Short-term bang of fireworks has long-term impact on wildlife

Popular fireworks should be replaced with cleaner drone and laser light shows to avoid the "highly damaging" impact on wildlife, domestic pets and the broader environment, new Curtin-led research has found.

The new research, published in Pacific Conservation Biology, examined the environmental toll of firework displays by reviewing the ecological effects of Diwali festivities in India, Fourth of July celebrations across the United States of America, and other events in New Zealand and parts of Europe.

Examples included fireworks in Spanish festivals impacting the breeding success of House Sparrows, July firework displays being implicated in the decline of Brandt's Cormorant colonies in California, and South American sea lions changing their behaviour during breeding season as a result of New Year's fireworks in Chile.

Lead author Associate Professor Bill Bateman, from Curtin's School of Molecular and Life Sciences, said fireworks remained globally popular despite the overwhelming evidence that they negatively impacted wildlife, domestic animals and the environment.

"Fireworks create short-term noise and light disturbances that cause distress in domestic animals that may be managed before or after a firework event, but the impacts to wildlife can be on a much larger scale," Associate Professor Bateman said.

"The annual timing of some large-scale firework events coincides with the migratory or reproductive movements of wildlife, and may therefore have adverse long-term population effects on them. Fireworks also produce significant pulses of highly pollutant materials that also contribute significantly to the chemical pollution of soil, water, and air, which has implications for human as well as animal health."

Associate Professor Bateman said firework bans at sensitive periods for wildlife migration or mating periods could limit the impact, as well as drone or other light-based shows.

"Other than horses, for which there is some evidence that they can be gradually familiarised with flashes of light, there is very little that can be done to address the disturbing impact of noise from fireworks on animals and wildlife," Associate Professor Bateman said.

"The future of firework displays may be in the use of safer and greener alternatives such as drones, eco-friendly fireworks or visible-wavelength lasers for light shows.

Read more at Science Daily

Transforming the way cancer vaccines are designed and made

A new way to significantly increase the potency of almost any vaccine has been developed by researchers from the International Institute for Nanotechnology (IIN) at Northwestern University. The scientists used chemistry and nanotechnology to change the structural location of adjuvants and antigens on and within a nanoscale vaccine, greatly increasing vaccine performance. The antigen targets the immune system, and the adjuvant is a stimulator that increases the effectiveness of the antigen.

The scientists used chemistry and nanotechnology to change the structural location of adjuvants and antigens on and within a nanoscale vaccine, greatly increasing vaccine performance. The antigen targets the immune system, and the adjuvant is a stimulator that increases the effectiveness of the antigen.

The study will be published Jan. 30 in Nature Biomedical Engineering.

"The work shows that vaccine structure and not just the components is a critical factor in determining vaccine efficacy," said lead investigator Chad A. Mirkin, director of the IIN. "Where and how we position the antigens and adjuvant within a single architecture markedly changes how the immune system recognizes and processes it.

Mirkin also is the George B. Rathmann Professor of Chemistry at the Weinberg College of Arts and Sciences and a professor of medicine at Northwestern University Feinberg School of Medicine.

This new heightened emphasis on structure has the potential to improve the effectiveness of conventional cancer vaccines, which historically have not worked well, Mirkin said.

Mirkin's team has studied the effect of vaccine structure in the context of seven different types of cancer to date, including triple-negative breast cancer, papillomavirus-induced cervical cancer, melanoma, colon cancer and prostate cancer to determine the most effective architecture to treat each disease.

Conventional vaccines take a blender approach

With most conventional vaccines, the antigen and the adjuvant are blended and injected into a patient. There is no control over the vaccine structure, and, consequently, limited control over the trafficking and processing of the vaccine components. Thus, there is no control over how well the vaccine works.

"A challenge with conventional vaccines is that out of that blended mish mosh, an immune cell might pick up 50 antigens and one adjuvant or one antigen and 50 adjuvants," said study author and former Northwestern postdoctoral associate Michelle Teplensky, who is now an assistant professor at Boston University. "But there must be an optimum ratio of each that would maximize the vaccine's effectiveness."

Enter SNAs (spherical nucleic acids), which are the structural platform -- invented and developed by Mirkin -- used in this new class of modular vaccines. SNAs allow scientists to pinpoint exactly how many antigens and adjuvants are being delivered to cells. SNAs also enable scientists to tailor how these vaccine components are presented, and the rate at which they are processed. Such structural considerations, which greatly impact vaccine effectiveness, are largely ignored in conventional approaches.

