UMass Amherst-led team discovers new way to make thermally insulative plastics

Plastics with low thermal conductivity could have aerospace and energy-efficient building applications

University of Massachusetts Amherst

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An illustration of THDBT (tetrahydroxy deoxybenzoin triazole) filler aggregates at the molecular level. In this “slow chaos” state, there are fewer vibrational pathways available for heat transport, resulting in lower thermal conductivity. Reproduced from Materials Horizons with permission from the Royal Society of Chemistry. 

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Credit: Yanfei Xu, UMass Amherst; Reproduced from Materials Horizons with permission from the Royal Society of Chemistry.

AMHERST, Mass. — University of Massachusetts Amherst researchers have demonstrated a possible new avenue for developing flame-retardant and generally low-conductivity (low heat transfer) plastics that retain the benefits of being strong and flexible by limiting the accessibility of heat-carrying vibrational channels of the material. This new design framework has promising applications, including lightweight thermal insulation materials for spacesuits, thermal protection components for spacecraft and advanced building materials that reduce heating and cooling losses. 

 

Thermal conductivity is a measure of how efficiently heat can move across a material. When heat moves quickly, the material is conductive. If heat moves slowly, the material is a good insulator. Conventionally, materials are made more insulative by the introduction of pockets of air, which are poor conductors. While effective for inorganic materials, this method does not work for plastics because it can weaken the material and complicate manufacturing.  

 

Yanfei Xu, corresponding author of the study and assistant professor in the Riccio College of Engineering at UMass Amherst, and her team investigated a new way to reduce conductivity without introducing porosity. Instead, they looked at the material’s vibration on an atomic level. Heat moves when vibrational energy is passed from one atom to another, much like a bucket brigade passes water down a line. Firefighters (here representing the atoms) move the bucket (representing heat) in coordinated movement, efficiently from point A to point B. 

 

To reduce conductivity, Xu and her team used vibrational engineering so that, instead of strong firefighters efficiently passing big buckets from one person to the next, the polymer behaves like a group of disorganized toddlers—no two children are moving in the same direction and the small hands can only carry small cups instead of big buckets.  

 

As a result, the heat moves along the material very slowly. In their initial trial of this new method (tested using a polymer hybrid of polyurethane and tetrahydroxy deoxybenzoin triazole), the researchers found that this “slow chaos,” as Xu describes the polymer’s behavior, reduced conductivity by 17%. The material also demonstrated flame-retardant behavior. 

 

Xu points out that their reduction in thermal conductivity is small in this initial testing, but she is excited about their discovery of a new mechanism for governing thermal conductivity.  

 

“There is a lot of potential,” she says. “By reducing the density of thermally accessible vibrational channels available for heat transport, thermal conductivity is suppressed. The materials remain dense, mechanically compliant and flame-retardant.”  

 

This research, published in Materials Horizons, was featured on the journal’s front cover. The work was conducted in collaboration with scientists from North Carolina State University, Massachusetts Institute of Technology, Texas A&M University, and Brookhaven, Oak Ridge and Argonne national laboratories. 

 

The research was supported by the U.S. National Science Foundation, the Federal Aviation Administration and UMass Amherst.  

 

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Journal

Materials Horizons

DOI

10.1039/D6MH00633G 

Method of Research

Experimental study

Subject of Research

Not applicable

Article Title

Suppressing thermal transport in nonporous polymer hybrids by limiting thermally accessible vibrational modes

 

Faster aging in younger generations linked to rise in early-onset cancer

Immune system aging linked to earlier lung cancer; fat tissue aging linked to earlier colorectal cancer

WashU Medicine

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Cancer is often considered a disease of aging. Older adults are at higher risk because they have had more time to accumulate cellular damage that can trigger tumor formation. But as cancer rates in younger adults rise, with each successive generation facing higher risks than the one before it, researchers are asking whether cellular damage is accumulating faster in recent generations, accelerating their body’s biological aging.

A new study led by researchers at Washington University School of Medicine in St. Louis provides evidence that younger generations are indeed aging faster biologically than their older counterparts. The causes remain under investigation around the world, including global efforts led by research members of Siteman Cancer Center, based at Barnes-Jewish Hospital and WashU Medicine, and Cancer Grand Challenges, a global initiative co-founded by the National Cancer Institute and Cancer Research U.K.; but importantly, the new research links this accelerated aging to an increased risk of early-onset cancers in younger generations. In general, early-onset cancers are those diagnosed at age 55 or younger.

