At least 20 turtles were dead and dozens more were rescued Sunday after being entangled in plastic waste washed ashore on one of the world’s longest beaches in Bangladesh, officials and conservationists said.
Locals said waves of waste—mostly plastic bottles, fishing nets and buoys—floated ashore late Saturday. They spotted turtle carcasses among the sand dunes early Sunday.
Bangladesh’s forestry department said it was the first time such a large volume of plastic had washed onto the 120-kilometre (75-mile) beach along the Bay of Bengal.
“Hundreds of locals rushed to the beach since early morning to rescue the wounded turtles,” forestry spokesman Sohail Hossain told AFP.
“We have buried the dead ones and are trying to release the rescued turtles back to sea.”
Beach clean-up charity Plastic Bank Bangladesh said their volunteers found and buried at least 20 Olive Ridley turtles among the estimated 50 tonnes of waste spread out over a 10 kilometre stretch of the beach at Cox’s Bazar.
“I haven’t seen these many dead turtles lying on the beach in my life and also haven’t seen such a massive pile of waste floating ashore,” fisherman Jashim Uddin told AFP.
Leading Bangladesh turtle and tortoise expert Shahriar Caesar Rahman of the NGO Creative Conservation Alliance said most of the turtles were at least 30 years old.
“The turtles often get trapped in gigantic waste patches floating in the sea and eventually die of suffocation. This seems to be a similar case,” he told AFP.
About 26 tonnes of waste produced from ships and neighbouring countries float into Bay of Bengal every year, said Moazzem Hossain of local conservation charity Save the Nature Bangladesh.
“This is a unique case of plastic invasion. It sends a great danger signal to our marine biodiversity,” he said.
It was not clear how many turtles were rescued.
Local district administrator Kamal Hossain said authorities were investigating the incident.
Olive Ridleys are the most abundant of all sea turtles around the world, according to conservationists.
But their numbers have been declining and the species is recognised as vulnerable by the IUCN Red list.
Russia’s forest service said there were nearly 300 wildfires blazing across the vast country’s northern wilderness on Saturday, as it attempted to contain them with methods including explosives and cloud seeding.
Freakishly warm weather across large swathes of Siberia since January, combined with low soil moisture, have contributed to a resurgence of wildfires that devastated the region last summer, the European Union’s climate monitoring network said this week.
Both the number and intensity of fires in Siberia and parts of Alaska have increased since mid-June, resulting in the highest carbon emissions for the month—59 million tonnes of CO2—since records began in 2003, it said.
Russia’s Aerial Forest Protection Service said it was trying to suppress 136 fires over 43,000 hectares (430 square kilometres) as of Saturday.
Firefighters are using explosives to contain the fires and seeding clouds with silver iodide to encourage rain, it said.
However 159 other fires have been deemed too remote and expensive to handle, with over 333,000 hectares currently ablaze in areas where firefighting efforts have stopped, it said.
The area currently burning is still considerably smaller than a week ago, when the service reported fires over a total of two million hectares.
From mid-June, regions in Russia’s northern Siberia, including beyond the Arctic circle, have registered unprecedented heat records.
Russia’s weather service expert Roman Vilfand said that anti-cyclones—which create abnormally clear skies with no clouds or rain—had increased in the northern hemisphere.
In the Arctic, where the sun doesn’t set in the summer, this means that sunlight is heating the Earth’s surface around the clock, increasing the risk of fires, he said.
On Thursday, the Russian weather service said wildfires this year have already covered an area that is 9.6 percent larger than last year over the same period.
Fresh satellite images showed Saturday that the largest fires are still in Russia’s vast Yakutia region, which is sparsely populated and borders the Arctic Ocean.
Emergencies services in the region, where temperatures have been consistently above 30 degrees Celsius (86 degrees Fahrenheit), were fighting off the flames near an oil storage facility most of this week.
On Friday they declared there was no danger to populated areas.
The region announced a state of emergency on July 2 due to the wildfires, which the governor of Yakutia said were caused by “dry thunderstorms”.
Greenpeace Russia’s forest programme, which analyses satellite data, said Saturday that a total of 9.26 million hectares—greater than the size of Portugal—have been impacted by wildfires since the beginning of 2020.
Russia’s weather officials and environmentalists have said climate change is a major factor behind the increase in fires, though exacerbated by an underfunded forest service forced to leave most blazes unattended.
Mars may now be considered a barren, icy desert but did Earth’s nearest neighbour once harbour life?
It is a question that has preoccupied scientists for centuries and fired up sci-fi imaginings.
Now three space exploration projects are gearing up to launch some of the most ambitious bids yet to find an answer.
Scientists believe that four billion years ago the two planets both had the potential to nurture life—but much of Mars’ intervening history is an enigma.
The new Mars probes from the United States, United Arab Emirates and China will launch this summer.
Their goal is not to find Martian life—scientists believe nothing would survive there now—but to search for possible traces of past lifeforms.
These vast and costly programmes could prove futile. But astrobiologists say the red planet is still our best hope for finding a record of life on other planets.
Mars is “the only planet with concrete chances of finding traces of extraterrestrial life because we know that billions of years ago it was inhabitable,” said Jean-Yves Le Gall, president of French space agency CNES in a conference call with journalists this week.
Le Gall is one of the architects of NASA’s Mars 2020 exploratory probe, which is scheduled for launch at the end of July when Earth and Mars will be the closest for more than two years.
The more than $2.5 billion project is the latest—and most technologically advanced—attempt to uncover Mars’ deep buried secrets.
But it is not alone, as enthusiasm for space exploration has reignited.
‘News from Mars’
Scientific enquiry of the red planet began in earnest in the 17th Century.