Vaccines developed through 'rational vaccinology' offer precise dosing for maximum effectiveness

This approach to systematically control antigen and adjuvant locations within modular vaccine architectures was created by Mirkin, who coined the term rational vaccinology to describe it. It is based on the concept that the structural presentation of vaccine components is as important as the components themselves in driving efficacy.

"Vaccines developed through rational vaccinology deliver the precise dose of antigen and adjuvant to every immune cell, so they are all equally primed to attack cancer cells," said Mirkin, who also is a member of the Robert H. Lurie Comprehensive Cancer Center of Northwestern University. "If your immune cells are soldiers, a traditional vaccine leaves some unarmed; our vaccine arms them all with a powerful weapon with which to kill cancer. Which immune cell 'soldiers' do you want to attack your cancer cells?" Mirkin asked rhetorically.

Building an (even) better vaccine

The team developed a cancer vaccine that doubled the number of cancer antigen-specific T cells and increased the activation of these cells by 30% by reconfiguring the architecture of the vaccine to contain multiple targets to help the immune system find tumor cells.

The team investigated differences in how well two antigens were recognized by the immune system depending on their placement -- on the core or perimeter -- of the SNA structure. For an SNA with optimum placement, they could increase the immune response and how quickly the nanovaccine triggered cytokine (an immune cell protein) production to boost T cells attacking the cancer cells. The scientists also studied how the different placements affected the immune system's ability to remember the invader, and whether the memory was long-term.

"Where and how we position the antigens and adjuvant within a single architecture markedly changes how the immune system recognizes and processes it," Mirkin said.

The most powerful structure throws two punches to outsmart the wily, mutating tumor

The study data show that attaching two different antigens to an SNA comprising a shell of adjuvant was the most potent approach for a cancer vaccine structure. It led to a 30% increase in antigen-specific T-cell activation and doubled the number of proliferating T cells compared to a structure in which the same two antigens were attached to two separate SNAs.

These engineered SNA nanostructures stalled tumor growth in multiple animal models.

"It is remarkable," Mirkin said. "When altering the placement of antigens in two vaccines that are nearly identical from a compositional standpoint, the treatment benefit against tumors is dramatically changed. One vaccine is potent and useful, while the other is much less effective."

Many current cancer vaccines are designed to primarily activate cytotoxic T cells, only one defense against a cancer cell. Because tumor cells are always mutating, they can easily escape this immune cell surveillance, quickly rendering the vaccine ineffective. The odds are higher that the T cell will recognize a mutating cancer cell if it has more ways -- multiple antigens -- to recognize it.

"You need more than one type of T cell activated, so you can more easily attack a tumor cell," Teplensky said. "The more types of cells the immune system has to go after tumors, the better. Vaccines consisting of multiple antigens targeting multiple immune cell types are necessary to induce enhanced and long-lasting tumor remission."

Another advantage of the rational vaccinology approach, especially when used with a nanostructure like an SNA, is that it's easy to alter the structure of a vaccine to go after a different type of disease. Mirkin said they simply switch out a peptide, a snippet of a cancer protein with a chemical handle that "clips" onto the structure, not unlike adding a new charm to a bracelet.

Path to most effective vaccine for any cancer type

"The collective importance of this work is that it lays the foundation for developing the most effective forms of vaccine for almost any type of cancer," Teplensky said. "It is about redefining how we develop vaccines across the board, including ones for infectious diseases."

In a previously published paper, Mirkin, Teplensky and colleagues demonstrated the importance of vaccine structure for COVID-19 by creating vaccines that exhibited protective immunity in 100% of animals against a lethal viral infection.

"Small changes in antigen placement on a vaccine significantly elevate cell-to-cell communication, cross-talk and cell synergy," Mirkin said. "The developments made in this work provide a path forward to rethinking the design of vaccines for cancer and other diseases as a whole."

Read more at Science Daily

Three or more concussions linked with worse brain function in later life

Experiencing three or more concussions is linked with worsened brain function in later life, according to major new research.

The study -- the largest of its kind -- also found having just one moderate-to-severe concussion, or traumatic brain injury (TBI), can have a long-term impact on brain function, including memory.

