Saturday, May 23, 2026

The Global Ocean Observing System is more fragile than we thought

Institute of Atmospheric Physics, Chinese Academy of Sciences

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Geographical distribution of ocean temperature profile data from different nations from 2005 to 2023.

Credit: Lijing Cheng

Every time a meteorologist predicts a hurricane's intensity, a fishing fleet plans its season, a port authority routes a cargo ship around dangerous seas, or a government braces for El Niño, they are drawing on one critical resource: real-time ocean data. The Global Ocean Observing System (GOOS), a network of robotic floats, research vessels, and moored buoys spanning every ocean basin, makes that possible. It is, in every practical sense, the nervous system of modern civilisation's relationship with the sea and weather.

Now, a new international study published in Nature Climate Change has done what was previously only feared: it has quantified how quickly that nervous system can be disabled and by whom.

Why Ocean Heat Content Is a Critical Operational Variable

Ocean heat content (OHC) is not merely an abstraction for ocean scientists. It is the quantity that underpins an extraordinary range of operational decisions made every hour of every day:

Weather forecasting & hurricane intensity. Warm ocean heat fuels tropical cyclones and intense storms. Subsurface temperature data are critical for predicting whether a storm will rapidly intensify before landfall — one of the most dangerous and difficult forecasting challenges in meteorology and climate. Without adequate ocean monitoring, the reliability of these life-saving predictions is directly compromised.
El Niño and La Niña prediction. ENSO events reshape rainfall, drought, wildfire seasons, and agricultural yields across the world and especially in South America, sub-Saharan Africa, South Asia, and Australia. Governments use El Niño forecasts to pre-position food aid, manage reservoir levels, and plan harvests months in advance. Those forecasts depend especially on GOOS subsurface ocean temperature data in the tropical Pacific.
Fisheries management. Fish stocks migrate with ocean heat and currents. Marine heatwaves — detectable only through sustained subsurface monitoring — have already collapsed kelp forests, devastated salmon runs, and triggered mass coral bleaching. Without GOOS, fishing industries worth hundreds of billions of dollars annually lose the early-warning systems that allow them to adapt.
Shipping and port operations. Accurate knowledge of ocean temperatures and currents affects fuel efficiency, route planning, and safety for the 90% of global trade that travels by sea. Ocean heat anomalies drive sea-level variations that directly affect port operations.
Monsoon and seasonal rainfall forecasting. The Indian Ocean and Pacific heat reservoirs drive monsoon timing across South and Southeast Asia, affecting water security for over two billion people. Indian Ocean heat anomalies are now recognised as primary drivers of East African drought cycles.
Military and national security. Submarine operations, naval routing, and acoustic underwater detection all depend on precise knowledge of ocean temperature structure. GOOS data underpin national defence capabilities worldwide.

What the Study Found

Led by Yujing Zhu and Prof. Lijing Cheng of the Chinese Academy of Sciences, with co-authors from the United States, France, and New Zealand, the research team systematically simulated what happens to ocean monitoring quality when GOOS data are progressively removed.

The results are unambiguous.

Removing just 20% of observations immediately degrades the accuracy of annual ocean heating estimates by 33%.
At 80% data loss, the global ocean warming signal becomes statistically indistinguishable from noise and the monitoring system ceases to be useful.
Removing U.S. observations alone, which represent more than half of global data by volume, produces a 163% increase in monitoring error: worse than randomly losing 80% of all global data. The reason is geography: U.S.-funded platforms span every ocean basin, plugging critical gaps that no other nation currently covers.
In the U.S.-removal scenario, the error in estimating how fast ocean warming is accelerating, a key input for infrastructure planning, insurance pricing, and coastal adaptation, reaches 20%.

“The ocean observing system we have built over the past two decades is a collective scientific achievement of the first order. Our results show, with quantitative precision, just how dependent we are on it — and how rapidly that dependence becomes a vulnerability if national commitments falter.”

— Prof. Lijing Cheng, lead author, Institute of Atmospheric Physics, Chinese Academy of Sciences

“What surprised us most is that geographic reach matters more than sheer data volume. Losing U.S. ocean observations alone would damage global monitoring more than randomly losing 80% of all the world’s ocean data. That is not only a climate science problem. It is a weather forecasting problem, a fisheries problem, and a national security problem.”