The larger the gap between biological age — that is, how old our bodies appear to be — and chronological age — which is how many years we have actually lived — the higher the cancer risk, according to the researchers. They found that people in more recent birth cohorts had larger age gaps than those in older birth cohorts, which may help explain the rise in early-onset cancer in recent generations.

Their study also identified links between faster aging in particular organ systems and increased risks for certain cancers. For instance, an immune system that appears older than its actual age was associated with early-onset lung cancer. Similarly, fat tissue that appears older than its chronological age was associated with early-onset colorectal cancer.

The study, published June 22 in the journal Nature Medicine, suggests that measures of accelerated aging could help identify individuals at higher risk of early-onset cancer and guide new strategies for cancer prevention and early detection.

“Our ultimate goal is to decode how modern environments become biologically embedded to drive cancer risk, transforming prevention from broad recommendations to personalized interventions,” said Yin Cao, ScD, a molecular epidemiologist and an associate professor of surgery and of medicine at WashU Medicine. “This brings us closer to identifying risk earlier and developing prevention strategies that are tailored to an individual’s biology.”

Exploring biological aging

Cao’s team has been at the forefront of identifying individual factors that influence cancer risk across the life course, such as obesity, metabolic dysregulation, alcohol consumption, sedentary behavior, poor diet quality and cesarean delivery. Although these discoveries have revealed important clues to the origins of cancer at younger ages, the contribution of any single factor is modest.

With that in mind, Cao, also a research member of Siteman, and her colleagues have sought ways to capture the influence of multiple risk factors operating together to spur cancer development. With support from Cancer Grand Challenges, Cao, as co-lead of Team PROSPECT, has been able to go after this problem.

For the current study, Cao’s team analyzed data from more than 154,000 young adults in the UK Biobank, a large biomedical dataset containing biological, health and lifestyle data, and from more than 10,000 individuals in the U.S. participating in the National Institutes of Health’s (NIH) All of Us Research Program, an effort to build a comprehensive health dataset on more than 1 million people living in the U.S.

To estimate the level of biological aging — or age gap — the researchers, including first author Ruiyi Tian, a doctoral student in the Cao lab, examined aging at two levels: across the body as a whole, known as systemic aging, and within individual organs, known as organ-specific aging. For systemic aging, the researchers used established measures, including clinical biomarker-based measures such as PhenoAge and the Klemera-Doubal Method, as well as a metabolomic age score, which provides a measure of individual metabolism.

PhenoAge, for example, measures nine blood biochemistry markers such as albumin, made by the liver, and creatinine, a waste product removed by the kidneys. For organ-specific aging, the researchers used blood proteomic data, which measure levels of multiple proteins linked to specific organ systems, to estimate biological aging in individual organs.

The researchers calculated the average age gap for each birth cohort and used standard deviation to describe how much each group differed from the study average. Standard deviation is a measure of how spread out data points are around the average.

The researchers found that individuals in the UK born between 1965 and 1974 had systemic aging that was 23% of one standard deviation higher compared with those born between 1950 and 1954, after accounting for chronological age. In other words, people in the younger birth cohort showed a modest shift toward older biological profiles than people in the older birth cohort when at the same chronological age.

The researchers observed a similar pattern in the U.S cohort. Participants born between 1990 and 1999 had systemic aging that was 92% of one standard deviation higher compared with those born between 1965 and 1969.

This increased systemic aging in the younger group was associated with an 8% increased risk of early-onset solid cancers, especially lung, gastrointestinal and uterine cancers. When participants were divided into three groups based on their level of systemic aging, those with the most advanced systemic aging had a 15% increased risk of early-onset solid cancer compared with those with the least advanced systemic aging. According to the analysis, the increased risk persisted even after controlling for inherited genetic risks of cancer and genetic susceptibility to accelerated aging.

By zooming into organ-specific aging, the researchers found that advanced immune system aging was associated with increased risk of early-onset lung cancer, and advanced adipose (fat) tissue aging was associated with increased risk of early-onset colorectal cancer.

“If we can identify younger people with the highest cancer risk when they are still healthy, we can focus on prevention and early-detection strategies for the individuals who will benefit most from early interventions,” Cao said.

This research is part of Team PROSPECT, a Cancer Grand Challenges team co-led by Cao. Cancer Grand Challenges is a global research funding initiative co-founded by Cancer Research UK and the National Cancer Institute (NCI) that brings together world-leading researchers to take on cancer’s toughest challenges.