Led by teams at the University of Oxford and the University of Exeter, the research included data from more than 15,000 participants of the online PROTECT study, who were aged between 50 and 90 and based in the UK. They reported the severity and frequency of concussions they had experienced throughout their lives, and completed annual, computerised tests for brain function.

Published in the Journal of Neurotrauma, the paper found that people who reported three or more concussions had significantly worse cognitive function, which got successively worse with each subsequent concussion after that. Attention and completion of complex tasks were particularly affected.

Researchers say people who have had concussions should be warned of the dangers of continuing high-risk sport or work.

Lead investigator Dr Vanessa Raymont, from the University of Oxford, said: "We know that head injuries are a major risk factor for dementia, and this large-scale study gives the greatest detail to date on a stark finding -- the more times you injure your brain in life, the worse your brain function could be as you age.

"Our research indicates that people who have experienced three or more even mild episodes of concussion should be counselled on whether to continue high-risk activities. We should also encourage organisations operating in areas where head impact is more likely to consider how they can protect their athletes or employees."

The team found that participants who reported three episodes of even mild concussion throughout their lives had significantly worse attention and ability to complete complex tasks. Those who had four or more mild concussion episodes also showed worsened processing speed and working memory. Each additional reported concussion was linked to progressively worse cognitive function.

Furthermore, the researchers found that reporting even one moderate-to-severe concussion was associated with worsened attention, completion of complex tasks and processing speed capacity.

In the online PROTECT study, participants share detailed lifestyle information, and complete a suite of cognitive tests every year, for up to 25 years. This rich mine of data helps researchers understand how the brain ages, and the factors involved in maintaining a healthier brain in later life.

Dr Helen Brooker, a study co-author from the University of Exeter, said: "As our population ages, we urgently need new ways to empower people to live healthier lives in later life. This paper highlights the importance of detailed long-term studies like PROTECT in better understating head injuries and the impact to long term cognitive function, particularly as concussion has also been linked to dementia. We're learning that life events that might seem insignificant, life experiencing a mild concussion, can have an impact on the brain. Our findings indicate that cognitive rehabilitation should focus on key functions such as attention and completion of complex tasks, which we found to be susceptible to long-term damage."

Read more at Science Daily

Honey bee colony loss in the U.S. linked to mites, extreme weather, pesticides

About one-third of the food eaten by Americans comes from crops pollinated by honey bees, yet the insect is dying off at alarming rates. In one year alone, between April of 2019 and April of 2020, one study reported a 43% colony loss in honey bees across the United States.

A new study led by Penn State researchers provides preliminary insight on the potential effects of several variables, including some linked to climate change, on honey bees. Their findings show that honey bee colony loss in the U.S. over the last five years is primarily related to the presence of parasitic mites, extreme weather events, nearby pesticides, as well as challenges with overwintering, according to a new study led by Penn State researchers. The study took advantage of novel statistical methods and is the first to concurrently consider a variety of potential honey bee stressors at a national scale. The study, published online in the journal Scientific Reports, suggests several areas of concern to prioritize in beekeeping practices.

"Honey bees are vital pollinators for more than 100 species of crops in the United States, and the widespread loss of honey bee colonies is increasingly concerning," said Luca Insolia, first author of the study, a visiting graduate student in the Department of Statistics at Penn State at the time of the research, and currently a postdoctoral researcher at the University of Geneva in Switzerland. "Some previous studies have explored several potential stressors related to colony loss in a detailed way but are limited to narrow, regional areas. The one study that we know of at the national level in the United States explored only a single potential stressor. For this study, we integrated many large datasets at different spatial and temporal resolutions and used new, sophisticated statistical methods to assess several potential stressors associated with colony collapse across the U.S."

The research team, composed of statisticians, geographers, and entomologists, gathered publicly available data about honey bee colonies, land use, weather, and other potential stressors from the years 2015 to 2021. Because these data came from a variety of sources, they varied in resolution over both space and time. The weather data, for example, contained daily data points for areas only few square miles in size, but data on honey bee colonies was at the state level for a several-month period.

"In order to analyze the data all together, we had to come up with a technique to match the resolution of the various data sources," said Martina Calovi, corresponding author of the study, a postdoctoral researcher in the Department of Ecosystem Science and Management at Penn State at the time of the research, and currently an associate professor of geography at the Norwegian University of Science and Technology. "We could have just taken an average of all the weather measurements we had within a state, but that boils all the information we have into one number and loses a lot of information, especially about any extreme values. In addition to averaging weather data, we used an 'upscaling' technique to summarize the data in several different ways, which allowed us to retain more information, including about the frequency of extreme temperature and precipitation events."