— Prof. John P. Abraham, co-author, University of St. Thomas School of Engineering

Why a Truly Global Ocean Observing System Is Not Optional

GOOS is one of the most important and least celebrated achievements of international scientific cooperation. Since around 2005, it has provided near-continuous, near-global coverage of ocean temperatures from the surface to 2,000 metres depth — the result of decades of sustained political commitment and coordinated investment from dozens of nations.

But GOOS is not a treaty. It has no binding obligations. It is, in effect, a collective action of global scale — and right now, the collective is under increasing strain.

Europe’s Argo float deployments have declined for several years due to constrained funding and rising platform costs. The COVID-19 pandemic caused multi-year losses of observations that have still not been fully recovered. And proposed U.S. federal budget cuts targeting NOAA and the National Science Foundation threaten the single largest contributor to the global system.

The TAO/TRITON mooring network in the tropical Pacific — the primary early-warning system for El Niño — already suffered a severe data gap from 2012 to 2014 due to budget pressures and deferred maintenance, a precedent whose scientific and operational consequences continue to be assessed.

“No single nation can monitor the global ocean alone. And no nation can afford not to. The ocean does not respect borders — but the consequences of losing track of it will be felt everywhere: in food prices, in extreme weather and early warnings, in risk management and in the decisions that governments make for their economies and citizens.”

— Prof. Sabrina Speich, co-author, École Normale Supérieure – Université PSL, Paris

The authors argue that sustaining GOOS as a global public good requires a fundamental shift in how nations think about ocean observing: not as a discretionary scientific expenditure, but as critical infrastructure equivalent to satellite navigation or meteorological services — services whose value is most obvious precisely when they fail.

Crucially, the study shows that the system’s vulnerability is not merely about data volume. Because GOOS is assembled from nationally funded programmes with distinct geographic footprints, the loss of any single major contributor creates geographically concentrated blind spots that cannot be compensated by data from elsewhere. This makes the case not just for sustained funding, but for a genuinely global, coordinated system where contributions scale with economic capacity.

“Ocean heat increases are a major contributor to sea level rise and changes in ocean currents, with profound influences on ecosystems, including fish and marine life, as well as oxygenation of waters and uptake of carbon dioxide. They relate directly to Earth’s Energy Imbalance.”

—Dr. Kevin Trenberth, coauthor, University of Auckland, New Zealand

Context

This study arrives at a moment of acute uncertainty for ocean science. Proposed cuts to NOAA and NSF in the United States, declining European investment in Argo, and a still-incomplete recovery from pandemic-era data losses have placed GOOS at a crossroads. As the paper concludes: “nations depend on the state of the global ocean, not only on the portion of the ocean close to their own coastlines.”

The El Niño event underway in 2026 will affect harvests, water supplies, and disaster budgets from California to Kenya to Indonesia. Whether forecasters can see it coming clearly enough to act depends on the health of GOOS today.

If the observing system degrades further, the consequences will not be confined to scientific uncertainty. They will materialise in missed storm warnings, failed El Niño forecasts, disrupted fisheries, and the compounding costs of decisions made without adequate ocean information.

Journal

Nature Climate Change

DOI

10.1038/s41558-026-02661-6

Article Title

Critical dependence of global ocean heat monitoring on the ocean observing system

Article Publication Date

22-May-2026

Ocean acidification is ruining reef fishes’ social lives

Adelaide University

A new study from Adelaide University has found that when ocean acidification makes reef habitat less complex, the fish living there gather in smaller shoals that offer less social protection.

“Watch a reef long enough and you realise that fish are almost never alone. They move in groups, feed in groups, and react to danger as a group,” said lead author Dr Angus Mitchell, from Adelaide University.

“For small reef fish, being part of a shoal is a survival strategy – more eyes spot predators sooner, more bodies mean any one fish is less likely to be the unlucky one.”

Mitchell’s study found that the size of a fish shoal affects their collective and individual behaviour.

