Historians have often argued that inequality increased when small farming settlements developed into cities. Under this traditional model, kings, priests, and other powerful leaders gained control of wealth and resources, causing the divide between rich and poor to expand.

An Ancient City That Became More Equal

A University of York study of Mohenjo-daro, the largest city of the Indus civilization, points to the opposite pattern. Researchers examined differences in house sizes across the city and found that wealth became more evenly distributed as Mohenjo-daro matured.

The city also appears to have been more equal than comparable societies in Mesopotamia and Greece. Instead of producing increasingly dramatic differences between wealthy and ordinary households, Mohenjo-daro saw the size gap between its largest and smallest homes become narrower over time.

The lead author, Dr. Adam Green from the University of York’s Department of Archaeology and Department of Environment and Geography, said: “Legacy data from the ancient city shows that as the city matured, the gap between the largest and smallest homes narrowed. In fact, by its later years, the wealth gap in this massive urban center had dropped to levels typical of the first farming villages.

“While ancient Egyptians were building pyramids for god-kings, and the Greeks were constructing massive palaces at Knossos, the people of the Indus were building something entirely different.

“Instead of gold-filled tombs and huge temples, Mohenjo-daro focused on sophisticated brick-lined drains and organized street layouts. Instead of allowing the perks of society to accumulate with a tiny elite, the city’s amenities were widely distributed amongst the everyday households.”

Drains and Streets Instead of Palaces

Mohenjo-daro devoted significant effort to practical features that benefited the wider population. Its carefully planned streets and advanced brick drainage systems indicate that resources were directed toward shared infrastructure rather than monuments celebrating rulers or religious elites.

The distribution of Indus seals offers further evidence of this approach. These seals were important tools for trade and business, yet archaeologists usually find them inside ordinary homes rather than concentrated in public buildings. The city had no known palaces where a ruler or ruling class could have controlled these tools of commerce and administration.

This pattern suggests that wealth and authority were not monopolized by a single powerful leader. Instead, the residents of Mohenjo-daro may have cooperated to give households broad access to the resources needed for a comfortable standard of living.

Shared Infrastructure and Fair Trade

Continued investment in drainage, road upkeep, and other public services also reflects collective support for the city’s everyday needs. These projects improved life across Mohenjo-daro rather than primarily serving a small group at the top of society.

A standardized system of weights and measures used throughout the region may have supported fairer trade as well. By giving merchants and residents a common way to measure goods, the system helped make exchanges more consistent for everyone.

Published in the journal Antiquity, the findings challenge the belief that greater inequality must accompany economic growth. Researchers argue that Mohenjo-daro demonstrates how a technologically advanced and highly productive society could distribute prosperity broadly instead of allowing it to accumulate among a small elite.

A Lesson From the Indus Civilization

Dr. Green said: “Mohenjo-daro is often cited as being famous for what it doesn’t have, such as the absence of palaces for kings, gold-filled tombs, and no statues of rulers. But what it does have is so important.

“In the period when inequality appears to be lowest, productivity appears to rise. It challenges the idea that prosperity requires us to concentrate decision-making powers in the hands of the few.

“It is quite an interesting lesson for modern societies, as the Indus civilization demonstrates clearly that an urban society can be highly productive and inventive at scale, whilst also ensuring that resources and power are shared equitably. In fact, doing so may even have been essential to sustaining prosperity over the centuries.”

The study, led by Dr. Keisuke Obara, Dr. Kento Yoshioka, and Professor Yoshio Tanaka of the Faculty of Pharmaceutical Sciences, found that ferulic acid (FA) can reduce intestinal smooth muscle contractions by blocking voltage-dependent calcium channels. The discovery could eventually support new dietary approaches for intestinal motility disorders such as irritable bowel syndrome (IBS) and inflammatory bowel disease (IBD).

A Common Compound in Whole Grains

Ferulic acid is a polyphenol found in many plant-based foods, especially whole grains and rice bran. It is already known for its antioxidant and neuroprotective effects, and previous research has largely examined how it may benefit the body more broadly.

Much less was known, however, about its effects on gastrointestinal motility, the coordinated muscle activity that moves food and waste through the digestive system.

People with IBS and IBD can experience abnormal intestinal movement. In some cases, the gut contracts too much, while in others, movement is reduced. The researchers set out to determine whether FA could directly alter these contractions.

Ferulic Acid Reduced Intestinal Contractions

The team tested FA using guinea pig ileal longitudinal smooth muscle (ILSM). The compound significantly reduced contractions triggered by several signaling molecules, including acetylcholine, histamine, prostaglandin F_2α, and serotonin.

