Published in Nature Ecology & Evolution, the research presents the first solid evidence of frugivory in Notiomastodon platensis, a South American Pleistocene mastodon. The findings are based on a multiproxy analysis of 96 fossil teeth collected over a span of more than 1,500 kilometers, from Los Vilos to Chiloé Island in southern Chile. Nearly half of the specimens come from the emblematic site of Lake Tagua Tagua, an ancient lake basin rich in Pleistocene fauna, located in the present-day O’Higgins Region.

The study was led by Dr. Erwin González-Guarda, researcher at the University of O’Higgins and associate at IPHES-CERCA, alongside an international team that includes IPHES-CERCA researchers Dr. Florent Rivals, a paleodiet specialist; Dr. Carlos Tornero and Dr. Iván Ramírez-Pedraza, experts in stable isotopes and paleoenvironmental reconstruction; and Alia Petermann-Pichincura. The research was carried out in collaboration with the Universitat Rovira i Virgili (URV) and the Universitat Autònoma de Barcelona (UAB).

An ecological hypothesis finally proven

In 1982, biologist Daniel Janzen and paleontologist Paul Martin proposed a revolutionary idea: many tropical plants developed large, sweet, and colorful fruits to attract large animals — such as mastodons, native horses, or giant ground sloths — that would serve as seed dispersers. Known as the “neotropical anachronisms hypothesis,” this theory remained unconfirmed for over forty years. Now, the study led by González-Guarda provides direct fossil evidence that validates it. To understand the lifestyle of this mastodon, the team employed various techniques: isotopic analysis, microscopic dental wear studies, and fossil calculus analysis. “We found starch residues and plant tissues typical of fleshy fruits, such as those of the Chilean palm (Jubaea chilensis),” explains Florent Rivals, ICREA research professor at IPHES-CERCA and an expert in paleodiet. “This directly confirms that these animals frequently consumed fruit and played a role in forest regeneration.”

The forgotten role of large seed dispersers

“Through stable isotope analysis, we were able to reconstruct the animals’ environment and diet with great precision,” notes Iván Ramírez-Pedraza. The data point to a forested ecosystem rich in fruit resources, where mastodons traveled long distances and dispersed seeds along the way. That ecological function remains unreplaced.

“Dental chemistry gives us a direct window into the past,” says Carlos Tornero. “By combining different lines of evidence, we’ve been able to robustly confirm their frugivory and the key role they played in these ecosystems.”

A future threatened by an incomplete past

The extinction of mastodons broke a co-evolutionary alliance that had lasted for millennia. The researchers applied a machine learning model to compare the current conservation status of megafauna-dependent plants across different South American regions. The results are alarming: in central Chile, 40% of these species are now threatened — a rate four times higher than in tropical regions where animals such as tapirs or monkeys still act as alternative seed dispersers.

“Where that ecological relationship between plants and animals has been entirely severed, the consequences remain visible even thousands of years later,” says study co-author Andrea P. Loayza.

Species like the gomortega (Gomortega keule), the Chilean palm, and the monkey puzzle tree (Araucaria araucana) now survive in small, fragmented populations with low genetic diversity. They are living remnants of an extinct interaction.

Paleontology as a key to conservation

Beyond its fossil discoveries, the study sends a clear message: understanding the past is essential to addressing today’s ecological crises. “Paleontology isn’t just about telling old stories,” concludes Florent Rivals. “It helps us recognize what we’ve lost — and what we still have a chance to save.”

Although it is well understood that genetics influence the development of autism spectrum disorder, no one could yet pinpoint the precise cause and mechanism. To study the biological background of diseases, researchers use models: Cell models allow us to study how changes in the genes affect the shape and function of the cell, while animal models show how the change in its cellular components affects health and behavior. Despite significant differences between mice and humans, many disease-causing genes are very similar and cause similar conditions across these species. “One of the problems, however, is the lack of a standardized biological model to study the effects of the different mutations associated with autism spectrum disorder. This makes it difficult to find out, for example, whether they have common effects or what is specific to certain cell types,” explains Kobe University neuroscientist TAKUMI Toru.