“Fish in bigger groups tend to be bolder, as they forage more efficiently, stay out in the open more, and spend less time hiding,” said Dr Mitchell, whose study was published in the Journal of Animal Ecology.

Importantly, the study found that these changes in behaviour were not attributable to the direct impacts of higher temperatures and lower pH.

“The direct effects of warming, acidification, and heatwave stress on individual fish behaviour were mostly minimal,” said project leader Professor Ivan Nagelkerken, from Adelaide University.

“Across all reef types, even during a heatwave, the fish behaved in much the same way. They kept feeding. They did not suddenly become more active.”

Dr Mitchell said while studies looking into direct impacts of climate change on the environment are important, the broader context should also be considered when assessing climate change impacts.

“In the real world, fish do not experience climate change in isolation; they experience it as members of communities, shaped by the habitat around them and the other individuals they live alongside,” he said.

“Our results suggest that even when individual fish seem to be coping fine behaviourally under climate stress, the social structures supporting their behavioural expression can quietly fall apart.”

Ocean acidification driven by climate change is causing a decline in reef complexity around the world.

Professor Nagelkerken and his team were able to project the impacts on reef fish of future levels of ocean acidification by examining reefs where natural processes increase localised levels of acidity.

“The reefs we work at in Japan are unusual in that they are near volcanic CO2 seeps on the seafloor, which create climatic conditions analogous to projected future ocean conditions,” Professor Nagelkerken said.

“Some reefs sit under present-day seawater chemistry, others are warmer, and some experience both elevated temperature and acidity together.

“These natural climate analogues allowed us to ask real ecological questions in a natural setting.”

Headline: The ocean's pharmacy: scientists chart a new path for marine peptide drug discovery

A review in the Chinese Journal of Natural Medicines surveys how new extraction, chromatography, and bioinformatics tools are accelerating the discovery of bioactive peptides from the sea

Chinese Journal of Natural Medicines

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Advanced production technologies for marine peptides
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Credit: Chinese Journal of Natural Medicines

Marine organisms have evolved a remarkable arsenal of host-defense peptides under conditions of extreme variability and constant pathogen exposure. Generally defined as short chains of 2 to 20 amino acid residues, these molecules have become a focal point for biomedicine, food science, and materials science. In a review published in the Chinese Journal of Natural Medicines, researchers from the School of Pharmacy at China Pharmaceutical University provide an integrated overview of how marine bioactive peptides are produced, purified, and evaluated, and how bioinformatics is reshaping the discovery pipeline.

Peptide production has expanded well beyond classical solvent extraction and chemical hydrolysis. Green deep eutectic solvents have recovered collagen peptides from cod skin with extraction efficiencies of 96%, while enzymatic hydrolysis and microbial fermentation enable targeted release of bioactive sequences. For example, fermentation of scallop skirt with a high-altitude Bacillus strain yielded the iron-chelating heptapeptide FEDPEFE while cutting production cost by up to 50%. Once released, peptides are resolved by membrane separation, multi-mode chromatography, and capillary electrophoresis, with nano-reversed-phase ultra-high-performance liquid chromatography coupled to high-resolution mass spectrometry now enabling accurate sequencing of trace peptides from complex hydrolysates.

The review surveys six major activity categories. Anti-inflammatory peptides such as the phycocyanin-derived PCP3 act through the Akt and AMPK/autophagy pathways, while the Sipunculus nudus tripeptide SRP attenuates cadmium-induced kidney injury via MAPK signaling. Antimicrobial peptides from Antarctic icefish and other species disrupt bacterial membranes and bind microbial DNA, offering candidates against multidrug-resistant pathogens. Antioxidant peptides scavenge free radicals and modulate Keap1/Nrf2 signaling. Anticancer peptides such as MP06 from green algae induce apoptosis in non-small cell lung cancer cells. Antihypertensive peptides like LEPWR and TLRFALHGME inhibit angiotensin-converting enzyme with low-micromolar potency, and antidiabetic peptides improve glycemic control through DPP-IV inhibition and the PI3K/AKT and AMPK pathways.