The inhibitory effect was reversible, meaning normal contractions returned after FA was removed. It was also concentration-dependent, with stronger effects appearing at higher concentrations.

The researchers found that FA acted in a noncompetitive manner. This suggests that it did not simply block the receptors used by the signaling molecules. Instead, it appeared to interfere with a shared mechanism involved in muscle contraction.

Blocking Calcium Signals in Smooth Muscle

Additional experiments using vascular smooth muscle cell models offered a possible explanation. FA reduced the rise in intracellular calcium caused by potassium chloride.

Calcium entering smooth muscle cells plays a central role in triggering contraction. The results indicate that FA suppresses this process by inhibiting voltage-dependent calcium channels, reducing the calcium signals needed for the muscles to tighten.

Possible Benefits and Risks for Gut Disorders

The findings suggest that FA may act as a natural regulator of intestinal motility. By calming excessive smooth muscle activity, it could potentially help people with diarrhea-predominant IBD.

The same effect may not be beneficial for everyone. In people with constipation-predominant IBS, or in healthy individuals, further slowing intestinal movement could make constipation or related symptoms worse.

Human Studies Are Still Needed

The researchers emphasized that the concentrations of FA that produced an effect in vitro were higher than the blood levels usually reached through normal dietary intake.

However, FA concentrations inside the intestines may be higher after food or supplements are consumed because the compound comes into direct contact with the digestive tract. More research will be needed to determine whether the laboratory findings reflect what happens in the human body.

The study provides a foundation for investigating whether ferulic acid could eventually be used in dietary interventions or supplements designed to regulate gut movement. Clinical trials will be necessary to confirm its effects in people, identify which patients might benefit, and determine safe and effective intake levels.

The finches eventually became powerful evidence for Darwin’s theory of evolution by natural selection. The theory explains how populations can gradually change as individuals with traits suited to their surroundings are more likely to survive and reproduce.

The birds also demonstrate a process known as parallel evolution. In this process, organisms independently develop similar solutions to environmental challenges, even though the underlying genetic changes may be different.

Darwin’s Islands Continue to Reveal Evolution

“More than 150 years after Darwin’s work on the Galápagos transformed our understanding of life on Earth, these islands continue to reveal new biology,” says Professor Michael D. Martin at the Norwegian University of Science and Technology’s (NTNU) University Museum.

Martin is part of a large international research team that includes scientists from the Royal Botanic Gardens, Kew; the University of California, Davis; the University of Copenhagen; the Charles Darwin Foundation, Galápagos; the University of Georgia, Athens; the University of British Columbia; and several other institutions.

The team investigated evolution in Scalesia, a group of plants commonly called the Galápagos giant daisies. Their findings were recently published in Nature Communications.

Galápagos Giant Daisies Evolved Rapidly

“Just like Darwin’s famous finches, these plants evolved rapidly after arriving on the Galápagos from mainland South America,” explains Vanessa Bieker, a researcher at the Royal Botanic Gardens, Kew, and the first author of the new publication.

Scalesia is a relatively young plant genus. Every species that exists today emerged during the past one million years. Despite that short evolutionary history, the plants have adapted to remarkably different habitats across the islands, including humid highland forests and hot, dry lowlands.

“The appearance of different species varies dramatically, from low shrubs to tall trees. Most striking are the leaves, which range from large and entire to small and deeply lobed,” says Martin.

These lobed leaves often have intricate, serrated edges. Scientists think the shape may help plants survive dry and hot conditions by limiting water loss and releasing heat more effectively. Until now, however, the genetic changes behind this adaptation remained unclear.

Different Genes Produced the Same Leaf Shape

The researchers analyzed the complete genomes of every known Scalesia species. Their results showed that deeply lobed leaves evolved independently several times in separate branches of the Scalesia family tree.

The findings also suggest that new species may currently be developing. Numerous Scalesia populations could represent separate evolutionary lineages that scientists have not yet formally recognized.

“Even more surprising was that each time this trait evolved, it did so through different genes — even though all of them belong to the same biological system controlling leaf development,” says Bieker.

“This provides a clear example of parallel evolution: nature arriving at the same solution multiple times, but through different genetic pathways. Instead of being controlled by a single ‘master gene’, evolution appears to draw on an entire network of interacting genes, tweaking different components to produce similar outcomes.”

Rather than relying on one gene to determine leaf shape, evolution appears to modify different parts of a larger genetic network. Those separate genetic changes can ultimately produce similar physical traits.

The discovery gives scientists a clearer picture of how complex features can repeatedly emerge in unrelated populations or in different branches of the same evolutionary family.