“Right now, we don’t have a definitive answer to what’s driving the rise of early-onset cancers around the world, but studies like this are helping us piece together the bigger picture, showing that cancer may be influenced not just by changes inside individual cells, but by wider changes happening across the body as a whole,” said David Scott, PhD, director of Cancer Grand Challenges.  “Research on this scale is possible through Cancer Grand Challenges, which brings together scientists from different fields around the world to tackle these complex questions together.”

Cao and her colleagues are leading efforts to transform the understanding of why cancers are increasingly striking younger generations. Their next frontier is to decipher how environmental, lifestyle and societal changes leave lasting biological imprints, including accelerated aging and other markers of heightened susceptibility. By illuminating the pathways through which risk accumulates across the life course, they seek to uncover the origins of early-onset cancers and redefine opportunities for prevention. In parallel, their work will enable more precise approaches to identify those at greatest risk and intervene earlier, shifting the paradigm from reacting to disease to preventing it before it begins.

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Tian R, Zong Y, Ren D, Tica S, Hong D, Odulyale O, Buenrostro J, Govindan R, Cao Y. Biological aging and generational shifts in early-onset cancer risk. Nature Medicine. June 22, 2026. DOI: 10.1038/s41591-026-04448-w.

This work was part of the PROSPECT team supported by the Cancer Grand Challenges initiative funded by Cancer Research UK, grant numbers CGCATF-2023/100043 and CGCATF-2023/100037; the National Cancer Institute of the NIH, grant numbers OT2CA297577 and OT2CA297576; the French National Cancer Institute; and the Bowelbabe Fund for Cancer Research UK. The project was also supported by grants from NIH/National Cancer Institute, grant number R37CA246175; the NIH/National Institute of Diabetes and Digestive and Kidney Diseases, grant number P30DK052574; the Alvin J. Siteman Cancer Center through the Foundation for Barnes-Jewish Hospital. Further support was provided by a pre-doctoral fellowship in the Cancer Biology pathway supported by NIH Molecular Oncology Training Grant T32CA113275 to Washington University School of Medicine in St. Louis; the Pediatric Gastroenterology Research Training Program grant T32DK077653 to Washington University School of Medicine in St. Louis; the Washington University School of Medicine in St. Louis Institute of Clinical and Translational Sciences, grant number UL1TR002345; and the Foundation for Barnes-Jewish Hospital. The content is solely the responsibility of the authors and does not necessarily represent the official views of the NIH.

About WashU Medicine

WashU Medicine is a global leader in academic medicine, including biomedical research, patient care and educational programs with 3,100 faculty. Its National Institutes of Health (NIH) research funding portfolio is the second largest among U.S. medical schools and has grown 78% since 2016. Together with institutional investment, WashU Medicine commits over $1.6 billion annually to basic and clinical research innovation and training. Its faculty practice is consistently among the top five in the country, with more than 2,550 faculty physicians practicing at 200 locations. WashU Medicine physicians exclusively staff Barnes-Jewish and St. Louis Children’s hospitals — the academic hospitals of BJC HealthCare — and Siteman Cancer Center, a partnership between BJC HealthCare and WashU Medicine and the only National Cancer Institute-designated comprehensive cancer center in Missouri and southern Illinois. WashU Medicine physicians also treat patients at BJC’s community hospitals in our region. With a storied history in MD/PhD training, WashU Medicine recently dedicated $100 million to scholarships and curriculum renewal for its medical students, and is home to top-notch training programs in every medical subspecialty as well as physical therapy, occupational therapy, and audiology and communications sciences.

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Journal

Nature Medicine

DOI

10.1038/s41591-026-04448-w 

Article Title

Biological aging and generational shifts in early-onset cancer risk

Article Publication Date

22-Jun-2026

 

Artificial light Is keeping reef fish awake, and the effects may ripple across coral reefs

Bar-Ilan University study finds that coastal light pollution disrupts sleep and is associated with increased markers of DNA damage in the brains of reef fish

Bar-Ilan University

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Schools of Chromis viridis hovering near branching corals in the Gulf of Aqaba, Red Sea, Eilat,
Israel

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Credit: Shachaf Ben-Ezra

Artificial light spilling into coastal waters from cities, ports, roads, and hotels is disrupting sleep in coral reef fish and is associated with changes in markers linked to brain health, according to a new study from Bar-Ilan University.