Thus, twelve years ago, Takumi and his team embarked on a journey to change that. Being experts in studying mouse models of the disorder, they combined a conventional manipulation technique for mouse embryonic stem cells — cells that can be made to develop into almost any kind of cell in the body — with the then-newly discovered, highly specific and easy-to-handle CRISPR gene editing system. This new method proved highly efficient in making genetic variants of these cells and allowed the Kobe University team to produce a bank of 63 mouse embryonic stem cell lines of the genetic variants most strongly associated with autism spectrum disorder.

In the journal Cell Genomics, Takumi and his team now published that they were able to develop their cells into a broad range of cell types and tissues, and even generate adult mice with their genetic variations. The analysis of these alone proved that their cell lines were adequate models for studying autism spectrum disorder. However, the cell lines also allowed them to conduct large-scale data analyses to clearly identify genes that are abnormally active, and in which cell types this is the case. 

One of the things the data analysis brought to light is that autism-causing mutations often result in neurons being unable to eliminate misshapen proteins. “This is particularly interesting since the local production of proteins is a unique feature in neurons, and a lack of quality control of these proteins may be a causal factor of neuronal defects,” explains Takumi.

The Kobe University neuroscientist expects that his team’s achievement, which has been made available to other researchers and can be flexibly integrated with other lab techniques and adjusted to other targets, will be an invaluable resource for the scientific community studying autism and trying to find drug targets. He adds: “Interestingly, the genetic variants we studied are also implicated in other neuropsychiatric disorders such as schizophrenia and bipolar disorder. So, this library may be useful for studying other conditions as well.”

This research was funded by the Japan Society for the Promotion of Science (grants 16H06316, 16F16110, 21H00202, 21H04813, 23KK0132, 23H04233, 24H00620, 24H01241, 24K22036, 17K07119 and 21K07820), the Japan Agency for Medical Research and Development (grant JP21wm0425011), the Japan Science and Technology Agency (grants JPMJPF2018, JPMJMS2299 and JPMJMS229B), the National Center of Neurology and Psychiatry (grant 6-9), the Takeda Science Foundation, the Smoking Research Foundation, the Tokyo Biochemical Research Foundation, the Kawano Masanori Memorial Public Interest Incorporated Foundation for Promotion of Pediatrics, the Taiju Life Social Welfare Foundation, the Tokumori Yasumoto Memorial Trust for Researches on Tuberous Sclerosis Complex and Related Rare Neurological Diseases, and Takeda Pharmaceutical Company Ltd. It was conducted in collaboration with researchers from the RIKEN Center for Brain Science, Radboud University, the RIKEN Center for Integrative Medical Sciences, the Agency for Science, Technology and Research, the RIKEN Center for Biosystems Dynamics Research, and Hiroshima University.

Kobe University is a national university with roots dating back to the Kobe Higher Commercial School founded in 1902. It is now one of Japan’s leading comprehensive research universities with nearly 16,000 students and nearly 1,700 faculty in 11 faculties and schools and 15 graduate schools. Combining the social and natural sciences to cultivate leaders with an interdisciplinary perspective, Kobe University creates knowledge and fosters innovation to address society’s challenges.

The device, a new type of atom “interferometer,” could one day help people navigate submarines, spacecraft, cars and other vehicles more precisely.

“Traditional atom interferometers can only measure acceleration in a single dimension, but we live within a three-dimensional world,” said Kendall Mehling, a co-author of the new study and a graduate student in the Department of Physics at CU Boulder. “To know where I’m going, and to know where I’ve been, I need to track my acceleration in all three dimensions.”

The researchers published their paper, titled “Vector atom accelerometry in an optical lattice,” this month in the journal Science Advances. The team included Mehling; Catie LeDesma, a postdoctoral researcher in physics; and Murray Holland, professor of physics and fellow of JILA, a joint research institute between CU Boulder and the National Institute of Standards and Technology (NIST).

In 2023, NASA awarded the CU Boulder researchers a $5.5 million grant through the agency’s Quantum Pathways Institute to continue developing the sensor technology.

The new device is a marvel of engineering: Holland and his colleagues employ six lasers as thin as a human hair to pin a cloud of tens of thousands of rubidium atoms in place. Then, with help from artificial intelligence, they manipulate those lasers in complex patterns — allowing the team to measure the behavior of the atoms as they react to small accelerations, like pressing the gas pedal down in your car.

