It’s possible that I shall make an ass of myself. But in that case one can always get out of it with a little dialectic. I have, of course, so worded my proposition as to be right either way (K.Marx, Letter to F.Engels on the Indian Mutiny)
Thursday, August 27, 2026
Looking into the eyes of gibbons
Non-invasive eye-tracking reveals gibbons gaze into the eyes when looking at others
Credit: Gaku Ohashi / Institute for the Evolutionary Origins of Human Behavior, Kyoto University
Kyoto, Japan -- When you look at someone, you usually look at their face. It serves as one of the most important sources of social information in primates, so the evolution of face perception has attracted considerable scientific attention. While an abundance of this research has centered on humans and other great apes, very little has focused on gibbons.
Gibbons were the earliest to diverge from the line leading to humans 17 million years ago, and they have developed a distinct social system characterized by small family groups and long-term pair bonding. They provide a particularly valuable model for investigating the relationship between social organization and the evolution of social cognition, motivating a team of researchers at Kyoto University to give gibbons the attention they deserve.
"Understanding the evolutionary origins of the human mind requires comparative studies across the ape lineage," says first author Makiko Uchikoshi. "Despite their evolutionary importance, gibbons remain one of the least studied ape groups in cognitive research."
The researchers used a voluntary, non-invasive eye-tracking method -- developed for previous studies -- to measure the eye movements of three adult male gibbons while they viewed photographs of both gibbon and human faces displayed on a screen. The experiment was conducted in the gibbons' regular living environment, allowing them to participate in or stop the session at their will at any time.
Though the researchers were concerned about the effect that the equipment and the dimmed light would have on the subjects' comfort in their home, the gibbons soon began to sit in their designated place and wait while everything was set up. With the resulting data, the team examined how long the gibbons looked at the eyes, nose, mouth, and peripheral areas, and then compared the responses to gibbon and human faces.
The results reveal that, when viewing both gibbon and human faces, gibbons spend more time looking at the eyes compared to other facial regions. Their gazes also linger on the eyes of their own species significantly longer than those of humans, indicating that gibbons share key patterns of visual attention with humans, great apes, and macaques, while also exhibiting a stronger focus on the eyes of members of their own species.
The success of this eye-tracking approach expands opportunities for comparing species with markedly different social structures, and for understanding how social organization has shaped the evolution of social cognition across the primate lineage. These findings also provide new insights into the evolutionary foundations of face perception and social information processing in primates.
"I have known the gibbons that participated in this study for nearly 28 years and have often experienced moments of eye contact, but I had never been able to measure objectively what they were actually looking at," says Uchikoshi. "Being able to quantify where they look and for how long felt almost like magic."
###
The paper "Gibbons (Hylobates spp.) show increased attention to eyes when viewing conspecific faces: An eye-tracking study" appeared on 3 August 2026 in Animal Behavior and Cognition, with doi: 10.26451/abc.13.03.02.2026
About Kyoto University
Kyoto University is one of Japan and Asia's premier research institutions, founded in 1897 and responsible for producing numerous Nobel laureates and winners of other prestigious international prizes. A broad curriculum across the arts and sciences at undergraduate and graduate levels complements several research centers, facilities, and offices around Japan and the world. For more information, please see: http://www.kyoto-u.ac.jp/en
Overview of the study
Credit
Makiko Uchikoshi / Institute for the Evolutionary Origins of Human Behavior, Kyoto University
An adult male Turks and Caicos Anole (Anolis scriptus scriptus) watching his territory from the trunk of a tree. Big Ambergris Cay, Turks and Caicos Islands.
Credit: Photograph by R. Graham Reynolds, UNC Asheville.
A researcher from the University of North Carolina Asheville has published the first comprehensive checklist of the native terrestrial reptiles of the Turks and Caicos Islands (TCI), drawing on 20 years of collaborative fieldwork to create a single illustrated reference for scientists, conservationists and nature enthusiasts.
The study, led by Professor R. Graham Reynolds of UNC Asheville's Department of Biology, is published in the open-access journal ZooKeys. It documents the 11 native reptile species across the archipelago's Turks and Caicos Banks, eight of which are found nowhere else on Earth.
Two further species are represented in the islands by their own endemic subspecies. The checklist combines published research through 2026 with original field data collected by Dr Reynolds between 2006 and 2025, and includes original photographs, distribution information and conservation assessments for every species.