A central theme is the rise of bioinformatics. Virtual proteolysis using BIOPEP, PeptideCutter, and EnzymePredictor lets researchers triage candidate sequences before laboratory work. Structural prediction platforms such as AlphaFold2, ESMFold, and RoseTTAFold now generate high-confidence three-dimensional models for structure-guided design, and the authors flag the newer AlphaFold3 as a particularly promising tool. Quantitative structure-activity relationship modeling, residue-pattern analysis, and molecular docking, validated by cellular thermal shift assays and surface plasmon resonance, complete the computational layer that links sequence to function.

On the translational side, the global marine peptide market was valued at approximately USD 310 million in 2023, with a projected compound annual growth rate of 6.7%. Yet only a small number of marine peptide drugs, such as ziconotide for severe chronic pain and plitidepsin for multiple myeloma, have reached approval, with several promising candidates discontinued because of toxicity or unfavorable pharmacokinetics. The authors argue that strategies such as cyclization, D-amino acid substitution, PEGylation, conjugation with cell-penetrating peptides, and AI-driven optimization of ADME properties, together with multi-omics analysis and intelligent delivery systems, can move marine peptides from laboratory leads to next-generation drugs, functional foods, and nutraceuticals.

Original article: https://doi.org/10.1016/S1875-5364(26)61178-8

Journal

Chinese Journal of Natural Medicines

DOI

10.1016/S1875-5364(26)61178-8

Method of Research

Literature review

Subject of Research

Not applicable

Article Title

Marine-derived products as pharmaceutical treasure troves: a focus on recent research techniques and potential bioactive activities of marine peptides

Article Publication Date

21-May-2026

Scientists map rocks with rare earth element potential, helping pinpoint new deposits

University of Cambridge

A new atlas charts the global distribution of unusual, critical‑metal‑bearing igneous rocks, finding that they often form near the thick and ancient cores of the world’s major continents.

Researchers from Cambridge’s Department of Earth Sciences mapped occurrences of CO2-rich igneous rocks – the world’s primary source of rare earth elements – finding that their distribution is strongly tied to variations in Earth’s rigid outer layer, the lithosphere.

Thicker lithosphere is key to creating the right rocks for enrichment, say the researchers, allowing pockets of molten rock to become trapped at depth where they slowly steep to concentrate metals.

The findings, published in the journal Nature Geoscience, could be used to guide the search for new rare earth deposits, said Dr Emilie Bowman, lead author of the study from Cambridge Earth Sciences. “Our research is beginning to provide a kind of predictive power for where we can expect these rocks and, by extension, their associated rare earth element deposits, to form.”

Rare earth elements are used in the production of many everyday and advanced technologies, including smartphones and clean energy solutions such as wind turbines and electric vehicles.

Much of the world is dependent on imports of rare earth elements from China, but countries are seeing a growing need to move toward domestic sources which have greater security and sustainability of supply.

“There is significant scientific interest in why rare earth deposits form where they do,” said Professor Sally Gibson, senior author of the study from Cambridge Earth Sciences, who currently holds a £1-million project to investigate this.

Previous investigations have tended to focus on rare earth formation at a specific site, or within a given region, said Gibson, “but we’re scaling up and exploring the question at a global scale, whilst looking for deeper clues that might explain the surface geology.”

Bowman assembled chemical data on 9,000 igneous rock samples from around the world, all enriched in dissolved CO₂ – a key ingredient that enhances the potential for rare‑earth element concentration.

“Until relatively recently, this subset of igneous rocks were mere curiosities,” said Gibson. “Geologists collected them avidly; undergraduates were baffled by them in practical classes. But in recent years they have become very relevant.”

Coming in a range of weird and wonderful forms, many of the rocks were first classified in the 19th and early 20th centuries – taking their names from the places where they were first collected or according to the unusual minerals they contained.

“The terminology is so sprawling that you could almost make a new language from these rock names,” said Gibson. “This, and their scientific complexity, has added confusion, and people have tended to steer away from them.”

The team, including project co-lead Professor Sergei Lebedev and Dr Siyuan Sui, both geophysicists at Cambridge Earth Sciences, plotted the rock data onto a map alongside detailed information about Earth’s interior.