Today, most vehicles track acceleration using GPS and traditional, or “classical,” electronic devices known as accelerometers. The team’s quantum device has a long way to go before it can compete with these tools. But the researchers see a lot of promise for navigation technology based on atoms.

“If you leave a classical sensor out in different environments for years, it will age and decay,” Mehling said. “The springs in your clock will change and warp. Atoms don’t age.”

Fingerprints of motion

Interferometers, in some form or another, have been around for centuries — and they’ve been used to do everything from transporting information over optical fibers to searching for gravitational waves, or ripples in the fabric of the universe.

The general idea involves splitting things apart and bringing them back together, not unlike unzipping, then zipping back up a jacket.

In laser interferometry, for example, scientists first shine a laser light, then split it into two, identical beams that travel over two separate paths. Eventually, they bring the beams back together. If the lasers have experienced diverging effects along their journeys, such as gravity acting in different ways, they may not mesh perfectly when they recombine. Put differently, the zipper might get stuck. Researchers can make measurements based on how the two beams, once identical, now interfere with each other — hence the name.

In the current study, the team achieved the same feat, but with atoms instead of light.

Here’s how it works: The device currently fits on a bench about the size of an air hockey table. First, the researchers cool a collection of rubidium atoms down to temperatures just a few billionths of a degree above absolute zero.

In that frigid realm, the atoms form a mysterious quantum state of matter known as a Bose-Einstein Condensate (BEC). Carl Wieman, then a physicist at CU Boulder, and Eric Cornell of JILA won a Nobel Prize in 2001 for creating the first BEC.

Next, the team uses laser light to jiggle the atoms, splitting them apart. In this case, that doesn’t mean that groups of atoms are separating. Instead, each individual atom exists in a ghostly quantum state called a superposition, in which it can be simultaneously in two places at the same time.

When the atoms split and separate, those ghosts travel away from each other following two different paths. (In the current experiment, the researchers didn’t actually move the device itself but used lasers to push on the atoms, causing acceleration).

“Our Bose-Einstein Condensate is a matter-wave pond made of atoms, and we throw stones made of little packets of light into the pond, sending ripples both left and right,” Holland said. “Once the ripples have spread out, we reflect them and bring them back together where they interfere.”

When the atoms snap back together, they form a unique pattern, just like the two beams of laser light zipping together but more complex. The result resembles a thumb print on a glass.

“We can decode that fingerprint and extract the acceleration that the atoms experienced,” Holland said.

Planning with computers

The group spent almost three years building the device to achieve this feat.

“For what it is, the current experimental device is incredibly compact. Even though we have 18 laser beams passing through the vacuum system that contains our atom cloud, the entire experiment is small enough that we could deploy in the field one day,” LeDesma said.

One of the secrets to that success comes down to an artificial intelligence technique called machine learning. Holland explained that splitting and recombining the rubidium atoms requires adjusting the lasers through a complex, multi-step process. To streamline the process, the group trained a computer program that can plan out those moves in advance.

So far, the device can only measure accelerations several thousand times smaller than the force of Earth’s gravity. Currently available technologies can do a lot better.

But the group is continuing to improve its engineering and hopes to increase the performance of its quantum device many times over in the coming years. Still, the technology is a testament to just how useful atoms can be.

“We’re not exactly sure of all the possible ramifications of this research, because it opens up a door,” Holland said.

Pangolins are the most heavily trafficked wild mammal in the world. A solitary, insect-eating animal about the size of a large domestic cat*, pangolins are famous for their highly prized keratin scales — a staple of traditional Chinese medicine.

All eight existing pangolin species are threatened with extinction and on the IUCN’s Red List, with three Asian species categorised as critically endangered.

As Asian pangolins have declined dramatically, Nigeria has seen a boom in the export of pangolin scales to Asia. While hunting pangolins is illegal in Nigeria the West African country is now the world’s largest hub for the criminal trade in pangolin products.

However, a new study published in the journal Nature Ecology & Evolution suggests that some 98% of Nigerian pangolins are caught for meat first and foremost, with around two-thirds of scales from these animals simply thrown away.

A research team led by Cambridge collected data from over eight hundred hunters and traders in thirty-three locations across Nigeria’s Cross River Forest region, primarily between 2020 and 2023, during which time the conservationists estimate that around 21,000 pangolins were killed annually in the area.