The researchers used the resulting integrated resolution-matched dataset -- which they have made available for use by other researchers -- alongside sophisticated statistical modeling techniques that they developed to assess the large number of potential stressors at the same time.

The research team found that several stressors impacted honey bee colony loss at the national level, including the presence of nearby pesticides, frequent extreme weather events, and weather instability. Colony loss was also related to the presence of parasitic mites, Varroa destructor, which reproduce in honey bee colonies, weaken the bees, and potentially expose them to viruses. The researchers also found that losses typically occurred between January and March, likely related to challenges with overwintering, but that some states do not follow this pattern.

"Our results largely reinforce what regional studies have observed and confirm that regional patterns around these stressors are actually more widespread," said Insolia, a beekeeper himself. "These results also inform actions that beekeepers could take to help circumvent these stressors and protect their colonies, including treatments for the Varroa mite‚ especially in areas of weather instability. Beekeepers could also consider strategies to move their colonies to areas with high food availability or away from nearby pesticides or to provide supplementary food during certain seasons or months with frequent extreme weather events."

The researchers note that having data about beekeeping practices and colony loss at a finer resolution would allow validation of their results and a more nuanced look at honey bee stressors.

"It would be incredibly beneficial to explore beekeeping practices at a finer scale than the state level," said Calovi. "In many cases, beekeeping associations and other organizations collect this data, but it is not made available to researchers. We hope our study will help motivate more detailed data collection as well as efforts to share that data -- including from smaller organizations such as regional beekeeper associations."

The research team also found a strong relationship between colony loss and a broad category of beekeeping practices noted on a USDA survey as "other," which contained everything from hives being destroyed to food scarcity to queen failure. They noted that collecting this data in more detail and breaking up this catch-all type variable would improve their ability to connect particular stressors to colony collapse.

"A changing climate and high-profile extreme weather events like Hurricane Ian -- which threatened about 15% of the nation's bees that were in its path as well as their food sources -- are important reminders that we urgently need to better understand the stressors that are driving honey bee colony collapse and to develop strategies to mitigate them," said Francesca Chiaromonte, professor of statistics and the holder of the Lloyd and Dorothy Foehr Huck Chair in Statistics for the Life Sciences at Penn State and a senior member of the research team. "Our results highlight the role of parasitic mites, pesticide exposure, extreme weather events, and overwintering in bee colony collapse. We hope that they will help inform improved beekeeping practices and direct future data collection efforts that allow us to understand the problem at finer and finer resolutions."

Read more at Science Daily

Ancestral variation guides future environmental adaptations

The speed of environmental change is very challenging for wild organisms. When exposed to a new environment individual plants and animals can potentially adjust their biology to better cope with new pressures they are exposed to -- this is known as phenotypic plasticity.

Plasticity is likely to be important in the early stages of colonising new places or when exposed to toxic substances in the environment. New research published in Nature Ecology & Evolution, shows that early plasticity can influence the ability to subsequently evolve genetic adaptations to conquer new habitats.

Sea campion, a coastal wildflower from the UK and Ireland has adapted to toxic, zinc rich industrial-era mining waste which kills most other plant species. The zinc-tolerant plants have evolved from zinc-sensitive, coastal populations separately in different places, several times.

To understand the role of plasticity in rapid adaptation, a team of researchers lead by Bangor University conducted experiments on sea campion.

As zinc-tolerance has evolved several times, this gave the researchers the opportunity to investigate whether ancestral plasticity made it more likely that the same genes would be used by different populations that were exposed to the same environment.

By exposing the tolerant and sensitive plants to both benign and zinc contaminated environments and measuring changes in the expression of genes in the plant's roots, the researchers were able to see how plasticity in the coastal ancestors has paved the way for adaptation to take place very quickly.

Dr Alex Papadopulos, senior lecturer at Bangor University explained:

"Sea campion usually grow on cliffs and shingle beaches, but mining opened up a new niche for them that other plants weren't able to exploit. Our research has shown that some of the beneficial plasticity in the coastal plants has helped the mine plants to adapt so quickly."