“Using seismic waves from earthquakes, we can create a slice-through image of the lithosphere, much like a sonar can pick out features on the seabed,” said Lebedev. “From this mapping we can see that lithospheric thickness plays a guiding role in where we find these deposits.”

“We needed to put together these two pieces of the puzzle, the rock chemistry and seismic data, in order to make the connection,” said Gibson. “Rocks with the right chemistry for enrichment occur only in very specific places, mainly along the steep edges of Earth’s thickest and oldest lithosphere,” she explained.

Thicker parts of the lithosphere keep the underlying mantle rocks at high pressures and relatively cool, suppressing melting, Gibson explained. Only tiny amounts of the mantle can melt under these conditions, producing small pockets of magma that often get stuck at the base of the lithosphere where they solidify into CO₂‑rich igneous rocks. But it’s only when those rocks are re-melted later that the metals get a second stewing – becoming concentrated enough to form a useful ore deposit.

Now the team plan to extend their map to include rocks older than 200 million years old, which host most of the economic rare earth element deposits and mines globally.

“For this work we focussed initially on deposits that were formed after the main phases of breakup of Earth’s big continents,” said Gibson. She explained that tectonic processes such as mountain building and rifting had churned up the older rocks, making them harder to study. “Now we have established this systematic behaviour exists, we can go back further in time. It’s going to be more challenging, but I’m hopeful that this will be a key step in predicting mineral occurrences.”

Journal

Nature Geoscience

DOI

10.1038/s41561-026-01990-7

Article Title

The global distribution of CO2-rich magmas is determined by lithospheric thickness.

Article Publication Date

22-May-2026

Global rice paddy greenhouse gas emissions have doubled during the past six decades

Practical farming changes can render cleaner cultivation and reduced emissions without sacrificing global food production, Boston College researchers report

Boston College

Chestnut Hill, Mass (5/22/2026) – Rice paddy greenhouse gas emissions have doubled during the past 60 years—but practical farm changes could cut methane emission and support global climate targets without reducing food production, a team led by Boston College scientists reports today in the journal Nature Food.

Rice feeds more than half the world's population, but has a growing climate footprint. Flooded paddies emit methane and nitrous oxide, two powerful greenhouse gases. As rice farming intensifies worldwide, understanding its methane footprint—and how to reduce it without threatening food security—has become a global priority.

“Our goal was to understand the full climate impact of rice systems—not just methane, but all major greenhouse gases together—and to identify realistic pathways for mitigation,” said Boston College Professor of Earth and Environmental Sciences Hanqin Tian, lead author of the report and director of the Center for Earth System Science and Global Sustainability at the Schiller Institute for Integrated Science and Society.

Since the 1960s, greenhouse gas emissions from rice paddies have doubled to approximately the equivalent of 1.1 billion tons of carbon dioxide annually, the researchers report. Methane is a major contributor, particularly in regions such as East Asia, while Africa is emerging as a new hotspot due to expanding rice cultivation, according to the study.

Methane is especially important because it drives near-term warming, making it a central focus of global climate efforts such as the Global Methane Pledge, which aims to cut methane emissions by at least 30 percent this decade, said Tian, who also directs the Global Carbon Project’s Boston Office.

This study provides the most comprehensive global assessment of rice-related greenhouse gas emissions to date, covering methane, nitrous oxide, and soil carbon changes from 1961 to 2020, Tian said. Annual global rice cultivation ranged from 397.4 million acres in 2015 to 426 million acres in 2024.

The researchers combined machine learning trained on more than 21,000 field observations, a process-based ecosystem model, and a global meta-analysis. By integrating these approaches, Tian said the team quantified total emissions, identified key drivers such as land expansion and residue management, and evaluated how future mitigation strategies could contribute to climate targets—including methane reduction goals under international initiatives.

Tian said the team wanted to quantify the role rice paddy cultivation plays in global greenhouse gas emissions—especially methane—and the factors driving their rapid increase. Just as crucial was understanding how emissions can be reduced through realistic changes in farming practices, and the potential for reductions to contribute to climate goals set by entities such as the Global Methane Pledge, which counts 159 participating countries.