Almost all pangolins were captured “opportunistically” or during general hunting trips (97%) rather than sought out, and caught primarily for meat (98%). Around 71% of pangolins were consumed by hunters themselves, with 27% traded locally as food.

Perhaps surprisingly, given their potential overseas value, around 70% of the scales were discarded, while less than 30% were sold on. However, researchers calculated that, per animal, pangolin meat fetched 3-4 times the price of scales at local Nigerian markets.

“Thousands of kilos of pangolin scales are seized at Nigeria’s ports, creating the impression that the international demand for scales is behind pangolin exploitation in West Africa,” said study lead author and Gates Cambridge Scholar Dr Charles Emogor, who conducted the research for his PhD at the University of Cambridge’s Department of Zoology.

“When we spoke to hunters and traders on the ground around the Cross River forest, the largest stronghold for Nigeria’s pangolins, it was obvious that meat was the motivation for almost all of the pangolin killings.”

“We found that dedicated pangolin hunts are virtually non-existent. Most pangolins are killed by hunters out for any type of game,” said Emogor, now a Schmidt Science Fellow split between Cambridge, UK, and Harvard, US.

“Around a third of pangolins are caught opportunistically, often while people are working in the fields. Pangolins curl into a ball when threatened, which sadly makes them easy to catch.” Among frequent hunters, by far the most common method of catching pangolins was given as simply picking them up by hand.

While Emogor says the demands of traditional medicine markets are exacerbating the decline of African pangolins — his previous research showed that just shipments intercepted by Nigerian authorities between 2010 and 2021 amounted to 190,407 kilos of pangolin scales taken from around 800,000 dead creatures — pangolins have been exploited in West Africa long before being trafficked to Asia.

The meat is a delicacy in parts of Nigeria, often procured for pregnant women in the belief it helps produce strong babies. Emogor and colleagues surveyed hunters and Cross River locals on “palatability”: asking them to rank the tastiness of almost a hundred different animals eaten in the region, from domestic beef and chicken to catfish, monkeys and antelope.

The three major African pangolin species were rated as the most palatable of all available meats, with average scores of almost nine out of ten, and the giant pangolin considered the topmost appetising meat in the region.

“Pangolins face a lethal combination of threats,” said Emogor. “Pangolins are easy to hunt, breed slowly, taste good to humans, and are falsely believed to have curative properties in traditional medicines. In addition, their forest habitat is being destroyed.”

Emogor’s research led him to set up Pangolino in 2021, a global network of volunteers, scientists and pangolin enthusiasts committed to saving the endangered animal. He points out that the cost of policy interventions to tackle meat-driven pangolin trading might be cheaper than those for an international scales market.

These should include anti-poaching patrols as well as community programmes focused on food security. Through Pangolino, Emogor is piloting interventions in four Southeast Nigerian communities by helping create by-laws that prohibit pangolin killing, with financial rewards for compliance.

“Clearly in designing any intervention we need good information on what’s motivating the hunters,” said Prof Andrew Balmford, co-author from Cambridge’s Department of Zoology. “That’s why studies such as this are vital for effective conservation of endangered species.”

While the latest study focused on Nigeria, researchers say their pangolin hunting and consumption data echo that from countries such as Cameroon and Gabon — suggesting these patterns may be Africa-wide.

Raised on the edge of the Cross River National Park, home to Nigeria’s endangered white-bellied and black-bellied pangolins, Emogor grew up surrounded by wildlife. Yet during childhood he only ever saw dead pangolins, and didn’t encounter a living animal until his mid-twenties.

“If we lose the pangolin, we lose 80 million years of evolution,” said Emogor. “Pangolins are the only mammals with scales, and their ancestors existed when dinosaurs still roamed the planet,” added Emogor.

The latest study was conducted by an international team of researchers from the University of Cambridge, Wildlife Conservation Society, Pangolin Protection Network, University of Washington, CIFOR, CARE International, as well as the UK universities of Oxford, Exeter and Kent.

Notes:

*While this is a rough size for some African species, such as the White-bellied pangolin, the Giant Pangolin can grow up to 30kg in weight.

In a paper published in Nature Ecology and Evolution on June 11, researchers from the University of Birmingham and University of Bristol have used a new method of geographical analysis to infer how these ancestral reptiles, known as archosauromorphs, dispersed following one of the most impactful climate events the Earth has ever seen, the end-Permian mass extinction.