Evolution May Still Be Creating New Species

The genetic evidence indicates that the evolutionary story of Scalesia is not finished.

“Populations within the same species show large genetic differences and have been isolated from one another for long periods. This means new species may be in the process of forming. Many Scalesia populations may represent distinct evolutionary lineages that have not yet been formally described,” says Martin.

Because these isolated populations may be following separate evolutionary paths, the researchers argue that each one should be managed as an individual conservation unit. This approach could change how conservationists protect the distinctive plants and ecosystems of the Galápagos.

The study also provides an unusually detailed view of adaptive radiation, the process through which one ancestral species rapidly gives rise to many forms suited to different habitats.

“Our findings highlight the flexibility and creativity of evolution,” says Bieker.

Darwin’s famous bird collections were not his only important discoveries on the islands. He also gathered numerous plants during his visit. Seventy-eight of those specimens were later used to identify species that were entirely new to science — including four species of Scalesia.

One was Hesperosuchus agilis, a fast land predator with a long snout, powerful hind legs, and smaller, more slender front limbs. It likely searched for prey along rivers and streams.

The second animal had a noticeably different head. Its snout was shorter, its skull was more strongly reinforced, and its enlarged jaw muscles would have helped it snap down on larger prey.

Neither animal escaped the sudden event that followed. Researchers believe both died at the same time, possibly during a flash flood or mudslide. Their remains were buried together, and favorable chemical conditions preserved their bones through the “Age of Reptiles,” the later rise of mammals, and their eventual excavation in large blocks of rock now housed at the Peabody Museum of Natural History at Yale.

A New Species Emerges From an Old Fossil

After closely examining the short-snouted animal, Yale paleontologists determined that it belonged to a previously unknown species. They named it Eosphorosuchus lacrimosa in a new study.

“This speaks to the diversification of proto-crocs toward the beginning of the ‘Age of Reptiles,'” said Bhart-Anjan Bhullar, associate professor of Earth and planetary sciences in Yale’s Faculty of Arts and Sciences (FAS), associate curator of vertebrate paleontology and vertebrate zoology at the Peabody Museum, and senior author of the new study published in the journal Proceedings of the Royal Society B.

“During this period, the late Triassic, there were two reptile dynasties vying for dominance: the line that would produce crocodiles and alligators on one side, and that which would produce birds, which of course are dinosaurs, on the other,” Bhullar added. “The dinosaurs at this time were slim, delicate animals that walked on two slender legs almost like herons, and the crocodiles were fast-running, four-legged predators, low-slung and more heavily built — analogous to a jackal, a big fox, or a dog.”

During the late Triassic, the ancestors of crocodiles and the lineage that produced dinosaurs were both beginning to expand into new ecological roles. Unlike today’s mostly aquatic crocodilians, many early crocodile relatives were agile predators that ran across land.

A Rare Window Into the Late Triassic

Reconstructing the diversity of life in a particular place and time can be difficult for paleontologists. Fossils are often incomplete, and researchers cannot always determine whether animals found in the same rock layer actually lived together.

Exceptionally preserved fossil sites can provide much clearer evidence. Ghost Ranch in New Mexico is one such location.

For about a century, scientists have studied fossils from Ghost Ranch that include near-crocodiles, lizard relatives, fish, and dinosaurs (most prominently, the carnivorous Coelophysis bauri). The Yale Peabody Museum holds two large sections of rock from the “Ghost Ranch Bone Bed.” Together, the blocks are roughly the size of a car.

The fossil containing the two crocodile relatives was excavated in 1948. Although it had been available to scientists for about 75 years, it had never been fully analyzed or formally identified.

“I had been staring at this fossil for a while,” Bhullar said. “For years, both Ghost Ranch crocs were thought to be examples of Hesperosuchus, but it looked like the Yale animal had a different facial structure.”

CT Scans Reveal Hidden Anatomy

To investigate those differences, Miranda Margulis-Ohnuma, a Ph.D. student in Earth and planetary sciences in Yale’s Graduate School of Arts and Sciences (GSAS), studied a computed tomography (CT) scan of the animal. The scan was performed at the Yale Chemical and Biophysical Imaging Center by former Peabody Museum senior preparator Marilyn Fox.

CT imaging allowed Margulis-Ohnuma to examine structures that remained embedded in the rock. She digitally “disassembled” the fossil one bone at a time and uncovered several anatomical features that differed from known Hesperosuchus specimens.

Those differences supported the identification of Eosphorosuchus as a separate genus and species.

The name combines Eosphorus, the Greek god known as the “dawn-bringer,” with the Greek word “soukhos,” meaning crocodile.