Dr Reynolds began studying the islands' reptiles in 2006, in his first year of graduate school, working alongside Dr Glenn Gerber of the San Diego Zoo Wildlife Alliance. “This quickly turned into a passion, and I have made studying these animals the focus of my career,” he said.
“I conduct fieldwork several times a year on the islands, and this year is the 20th year of this work. In that time, I have published dozens of papers on the reptiles of the region and collected a huge amount of data, and I felt that, after two decades, it was time to produce something to showcase everything we've learned about these animals.”
Although information on the islands' reptiles has existed scattered across books, online databases and journal articles, no single resource has previously combined photographs, distribution maps, natural history and conservation status for every species.
“Somewhat surprisingly, there has never been a comprehensive checklist for the terrestrial reptiles of the region,” Dr Reynolds explained. “Portions of this are available elsewhere, such as distribution maps and some photographs on the online database CaribHerp, or island checklists and natural history information in a book chapter. But this is the first time that all of this information has been brought together to fully describe and illustrate the amazing terrestrial reptiles of the Turks and Caicos.”
Seven of the 11 native species are of conservation concern. The Turks Island Skink is Critically Endangered and may now survive as a single protected population, while the Turks and Caicos Iguana, classified as Endangered, has been lost from around 90% of its historical range. Introduced predators, particularly feral cats and rats, are identified as the main cause of these declines, alongside habitat loss and road mortality.
The study also revises the taxonomy of the Curly-tailed Lizard, recommending that six previously recognised subspecies be reduced to two, reflecting recent genetic evidence.
An adult male Turks and Caicos Curlytail (Leiocephalus psammodromus apocrinus) perches on top of a Turks cap Cactus (Melocactus intortus). Big Ambergris Cay, Turks and Caicos Islands.
Sea turtles are famous for being prodigious wanderers. Guided by the Earth’s magnetic field, oceanic currents, and the sun, they tend to crisscross the seas in search of food, returning to the region of their birth every few years to breed. So when scientists discovered a population of sea turtles who appear to be very much homebodies, they were taken aback.
“Here we show that ‘yellow-morph’ green sea turtles – one of two genetically distinct forms – occupy individual foraging areas which span one or more islands in the Galápagos. We expected them to migrate to distant beaches in the western Pacific to reproduce, yet interestingly, none of our satellite-tagged turtles even left the Galápagos Marine Reserve over the three years of our study,” said Dr John W Rowe, a professor at Alma College in the United States and the corresponding author of a new study in Frontiers in Amphibian and Reptile Science.
Black and yellow
Green sea turtles are unique among the seven living species in being mainly vegetarian. Hatchlings start life as omnivores, but once fully grown, their diet consists of seagrasses and algae. Yellow-morph green sea turtles roam the western Pacific Ocean’s tropical and subtropical latitudes, while black-morphs live in the eastern Pacific west of the Americas below southern California. The only known waters in the world where these two coexist is around the Galápagos, where they intermingle and happily feed on the same species of marine plants. However, yellow morphs tend to grow faster than black morphs when young, which suggests that uncharacterized physiological differences do exist.
Rowe and colleagues set out to study the yellow morph’s habitat preferences, range, and movements between islands within the 198,000 sq km of the Galápagos Marine Reserve. In 2015, they gently caught seven adult males and two adult females in the shallow waters off four islands. They gave them nicknames and fitted them with electronic tags that sent ‘pings’ to the low-orbit Argos satellite network. The scientists tracked their charges for up to 418 days, typically until the tags fell off or stopped transmitting.
Overall, the turtles preferred to stay in shallow coastal waters, although occasionally they ventured up to 25km offshore. Five of the nine animals stayed mostly in the vicinity of a single island during the study period, while Bernardo and Sara traveled between the islands of Isabela and San Cristóbal. Leandro trekked between Isabela and Española, while Ainoa displayed the most wanderlust: originally tagged off San Cristóbal, she subsequently moved to Santa Cruz and later to Isabela. Interestingly, such movement between islands was only seen during the cooler months from April to October. The mean size of a single turtle’s home range was 1,498 sq km, but this varied greatly among individuals.
The turtle moves (but not much)
The authors concluded that yellow-morph green turtles in the Galápagos are remarkably stay-at-home. However, they warned that the study was only a snapshot in time, so that periodic long-distance dispersal may have been missed.