Tian and colleagues from Alcorn State University, Auburn University, Stanford University, University of Maryland, and France's University of Versailles Saint-Quentin-en-Yvelines identified two dominant drivers behind the six-decade surge in emissions:

Expansion of rice cultivation, particularly in developing regions, which has increased total emissions globally
Intensified residue incorporation, where crop residues are returned to flooded soils, boosting methane production

Regionally, East Asia experienced renewed methane increases linked to heavy straw incorporation, while Africa emerged as a fast-growing emissions hotspot as rice cultivation acreage increased seven-fold between 1961 and 2024, to 40 million acres, Tian said.

Despite rising emissions, the study highlights a clear opportunity: improved farm management could reduce emissions by about 10 percent without compromising yields. Key strategies include: optimizing water management to reduce methane formation, reducing excessive residue return to soils, and improving nitrogen fertilizer efficiency.

“These are practical, scalable solutions that farmers can adopt today,” said study co-author and Boston College Associate Professor of Engineering Susan Pan, research director at the Center for Earth System Science and Global Sustainability. “They offer a meaningful pathway for agriculture to contribute to near-term climate targets, including methane reduction goals.”

Journal

Nature Food

DOI

10.1038/s43016-026-01355-8

Method of Research

Meta-analysis

Subject of Research

Not applicable

Article Title

Global Rice Paddy Greenhouse Gas Emissions Have Doubled over the Past Six Decades Driven by Area Expansion and Intensified Residue Incorporation

Article Publication Date

22-May-2026

Bodies in fashion: Diversity is up, but the ideal stays the same

Fashion looks more diverse than ever, but the body ideal hasn't really changed in 25 years

Technical University of Denmark

Fashion and media have become visibly more diverse over the past quarter-century. Yet beneath that surface change, a new study suggests that the industry's central female body ideal has barely shifted.

A large-scale analysis of nearly 800,000 fashion images finds that while representation has broadened, the typical female model body has remained remarkably stable, with non-white models 4.5 times more likely to also be plus size.

In the paper Cultural evolution of beauty standards, published in Proceedings of the National Academy of Sciences (PNAS), researchers analyzed 793,199 images from 2000 to 2024, drawn from fashion shows, advertisements, magazine covers, and editorial fashion coverage. Using computer vision, network analysis, and clinical population health data, they tracked how model body size has evolved over time, across regions, and within segments of the fashion industry. The primary focus of the research is on female models (see fact box).

Their main findings are unexpectedly simple. While a wider range of body types now appears in fashion imagery, the typical model’s body has not changed. Diversity has increased through the inclusion of a small number of models at the extremes, rather than through a shift in that norm itself.

“On the mean, nothing happens. Everything is super stable,” says Louis Boucherie, a researcher at DTU (the Technical University of Denmark), and lead author of the paper, co-authored with researchers in Denmark, the United States, and Austria (see fact box).

“When we then look at the change in variation, we find what you'd expect: body size diversity has grown. But when we look at how that variation is distributed, we can see that the middle stays stable. So, the change is happening at the outliers.”

Plus size models and the population gap

To benchmark fashion against reality, the researchers compared US-based models with the US government's large-scale health survey (NHANES). The contrast is stark.

“When we compare the US models to the general US population, there is almost no overlap between the two. And if you look carefully, you see that even the plus size models are still below the average US body size. So, what the fashion industry calls plus size corresponds much more closely to the average American woman,” Louis Boucherie.

In other words, even the models labeled as “plus size” are, on average, smaller than the typical adult woman in the general population. The overlap between fashion imagery and body sizes in the population remains extremely limited.

The researchers highlight that exposure to narrow body ideals has been repeatedly linked, in meta-analyses across genders and age groups, to body dissatisfaction, disordered eating, and psychological distress.

Intersectionality: the burden of representing diversity

The study also examines how different dimensions of diversity intersect. As it turns out, ethnic representation in fashion imagery has changed markedly in the same 25-year period. The share of models identified as non white rose from roughly 13 percent in 2011 to more than 40 percent in recent years, according to the analysis.