“Eosphorosuchus is one of only a handful of well-preserved early crocodile relatives, and its coexistence with Hesperosuchus represents the ‘dawn’ of functional diversification in the lineage that would give rise to modern crocodiles,” said Margulis-Ohnuma, who is first author of the new study. “In addition to its unique anatomy and preservational history, the specimen demonstrates the potential of existing museum collections to continue revealing novel insights into the history of life.”

Early Crocodile Relatives Hunted Differently

The discovery is especially valuable because the two animals appear to have lived in the same ecosystem at the same time. Their contrasting skulls and jaws suggest that closely related predators were already dividing up available food resources by developing different feeding strategies.

Hesperosuchus had a longer, narrower snout, while Eosphorosuchus had a shorter and more heavily reinforced skull with stronger jaw muscles. These differences may have reduced direct competition by allowing the animals to pursue different kinds of prey.

“It’s a time-slice of a single moment 210 million years ago,” Bhullar said. “These two individuals had to compete and interact with each other. They were quite possibly looking at each other when they died.”

Co-authors of the study are Alexander Ruebenstahl, a current student at Yale GSAS, and recent Yale graduate Dalton Meyer ’25 Ph.D., who is now a lecturer at Roanoke College.

What Is Eosphorosuchus lacrimosa?

Eosphorosuchus lacrimosa was an extinct proto-crocodile identified by Yale University researchers. It was a fast-running land predator that lived near rivers and lakes about 210 million years ago.

Why Is Eosphorosuchus lacrimosa Important?

Eosphorosuchus lacrimosa offers evidence that early crocodile relatives were already developing different feeding adaptations near the beginning of the “Age of Reptiles,” during the late Triassic Period, 252 to 201 million years ago.

Its presence beside Hesperosuchus gives researchers a rare view of two related predators occupying different ecological roles within the same ancient environment.

What Did Eosphorosuchus lacrimosa Look Like?

According to Yale paleontologists, Eosphorosuchus lacrimosa had a short snout, a heavily reinforced skull, and enlarged jaw muscles suited for snapping shut on large prey. It also had large hind legs and smaller, thinner front limbs.

Using rapid X-ray flashes produced at the European XFEL, the researchers followed changes at specific atoms as the molecule released and redistributed the absorbed energy. Their results show that exposure to light can make an atom more responsive to the movement of neighboring atoms.

The technique gives scientists a way to examine extremely fast chemical reactions at the atomic scale and in real time. It could eventually improve understanding of how DNA withstands light exposure, how energy travels through materials designed to harvest light, and how other fundamental light-driven processes occur.

Following Energy Through a Molecule

The researchers studied 3-fluoropyridine, a small ring-shaped molecule containing both nitrogen and fluorine atoms.

When the molecule absorbs energy from a brief ultraviolet laser pulse, its electrons enter a higher energy state. The molecule then quickly bends out of its normally flat structure.

As it changes shape, it passes through what scientists call a conical intersection: a short-lived but crucial crossing point where movements of electrons and the atoms’ cores become strongly coupled. These intersections play an important role in many reactions triggered by light because they allow energy to move rapidly between electronic and structural motion.

After crossing this region, the molecule returns to its ground state. The excess electronic energy is then converted into vibrations that travel through the molecular structure.

Different Atoms Reveal Different Changes

The conversion of energy produced distinct signals at different locations within the molecule. The fluorine atom served as a relatively clear indicator of how the molecule’s vibrations relaxed over time.

The nitrogen atom told a more complicated story. Because it played a more direct role in the original electronic excitation, its signal reflected both the redistribution of electrons and the molecule’s changing structure.

“We can now see that not every atomic site tells the same story in the signals we capture from our X-ray pulses,” says Antonio Picón from the Instituto de Ciencia de Materiales de Madrid Consejo Superior de Investigaciones Científicas (ICMM-CSIC), co-author of the study. “Some atoms report where the charge is going, while others reveal how the whole molecule vibrates.”

Reconstructing a Picosecond Transformation

To capture the process, the team used time-resolved X-ray photoelectron spectroscopy (tr-XPS) at the Small Quantum Systems instrument (SQS) of European XFEL.

First, an ultraviolet laser pulse delivered energy to the molecules. A carefully timed soft X-ray pulse then ionized them by removing deeply bound electrons from either the nitrogen or fluorine atoms.

The researchers repeated the measurement with the X-ray pulse arriving at many different delays after the initial laser pulse. By recording the energies of the released electrons, they reconstructed how the chemical environment surrounding each atom changed over just a couple of picoseconds (trillionths of seconds).