“Since female yellow-morph green sea turtles are not known to lay eggs on the beaches of the Galápagos, we believe that they will eventually leave the area to return to their natal beaches in the western Pacific. In contrast, some female black-morph green turtles do nest in the Galápagos: depending on the individual, those may be year-round residents in the archipelago, travel to other nearby oceanic islands, or even to feeding grounds off Central and South America,” said coauthor Dr Juan Pablo Muñoz Pérez, a professor at the Universidad San Francisco de Quito in Ecuador.
The scientists also emphasized the importance of conserving pristine the coastal and between-island routes that the turtles use within these islands.
“Since individual turtles may rely on waters around multiple islands, the quality of habitat that is available for foraging should be maintained intact across all islands, and not allowed to degrade anywhere,” said Rowe.
This “tiny house lab,” which sits outside Purdue’s Delon and Elizabeth Hampton Hall of Civil Engineering, allows researchers to study indoor air quality more comprehensively than has been possible in other settings.
CHICAGO, Aug. 27, 2026 — What does a clean room smell like? Many people say citrus, pine, or flowers because these fragrances are common in cleaning products. A research team led by Brandon Boor found that scent compounds in cleaning products — conventional and botanical essential oil-based — quickly react in the air, forming nanoparticles that can travel deep into the lungs if inhaled. To reduce exposure to this invisible pollution, the team suggests using unscented products, running exhaust fans, and avoiding ozone-generating devices while cleaning.
The researchers will present their results at the fall meeting of the American Chemical Society (ACS) during the “Healthy Indoor Spaces: Bridging the Microbiome and Chemistry” symposium in McCormick Place. ACS Fall 2026 is being held August 23-27.
“Importantly, cleaning removes viruses and bacteria from surfaces, but it can also generate invisible air pollution. There's no visible dust or smoke in the air, but these particles are forming.” — Brandon Boor
“We showed that indoor ozone reactions with fragrances from cleaning produce nanoparticles that carry a respiratory dose comparable to, or greater than, what you would experience from standing outside along a busy road,” says Boor, an Assistant Professor of Civil and Construction Engineering at Purdue University who studies indoor air quality. “The particles are different in terms of their composition, but the total dose can be higher. You're not seeing smoke, dust, or haze in the air. Instead, you think the air smells great so it must be clean.”
Boor and his colleague Nusrat Jung, a Purdue Assistant Professor of Civil and Construction Engineering, started studying the impact of cleaning products and chemical disinfectants on indoor environments during the COVID-19 pandemic. In that work, they observed that many of these products are heavily scented. “That's often to create a pleasant smellscape in the indoor space,” says Boor. “But clean air should not smell like highly concentrated citrus fruit. It should not really smell of anything.”
Atmospheric chemists previously established that terpenes emitted by plants, such as pinene from pine trees, react with ozone to create airborne nanoparticles. The nanoparticles aggregate and eventually grow large enough to seed clouds. But in forests, terpene levels are relatively low, so particle formation occurs slowly.
Using scented products indoors releases terpenes as the fragrance compounds evaporate from surfaces or spray droplets. Common terpenes in cleaning liquids include pinene, limonene (lemon), thymol (thyme), and linalool (lavender), and at concentrations much higher than are found naturally outdoors. As a result, airborne terpene levels during cleaning can reach tens to hundreds of times those found in a forest, says Boor.
To study what happens in the process of routine cleaning, the researchers tested scented conventional liquid products and botanical-containing disinfectant sprays and wipes in a model house on Purdue’s campus. The tiny house has a working kitchen, wood flooring, and a bathroom. They found that the same chemistry that forms nanoparticles outside occurs inside at faster and at higher concentrations, which has important implications for human health.
Activities such as mopping, spraying countertops, and wiping surfaces with scented products formed billions or trillions of particles, depending on the product used. Most of the particles, called nanoparticles or ultrafine particles, were 1–30 nanometers wide, a size range often missed by at-home air quality monitors. By tracking them, the researchers observed that routine cleaning can generate ultrafine particle pollution at levels above those found outdoors. This poses potential health risks because ultrafine particles are small enough to deposit throughout the airways and deep into the lungs. There, they can contribute to respiratory system irritation and inflammation, or they can potentially enter the bloodstream.