The study, published in Current Biology, shows that even low levels of nighttime illumination can significantly alter the behavior and physiology of reef fish. Fish exposed to artificial light slept less, showed more fragmented sleep, became more aggressive, and fed at unusual hours, effectively behaving as if night had turned into day.

"Artificial light at night is rapidly expanding across coastal environments worldwide," said Prof. Oren Levy of Bar-Ilan University's Faculty of Life Sciences and the H. Steinitz Marine Biology Laboratory in Eilat, who co-led the study with Prof. Lior Appelbaum and doctoral student Shachaf Ben-Ezra, from the Bar-Ilan Faculty of Life Sciences. "We found that even relatively low levels of illumination can disrupt natural sleep patterns and are associated with changes in markers of neuronal health."

The researchers studied the blue-green damselfish (Chromis viridis), a common reef fish that feeds above coral during the day and shelters in branching corals at night.  Using infrared video, machine-learning tracking, lab experiments, and in situ reef studies in the Gulf of Aqaba/Eilat, Israel, they first confirmed that these fish exhibit clear sleep-like states, including inactivity, characteristic posture, and reduced responsiveness.

When exposed to ecologically relevant artificial light at night (ALAN) levels, however, these patterns broke down. Fish no longer remained confined to their usual nighttime territories within the coral, instead expanding their activity range, feeding at unusual hours, interacting more aggressively, and sleeping significantly less.

To assess biological effects, the team examined neurons in a brain region involved in sleep-dependent brain functions. Fish exposed to nighttime light pollution showed elevated levels of markers associated with DNA damage compared with fish under natural dark conditions. While the study does not demonstrate that light directly damages DNA, the findings suggest that sleep disruption may interfere with essential nighttime maintenance and repair processes in the brain. These changes appeared after only a few nights of exposure and persisted during a five-month field experiment conducted directly on a coral reef, suggesting that chronic exposure to artificial light may have lasting biological consequences.

"Sleep is a critical period for biological repair," said Prof. Appelbaum. "Our findings suggest that disrupting sleep with artificial light may have measurable consequences even in wild marine animals."

Approximately 22% of the world's coastal regions and 35% of marine protected areas are already affected by ALAN. In the Gulf of Eilat, where this study was conducted, nighttime light levels near developed coastal areas can reach up to 60 times the brightness of natural starlight due to urban and port development. Previous work from Levy's lab showed that artificial light can affect coral physiology, disrupt the symbiotic relationship between corals and algae, and interfere with the synchronization of coral spawning. The new findings indicate that fish living within those ecosystems are also affected, pointing to broader ecosystem-level consequences.

"Coral reefs depend on tightly connected biological interactions," Levy said. "If artificial light is affecting both corals and the fish that depend on them, the consequences could ripple throughout the reef ecosystem."

The light levels used in the study match those measured near developed coastal areas, underscoring the real-world relevance of the findings. The researchers call for improved coastal lighting practices, including reducing unnecessary nighttime illumination, directing light away from the shoreline and water, adopting smart lighting technologies, and developing guidelines for wavelengths that minimize ecological disruption.

Future research will examine whether these effects are reversible and how widespread they are across marine species.

Photos, video, captions and credits may be found here.

  

Artificial light at night at the Gulf of Aqaba, Red Sea, Eilat, Israel

Credit

Shachaf Ben-Ezra

Artificial light at night at the Gulf of Aqaba, Red Sea, Eilat, Israel [VIDEO] 

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Journal

Current Biology

DOI

10.1016/j.cub.2026.05.058 

Article Title

Artificial light pollution disrupts sleep and neuronal genomic stability in wild reef fish

Article Publication Date

22-Jun-2026

 

Crashing insect populations have resulted in smaller tree swallows that reproduce less

In bringing the role of biodiversity loss into better focus alongside climate change, researchers say that there may be opportunities to better protect wild birds

University of Michigan

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Since 1977, tree swallows at Long Point Bird Observatory have been losing mass and producing fewer offspring due to a collapse in the insect population, according to new research led by the University of Michigan.

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Credit: Sherri and Brock Fenton

Since the 1970s, the amount of insects at Canada's Long Point Bird Observatory has dropped by more than 60%, according to a new study led by the University of Michigan. Because of this, today's birds are smaller and facing greater challenges to their breeding success compared with previous generations.

