to perfect pie crust? It might be chemistry! Butter, shortening, or bacon fat? LabX's Chemists in the Kitchen puts different fats to the test to explore what makes a deliciously flaky crust. Dig into the experiment: https://ow.ly/sLCP5100mwL

Multiple studies have suggested that some #vaccines seem to mitigate #dementia. What’s the biological basis of these apparent effects? A PNAS Inner Workings: https://ow.ly/wWX45100muc #shingles #RSV #diphtheria #tetanus #Alzheimers #ImmuneSystem #vaccination

Toxic “forever chemicals” can be filtered out of water and destroyed by a hydrogen‑based catalytic membrane. The surface of the membrane features a film of palladium nanoparticles that adsorbs reactive hydrogen, which captures and breaks apart PFAS. In PNAS: https://ow.ly/9uqr5100m7v

The new PNAS Early-Career Researcher Portal includes resources to help emerging researchers better understand publishing, peer review, submission requirements, and opportunities to engage with PNAS and PNAS Nexus. Explore the portal: https://ow.ly/NwqU5100mHR

A Perspective calls for a Discovery Compact for science: an agreement that treats scientific discovery as essential infrastructure and goes beyond simply returning to the funding levels and predictability of the postwar era. In PNAS Nexus: https://ow.ly/MMFg5100mKk

Honoring Barry Bloom, a pioneering immunologist whose work helped refocus policy on controlling infectious diseases. His legacy includes lasting contributions to scientific research, global health leadership, and mentorship. Read the PNAS Retrospective: https://ow.ly/5iW35100muf

Online surveys have been a boon for science, but in the AI era, not all respondents may be human. A study validates AI detection tests that effectively separate verified-human participants from AI agents and finds 6–41% of respondents are likely bots. In PNAS: https://ow.ly/8ILa5100m4F

Opinion: Don’t tax the talent that builds American science. A proposed #DHS rule could have lasting consequences for #GraduateStudents and U.S. scientific competitiveness. In PNAS Front Matter: https://ow.ly/3pox5100mm8 #StudentVisa #ScienceEnterprise #EarlyCareerResearch

Animal abundance in the deepwater ecosystem of the Gulf of Mexico declined by 60–85% between 2011 and 2015, according to deep-ocean sampling and acoustic sensing. The authors suggest a potential link to the Deepwater Horizon oil spill. In PNAS: https://ow.ly/FjM75100m63

One of the most-viewed PNAS Nexus articles in the last week is “Broadcast ritual dynamics among US Catholics during the 2025 papal conclave.” Explore the article here: https://ow.ly/5sVz5100bln To learn more about submitting your own research, visit PNAS Nexus at https://ow.ly/jHjn5100blo.

Deploying renewable energy and battery storage near existing fossil and renewable power plants across the United States could increase electricity generation without requiring major grid expansion, according to a study using satellite images. In PNAS: https://ow.ly/uRZG51008Ct

In this week’s PNAS Nexus Advance Articles: Social signal and norm misperception; MASLD-Mitochondrial digital twin; and governing global capital. Explore now: https://ow.ly/lRS35100bo5

One of the most-viewed PNAS articles in the last week is “The more you automate, the less you see: Hidden pitfalls of autonomous AI scientists.” Explore the article here: https://ow.ly/IkQT5100aEv For more trending articles, visit https://ow.ly/Br6s5100aEw.

A Bayesian model forecasts where mass shootings are most likely to occur in the United States. Firearm access, derived from the density of federal firearms licenses, emerged as the dominant predictor of risk in the model. In PNAS Nexus: https://ow.ly/lBkm5100bjK

Discover one of the top-performing PNAS Nexus articles on Altmetric for the past three months! “Nanotubes enable intercellular communication in early-branching eukaryotes” by Suma et al. scored 72—driven by strong media attention. Read more: https://ow.ly/8tMg5100bgk

A study of articles suspected of being associated with “paper mills”in the field of molecular cancer shows the papers cite other paper mill papers to inflate their metrics. These practices can amplify unreliable findings and slow scientific progress. In PNAS: https://ow.ly/g7W251008lG

Opinion: Size matters when it comes to #microplastics. Researchers urge reporting of every particle to better understand how microplastics move through the #environment and their ecological impacts. In PNAS Front Matter: https://ow.ly/9RFB51009ax #Pollution #Ecology #toxicology

Most European bees have seen their ranges contract over the last century, but continental-scale bee and hoverfly extinctions are rare and species richness in Alpine regions has increased, likely due to warming of the high latitudes. In PNAS: https://ow.ly/kJzm51008wl

As dinosaurs evolved into birds, their ear canals changed shape, which was thought to be an adaptation for flight. A study finds that the avian inner ear may have instead been shaped by the reorientation of the skull–neck joint. In PNAS: https://ow.ly/Q4kY50ZZomh

One of the most-viewed PNAS articles in the last week is “Children from six cultures reliably help their peers—but in different ways.” Explore the article here: https://ow.ly/HkFg50ZZpmF For more trending articles, visit https://ow.ly/6NFn50ZZpmC.