“We don’t have very fine grained racial categories in the data. We essentially must work with a white versus non white distinction, which is obviously a coarse way of doing it. But it’s the only way to do the analysis consistently across the full dataset and over time,” says Louis Boucherie.

The study finds that these two dimensions of diversity, body size and ethnicity, intersect rather than expand independently. And thus, a plus size model is 4.5 times more likely to be non-white, suggesting that multiple markers of difference are often concentrated in the same individuals. This means the industry's gains in diversity are intersectionally concentrated on the same individuals rather than broadly distributed.

“What these patterns of representation end up meaning is that the burden of representing diversity often falls on a relatively small group of non white models,” says Louis Boucherie.

Fashion institutions can therefore increase visible diversity without altering the central aesthetic standard. However, not all parts of the fashion industry shape norms to the same degree. To examine whether these patterns differ across the industry, the researchers built a data-driven hierarchy of brands and magazines from the collaboration network. measuring status by which brands book the same models as other high-status players.

A distinctive pattern emerges at the top. High-prestige brands feature both the thinnest models and a higher share of visibly plus-size models than their less prestigious peers. This shows that the industry's evolution is heterogeneous: aggregate measures of diversity mask significant variation across prestige tiers.

Regulation: what has already been tried

The paper also explores whether formal regulation has influenced model selection. It examines two contrasting European interventions: a hard, numerical minimum body mass index requirement enforced at Milan Fashion Week, and a softer, certification-based system implemented in France.

The researchers compare how these differing regulatory designs coincided with changes in the prevalence of extremely thin models over time, explains Louis Boucherie:

“What we see is that in Milan, where there was a hard numerical threshold, there is a clear reduction in the number of extremely thin models after the regulation was introduced. In France, however, where the regulation was much softer and based on doctor certification, we don’t see the same kind of effect. We’re very careful not to claim causality here, but descriptively the difference between a hard threshold and a flexible system is quite striking.”

The researchers emphasize that the analysis identifies correlations rather than causal effects. Still, the contrast suggests that the design of regulatory interventions may matter for how body ideals are expressed in fashion imagery.

Progress with limits

Taken together, the findings point to a paradox at the heart of contemporary fashion culture. Representation has broadened, and diversity has increased in visible ways. Yet the core definition of what counts as a normative or aspirational body has proven far more resistant to change, which suggests that inclusion alone does not necessarily reshape standards.

Shifting cultural norms may require change not just at the margins, but at the center of the industry itself.

“I think people already knew there was a problem, which has been debated repeatedly. What we’ve done is to quantify it. And I think that’s the new part. We’re just here to say that there is this problem, and then it’s the responsibility of the advertisers and the people organizing fashion shows and editing magazines to decide what to do with that information,” says Louis Boucherie.

About the paper

What about male models?

The study also includes male models, and the analysis shows that patterns differ from those observed for women. While male fashion imagery likewise exhibits very narrow and idealized body standards, changes over time are less pronounced, both in terms of body size and diversity.

The researchers found no comparable expansion in variation among male models and noted that the fashion industry’s male body ideal appears more stable and less contested over the period studied. Statistically, however, there is less signal to analyze.

As a result, the authors focus primarily on women’s fashion imagery, where both the scale of change and its social implications are more clearly detectable in the data.

About the paper:

Read the paper: Cultural evolution of beauty standards | PNAS

For a visual representation of the data, see Who Gets to Be Beautiful?

Authors:

Louis Boucherie: DTU Compute, the Technical University of Denmark, and Center for Social Data Science, University of Copenhagen, Denmark.
Sagar Kumar: Network Science Institute, Northeastern University, Boston, USA.
Katharina Ledebur: Complexity Science Hub, Austria.
August Lohse: DTU Compute, Denmark.
Karolina Sliwa: WU Vienna, Vienna University of Economics and Business, Austria.

Journal

Proceedings of the National Academy of Sciences

DOI

10.1073/pnas.2602380123

Article Title

Cultural evolution of beauty standards

Article Publication Date

21-May-2026

Beyond black: Research explores the feather color of American crows — as seen by crows

Birds can see into the UV spectrum, which allows them to pick up on signals that the human eye cannot

Binghamton University

image:
Binghamton University Associate Professor Emerita of Biological Sciences Anne B. Clark
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Credit: Binghamton University

To understand birds — their social relationships, their choices, even their feathers — you need to understand the way they see the world.