The researchers focused on tree swallows, a rapidly declining bird species that feeds on flying insects.

"Tree swallow clutch size is really tightly tied to insect availability," said Charlotte Probst, lead author of the new study and a doctoral student in the U-M School for Environment and Sustainability, or SEAS. "When there's fewer insects available, the birds are smaller and the birds also produce fewer young."

The study also integrates climate data, making it one of the first to consider the role of resource availability alongside climate change in understanding how these pressures are reshaping bird biology. The results show that climate impacts cannot be fully understood without considering biodiversity loss. In the case of tree swallows, finding ways to combat that loss outside of solving climate change could be reasons for cautious optimism, the team said.

"I think this work highlights the significance of biodiversity loss and the complexity of natural systems. We can often lose sight of that and get focused on single processes like climate change," said Brian Weeks, an associate professor at SEAS and senior author of the new study. 

"It's clearly important to contextualize climate change within a broader understanding of how humans are altering the environment. In this case, climate change is one thing, and it's shifting the system. But it's not the biggest thing and its consequences cannot be understood without also understanding biodiversity loss."

The study, supported by the David and Lucile Packard Foundation and the Doug and Nancy Schrank Family Fund, was published in the Proceedings of the National Academy of Sciences. 

Phenological mismatch

The populations of flying insectivores, including tree swallows, are declining across North America. One factor that's suspected to be limiting their reproductive success is a mismatched timing between their breeding and when insects emerge for the season. 

"Breeding is a really energetically intensive part of the annual cycle for birds. It takes a lot of energy to make eggs and it takes a lot of energy to rear young," Probst said. "In general, birds should want to synchronize their breeding with peaks in insect abundance."

When that timing is off, it becomes what's known as a phenological mismatch and these mismatches are one of the major outcomes of climate change. At Long Point, peak insect abundance happens in May, not long after the weather becomes warm enough for the insects to launch into their active lifecycles. But as winters trend warmer, insects are emerging earlier at a rate that's faster than the birds are tracking it.  

"People have known about mismatches in important events for decades and they are very worried about it, understandably so," Weeks said. "Our study shows that you really can't understand the consequences of that without also understanding the context from a biodiversity decline perspective."

The team found that the mismatch between the timing of tree swallow breeding and peak insect emergence has been increasing by more than 3 days per decade since 1977 at Long Point. But, because of the plummeting insect abundance, the costs of this mismatch are actually declining through time. 

To understand how disappearing insects could dampen the mismatch impacts, consider a year when peak insect abundance occurs particularly early. This also increases the likelihood of the birds experiencing a cold snap that could spell disaster for their nests, Probst said. Were things the way they were in 1977, the risk might be worth it for the nutritional reward, but that reward is much, much smaller now.

"Now, when insects emerge, it's half as many insects and they emerge in a much flatter process, so you don't get a huge pulse at the beginning," Weeks said. "So the fact that those dates are not coinciding as closely anymore, it doesn't really matter as much."

Fully characterizing what's behind the insect population collapse will require further study, but the decline does not appear to be the result of rising temperatures, the researchers said. They did note, however, that the declines accelerated in the 1990s, which coincides with a surge in the use of neonicotinoid pesticides.

These pesticides are incredibly effective and even small amounts that make it into wetlands could be devastating to the aquatic larvae of insects in the tree swallow diet, including midges and mosquitos, Probst said.

"Although insect decline is also a really complicated problem to solve, in our system, it appears to be something that can be addressed at a very local level," she said. "This is a problem that we can fix on a short timescale and without needing to have the entire global community come together to do something like climate change."

Big data for small birds

The team's findings are based on analysis and modeling using data that exists thanks to the foresight of Long Point Bird Observatory, the oldest continuously operating bird observatory in North America. Under the leadership of the late David Hussel, who helped found the observatory after earning his doctorate at U-M, its staff and volunteers started recording data for the birds and the insects decades ago. The team had access set to tree swallow data sets ranging from 1969 to 2024, while the insect data covered 1977 to 2011.

"Basically, the people at Long Point did an incredible amount of work and we're really lucky to have been able to collaborate with them," Probst said.

It was essential to have robust data covering such a long timespan to understand the relationships between climate, food abundance and what's happening to a single bird species at a particular location, Weeks said.

"Another main takeaway of this is the value of long-term, sustained data collection in an era when there's a rapid reduction in public investment in efforts like this," he said. "When you're trying to model complex relationships, you need a whole bunch of data and it typically takes an effort beyond what an individual person or lab can do."