Alex added,

"Remarkably, if a gene responds to the new environment in a beneficial way in the ancestral plants, it is much more likely that that gene will be reused in all of the lineages that are independently adapting to the new environment. Phenotypic plasticity may make it more likely that there would be the same evolutionary outcome if the tape of life were replayed. If we understand the plastic responses that species have to environmental change, we may be better equipped to predict the impacts of climate change on biodiversity."

Read more at Science Daily

Why a high fat diet could reduce the brain's ability to regulate food intake

Regularly eating a high fat/calorie diet could reduce the brain’s ability to regulate calorie intake. New research in rats published in The Journal of Physiology found that after short periods of being fed a high fat/high calorie diet, the brain adapts to react to what is being ingested and reduces the amount of food eaten to balance calorie intake. The researchers from Penn State College of Medicine, US, suggest that calorie intake is regulated in the short-term by cells called astrocytes (large star-shaped cells in the brain that regulate many different functions of neurons in the brain) that control the signalling pathway between the brain and the gut. Continuously eating a high fat/calorie diet seems to disrupt this signalling pathway.

Understanding the brain’s role and the complex mechanisms that lead to overeating, a behaviour that can lead to weight gain and obesity, could help develop therapies to treat it. Obesity is a global public-health concern because it is associated with increased risk of cardiovascular diseases and type 2 diabetes. In England, 63% of adults are considered above a healthy weight and around half of these are living with obesity. One in three children leaving primary school are overweight or obese1.

Dr Kirsteen Browning, Penn State College of Medicine, US, said,

“Calorie intake seems to be regulated in the short-term by astrocytes. We found that a brief exposure (three to five days) of high fat/calorie diet has the greatest effect on astrocytes, triggering the normal signalling pathway to control the stomach. Over time, astrocytes seem to desensitise to the high fat food. Around 10-14 days of eating high fat/calorie diet, astrocytes seem to fail to react and the brain’s ability to regulate calorie intake seems to be lost. This disrupts the signalling to the stomach and delays how it empties.”

Astrocytes initially react when high fat/calorie food is ingested. Their activation triggers the release of gliotransmitters, chemicals (including glutamate and ATP) that excite nerve cells and enable normal signalling pathways to stimulate neurons that control how the stomach works. This ensures the stomach contracts correctly to fill and empty in response to food passing through the digestive system. When astrocytes are inhibited, the cascade is disrupted. The decrease in signalling chemicals leads to a delay in digestion because the stomach doesn’t fill and empty appropriately.

The vigorous investigation used behavioural observation to monitor food intake in rats (N=205, 133 males, 72 females) which were fed a control or high fat/calorie diet for one, three, five or 14 days. This was combined with pharmacological and specialist genetic approaches (both in vivo and in vitro) to target distinct neural circuits. Enabling the researchers to specifically inhibit astrocytes in a particular region of the brainstem (the posterior part of the brain that connects the brain to the spinal cord), so they could assess how individual neurons behaved to studying rats' behaviour when awake.

Human studies will need to be carried out to confirm if the same mechanism occurs in humans. If this is the case, further testing will be required to assess if the mechanism could be safely targeted without disrupting other neural pathways.

The researchers have plans to further explore the mechanism. Dr Kirsteen Browning said.

Read more at Science Daily

A neuro-chip to manage brain disorders

Mahsa Shoaran of the Integrated Neurotechnologies Laboratory in the School of Engineering collaborated with Stéphanie Lacour in the Laboratory for Soft Bioelectronic Interfaces to develop NeuralTree: a closed-loop neuromodulation system-on-chip that can detect and alleviate disease symptoms. Thanks to a 256-channel high-resolution sensing array and an energy-efficient machine learning processor, the system can extract and classify a broad set of biomarkers from real patient data and animal models of disease in-vivo, leading to a high degree of accuracy in symptom prediction.

"NeuralTree benefits from the accuracy of a neural network and the hardware efficiency of a decision tree algorithm," Shoaran says. "It's the first time we've been able to integrate such a complex, yet energy-efficient neural interface for binary classification tasks, such as seizure or tremor detection, as well as multi-class tasks such as finger movement classification for neuroprosthetic applications."

Their results were presented at the 2022 IEEE International Solid-State Circuits Conference and published in the IEEE Journal of Solid-State Circuits, the flagship journal of the integrated circuits community.

Efficiency, scalability, and versatility

NeuralTree functions by extracting neural biomarkers -- patterns of electrical signals known to be associated with certain neurological disorders -- from brain waves. It then classifies the signals and indicates whether they herald an impending epileptic seizure or Parkinsonian tremor, for example. If a symptom is detected, a neurostimulator -- also located on the chip -- is activated, sending an electrical pulse to block it.