That can be a challenging task, because birds and humans literally see their environments differently. Primates have three types of cone cells in their eyes, which provide the range of colors that we see; avians have four, explained Binghamton University Associate Professor Emerita of Biological Sciences Anne B. Clark.

“They actually see further into the UV (ultraviolet) range than we do,” Clark said. “That gives them a channel of communication that we may not detect.”

Research recently published in the Journal of Avian Biology takes an in-depth look at how crows see each other. Co-authored by Jessica Yorzinski of Texas A&M University’s Department of Conservation Biology and Binghamton’s Clark, “Inter- and intra-individual variation in the feather coloration of American crows” used a full-spectrum camera and visual modeling to analyze the plumage of 28 museum specimens from a crow’s visual perspective.

The feathers of melanistic birds, such as crows, haven’t been heavily studied by researchers. Unlike species such as fish crows or grackles, American crows aren’t known for iridescence, which, in black feathers, shows up as light refracted to create subtle purple or greenish hues. To human eyes, crows are difficult to tell apart: solid black, with no visual demarcation between males and females.

Research has shown that some bird species have feather patches that reflect UV light, perhaps to signal health status or biological sex; these include blue tits, a British species related to chickadees, as well as budgerigars, the small parakeets commonly kept as pets.

It turns out that crows lack UV-reflective patches, and that the sexes really do look the same, plumage-wise. However, the research in Yorzinski’s lab unearthed subtle changes that indicate age: On the sides, back and even under the tail, feathers changed in hue, both in the human visual range and in the UV or violet range as the birds reached the age of 3.

“There are many possible mechanisms. There may be a greater concentration of melanin, or changes in the feather structure,” Clark said.

The reasons behind the changing hue could be reproductive in nature. Under the age of 3, crows are typically unable to find mates or defend territory, Clark said. Attractive feathers may indicate the birds’ prime of life, health status, and resources to potential mates.

Some age-linked differences are apparent to the naked eye. Yearling birds have poor-quality feathers that tend to take on a brownish cast until they experience their first molt. And Clark, who researches crow populations, notes that elderly birds — 18 or 19 years old — tend to look their age, so to speak, when it comes to the condition of their feathers.

“There’s a sense that perhaps feathers get better and better, and then that falls off as they age,” Clark said. “Unfortunately, this should be familiar to most people; it gets harder to look great.”

How do crows tell each other apart? The experiment showed something else: Crows’ foreheads are even blacker than the rest of their plumage and don’t reflect the light. Crows are ground foragers, and these ultra-black feathers above their eyes may reduce glare in strong sunlight, essentially functioning like a baseball cap.

“It may help augment their vision and cut down on hyper-reflections from the ground,” Clark said. “That’s all hypothesis, but it runs across all of the crow species we have looked at.”

With the same black plumage, how do crows tell one another apart? Earlier research has shown that their calls are individually specific, functioning in the same way as human voices. Female crows tend to have higher voices than males, partly due to body size.

Crows also vary in body size and shape and have similarly diverse bills; the tips grow continuously, but the bill shape is stable nearer the base. One crow family that Clark has observed featured a member with a bill shaped almost like a Roman nose, while his mate had a petite, straight bill; their offspring exhibited one or the other.

Clark hypothesizes that, like humans, crows may also be able to recognize individuals by how they move — in their case, fly. One older crow, sitting in her territory at sunset, didn’t respond as other crows winged by overhead, returning home after a day of foraging. That is, until she saw one specific bird fly overhead; she perked up and apparently called a greeting, at which it looked down while in flight and replied, Clark recounted.

“Our recognition of the quality and identity of our social companions uses many sensory modalities,” Clark said. “What we’ve shown is that the black of a crow does vary and has information in it, even though it’s sexually monomorphic.”

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Journal

Journal of Avian Biology

DOI

10.1002/jav.03604

Method of Research

Observational study

Subject of Research

Animals

Article Title

Inter- and intra-individual variation in the feather coloration of American crows