Advanced computer simulations and theoretical models were then used to interpret the experimental signals and connect them with the underlying electronic and structural changes.

A New View of Ultrafast Photochemistry

The findings demonstrate how the ultrashort, high-brightness X-ray pulses available at European XFEL can separate some of the fastest interconnected motions in matter.

Although the experiment focused on one relatively simple molecule, the same approach could be applied to increasingly complex systems. Possible targets include functional organic molecules, biomolecular building blocks, and materials designed to capture or transfer energy from light.

“This is what European XFEL was built to enable: watching chemical change where it begins, at specific atomic sites and on its natural timescale,” says Daniel Rivas, former instrument scientist, now guest scientist at SQS and co-author of the study. “By combining multi-site sensitivity with femtosecond resolution, we are opening a new window on the microscopic mechanisms that govern photochemistry.”

A low-cost liquid known as silver diamine fluoride, or SDF, may offer a much simpler option. Dentists apply it directly to a cavity with a small sponge-tipped applicator, a process that takes only a few seconds for each tooth. The treatment can stop decay without drilling, injections, or sedation.

A Long-Used Treatment Gains Stronger Evidence

SDF has been used successfully in many countries for decades. In the United States, dentists have used it off-label since 2014, when it was approved as a medical device for reducing tooth sensitivity.

However, researchers had not yet completed the large U.S. clinical trials needed to demonstrate its safety and effectiveness as a cavity treatment. That evidence would be necessary for the Food and Drug Administration to approve SDF as a drug for treating tooth decay.

A clinical trial led by the University of Michigan has now supplied those data.

The Phase III study, published in JAMA Pediatrics, included 830 children younger than age 6. Participants were recruited through dental offices, pediatric medical practices, Head Start and Early Head Start programs in Michigan, New York and Iowa.

SDF Stopped Decay in Many Baby Teeth

The researchers found that 38% SDF stopped tooth decay in more than half of the affected baby teeth when the treatment was applied every six months.

Traditional cavity treatment usually involves removing damaged tooth material and placing a filling. SDF requires no removal of the tooth. Instead, the liquid is painted directly onto the decayed area.

“This is a very effective and safe treatment — even in children as young as 1,” said Margherita Fontana, professor of dentistry at the University of Michigan School of Dentistry and the study’s lead investigator.

Tooth decay is the most common chronic disease among children and affects more than 40% of children in the United States. Cavities that are not treated can lead to intense pain, infections, difficulty sleeping or eating, missed school days and repeated medical appointments.

A Potential Option for Hard-to-Treat Patients

Fontana said SDF could be particularly useful for very young children, older adults, people with developmental or physical disabilities, and patients with severe dental anxiety. It may also help people who have limited access to conventional dental care or cannot easily tolerate standard procedures.

The treatment does have a visible drawback. The silver permanently turns the decayed part of the tooth dark.

“If we want more children and families to benefit from this treatment, we need rigorous evidence showing both that it works and that it’s safe. From a public health perspective, if we want broader implementation across the United States, including in medical settings, we need carefully collected data in U.S. populations, and we now have that,” Fontana said.

The research began in 2018 and continued despite disruptions caused by the COVID-19 pandemic.

“In medicine, clinicians want high-quality evidence before changing practice,” Fontana said. “It is important to have data they can refer to because young children often see pediatricians years before they ever visit a dentist; broader acceptance could allow many more cavities to be treated while a referral to a dental home is successful, and before they become painful, infected, or require surgery.”

Findings Could Support FDA Approval

Fontana worked with researchers from New York University, the University of Iowa and Indiana University, as well as the NIH’s National Institute of Dental and Craniofacial Research. The institute provided more than $12 million to support the study.

The trial generated the clinical evidence the manufacturer needs to submit a dental caries drug application to the FDA. Elevate Oral Care supplied Advantage Arrest 38% SDF, the product tested in the study.

Amr Moursi, professor of pediatric dentistry at New York University College of Dentistry, said the findings could help expand access to the treatment.

“Our results support FDA approval of SDF for managing arrest of tooth decay in young children. Removing SDF from off-label status would be an important innovation which could lead to increased utilization by providers, enhanced payments by insurers and more consistent product quality,” said Moursi, a co-principal investigator on the study.

A Bridge or Long-Term Treatment

For some children, applying SDF again every few months may control the cavity until the baby tooth falls out naturally. In adults, it could function as a long-term treatment or provide temporary protection until a restorative procedure becomes affordable or practical.

“For almost anyone, this can arrest the decay and stop the infection and the pain it causes,” Fontana said. “This could benefit many people.”