Shoaran explains that NeuralTree's unique design gives the system an unprecedented degree of efficiency and versatility compared to the state-of-the-art. The chip boasts 256 input channels, compared to 32 for previous machine-learning-embedded devices, allowing more high-resolution data to be processed on the implant. The chip's area-efficient design means that it is also extremely small (3.48mm2), giving it great potential for scalability to more channels. The integration of an 'energy-aware' learning algorithm -- which penalizes features that consume a lot of power -- also makes NeuralTree highly energy efficient.

In addition to these advantages, the system can detect a broader range of symptoms than other devices, which until now have focused primarily on epileptic seizure detection. The chip's machine learning algorithm was trained on datasets from both epilepsy and Parkinson's disease patients, and accurately classified pre-recorded neural signals from both categories.

"To the best of our knowledge, this is the first demonstration of Parkinsonian tremor detection with an on-chip classifier," Shoaran says.

Self-updating algorithms

Shoaran is passionate about making neural interfaces more intelligent to enable more effective disease control, and she is already looking ahead to further innovations.

"Eventually, we can use neural interfaces for many different disorders, and we need algorithmic ideas and advances in chip design to make this happen. This work is very interdisciplinary, and so it also requires collaborating with labs like the Laboratory for Soft Bioelectronic Interfaces, which can develop state-of-the-art neural electrodes, or labs with access to high-quality patient data."

As a next step, she is interested in enabling on-chip algorithmic updates to keep up with the evolution of neural signals.

"Neural signals change, and so over time the performance of a neural interface will decline. We are always trying to make algorithms more accurate and reliable, and one way to do that would be to enable on-chip updates, or algorithms that can update themselves."

Read more at Science Daily

Meteorites reveal likely origin of Earth's volatile chemicals

By analysing meteorites, Imperial researchers have uncovered the likely far-flung origin of Earth's volatile chemicals, some of which form the building blocks of life.

They found that around half the Earth's inventory of the volatile element zinc came from asteroids originating in the outer Solar System -- the part beyond the asteroid belt that includes the planets Jupiter, Saturn, and Uranus. This material is also expected to have supplied other important volatiles such as water.

Volatiles are elements or compounds that change from solid or liquid state into vapour at relatively low temperatures. They include the six most common elements found in living organisms, as well as water. As such, the addition of this material will have been important for the emergence of life on Earth.

Prior to this, researchers thought that most of Earth's volatiles came from asteroids that formed closer to the Earth. The findings reveal important clues about how Earth came to harbour the special conditions needed to sustain life.

Senior author Professor Mark Rehka?mper, of Imperial College London's Department of Earth Science and Engineering, said: "Our data show that about half of Earth's zinc inventory was delivered by material from the outer Solar System, beyond the orbit of Jupiter. Based on current models of early Solar System development, this was completely unexpected."

Previous research suggested that the Earth formed almost exclusively from inner Solar System material, which researchers inferred was the predominant source of Earth's volatile chemicals. In contrast, the new findings suggest the outer Solar System played a bigger role than previously thought.

Professor Rehka?mper added: "This contribution of outer Solar System material played a vital role in establishing the Earth's inventory of volatile chemicals. It looks as though without the contribution of outer Solar System material, the Earth would have a much lower amount of volatiles than we know it today -- making it drier and potentially unable to nourish and sustain life."

The findings are published today in Science.

To carry out the study, the researchers examined 18 meteorites of varying origins -- eleven from the inner Solar System, known as non-carbonaceous meteorites, and seven from the outer Solar System, known as carbonaceous meteorites.

For each meteorite they measured the relative abundances of the five different forms -- or isotopes -- of zinc. They then compared each isotopic fingerprint with Earth samples to estimate how much each of these materials contributed to the Earth's zinc inventory. The results suggest that while the Earth only incorporated about ten per cent of its mass from carbonaceous bodies, this material supplied about half of Earth's zinc.

The researchers say that material with a high concentration of zinc and other volatile constituents is also likely to be relatively abundant in water, giving clues about the origin of Earth's water.

First author on the paper Rayssa Martins, PhD candidate at the Department of Earth Science and Engineering, said: "We've long known that some carbonaceous material was added to the Earth, but our findings suggest that this material played a key role in establishing our budget of volatile elements, some of which are essential for life to flourish."

Next the researchers will analyse rocks from Mars, which harboured water 4.1 to 3 billion years ago before drying up, and the Moon. Professor Rehka?mper said: "The widely held theory is that the Moon formed when a huge asteroid smashed into an embryonic Earth about 4.5 billion years ago. Analysing zinc isotopes in moon rocks will help us to test this hypothesis and determine whether the colliding asteroid played an important part in delivering volatiles, including water, to the Earth."

Read more at Science Daily

What crocodile DNA reveals about the Ice Age

What drives crocodile evolution? Is climate a major factor or changes in sea levels? Determined to find answers to these questions, researchers from McGill University discovered that while changing temperatures and rainfall had little impact on the crocodiles' gene flow over the past three million years, changes to sea levels during the Ice Age had a different effect.

"The American crocodile tolerates huge variations in temperature and rainfall. But about 20,000 years ago - when much of the world's water was frozen, forming the vast ice sheets of the last glacial maximum - sea levels dropped by more than 100 metres. This created a geographical barrier that separated the gene flow of crocodiles in Panama," says postdoctoral fellow José Avila-Cervantes, working under the supervision of McGill professor Hans Larsson.

The researchers point out that the crocodiles are good swimmers, but they can't travel long distances on land. As a result, the Caribbean and Pacific crocodile populations were isolated from each other, and consequently have undergone different genetic mutations.

The team compared the climate tolerance of living populations of American crocodiles (Crocodylus acutus) to the paleoclimate estimates for the region over the past 3 million years - the time span of extreme climate variation during the Ice Age.

"This is one of the first times Ice Age effects have been found in a tropical species. It's exciting to discover effects of the last Ice Age glaciation still resonate in the genomes of Pacific and Caribbean American crocodiles today," says Larsson, Professor of Biology at the Redpath Museum of McGill University.

"Discovering that these animals would have easily tolerated the climate swings of the Ice Age speaks to their resilience over geological time. Only humans in recent decades of hunting and land development seem to really affect crocodiles," he says. The findings offer new insight into how environmental drivers affect genetic evolution and where conservation efforts of particular crocodile populations in Panama should be focused.

From Science Daily

New geosciences study shows Triassic fossils that reveal origins of living amphibians

The smallest of newly found fossils can upend what paleontologists know about our history.

A team of paleontologists from Virginia Tech and the U.S. Petrified Forest National Park, among others, have discovered the first "unmistakable" Triassic-era caecilian fossil -- the oldest-known caecilian fossils -- thus extending the record of this small, burrowing animal by roughly 35 million years. The find also fills a gap of at least 87 million years in the known historical fossil record of the amphibian-like creature.

The fossil was first co-discovered by Ben Kligman, a doctoral student in the Department of Geosciences, part of the Virginia Tech College of Science, at Arizona's Petrified Forest National Park during a dig in 2019. Named by Kligman as Funcusvermis gilmorei, the fossil extends the history of caecilians 35 million years back to Triassic Period, roughly 250 million to 200 million years ago.

Prior to this new study, published today in the journal Nature, only 10 fossil caecilian occurrences were known, dating back to the Early Jurassic Period, about 183 million years ago. However, previous DNA studies estimated evolutionary origins of caecilians back to the Carboniferous or Permian eras, some 370 million to 270 million years ago, according to Kligman, marking that 87-million-year gap. However, no such fossils had been found.

"The discovery of the oldest caecilian fossils highlights the crucial nature of new fossil evidence. Many of the biggest outstanding questions in paleontology and evolution cannot be resolved without fossils like this," said Kligman, who previously discovered a 220-million-year-old species of cynodont or stem-mammal, a precursor of modern-day mammals. "Fossil caecilians are extraordinarily rare, and they are found accidentally when paleontologists are searching for the fossils of other more common animals. Our discovery of one was totally unexpected, and it transformed the trajectory of my scientific interests."

The discovery of the fossils was made in 2019 by Kligman and Petrified Forest National Park student intern Xavier Jenkins, now a Ph.D. student at Idaho State University, while the duo was processing fossiliferous sediment from the park's nicknamed Thunderstorm Ridge via a microscope. Funcusvermis was found in a layer of the Chinle Formation dated to approximately 220 million years ago, when Arizona was positioned near the equator at the central part of the supercontinent Pangaea, Kligman said. This region at the time was subject to a hot, humid climate. Today, Arizona is still hot, but has low humidity.

"Seeing the first jaw under the microscope, with its distinctive double row of teeth, sent chills down my back," Kligman said. "We immediately knew it was a caecilian, the oldest caecilian fossil ever found, and a once-in-a-lifetime discovery."

Previous to this find, the 87-million-year gap in the fossil record hid the early evolutionary history of caecilians, leading to a decades-long debate amongst scientists over the relationships of caecilians to their amphibian relatives, frogs and salamanders.

"Funcusvermis extends the humid equatorial pattern of occurrence seen in all known fossil and living caecilians, suggesting that the biogeographic history of caecilians has been guided by restriction to these ecological settings, likely due to physiological constraints linked to humidity, and constrained by the drift of continental plates into and out of the humid-equatorial zone after the fragmentation of Pangaea," Kligman said.

Modern caecilians are limbless amphibians with cylindrical bodies with a compact, bullet-shaped skull that helps them burrow underground. Now exclusively home to South and Central America, Africa, and southern Asia, caecilians spend their lives burrowing in leaf-litter or soil searching for prey such as worms and insects. This underground existence has made studying caecilians difficult for scientists. Kligman, tongue in cheek, describes modern caecilians as an "eyeless sock puppet with the body of a worm."

Funcusvermis actually shares skeletal features related more with early frog and salamander fossils, strengthening evidence for a shared origin and close evolutionary relationship between caecilians and these two groups. Funcusvermis also shares skeletal features with an ancient group of amphibians known to paleontologists as dissorophoid temnospondyls. Kligman adds, "Unlike living caecilians, Funcusvermis lacks many adaptations associated with burrowing underground, indicating a slower acquisition of features associated with an underground lifestyle in the early stages of caecilian evolution."

Name that tune

Now, here's the fun part: The genus name 'Funcusvermis' was inspired by the Ohio Players' 1972 song "Funky Worm" from their album Pleasure, a favorite song of the authors that was often played while excavating fossils at Thunderstorm Ridge. 'Funcus' is derived from the Latinized form of the English word Funky for the upbeat, rhythmic form of dance music, while 'vermis' is derived from the Latin word for worm. (It's an excellent song, by the way. Instant earworm, so to speak.)

The species name, gilmorei, honors Ned Gilmore, the collections manager at the Academy of Natural Sciences of Philadelphia's Drexel University. (Kligman is from Philadelphia and volunteered with Gilmore's herpetology wet collection as an undergraduate student. "He was an important mentor who helped inspire my interest in fossils and amphibians," Kligman said.)

Co-authors on the study include Michelle Stocker, an assistant professor, and Sterling Nesbitt, an associate professor, in the Virginia Tech Department of Geosciences and members of the Global Change Center that is part of the Fralin Life Sciences Institute. Other authors include Adam Marsh, lead paleontologist; Matthew Smith, museum curator; and William Parker, chief of science and resource management, all at the Petrified Forest National Park; and Bryan Gee, postdoctoral fellow at the University of Washington's Burke Museum and Department of Biology.

"As the eponymous song says, it's the funkiest worm in the world," Marsh quipped.

Stocker added, "What we collect really determines what we can say about which animals that were present, how many of them there were, and what they looked like. Without using these methods for fossil collection and analysis we would be missing out on knowing so many important aspects of this Triassic ecosystem. Now that we have a search image of what bones to look for and how to look for them, it will be exciting to see what other fossil localities preserve these early lissamphibians."

Nesbitt said finds such as this can reset the game board on paleontology, in the best sense of the phrase. "This find clearly demonstrates that some fossils that you can barely see can greatly change our understanding of entire groups that you can see today," he said.

What's happened since 2019

At the Petrified Forest National Park, where the initial discovery was found in 2019, the lower jaws of at least 70 individuals of Funcusvermis have been recovered as of summer 2022, making the area "the most abundant fossil caecilian-producing bonebed ever discovered," Kligman said.

Only a handful of bones of Funcusvermis have been found, including upper and lower jaws, a vertebra, and part of a hind-limb, Kligman said. All of the found bones were disarticulated, not as complete skeletons. Without complete skeletons, Kligman and his fellow researchers cannot exactly determine the body length of Funcusvermis, but inferences from isolated elements, such as the lower jaw being less than a quarter of an inch long, indicate that Funcusvermis was a tiny animal.

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