The first archosauromorphs, some resembling modern reptiles and many times smaller than familiar dinosaurs, were previously believed to only survive in certain parts of the globe due to extreme heat across the tropics, viewed by many paleontologists as a dead zone, in the earliest Triassic.

By developing a new modelling technique based on landscape reconstructions and evolutionary trees, the team of researchers have been able to discover clues about how these reptiles moved around the world during the Triassic period, following the mass extinction where more than half of land-based animals and 81% of marine life died.

The archosauromorphs that survived the extinction event rose to prominence in Earth’s ecosystems in the Triassic, leading to the evolution of dinosaurs. The team now suggest that their later success was in part due to their ability to migrate up to 10,000 miles across the tropical dead zone to access new ecosystems.

Dr Joseph Flannery-Sutherland from the University of Birmingham and corresponding author of the study said:

“Amid the worst climatic event in Earth’s history, where more species died than at any period since, life still survived. We know that archosauromorphs as a group managed to come out of this event and over the Triassic period became one of the main players in shaping life thereafter.

“Gaps in their fossil record have increasingly begun to tell us something about what we weren’t seeing when it comes to these reptiles. Using our modelling system, we have been able to build a picture of what was happening to the archosauromorphs in these gaps and how they dispersed across the ancient world. This is what led us to call our method TARDIS, as we were looking at terrains and routes directed in space-time.

“Our results suggest that these reptiles were much hardier to the extreme climate of the Pangaean tropical dead zone, able to endure these hellish conditions to reach the other side of the world. It’s likely that this ability to survive the inhospitable tropics may have conferred an advantage that saw them thrive in the Triassic world.”

“The evolution of life has been controlled at times by the environment,” says Professor Michael Benton from the University of Bristol, senior author of the study, “but it is difficult to integrate our limited and uncertain knowledge about the ancient landscape with our limited and uncertain knowledge about the ecology of extinct organisms. But by combining the fossils with reconstructed maps of the ancient world, in the context of evolutionary trees, we provide a way of overcoming these challenges.”

Results show that teens who got up to two more hours of sleep on weekends than on weekdays exhibited fewer anxiety symptoms compared with those who did not sleep longer on weekends. However, longer durations of catch-up sleep on weekends were associated with slightly more internalizing symptoms.

“The results show that both sleeping less on weekends than weekdays and sleeping substantially more on weekends were associated with higher anxiety symptoms,” said lead author Sojeong Kim, a doctoral candidate in the department of clinical psychology and psychology graduate advisor at the University of Oregon in Eugene. “In contrast, moderate catch-up sleep — defined as less than two hours — was associated with lower anxiety symptoms, suggesting that some weekend recovery sleep may be beneficial.”

The American Academy of Sleep Medicine recommends that teenagers 13 to 18 years of age should sleep 8 to 10 hours on a regular basis to promote optimal health. However, CDC data show that only 23% of high school students get sufficient sleep on an average school night.

“Many teens try to make up for lost sleep by sleeping in on weekends,” Kim said.

Consistently getting sufficient sleep is associated with better health outcomes including improved attention, behavior, learning, memory, emotional regulation, quality of life, and mental and physical health. In contrast, insufficient sleep in teenagers is associated with increased risks of problems such as depression and suicidal thoughts.

The study involved 1,877 adolescents with a mean age of 13.5 years. Sleep duration was estimated using Fitbit devices, while internalizing symptoms were assessed using the Child Behavior Checklist survey. Weekend catch-up sleep was calculated as the difference between weekend and weekday sleep duration.

Kim noted that it is important to identify the right amount of catch-up sleep that is beneficial to teens who restrict their sleep during the week.

“Too little or too much sleep variability from weekday to weekend may contribute to the symptoms someone is trying to combat, like physical or mental fatigue and feelings of anxiety,” she said.

The research abstract was published recently in an online supplement of the journal Sleep and will be presented Wednesday, June 11, during SLEEP 2025 in Seattle. SLEEP is the annual meeting of the Associated Professional Sleep Societies, a joint venture of the American Academy of Sleep Medicine and the Sleep Research Society.

Abstract Title: The Sweet Spot of Weekend Catch-Up Sleep: A Protective Factor Against Depressive Symptoms?

Abstract ID: 0263