Discover one of the most talked-about PNAS Nexus articles on Altmetric over the past three months! “Why the mortality penalty of smoking is rising over time” by R. Lawton et al. earned an Altmetric score of 101, driven by strong media coverage. Read more: https://ow.ly/Tmyu50ZZpbJ

LLMs were prompted to correct people’s misperceptions about economic policy. The chatbots were 28% less persuasive when study participants were told that they were biased against the participant’s political party. In PNAS Nexus: https://ow.ly/xVzA50ZZpGI

Discover peer-reviewed plant biology research from PNAS! 🌱 From plant–microbe symbiosis to nutrient uptake and environmental interactions, explore studies advancing sustainable agriculture, climate resilience, and innovation. https://ow.ly/Q3bQ50ZZoVK

Orangutan mothers plan play dates for their offspring, according to 15 years of behavioral and movement data from 31 Bornean orangutan mother–child pairs. The generally solitary apes expend energy to take their offspring to visit similarly aged peers. In PNAS: https://ow.ly/mwlb50ZZoiu

Can the cables connecting our world help us understand what happens beneath the ocean? 🌊🐋 In this PNAS Science Sessions episode, researchers explore how undersea fiber-optic cables can detect and track blue whales as they move through the water. Listen now: https://ow.ly/gW7J50ZZp39

Opinion piece: No, #AI cannot replace #HumanParticipants in #BehavioralResearch. In PNAS Front Matter: https://ow.ly/soQO50ZZoAY 3 #ClinicalTrials #ArtificialIntelligence #LLMs #SiliconSamples #DigitalTwins

Honey bee stingers continue to pump venom into their victims even after the stinger has detached and the bee has flown away. A study of stinger mechanics finds the structure functions as a double-piston micropump with two barbed lancets. In PNAS: https://ow.ly/cHYs50ZZofl

Whale falls—where whale carcasses land on the seafloor—become biodiversity hotspots. Elephant falls are less biodiverse than nearby areas, due to ammonium released by carcasses, but microbial respiration and herbivore grazing are elevated. In PNAS: https://ow.ly/eppw50ZZ2v5

Read highlights in this week’s issue of PNAS: We explore warm and cool droughts in Colorado; analyze how deep learning helps unravel grassland evolution; and examine brain weight and aging in great apes. https://ow.ly/NH3150ZZ3aF

Worldwide, 15-year-old boys are less likely than girls to believe trying hard in school matters. A study finds this gap is widest in highly developed countries and may help explain boys’ lower academic performance. In PNAS Nexus: https://ow.ly/iOsV50ZZ5yR

🌿 Plant diversity may help grasslands sustain productivity and store carbon as the climate warms. A study projects that major diversity loss could reduce CO2 uptake by 15% by 2050. In Science X / Phys.org: https://ow.ly/9AZi50ZZ5jM In PNAS: https://ow.ly/qVAf50ZZ5j6

One of the most-discussed PNAS Nexus articles on Reddit last month was “Like humans, language models demonstrate face-to-character biases.” Explore the article: https://ow.ly/SyFI50ZZ5oc

When ranchers are placed on the Brazilian Ministry of Labor’s “Dirty List” of employers that use slave labor, slaughterhouses are less willing to buy from them. A study shows many flagged ranchers “launder” their cattle by selling them to other ranchers. In PNAS: https://ow.ly/2z9Z50ZZ2aM

Opinion: Don’t tax the talent that builds American science. A proposed #DHS rule could have lasting consequences for graduate students and U.S. scientific competitiveness. In PNAS Front Matter: https://ow.ly/Gv0q50ZZ391 #ECR #GraduateSchool #StudentVisa #InternationalStudents

An analysis of insect genomes suggests that the lineages Ephemeroptera and Odonata form a single evolutionary group with a Late Devonian origin, known as Palaeoptera. The study clarifies the evolutionary origins of flying insects. In PNAS: https://ow.ly/cC9G50ZZ1sH

Watch video interviews with the 2025 Cozzarelli Prize winners and discover the remarkable research behind their award-winning work! https://ow.ly/hNcE50ZYwFn. Think you’ve read a standout PNAS paper this year? Nominations are now open: https://ow.ly/h8W150ZYwFi.

What can skeletal remains reveal about gender inequality? 💀 From the PNAS Science Sessions archive, discover how ancient dental records and modern surveys reveal the persistence of gender bias across centuries. 🎧 Listen: https://ow.ly/HSCi50ZYvQ0

🥕 Soup season just got scientific! Roasted or boiled—which carrots make the better soup? Join LabX's Chemists in the Kitchen as they experiment with cooking techniques and explore the science behind a cozy classic. See what's simmering: https://ow.ly/gPWI50ZYuZW

Glaciers in the coterminous United States have lost 35% of their area since the mid-20th century. That’s 195.29 square kilometers of ice gone, representing 5.53 gigatons of water. In PNAS: https://ow.ly/RYPB50ZYsRc

In this week’s PNAS Nexus Advance Articles: Deformation of hard magnetic soft matter, programmable extracellular matrix heterogeneity, arterial stiffness from a single distal velocity waveform, and more. https://ow.ly/84G450ZYx5p

How does segregation shape urban ecosystems? A PNAS Special Feature explores how spatial exclusion intersects with environmental conditions, infrastructure, biodiversity, and climate adaptation across cities worldwide. Explore the research: