Plastics treaty must tackle problem at source

 The new Global Plastics Treaty must tackle the problem at source, researchers say.

An international negotiation meeting (INC-3) in Kenya begins on Monday, aiming to further develop a legally binding treaty on plastic pollution.

Writing in the journal Science, researchers say the treaty must prioritise "upstream" issues: cutting total production and consumption of plastics, phasing out hazardous chemicals and tackling fossil fuel subsidies.

They highlight a "worrying" level of focus on downstream recycling and waste management -- when the true solution must address the full life cycle of plastics.

They say the treaty must be holistic -- with more focus on early interventions and the people, places and ecosystems most impacted by plastic pollution.

"Right now, simply too much attention and capital is focussed 'downstream' -- recycling and cleaning up plastic already in the environment, in many cases just after a single use " said Dr Mengjiao (Melissa) Wang, from Greenpeace Research Laboratories at the University of Exeter.

"That is vital work, but it can only be part of the solution, and only if done in a safe, environmentally sound and socially just way.

"Removing the mess while making more is a doomed strategy. We cannot recycle our way out.

"An effective treaty must be holistic, covering everything from fossil fuel extraction and plastic production to recycling and removing waste that already pollutes our land and ocean."

Currently, "downstream" recovery and recycling receives 88% of investment money -- while just 4% is directed to "upstream" reuse solutions.

The authors say this imbalance comes from "fossil-fuel-entwined political economy of plastics," which continues to accelerate production, consumption and waste, adding further to the triple Planetary Crisis -- climate change, biodiversity loss and pollution.

They say the zero draft of the treaty "disproportionately emphasises waste management investment and neglects opportunities" for more efficient and cost-effective upstream strategies like reduction, redesign and reuse.

The researchers say the treaty should require polymer manufacturers to pay a "substantial fee pegged to the quantity of primary plastics produced," define criteria for strong and independent Extended Producer Responsibility schemes, and ensure both public and private financing align with the zero waste hierarchy by prioritising upstream strategies.

An effective Plastics Treaty to close the back door for fossil fuels

The new treaty could and should become a global mechanism, to close a key loophole left by the Paris Agreement.

"The problem of plastic pollution is huge, and it can feel overwhelming," said Dr Lucy Woodall, from the University of Exeter.

"But there are opportunities and challenges at each stage of the life cycle of plastics -- from fossil fuel extraction onwards."

Global climate governance aims to stop the burning of fossil fuels, but they could still be extracted and used to make plastics -- so the Plastics Treaty provides a not-to-be-missed opportunity to close this "back door."

In three letters to Science, the researchers -- the majority from the Scientists' Coalition for an Effective Plastics Treaty -- highlight several other points that the treaty must include.

"One vital step is to focus on ecosystems," said Dr Woodall.

"Once in the environment, plastic litter can entangle and choke wildlife, and plastic objects can act as a reservoir for invasive species and concentrate other pollutants.

"Plastics can also break down into potentially toxic micro- and nanoplastics."

The treaty's zero draft used terms such as "hotspot" and "cleanup" -- putting the focus on concentrations rather than the natural systems and their specific context, therefore the well-being and livelihoods of the nature and people these pollutants affect are ignored.

"This implies that the plastics problem can be solved without considering ecosystem restoration and the disproportionate burden of plastic pollution in some ecosystems," Dr Woodall said.

"Vibrant ecosystems are vital for biodiversity and human health, so protecting them should be the centre of our approach."

'Chemical simplification'

Chemicals in plastics are one of the key barriers to addressing global plastic pollution.

Current regulations don't require producers to track or publish information on the levels of harmful chemicals.

The authors argue for "chemical simplification," significantly reducing the production and use of especially hazardous chemicals, and increasing transparency and traceability along the whole supply chain, to fulfil one of the many necessary steps to ensure products can be safely and effectively recycled.

The researchers are hopeful that an effective treaty can be agreed -- but some countries are expected to resist more ambitious language and delay the process.

"When we speak to negotiators, they give us a political 'reality check' about balancing ambition with getting a treaty agreed in due time," Dr Wang said.

"In return, our role as scientists is to provide a scientific reality check about the scale of this problem and the solutions that can actually work to bring us back to the safe operating space of the earth.

"We need a treaty that is holistic and ambitious, tackling every stage of this problem -- extraction, production, resource allocation -- to stop the build-up of plastic waste and harmful chemicals in our planet's precious ecosystems."

Palaeo-CSI: Mosasaurs were picky eaters

 The cradle of palaeontology -- the study of fossil remains of animals and plants -- lies in the Maastricht limestones, where the first Mosasaurus was discovered in 1766. The Dutch-Belgian border area around the Limburg capital is one of the best-explored areas in the world where Cretaceous rocks are concerned, the era that came to an abrupt end 66 million years ago. New data can now be added to all previous knowledge: the Maastricht mosasaurs turned out to be quite picky in their choice of diet. This is the conclusion of researchers from Utrecht University and the Natural History Museum Maastricht. In collaboration with English colleagues from the University of Leicester, they were the first in the world to study the wear marks on mosasaur teeth.

"We were curious whether different species of mosasaurs around Maastricht were really getting in each other's way in their choice of food, or whether this was not so much of a problem," explains Dr Femke Holwerda, palaeontologist at the Utrecht University Faculty of Geosciences. In the absence of data on stomach contents of the Maastricht monitor lizards, the researchers therefore looked at minute scratches on the teeth of these animals from southern Limburg (the Netherlands) and in the vicinity of Eben-Emael (province of Liège, Belgium).

Seafood banquet

"It seems that the various species of mosasaur reveal differences in diet. We noted these differences mainly between the smaller species -- by mosasaur standards -- of about three to seven metres in overall size, and the larger ones, eight to fifteen metres in length." But there were also some differences between the larger species. "Prognathodon in particular, with its large cone-shaped teeth, appears to have had a surprising amount of shellfish in its diet, so it apparently loved its seafood buffet. Another species, Plioplatecarpus, with narrow pointed teeth, showed a striking number of signs of wear. Perhaps this species was also fond of fish with strongly scaled bodies."

First

The researchers first made casts of the teeth in silicone rubber and put them in the 3D scanner. "This technique had already been used in dinosaurs, but we were the first to look at the teeth of mosasaurs in the same way," explains fellow palaeontologist Anne Schulp, also affiliated with Utrecht University.

Diversity

With this research, some missing pieces of the puzzle from the long-gone latest Cretaceous world are found. "We wish to understand diversity better," says Schulp. "And that is made easier for us because the animals studied all come from the same rocks, and therefore the same period. So instead of describing just one species, we look at the ecosystem as a whole."

Soft limestone

The limestone deposits around Maastricht are a goldmine for palaeontologists. Schulp: "Nowhere else in the world is the habitat of mosasaurus as well preserved as here. You can find them in very soft limestone, so wear and tear of the teeth from other causes may be ruled out."

Of course, such an abundance of potential finds also exerts a great attraction on amateur palaeontologists. "There's nothing wrong with that," emphasises John Jagt, curator at the Natural History Museum Maastricht. "Amateur literally means 'enthusiast' and thanks to 250 years of intensive research by these enthusiasts, we have learnt a lot about mosasaurs and other extinct life forms. A museum like ours benefits greatly from this. What also helps is that this kind of amateur science is stimulated in the Netherlands: it is simply allowed by law. That's not the case everywhere."

Barnacle bends shape to fend off warm-water sea snails on the move

 Some barnacles are 'morphing' to protect themselves from predatory warm-water sea snails, which are expanding into their territory due to climate change.

Research led by the University of Southampton and published in the Journal of Biogeography shows how temperate prey species are adapting to changing water temperatures, which carry the threat of warm-water predators encroaching into their territory.

As global sea-surface temperatures rise and the number of marine heatwaves increase under global heating, coastal marine communities are changing. Warm-water predators that were restricted to subtropical and tropical regions are now establishing themselves in more temperate waters. This phenomenon is known as 'tropicalisation'.

As these predators push out from the equator towards the poles, temperate prey species, like the barnacle Tetraclita rubescens, are encountering new, larger, predators. Researchers wanted to know how this barnacle species might adapt their defences in response to tropicalisation.

Specifically, they studied the prevalence of 'bent morphs' -- individual barnacles that morph into a bent shape, obscuring an opening in their shells which can be attacked by predatory sea snails (muricids). Bent morphs have slower growth and lower reproduction than the standard cone-shaped barnacles, but this could be a necessary trade-off in the face of increased predation.

"We found that bent morphs of T. rubescens were more common in the most southern part of its geographic range in the Baja California peninsula of Mexico, which is a region undergoing tropicalisation," says Dr Phillip Fenberg, Associate Professor in Ocean and Earth Science at the University of Southampton and lead author of the research. "In these waters, T. rubescens barnacles are preyed upon by at least three species of warm-water sea snails which are expanding their geographic range due to rising sea temperatures. These sea snails have large bodies, and some can secrete toxins, making them very effective predators."

The research team studied 30 sites along the Pacific coast of North America -- examining over a thousand photographs taken between 2017 and 2022. Using these photographs, they determined the prevalence of bent morphs, as well as their relative size compared to conic morphs. The team also used published research and field surveys to find out how barnacle populations overlap with the range expansion of warm-water predatory sea snails.

Bent morphs were only common along the Baja peninsula of Mexico, where tropicalisation is occurring. Here, they made up an average of 29% of the populations. Bent morphs were also significantly smaller than cone-shaped barnacles.

In regions further away (in California, USA), bent morphs were absent, suggesting cold-water predatory sea snails don't induce the same morphing defence.

Karolina Zarzyczny, a co-author of the paper also from the University of Southampton, explains there could be several reasons for this: "The bent morph defence might be unnecessary, ineffective or not possible for barnacles in the cooler regions of its geographic range in California. We know that T. rubescens are preyed upon by cold-water sea snails, but these snails are smaller than their warm-water relatives and might prefer to prey on other barnacle species which pose less of a challenge.

"The bent shape could also be a less effective defence against cold-water predators, who attack their prey differently. Finally, more northerly populations in California may not have the genetic capacity to produce bent morphs, but this has yet to be determined."

The research shows that some species may adapt in surprising ways to tropicalisation, which is likely to have a significant impact on marine ecosystems, on top of the direct consequences of warming sea temperatures. The researchers say more research is needed to understand the drivers and consequences of tropicalisation on marine ecosystems.

Bacteria-virus arms race provides rare window into rapid and complex evolution

 As conceived by Charles Darwin in the 1800s, evolution is a slow, gradual process during which species adaptations are inherited incrementally over generations. However, today biologists can see how evolutionary changes unfold on much more accelerated timescales.

Rather than the evocative plants and animals of the Galapagos Islands that Darwin studied in forming his theory of evolution, Postdoctoral Scholar Joshua Borin and Associate Professor Justin Meyer of UC San Diego's School of Biological Sciences are documenting rapid evolutionary processes in simple laboratory flasks.

Borin and Meyer set bacteria and viruses together in a closed laboratory flask -- just two teaspoons large -- to study coevolution in action. As viruses infect their bacterial neighbors, the bacteria evolve new defensive measures to repel the attacks. The viruses then counter these adaptations with their own evolutionary changes that work around the new defensive measures.

In only three weeks, this accelerated arms race between bacteria (Escherichia coli) and viruses (bacteriophage, or "phage") results in several generations of evolutionary adaptations. The new findings, published in the journal Science, reveal the emergence of distinct evolutionary patterns.

"In this study we show the power of evolution," said Meyer, an associate professor in the Department of Ecology, Behavior and Evolution. "We see how coevolution between bacteria and phage drive the emergence of a highly complicated ecological network. Evolution doesn't have to be slow and gradual as Darwin thought."

Meyer says the new study offers fresh perspectives on how intricate ecological networks develop across disparate ecosystems, whether they are food webs across the savanna, pollinator networks in the rainforest or microbes interacting in the ocean.

As bacteria and viruses adapted to each other's presence over time, two prominent repeating patterns emerged. These included nestedness, a development in which narrow interactions between bacteria and virus specialists are "nested" within a broader range of generalist interactions; and modularity, in which interactions between species form modules within specialized groups, but not between groups.

"We were amazed to discover that our evolution experiment in tiny flasks had recapitulated the complex patterns that had been previously observed between bacteria and viruses collected at regional and transoceanic scales," said Borin.

"When our research team first quantified this multiscale pattern in environmental bacteria and phage interaction data, we thought the emergence of such complexity required long periods of evolution," added study coauthor Professor Joshua Weitz from the Department of Biology at the University of Maryland.

Meyer says capturing these evolutionary developments "in action" reinforces the power of evolution, which is often underestimated. Rapid pathogenic evolution continues to shape our world in new ways. Through COVID-19 and new mutations of SARS-CoV-2, viruses have demonstrated the potent capability for evolutionary adaptations that result in new strains when they encounter antibodies, vaccines and other roadblocks that keep them from effectively infecting and spreading. Such new concepts in microbial evolution are reframing the way patients are treated.

"We show that evolution can produce complex ecological networks quickly from very little external help," said Meyer, who indicated that examples of such external evolutionary forces include isolation via geographical distance, environmental drivers and interactions with other species. "So we can use phage and bacteria as a model system to understand general evolutionary principles and help show how life on Earth has evolved into such diverse and complex ecosystems from simple beginnings."

In related work, Meyer and Weitz are using artificial intelligence to study how phage could be used in the growing antibiotic resistance crisis. The research includes analysis of evolutionary data to determine which mutations in phage and bacteria can lead to infection and resistance. The research also highlights a new effort supported by the Howard Hughes Medical Institute to study how "jumbo" phages could be used as new therapeutic agents.

Chimpanzees use hilltops to conduct reconnaissance on rival groups -- study

 Chimpanzees use high ground to conduct reconnaissance on rival groups, often before making forays into enemy territory at times when there is reduced risk of confrontation, a new study suggests.

Tactical use of elevated terrain in warfare situations is considered unique to humans -- until now. For the first time, one of the oldest military strategies has been observed in our closest evolutionary relatives.

Researchers conducted a three-year study of two neighbouring chimpanzee groups in the West African forests of Côte d'Ivoire, tracking the primates as they traversed their respective territories, including an overlapping border area where skirmishes occasionally took place.

The team found that chimpanzees were more than twice as likely to climb hills when heading towards this contested frontier as when they were travelling into the heart of their own territory.*

While atop border hills, chimpanzees were more likely to refrain from noisily eating or foraging and spend time quietly resting -- enabling them to hear distant sounds of rival groups, say researchers.

The further away the location of hostile chimpanzees, the greater the likelihood of an advance into dangerous territory upon descending the hill. This suggests that chimpanzees on high ground gauge the distance of rivals, and act accordingly to make incursions while avoiding costly fights.

Other mammal species such as meerkats use high ground to keep watch for predators or call to mates. However, researchers say this is the first evidence for an animal other than humans making strategic use of elevation to assess the risks of "intergroup conflict."

"Tactical warfare is considered a driver of human evolution," said Dr Sylvain Lemoine, a biological anthropologist from the University of Cambridge's Department of Archaeology, and lead author of the study published in the journal PLOS Biology.

"This chimpanzee behaviour requires complex cognitive abilities that help to defend or expand their territories, and would be favoured by natural selection."

"Exploiting the landscape for territorial control is deeply rooted in our evolutionary history. In this use of war-like strategy by chimpanzees we are perhaps seeing traces of the small scale proto-warfare that probably existed in prehistoric hunter-gatherer populations."

The study was conducted at the Taï Chimpanzee Project, where Lemoine worked during his PhD. The project is currently led by study senior author Dr Roman Wittig from CNRS in France.**

Teams of researchers spend 8-12 hours a day following four groups that are "habituated" to the presence of humans. It is one of the few sites where data is collected simultaneously on multiple communities of wild chimpanzees.

The project researchers have GPS trackers, through which the study authors were able to reproduce maps of two chimpanzee territories that border each other, including elevation data. These were matched to old French colonial maps to confirm topography.

Each group consisted of 30-40 adult chimpanzees at any one time. The study used over 21,000 hours of track logs from a total of 58 animals recorded between 2013 and 2016.

To establish and protect their territory, chimpanzees perform regular tours of the periphery that form a sort of "border patrol," says Lemoine. "Patrols are often conducted in subgroups that stay close and limit noise. As an observer, you get a sense that patrolling has begun. They move and stop at the same time, a bit like a hunt," he said.

The type of hills near the border used for reconnaissance are known as "inselbergs": isolated rocky outcrops that break up the forest canopy.*** Chimpanzees repeatedly returned to some of these inselbergs, where time on the summit was passed in a more muted state.

"These aren't so much lookout points as listen-out points," said Lemoine. "Chimpanzees drum on tree trunks and make excitable vocalisations called pant-hoots to communicate with group members or assert their territory. These sounds can be heard over a kilometre away, even in dense forest."

"It may be that chimpanzees climb hilltops near the edge of their territory when they have yet to hear signs of rival groups. Resting quietly on an elevated rock formation is an ideal condition for the auditory detection of distant adversaries."

Researchers analysed tactical movements in the half an hour after a stop longer than five minutes on a hill near the border, and compared it to movements after stops in low-lying border areas.

Following a hilltop recce, the likelihood of advancing into enemy territory increased from 40% when rivals were 500 metres away, to 50% when rivals were at 1000m, to 60% when rivals were at 3000m.

"Chimpanzees often expand their territory by encroaching and patrolling in that of their neighbours. Hilltop information-gathering will help them to do this while reducing risks of encountering any enemies," said Lemoine. "The border zone between the two groups was in a state of flux."

More territory can boost food provision and mating chances, says Lemoine. His previous work suggests that larger chimpanzee groups live in bigger territories with reduced pressure from rivals, which in turn increases birth rates within communities.

The latest research suggests that chimpanzees use hilltop reconnaissance to avoid confrontation, and violence is relatively rare, says Lemoine. But fights, and even kidnappings and killings, did occur between rival group members.

"Occasionally, raiding parties of two or three males venture deep into enemy territory, which can lead to fighting. Confrontations between rival chimpanzees are extremely noisy. The animals go into an intimidating frenzy, screaming and defecating and gripping each other's genitals."

Window to avoid 1.5°C of warming will close before 2030 if emissions are not reduced

 Without rapid carbon dioxide emission reductions, the world has a 50% chance of locking in 1.5°C of warming before 2030, according to a study led by Imperial College London researchers.

The study, published today in Nature Climate Change, is the most up-to-date and comprehensive analysis of the global carbon budget. The carbon budget is an estimate of the amount of carbon dioxide emissions that can be emitted while keeping global warming below certain temperature limits.

The Paris Agreement aims to limit global temperature increase to well below 2°C above preindustrial levels and pursue efforts to limit it to 1.5°C. The remaining carbon budget is commonly used to assess global progress against these targets.

The new study estimates that for a 50% chance of limiting warming to 1.5°C, there are less than 250 gigatonnes of carbon dioxide left in the global carbon budget.

The researchers warn that if carbon dioxide emissions remain at 2022 levels of about 40 gigatonnes per year, the carbon budget will be exhausted by around 2029, committing the world to warming of 1.5°C above preindustrial levels.

The finding means the budget is less than previously calculated and has approximately halved since 2020 due to the continued increase of global greenhouse gas emissions, caused primarily from the burning of fossil fuels as well as an improved estimate of the cooling effect of aerosols, which are decreasing globally due to measures to improve air quality and reduce emissions.

Dr Robin Lamboll, research fellow at the Centre for Environmental Policy at Imperial College London, and the lead author of the study, said: "Our finding confirms what we already know -- we're not doing nearly enough to keep warming below 1.5°C.

"The remaining budget is now so small that minor changes in our understanding of the world can result in large proportional changes to the budget. However, estimates point to less than a decade of emissions at current levels.

"The lack of progress on emissions reduction means that we can be ever more certain that the window for keeping warming to safe levels is rapidly closing."

Dr Joeri Rogelj, Director of Research at the Grantham Institute and Professor of Climate Science & Policy at the Centre for Environmental Policy at Imperial College London, said: "This carbon budget update is both expected and fully consistent with the latest UN Climate Report.

"That report from 2021 already highlighted that there was a one in three chance that the remaining carbon budget for 1.5°C could be as small as our study now reports.

"This shows the importance of not simply looking at central estimates, but also considering the uncertainty surrounding them."

The study also found that the carbon budget for a 50% chance of limiting warming to 2°C is approximately 1,200 gigatonnes, meaning that if carbon dioxide emissions continue at current levels, the central 2°C budget will be exhausted by 2046.

There has been much uncertainty in calculating the remaining carbon budget, due to the influence of other factors, including warming from gasses other than carbon dioxide and the ongoing effects of emissions that are not accounted for in models.

The new researchused an updated dataset and improved climate modelling compared to other recent estimates, published in June, characterising these uncertainties and increasing confidence around the remaining carbon budget estimates.

The strengthened methodology also gave new insights into the importance of the potential responses of the climate system to achieving net zero.

'Net zero' refers to achieving an overall balance between global emissions produced and emissions removed from the atmosphere.

According to the modelling results in the study, there are still large uncertainties in the way various parts of the climate system will respond in the years just before net zero is achieved.

It is possible that the climate will continue warming due to effects such as melting ice, the release of methane, and changes in ocean circulation.

However, carbon sinks such as increased vegetation growth could also absorb large amounts of carbon dioxide leading to a cooling of global temperatures before net zero is achieved.

Dr Lamboll says these uncertainties further highlight the urgent need to rapidly cut emissions. "At this stage, our best guess is that the opposing warming and cooling will approximately cancel each other out after we reach net zero.

"However, it's only when we only when we cut emissions and get closer to net zero that we will be able to see what the longer-term heating and cooling adjustments will look like.

"Every fraction of a degree of warming will make life harder for people and ecosystems. This study is yet another warning from the scientific community. Now it is up to governments to act."

Study uncovers hundred-year lifespans for three freshwater fish species in the Arizona desert

 A recent study found some of the oldest animals in the world living in a place you wouldn't expect: fishes in the Arizona desert. Researchers found the second genus of animal ever for which three or more species have known lifespans greater than 100 years, which could open the doors to aging studies across disciplines, such as gerontology and senescence (aging) among vertebrates.

The study centers around a series of fish species within the Ictiobus genus, known as buffalofishes. Minnesota has native populations of each of the three species studied: bigmouth buffalo, smallmouth buffalo and black buffalo. The importance of this research is underscored by the fact that these fishes are often misidentified and lumped in with invasive species, like carp, and the fishing regulations in many places, including Minnesota, do not properly protect these species, and what could become a wealth of information about longevity and aging.

This new research from the University of Minnesota Duluth (UMD), recently published in Scientific Reports, was a collaboration between Alec Lackmann, PhD, an ichthyologist and assistant professor in the Department of Mathematics and Statistics of the Swenson College of Science and Engineering at UMD; other scientists including from North Dakota State University; and a group of conservation anglers who fish the Apache Lake reservoir in Arizona.

"There is likely a treasure trove of aging, longevity and negligible senescence information within the genus Ictiobus," said Lackmann. "This study brings light to this potential and opens the door to a future in which a more complete understanding of the process of vertebrate aging can be realized, including for humans. The research begs the question: what is the buffalofishes' fountain of youth?"

Lackmann has studied buffalofishes before, and his research from 2019 went so far as to extend the previously thought maximum age of bigmouth buffalo from around 25 years of age, to more than 100 years of age by applying and validating a far more refined aging technique than had been used previously. Instead of examining the fish's scale, "you extract what are called the otoliths, or earstones, from inside the cranium of the fish, and then thin section the stones to determine their age," said Lackmann.

Approximately 97 percent of fish species have otoliths. They're tiny stone-like structures that grow throughout the fish's lifetime, forming a new layer each year. When processed properly, scientists like Lackmann can examine the otolith with a compound microscope and count the layers, like the rings on a tree, and learn the age of the fish.

Results of the study include:

• Unparalleled longevity for freshwater fishes. Namely, three species with lifespans more than a century, with greater than 90 percent of the buffalofishes in Apache Lake more than 85 years old.
• The discovery that some of the original buffalofishes from the Arizona stocking in 1918 are likely still alive.
• A fishery of catch-and-release buffalofish angling that has not only increased our knowledge of fisheries, but also our understanding of how buffalofishes can be identified and recaptured across years, including uniquely-marked centenarians.
• A robust citizens and scientists collaborative effort that has resulted in thorough and consistent scientific outreach and learning.

Buffalofishes are native to central North America, including Minnesota, but those in this recent study were found in Apache Lake, a reservoir in the desert southwest. Originally reared in hatcheries and rearing ponds along the Mississippi River in the Midwest, the government stocked buffalofishes into Roosevelt Lake (upstream of Apache Lake), Arizona in 1918. While Roosevelt Lake was fished commercially, Apache Lake's fish populations remained largely untouched until anglers recently learned how to consistently catch buffalofishes there on rod-and-line.

When these catch-and-release conservation anglers noticed unique orange and black spots on many of the fish they were catching, they wanted to learn more about the markings, and found Lackmann's previous research. An Arizona angler, Stuart Black, reached out and invited Lackmann to a fishing expedition at Apache Lake, where the fish collected would be donated to science.

By studying the fishes collected at the angling event and analyzing their otoliths for age, Lackmann found that some of the buffalofishes from the 1918 Arizona stocking are likely still alive today, and that most of the buffalofishes in Apache Lake hatched during the early 1920s. More importantly, they discovered that the three different buffalofish species found in the lake had ages more than 100 years. To their knowledge, such longevity across multiple freshwater fish species is found nowhere else in the world.

For Lackmann, there are exciting possibilities for the future of studying this unique group of fish, with far-reaching implications.

"These long-lived species of fishes and individuals could be monitored so that we can further study and understand their DNA, their physiology, their ability to fight infection and disease, and to compare these systems across the continuum of age," said Lackmann. "The genus Ictiobus has potential to prove of high value to the field of gerontology, and Apache Lake could become an epicenter for a variety of scientific research in the future."

How sunflowers see the sun

 Sunflowers famously turn their faces to follow the sun as it crosses the sky. But how do sunflowers "see" the sun to follow it? New work from plant biologists at the University of California, Davis, published Oct. 31 in PLOS Biology, shows that they use a different, novel mechanism from that previously thought.

"This was a total surprise for us," said Stacey Harmer, professor of plant biology at UC Davis and senior author on the paper.

Most plants show phototropism -- the ability to grow toward a light source. Plant scientists had assumed that sunflowers' heliotropism, the ability to follow the sun, would be based on the same basic mechanism, which is governed by molecule called phototropin and responds to light at the blue end of the spectrum.

Sunflowers swing their heads by growing a little more on the east side of the stem -- pushing the head west -- during the day and a little more on the west side at night, so the head swings back toward the east. Harmer's lab at the UC Davis College of Biological Sciences has previously shown how sunflowers use their internal circadian clock to anticipate the sunrise, and to coordinate the opening of florets with the appearance of pollinating insects in the morning.

In the new study, graduate student Christopher Brooks, postdoctoral researcher Hagatop Atamian and Harmer looked at which genes were switched on (transcribed) in sunflowers grown indoors in laboratory growth chambers, and in sunflowers growing in sunlight outdoors.

Indoors, sunflowers grew straight toward the light, activating genes associated with phototropin. But the plants grown outdoors, swinging their heads with the sun, showed a completely different pattern of gene expression. There was no apparent difference in phototropin between one side of the stem and another.

The researchers have not yet identified the genes involved in heliotropism.

"We seem to have ruled out the phototropin pathway, but we did not find a clear smoking gun," Harmer said.

Blocking blue, ultraviolet, red or far-red light with shade boxes had no effect on the heliotropism response. This shows that there are likely multiple pathways, responding to different wavelengths of light, to achieve the same goal. Upcoming work will look at protein regulation in the plants.

Sunflowers are quick learners. When plants grown in the lab were moved outdoors, they started tracking the sun on the first day, Harmer said. That behavior was accompanied by a burst of gene expression on the shaded side of the plant that did not recur on subsequent days. That suggests some kind of "rewiring" is going on, she said.

Apart from revealing previously unknown pathways for light-sensing and growth in plants, the discovery has broad relevance, Harmer said.

"Things that you define in a controlled environment like a growth chamber may not work out in the real world," she said.

Atamian is now an assistant professor at Chapman University.

Where is a sea star's head? Maybe just about everywhere

 If you put a hat on a starfish, where would you put it? On the center of the starfish? Or on the point of an arm and, if so, which one? The question is silly, but it gets at serious questions in the fields of zoology and developmental biology that have perplexed veteran scientists and schoolchildren in introductory biology classes alike: Where is the head on a starfish? And how does their body layout relate to ours?

Now, a new Stanford study that used genetic and molecular tools to map out the body regions of starfish -- by creating a 3D atlas of their gene expression -- helps answer this longstanding mystery. The "head" of a starfish, the researchers found, is not in any one place. Instead, the headlike regions are distributed with some in the center of the sea star as well as in the center of each limb of its body.

"The answer is much more complicated than we expected," said Laurent Formery, lead author and postdoc in the labs of Christopher Lowe at the Stanford School of Humanities and Sciences and Daniel S. Rokhsar at the University of California, Berkeley. "It is just weird, and most likely the evolution of the group was even more complicated than this."

Starfish (sea stars) belong to a group of animals called echinoderms. Echinoderms and humans are closely related, yet the life cycle and anatomy of sea stars are very different from ours.

Sea stars begin life as fertilized eggs that hatch into a free-floating larva. The larvae bob in the ocean in a plankton form for weeks to months before settling to the ocean floor to perform a magic trick of sorts -- transforming from a bilateral (symmetric across the midline) body plan into an adult with a five-point star shape called a pentaradial body plan.

"This has been a zoological mystery for centuries," said Lowe, who is also a researcher at Hopkins Marine Station and senior author of the paper that published Nov. 1 in Nature. "How can you go from a bilateral body plan to a pentaradial plan, and how can you compare any part of the starfish to our own body plan?"

Mapping stars

For puzzles such as this one, researchers often conduct comparative studies to identify similar structures in related groups of animals to glean clues about the evolutionary events that prompted the trait of interest.

"The problem with starfish is there is nothing on a starfish anatomically that you can relate to a vertebrate," said Lowe. "There is just nothing there."

At least, nothing on the outside of a starfish. And that is where genetic and molecular techniques come in.

During his graduate research, Formery studied early development in sea urchins -- echinoderms, like sea stars, that also start their life as bilateral larvae before transforming into adults with fivefold symmetry. When Formery joined Lowe's lab, Formery's knowledge of echinoderm development combined with Lowe's expertise in molecular biology techniques to help tackle the mystery of sea stars' baffling body plan.

The team used a group of well-studied molecular markers (Hox genes are an example) that act as blueprints for an organism's body plan by "telling" each cell which body region it belongs to.

"If you strip away the skin of an animal and look at the genes involved in defining a head from a tail, the same genes code for these body regions across all groups of animals," said Lowe. "So we ignored the anatomy and asked: Is there a molecular axis hidden under all this weird anatomy and what is its role in a starfish forming a pentaradial body plan?"

To investigate this question, the researchers used RNA tomography, a technique that pinpoints where genes are expressed in tissue, and in situ hybridization, a technique that zeroes in on a specific RNA sequence in a cell.

"First we sectioned sea star arms into thin slices from tip to center, top to bottom, and left to right," said Formery, noting that sea stars regenerate missing limbs. "We used RNA tomography to determine which genes were expressed in each slice and then 'reassembled' the slices using computer models. This gave us a 3D map of gene expression."

"In the second method, in situ hybridization chain reaction, we stained sea star tissue and visually inspected the samples to see where a gene was expressed," said Formery. This enabled the researchers to examine anterior-posterior (head to tail) body patterning in the outermost layer of cells called the ectoderm.

"This was made possible by the recent, big, technical improvement in in situ hybridization, known as in situ hybridization chain reaction, Formery said. "This new method provides better resolution of where the gene is expressed."

The research revealed that sea stars have a headlike territory in the center of each "arm" and a tail-like region along the perimeter. In an unexpected twist, no part of the sea star ectoderm expresses a "trunk" genetic patterning program, suggesting that sea stars are mostly headlike.

Mining truly diverse biodiversity

Research is often centered on groups of animals that look like us, the researchers explained. But if we focus on the familiar, we are less likely to learn something new.

"There are 34 different animal phyla living on this planet and in over roughly 600 million years they have all come up with different solutions to the same fundamental biological problems," Lowe said. "Most animals don't have spectacular nervous systems and are out chasing prey -- they are modest animals that live in burrows in the ocean. People are generally not drawn to these animals, and yet they probably represent how much of life got started."

This study demonstrates how a comparative approach that uses genetic and molecular techniques can be used to mine biodiversity for insights into why different animals look the way they do and how their body plans evolved.

"Even in recent molecular papers there's a question mark near echinoderms on the evolutionary tree because we don't know much about them," Formery said. "It was nice to show that -- at least at the molecular level -- we have a new piece of the puzzle that can now be put on the tree."

Solar farms in space are possible

 It's viable to produce low-cost, lightweight solar panels that can generate energy in space, according to new research from the Universities of Surrey and Swansea.

The first study of its kind followed a satellite over six years, observing how the panels generated power and weathered solar radiation over 30,000 orbits.

The findings could pave the way for commercially viable solar farms in space.

Professor Craig Underwood, Emeritus Professor of Spacecraft Engineering at the Surrey Space Centre at the University of Surrey, said:

"We are very pleased that a mission designed to last one year is still working after six. These detailed data show the panels have resisted radiation and their thin-film structure has not deteriorated in the harsh thermal and vacuum conditions of space.

"This ultra-low mass solar cell technology could lead to large, low-cost solar power stations deployed in space, bringing clean energy back to Earth -- and now we have the first evidence that the technology works reliably in orbit."

Researchers from the University of Swansea's Centre for Solar Energy Research developed new solar cells from cadmium telluride. The panels cover a larger area, are more lightweight, and provide far greater power than current technology -- as well as being relatively cheap to manufacture.

Scientists from the University of Surrey designed instruments that measured their performance in orbit. The satellite itself was designed and built at the Surrey Space Centre in partnership with a team of trainee engineers from the Algerian Space Agency (ASAL).

Although the cells' power output became less efficient over time, researchers believe their findings prove that solar power satellites work and could be commercially viable.

Dr Dan Lamb from the University of Swansea said:

"The successful flight test of this novel thin film solar cell payload has leveraged funding opportunities to further develop this technology."

"Large area solar arrays for space applications are a rapidly expanding market and demonstrations such as this help to build on the UK's world class reputations for space technology."

Climate report: 'Uncharted territory' imperils life on Earth

 An international coalition of climate scientists says in a paper published today that the Earth's vital signs have worsened beyond anything humans have yet seen, to the point that life on the planet is imperiled.

William Ripple, a distinguished professor in the Oregon State University College of Forestry, and former OSU postdoctoral researcher Christopher Wolf are the lead authors of the report, and 10 other U.S. and global scientists are co-authors.

"Without actions that address the root problem of humanity taking more from the Earth than it can safely give, we're on our way to the potential collapse of natural and socioeconomic systems and a world with unbearable heat and shortages of food and freshwater," Wolf said.

Published in BioScience, "The 2023 State of the climate report: Entering uncharted territory" notes that 20 of 35 planetary vital signs the authors use to track climate change are at record extremes.

The authors share new data illustrating that many climate-related records were broken by "enormous margins" in 2023, particularly those relating to ocean temperatures and sea ice. They also note an extraordinary Canadian wildfire season that produced unprecedented carbon dioxide emissions.

The report follows by four years the "World Scientists' Warning of a Climate Emergency" published by Ripple and collaborators in BioScience and co-signed by more than 15,000 scientists in 161 countries.

"Life on our planet is clearly under siege," Ripple said. "The statistical trends show deeply alarming patterns of climate-related variables and disasters. We also found little progress to report as far as humanity combating climate change."

Among the key numbers in the report:

• Fossil fuel subsidies -- actions by governments that artificially lower the cost of energy production, raise the price received by producers or lower the price paid by consumers -- roughly doubled between 2021 and 2022, from $531 billion to just over $1 trillion.
• Already this year wildfires in Canada have pumped more than 1 gigaton of carbon dioxide into the atmosphere, greater than Canada's total 2021 greenhouse gas emissions of 0.67 gigatons.
• In 2023, there have already been 38 days with global average temperatures more than 1.5 degrees Celsius above pre-industrial levels. Until this year, such days were a rarity, the authors note.
• The highest average Earth surface temperature ever recorded came this past July, and there's reason to believe it was the highest surface temperature the planet has seen in the last 100,000 years.

"As scientists, we are hugely troubled by the sudden increases in the frequency and severity of climate-related disasters," said Wolf, now a scientist with Corvallis-based Terrestrial Ecosystems Research Associates. "The frequency and severity of those disasters might be outpacing rising temperatures. By the end of the 21st century, as many as 3 to 6 billion people may find themselves outside the Earth's livable regions, meaning they will be encountering severe heat, limited food availability and elevated mortality rates."

The authors say policies are needed that take aim at the underlying issue of "ecological overshoot." When human demand on the Earth's resources is too large, the result in an array of environmental crises, including biodiversity decline. As long as humanity continues to put extreme pressure on the planet, any strategy that focuses only on carbon or climate will simply redistribute the pressure, they note.

"Our goal is to communicate climate facts and make policy recommendations," Ripple said. "It is a moral duty of scientists and our institutions to alert humanity of any potential existential threat and to show leadership in taking action."

The authors urge transitioning to a global economy that prioritizes human well-being and curtails overconsumption and excessive emissions by the rich. Specific recommendations include phasing out fossil fuel subsidies, transitioning toward plant-based diets, scaling up forest protection efforts and adopting international coal elimination and fossil fuel non-proliferation treaties.

They stress that all climate-related actions must be grounded in equity and social justice, noting that extreme weather and other climate impacts are being disproportionately felt by the poorest people, who have contributed the least to climate change.

Raining cats and dogs: Global precipitation patterns a driver for animal diversity

 Since the HMS Beagle arrived in the Galapagos with Charles Darwin to meet a fateful family of finches, ecologists have struggled to understand a particularly perplexing question: Why is there a ridiculous abundance of species some places on earth and a scarcity in others? What factors, exactly, drive animal diversity?

With access to a mammoth set of global-scale climate data and a novel strategy, a team from the Department of Watershed Sciences in Quinney College of Natural Resources and the Ecology Center identified several factors to help answer this fundamental ecological question. They discovered that what an animal eats (and how that interacts with climate) shapes Earth's diversity.

The work was recently published in the high-impact journal Ecology Letters.

"Historically studies looking at the distribution of species across Earth's latitudinal gradient have overlooked the role of trophic ecology -- how what animals eat impacts where they are found," said Trisha Atwood, author on the study from the Department of Watershed Sciences and the Ecology Center. "This new work shows that predators, omnivores and herbivores are not randomly scattered across the globe. There are patterns to where we find these groups of animals."

Certain locations have an unexpected abundance of meat-eating predators -- parts of Africa, Europe and Greenland. Herbivores are common in cooler areas, and omnivores tend to be more dominant in warm places. Two key factors emerged as crucial in shaping these patterns: precipitation and plant growth.

Precipitation patterns across time play a big role in determining where different groups of mammals thrive, Atwood said. Geographical areas where precipitation varies by season, without being too extreme, had the highest levels of mammal diversity.

"Keep in mind that we aren't talking about the total amount of rain," said Jaron Adkins, lead author on the research. "If you imagine ecosystems around the world on a scale of precipitation and season, certain places in Utah and the Amazon rainforest fall on one end with low variability -- they have steady levels of precipitation throughout the year. Other regions, like southern California, have really high variability, getting about 75 percent of the annual precipitation between December and March."

But the sweet spot for predators and herbivores fell in a middle zone between the two extremes, he said. Places like Madagascar, where precipitation patterns had an equal split between a wet season and a dry one (six months each), had the ideal ecological cocktail for promoting conditions for these two groups. Omnivore diversity tends to thrive in places with very stable climates.

The second important factor connected with mammal diversity the work uncovered was a measure of the amount of plant growth in an area, measured as "gross primary productivity."

"It makes intuitive sense for plant-eating animals to benefit from plant growth," Adkins said.

But this measure actually impacted carnivores most, according to the research. The strong relationship between predators and plant growth highlights the importance of an abundance of plants on an entire food chain's structural integrity.

"It was surprising that this factor was more important for predators than omnivores and herbivores," Atwood said. "Why this is remains a mystery."

Although evolutionary processes are ultimately responsible for spurring differences in species, climate conditions can impact related factors -- rates of evolutionary change, extinction and animal dispersal -- influencing species and trait-based richness, according to the research.

Animal diversity is rapidly declining in many ecosystems around the world through habitat loss and climate change. This has negative consequences for ecosystems. Forecasting how climate change will disrupt animal systems going forward is extremely important, Atwood said, and this research is a first step in better managing future conditions for animals around the world.

"Animal diversity can act as an alarm system for the stability of ecosystems," Atwood said. "Identifying the ecological mechanisms that help drive richness patterns provides insight for better managing and predicting how diversity could change under future climates."

In addition to Adkins and Atwood, the research included seven authors currently or previously associated with the Department of Watershed Sciences and the Ecology Center: Edd Hammill, Umarfarooq Abdulwahab, John Draper, Marshall Wolf, Catherine McClure, Adrián González Ortiz and Emily Chavez.

Bizarre new fossils shed light on ancient plankton

 A scientist from the University of Leicester has discovered a new type of fossil that reveals life in the oceans half a billion years ago.

The tiny organisms, detailed in a new study in the journal Proceedings of the Royal Society B, resemble modern-day algae and might also give scientists an insight into the climate changes that affected our oceans.

The fossils are microscopic and look like spiny balls connected together. The study's author Dr Tom Harvey, from the University of Leicester School of Geography, Geology and the Environment, said: "When I first saw them, I had no idea what they were. I wondered if they could be animal eggs, or some new type of organism. There's nothing quite like them, living or extinct."

But as further specimens came to light, Dr Harvey identified similarities with modern green algae that live floating in the plankton of ponds and lakes. He explains: "The fossils have the same sort of colonial structure as the modern algae, with cells linking together, explaining their neat, geometric arrangements. Surprisingly, though, the fossil examples lived in the sea, giving a rare glimpse of the early marine plankton."

The importance of the fossils lies in their immense age. They lived around the time when animals were first evolving, during the Cambrian 'explosion' of life -- and this is probably no coincidence. In today's world, phytoplankton provides the fundamental food source for almost all life in the oceans. However, the modern groups of phytoplankton evolved relatively recently, and we do not know which groups inhabited the Cambrian oceans.

Dr Harvey explains: "When we look at modern plankton, we see that algae develop colonies when animals are trying to eat them. It's a defence mechanism. So, the existence of colonial algae in the Cambrian Period suggests that early animals were evolving to feed in the plankton, starting a predator-prey relationship that has continued ever since.

"Considering that the plankton underpins life in the oceans, and fossil plankton helps us build ancient climate models, these small fossils have a big role in telling the history of life on Earth."

The new discovery will prompt a re-think on other early microfossils. For years, scientists have thought that the spiny balls found individually were the dormant cysts of single-celled life.

For Dr Harvey, the new fossils seriously challenge this view: "I wonder if we've been getting it all wrong, and in fact lots of these microfossils were living as colonies in the plankton. It's easy to accidentally break up the fossils as we extract them from the rocks, so we all need to get back to the collections, back to our labs, and find out how common they really were."

Researchers identify the oldest pieces of Baltic amber found on the Iberian Peninsula: imports began over 5,000 years ago

 A team of scientists from the Universities of Granada and Cambridge, as well as the Government of Catalonia, have identified the oldest pieces of Baltic amber ever found on the Iberian Peninsula, revealing that this luxury material used in jewellery and handicrafts around the world was already being imported more than 5,000 years ago.

The research was led by UGR lecturer Mercedes Murillo-Barroso and involved the collaboration of Marcos Martinón-Torres of the University of Cambridge and Araceli Martín Cólliga of the Government of Catalonia. According to Murillo-Barroso, the work "allows us to say with confidence that the arrival of Baltic amber on the Iberian Peninsula occurred at least in the 4th millennium BC, more than a millennium earlier than we thought, and that it was probably part of wider trade networks linked to the south of France."

Trade is one of the many mechanisms through which we establish social relations, and often the objects that are exchanged are not necessarily consumer goods needed to live, but rather decorative, luxury or symbolic objects. Sometimes, especially in adverse conditions, having trade networks means having a network of mutual support, but these trade networks can also generate social inequalities and relations of dependency, especially if not all the community enjoys equal access to the networks or if the objects exchanged are unequal.

In prehistoric times, amber, a fossil resin, was certainly not a raw material necessary for the development of daily life, but it was highly valued and was exchanged via the extensive trade networks that were established. The use of the multiple amber deposits on the Iberian Peninsula since the Upper Palaeolithic has been documented and, thanks to research carried out by archaeologists over the years, we know that from the 4th millennium BC onwards Sicilian amber began to reach the Iberian Peninsula through Mediterranean trade networks. However, until now it was believed that Baltic amber did not reach the Peninsula until the 2nd millennium BC, at which point it would become the primary raw material, replacing other types of amber such as Peninsular or Sicilian amber.

Regarding their research article, published in the Nature journal Scientific Reports, Mercedes Murillo-Barroso affirms: "we present the standard infrared spectroscopy analysis of an amber bead of Baltic origin found at the Cova del Frare site in a context dated between 3634-3363 cal BC."

"The site, which is truly exceptional, illustrates the transition between the Middle Neolithic of the 'Sepulcrand the Late Neolithic of Véraza," explains Araceli Martín Cólliga, director of the excavations at the site.

"As there are no written documents from prehistoric times, the only way to study human activity is through archaeological remains. To study the transport and exchange of materials, we use very precise analytical techniques, such as infrared spectroscopy, which give us a kind of fingerprint of the amber deposits and objects," says Mercedes Murillo-Barroso.

Based on a large amount of data and this type of analysis, combined with other bodies of archaeological information, the study confirms that Baltic amber arrived in the northeastern Iberian Peninsula as early as the Neolithic, which is "something that must be understood in the context of trade during this period of transition and change, either by agents of a declining 'Sepulcres de Fossa' culture, or by those who would set new cultural trends at the end of the Neolithic, led by the Véraza groups of Catalonia and southern France, and not necessarily as direct contact with northern Europe." In fact, there is currently no evidence of Baltic amber crossing the Ebro at such an early date into the southern Iberian Peninsula, where the use of Sicilian amber was predominant as a result of the Mediterranean networks.

The Baltic region is home to what is perhaps the best amber in the world for use in jewellery. Indeed, it was highly sought after in classical Rome and now sustains a whole industry, for example in Poland. We now know that it began to arrive in Iberia as early as the 4th millennium BC, and that it gradually replaced Peninsular and Sicilian amber.

"This finding undoubtedly has important implications for our understanding of early exchange networks of exotic materials and their influence on social structures," explains University of Cambridge professor Marcos Martinón-Torres.

Challenging prehistoric gender roles: Research finds that women were hunters, too

 It's a familiar story to many of us: In prehistoric times, men were hunters and women were gatherers. Women were not physically capable of hunting because their anatomy was different from men. And because men were hunters, they drove human evolution.

But that story's not true, according to research by University of Delaware anthropology professor Sarah Lacy, which was recently published in Scientific American and in two papers in the journal American Anthropologist.

Lacy and her colleague Cara Ocobock from the University of Notre Dame examined the division of labor according to sex during the Paleolithic era, approximately 2.5 million to 12,000 years ago. Through a review of current archaeological evidence and literature, they found little evidence to support the idea that roles were assigned specifically to each sex. The team also looked at female physiology and found that women were not only physically capable of being hunters, but that there is little evidence to support that they were not hunting.

Lacy is a biological anthropologist who studies the health of early humans, and Ocobock is a physiologist who makes analogies between modern day and the fossil record. Friends in graduate school, they collaborated after "complaining about a number of papers that had come out that used this default null hypothesis that cavemen had strong gendered division of labor, the males hunt, females gather things. We were like, 'Why is that the default? We have so much evidence that that's not the case,'" Lacy said.

The researchers found examples of equality for both sexes in ancient tools, diet, art, burials and anatomy.

"People found things in the past and they just automatically gendered them male and didn't acknowledge the fact that everyone we found in the past has these markers, whether in their bones or in stone tools that are being placed in their burials. We can't really tell who made what, right? We can't say, 'Oh, only males flintknap,' because there's no signature left on the stone tool that tells us who made it," Lacy said, referring to the method by which stone tools were made. "But from what evidence we do have, there appears to be almost no sex differences in roles."

The team also examined the question of whether anatomical and physiological differences between men and women prevented women from hunting. They found that men have an advantage over women in activities requiring speed and power, such as sprinting and throwing, but that women have an advantage over men in activities requiring endurance, such as running. Both sets of activities were essential to hunting in ancient times.

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The team highlighted the role of the hormone estrogen, which is more prominent in women than men, as a key component in conferring that advantage. Estrogen can increase fat metabolism, which gives muscles a longer-lasting energy source and can regulate muscle breakdown, preventing muscles from wearing down. Scientists have traced estrogen receptors, proteins that direct the hormone to the right place in the body, back to 600 million years ago.

"When we take a deeper look at the anatomy and the modern physiology and then actually look at the skeletal remains of ancient people, there's no difference in trauma patterns between males and females, because they're doing the same activities," Lacy said.

During the Paleolithic era, most people lived in small groups. To Lacy, the idea that only part of the group would hunt didn't make sense.

"You live in such a small society. You have to be really, really flexible," she said. "Everyone has to be able to pick up any role at any time. It just seems like the obvious thing, but people weren't taking it that way."

Man the Hunter

The theory of men as hunters and women as gatherers first gained notoriety in 1968, when anthropologists Richard B. Lee and Irven DeVore published Man the Hunter, a collection of scholarly papers presented at a symposium in 1966. The authors made the case that hunting advanced human evolution by adding meat to prehistoric diets, contributing to the growth of bigger brains, compared to our primate cousins. The authors assumed all hunters were male.

Lacy points to that gender bias by previous scholars as a reason why the concept became widely accepted in academia, eventually spreading to popular culture. Television cartoons, feature films, museum exhibits and textbooks reinforced the idea. When female scholars published research to the contrary, their work was largely ignored or devalued.

"There were women who were publishing about this in the '70s, '80s and '90s, but their work kept getting relegated to, 'Oh, that's a feminist critique or a feminist approach,'" Lacy said. "This was before any of the work on genetics and a lot of the work on physiology and the role of estrogen had come out. We wanted to both lift back up the arguments that they had already made and add to it all the new stuff."

Lacy said the "man the hunter" theory continues to influence the discipline. While she acknowledges that much more research needs to be done about the lives of prehistoric people -- especially women -- she hopes her view that labor was divided among both sexes will become the default approach for research in the future.

For 3 million years, males and females both participated in subsistence gathering for their communities, and dependence on meat and hunting was driven by both sexes, Lacy said.

"It's not something that only men did and that therefore male behavior drove evolution," she said. "What we take as de facto gender roles today are not inherent, do not characterize our ancestors. We were a very egalitarian species for millions of years in many ways."

Stolen genes allow parasitic control of behavior

 A team led by Tappei Mishina at the RIKEN Center for Biosystems Dynamics Research (BDR) has discovered that parasites manipulate their hosts using stolen genes that they likely acquired through a phenomenon called horizontal gene transfer. The study was published in the scientific journal Current Biology on October 19.

Many parasites manipulate the behavior of their hosts to ensure their survival and ability to reproduce. Horsehair worms display one of the most sophisticated examples of this type of control of behavior. Horsehair worms are born in water and use aquatic insects like mayflies to hitchhike to dry land, where they sit tight until they are eaten by terrestrial insects such as crickets or mantises. Once a horsehair worm reaches these hosts, it starts growing and manipulates the host's behavior. The matured horsehair worm finally induces the host to jump into water, often to the host's ultimate demise, so it can complete its life mission and reproduce.

Previous studies have suggested that horsehair worms hijack their hosts' biological pathways and increase movement towards light, which leads the hosts to approach water. Scientists believe this is accomplished with molecules that mimic those of the hosts' central nervous systems, but exactly how these parasites developed this kind of molecular mimicry has remained a mystery.

To answer this question, the researchers analyzed whole-body gene expression in a Chordodes horsehair worm before, during, and after manipulating its mantis host. They found over 3,000 hairworm genes that were expressed more when hosts were being manipulated, and 1,500 hairworm genes that were expressed less. On the other hand, gene expression in the mantis brains did not change, and in fact could not be distinguished from that found in uninfected mantises. These results indicate that horsehair worms produce their own proteins for manipulating their hosts' nervous systems.

The researchers next searched a protein database to explore the origins of the genes that Chordodes horsehair worms use to manipulate mantises. "Strikingly, many of the horsehair worm genes that could play important roles in manipulating their hosts were very similar to mantid genes, suggesting that they were acquired through horizontal gene transfer," says Mishina. Horizontal gene transfer is a biological process in which genes are transferred from one organism to another, but not through reproduction. It can have significant evolutionary consequences, allowing organisms to acquire new genes or functions rapidly, potentially helping them adapt to new environments or lifestyles.

Further analysis supported the idea that the molecular mimicry seen in the Chordodes horsehair worms is likely the result of horizontal gene transfer from mantises. In particular, over 1,400 Chordodes horsehair worm genes were found to match those in mantises, but were absent or very different from species of horsehair worms that do not use mantis hosts. The authors conclude that the numerous mimicry genes that they identified are likely the result of multiple horizontal gene-transfer events from various mantid species during the evolution of hairworms. These genes, particularly those associated with neuromodulation, attraction to light, and circadian rhythms, appear to play a role in host manipulation.

Horizontal gene transfer is one of the primary ways that bacteria evolve to resist antibiotics. Mishina believes that as we find more examples of horizontal gene transfer between multicellular organisms, we will gain insight into this phenomenon as well as evolution in general. "The many cases of horizontal gene transfer that we have found in the hairworm can be a good model for study," Mishina says. "Using this model, we hope to identify the mechanisms underlying horizontal gene transfer and advance our understanding of evolutionary adaptation."