Most surprising to the researchers was how fast the particles formed and grew — it took a matter of minutes. “By the time you finish cleaning up an indoor space, you’ve already formed a lot of nanoparticles and inhaled them,” says Boor.
More recently, Boor and Ernest Blatchley, a Professor at Purdue, found that simultaneously disinfecting air with germicidal far-UV (UV-C) lamps and cleaning surfaces with scented products creates an environment ripe for nanoparticle formation. In fact, the lamps interact with oxygen in the air and generate ozone, raising ozone levels in the tiny home to around 20 to 40 parts per billion, comparable to, though somewhat lower than, levels outdoors at the time of the experiments. The combination of elevated ozone and high terpene concentrations drove even more intense particle formation in the tiny house, raising potential inhalation concerns.
Boor wants these findings to inform consumers’ choices, not alarm them, and provides several steps people can take to reduce their exposure while cleaning:
Choose low-fragrance or fragrance-free products.
Avoid applying several scented products in the same cleaning session.
Run exhaust fans or open windows to ventilate the space.
Do not simultaneously clean surfaces with scented products while using ozone-generating devices, such as far UV-C lamps.
“Importantly, cleaning removes viruses and bacteria from surfaces, but it can also generate invisible air pollution,” says Boor. “There's no visible dust or smoke in the air, but these particles are forming.”
Boor thanks all the graduate students who have worked with him in the tiny house experiments along with the support of undergraduate students.
The research was funded by a National Science Foundation Faculty Early Career Development Program (CAREER) grant and the Alfred P. Sloan Foundation.
###
The American Chemical Society (ACS) is one of the world's largest scientific organizations and a global leader in advancing scientific knowledge. Founded in 1876, ACS' mission is to advance scientific knowledge, empower a global community, and champion scientific integrity. Guided by its vision of a world built on science, ACS brings together people, ideas, and resources to drive discovery and innovation, support the professional growth of scientists and students, and advance scientific discussion. Through its trusted publications, scientific meetings, community networks, education and career resources, and scientific information solutions, ACS helps scientists, educators, and students make a lasting impact on their communities and the world at large. Together, these efforts support ACS' commitment to improve all lives through the transforming power of chemistry.
Note to journalists: Please report that this research was presented at a meeting of the American Chemical Society. ACS does not conduct research.
The inside of Purdue’s tiny house lab has various sensors and equipment to accurately and precisely measure air pollutant emissions from common household activities in real time.
Credit
Purdue University photo/Kelsey Lefever
Cleaning the countertop inside a tiny house lab revealed that scented products produced high amounts of airborne nanoparticles within a few minutes.
Credit
Brian Magnuson
Title Indoor atmospheric nanoparticle formation from scented cleaning products
Abstract Scented volatile chemical products, including surface cleaning agents and botanical disinfectants, are widely used indoors and represent a major source of reactive organic emissions. These products are routinely applied in homes and workplaces for surface cleaning and disinfection to reduce the presence of viruses and bacteria. However, their role in driving indoor atmospheric chemistry and nanoparticle formation remains poorly constrained. This presentation investigates the impact of scented cleaning product use on airborne nanoparticle nucleation, growth, and human exposure to secondary pollutants in indoor environments. Field and laboratory experiments were conducted in controlled residential and office settings using real-time, high-resolution measurements of volatile organic compounds and nanoparticle size distributions extending to the nanocluster aerosol (1–3 nm) regime. Surface cleaning and disinfection activities produced rapid increases in terpene and terpenoid mixing ratios (10–1,000 ppb), often exceeding levels observed in outdoor forested environments. These compounds reacted with indoor oxidants, particularly ozone, to initiate intense nanoparticle nucleation and growth events. Observed nucleation rates (~105 cm-3 s-1) and condensational growth rates (up to 300 nm h-1) exceeded typical outdoor values by orders of magnitude, resulting in transient indoor nanoparticle number concentrations of 105–108 cm-3. Rapid nanoparticle growth enabled survival to sizes that efficiently deposit throughout the human respiratory system, yielding inhalation dose rates comparable to or exceeding those from primary combustion sources such as traffic emissions. Both conventional and botanical cleaning products generated complex multiphase exposure scenarios involving reactive gases and secondary organic aerosol. These findings identify indoor surface cleaning and disinfection as key drivers of indoor atmospheric nanoparticle formation and highlight the need for improved building ventilation, air cleaning, and product formulation to mitigate exposure to secondary pollutants.