The team's U-M cohort also included SEAS professor Inés Ibáñez, postdoctoral researcher Scott Yanco, master's student Isaiah Clark and undergraduate researcher Mark Ziebell. Co-authors Matthew Fuirst and Stuart Mackenzie from the Long Point Bird Observatory rounded out the full collaboration. 

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Journal

Proceedings of the National Academy of Sciences

DOI

10.1073/pnas.2607714123 

Article Title

Resource declines shape phenological and morphological responses to climate change

Article Publication Date

26-Jun-2026

 

Tree swallows are uniquely suited for a study like this because they will return to nesting sites that researchers have set up for them. Researchers can also peek into nests to count eggs and band chicks without the parents abandoning the nest.

Credit

Sherri and Brock Fenton

 

Although tree swallow populations are declining, this doesn't appear to be because of upticks in mortality, at least for the Long Point flock. Rather, they are having fewer offspring as a result of the declines in insect abundance.

Credit

Brian Weeks

Long Point Bird Observatory, located in southern Ontario on a piece of land that sticks out into Lake Erie, is the oldest continuously-operated bird observatory in North America. It was founded with help from U-M alumnus David Hussel, who served as its first executive director.

Credit

Charlotte Probst

 

Bigger bodies were a late addition for humans

University of Reading

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The biggest jump in body size among our ancestors happened around 2 to 2.5 million years ago, with the appearance of Homo rudolfensis or Homo erectus/ergaster, rather than gradually across the whole human family tree. 

New research published today (Monday, 22 June 2026) in the journal PNAS, found that some species bucked the trend completely. Homo floresiensis and Homo naledi stayed small, with the early hominin Australopithecus weighing 40kg, on average, and reaching the height of a child. Other branches of Homo grew larger. Homo erectus/ergaster were the first hominins to weigh around 60 kg or more, on average, achieving weights similar to many modern humans.    

The University of Reading and University of Oxford findings challenge the idea that bodies simply got bigger and bigger over time in a steady line, eventually leading to modern humans. 

Dr Jacob Gardner, lead author at the University of Reading, said: "For years, different studies have come to different conclusions about whether our ancestors steadily grew bigger over time or jumped in size at some key point in our Homo ancestors. We think that's because everyone was looking at slightly different pieces of a much bigger puzzle. When you put all the fossils together, examine multiple competing ideas, and account for how species are related to each other, a clearer picture emerges. The answer is most likely a combination of these ideas. 

“The human story is not simply one of constant growth, but also of a major change that happened later, within our own genus, while other branches of the family, including some surprisingly small relatives, went their own way entirely." 

Piecing together the human puzzle 

Researchers reached these conclusions by looking at body weight from 386 fossils across 21 different species of hominins, the group that includes humans and our extinct relatives. They used statistical models to track how body size changed over millions of years. 

Previous studies disagreed because some focused on early relatives such as Australopithecus, others on later members of Homo, and some used different methods to estimate body weight from fossil bones. These studies also did not account for how hominin species were related to one another or the various uncertainties that come with an incomplete fossil record, such as which fossils belong to which species. Bringing all of this together in one model shows that these studies weren't actually disagreeing with each other, they were just looking at different parts of a more complicated story. Body weight steadily increased over time in our earlier hominin relatives, like Australopithecus, but then jumped in size at a key point later in Homo.  

The timing of this growth spurt lines up with other changes in later Homo. These ancestors were walking on two legs more efficiently than earlier hominins, eating more meat, and roaming over much larger areas in search of food and suitable habitat. A bigger body may have helped with all of these things, making it easier to travel long distances and survive on a varied diet. The findings suggest that growing larger was closely tied to a wider shift in how these early humans lived. 

Dr Thomas Puschel, co-author from the School of Anthropology and Museum Ethnography, University of Oxford, said: “Our results suggest that human body size evolution was not simply a story of steady growth over time. Although body mass generally increased throughout our evolutionary history, the most significant shift occurred later within the genus Homo. This change coincided with broader developments in how our ancestors moved across landscapes and exploited their environments, pointing to a close relationship between body size and major ecological and behavioural transitions."

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Journal

Proceedings of the National Academy of Sciences

DOI

10.1073/pnas.2521732123 

Article Title

Competing models of hominin body size evolution

Article Publication Date

22-Jun-2026