In 1609 Italian Galileo Galilei observed Mars with a primitive telescope and in doing so became the first person to use the new technology for astronomical purposes.
Fifty years later Dutch astronomer Christiaan Huygens used a more advanced telescope of his own design to make the first ever topographical drawing of the planet.
Mars—compared to the “desolate, empty” moon—has long seemed promising for potential inhabitability by microorganisms, wrote astrophysicist Francis Rocard in his recent essay “Latest News from Mars”.
But the 20th century presented setbacks.
In the 1960s, as the race to put a man on the moon was accelerating towards its dazzling “Giant Leap”, Dian Hitchcock and James Lovelock were putting a dampener on hopes of finding life on Mars.
Their research analysed the planet’s atmosphere looking for a chemical imbalance, gases reacting with each other, which would hint at life.
“If there is no reaction, then there is probably no life there,” Lovelock told AFP.
“And that was the case—Mars has an atmosphere that is completely inactive as far as chemistry is concerned.”
Their conclusion was confirmed a decade later, when the Viking landers took atmospheric and soil samples that showed the planet was no longer inhabitable.
This discovery was a “real tanker” for Mars research, Rocard told AFP.
Mars programmes essentially paused for 20 years.
Then in 2000 scientists made a game-changing discovery: they found that water had once flowed over its surface.
Follow the water
This tantalising finding helped rekindle the latent interest in Mars exploration.
Scientists pored over images of gullies, ravines, scouring the Martian surface for evidence of liquid water.
More than 10 years later, in 2011, they definitively found it.
The “follow the water, follow the carbon, follow the light” strategy has paid off, Rocard said.
Every mission since the discovery of water has brought “more and more evidence to light that Mars is not quite as dead as we thought,” Michel Viso, an astrobiologist at CNES, told AFP.
The latest US rover to make the journey—aptly named Perseverance—is scheduled to touch down in February of next year after a six-month journey from launch time.
The probe is perhaps the most highly-awaited yet. Its landing spot, the Jezero Crater, may have once been a wide, 45-kilometre river delta.
Rich in sedimentary rocks, such as clay and carbonates—the same types of rocks that hold fossil traces on Earth—Jezero could be a treasure trove.
Or perhaps not.
“We know that water once flowed, but the question remains: for how long?” asked Rocard. “We don’t even know how long it took for life to appear on Earth.”
If the mission can bring these rocks back to Earth they might yield answers to the questions that have long confounded scientists.
But they will have to wait at least 10 years for the analysis to be available.
Viso said the results will likely be “a bundle of clues” rather than a clear answer.
In the beginning
Scientists are also considering perhaps an even more profound question.
If life never existed on Mars, then why not?
The answer to this could enrich our understanding of how life developed on our own planet, Jorge Vago, the spokesperson of the European Space Agency said.
Due to shifting plate tectonics below the Earth’s core, it is exceedingly difficult to find any traces of life here before 3.5 billion years ago.
Mars has no tectonic plates and so there is a chance that four-billion-year-old signs of life that “one could never find on Earth” may be preserved there, Vago said.
And if the latest Mars programmes fail to find signs of ancient Martian life, there are always further frontiers to explore.
Encelade and Europe, two of Saturn’s and Jupiter’s moons, respectively are considered promising contenders.
Although reaching them remains more science fiction than reality.
Conservationists have warned a sudden change in Myanmar’s law allowing the commercial farming of tigers, pangolins and other endangered species risks further fuelling demand in China for rare wildlife products.
The Southeast Asian nation is already a hub for the illegal trafficking of wildlife, a trade driven by demand from neighbouring China and worth an estimated $20 billion worldwide.
In June, Myanmar’s Forest Department quietly gave the green light to private zoos to apply for licences to breed 90 species, more than 20 of which are endangered or critically endangered.
It was an unexpected move that caught conservation groups off-guard but was explained by the Forest Department as a way to help reduce poaching of wild species and illegal breeding.
Tigers—thought to number just 22 in Myanmar—pangolins, elephants and various vulture species as well as the critically endangered Ayeyarwady dolphin and Siamese crocodile can now also be bred for their meat and skin.
But conservationists say commercial farming in the long-term legitimises the use of endangered species and fuels market demand.
“Commercial trade has been shown to increase illegal trade in wildlife by creating a parallel market and boosting overall demand for wild animal products,” conservation groups WWF and Fauna & Flora International (FFI) said in a joint statement.
Experts also fear Myanmar’s lack of capacity to regulate the trade raises the risk of disease spillover to humans from animals and even the “next COVID-19”.
John Goodrich from global wild cat conservation organisation Panthera warned farming can also “provide a means for laundering wild specimens”, complicating efforts to police the trade.
CITES (the Convention on International Trade in Endangered Species) does allow captive breeding of certain endangered species, but only under strict regulation.
But Myanmar’s ability to police the trade is disputed, say environmental groups, who fear the country risks following in the footsteps of Thailand, Laos and Vietnam, which have lost much of their wildlife.
The Forest Department said the new list was drawn up “in full adherence with the law” and after consultation with “conservation groups, academics, and experts in the field”.
Conservationists fear the rule change risk undermining all the progress Myanmar had made in recent years to end the illegal wildlife trade.
Rare footage caught by FFI camera traps showed the “treasure trove” of species in Myanmar’s forests, the group said.
Theft law needs reform so the crime is based on consent not dishonesty—reducing the risk of judgements which lack “common sense”—a new study warns.
At the moment technically “putting a can of beans into a shopping basket is acting like a thief”, the study warns.The current law, from 1968, has long-been criticised for being unsuitable because it requires proof property was taken dishonesty, and someone can be guilty of theft even if the victim has not lost their property.
The study says a solution would be to base theft law purely on consent, for it to be “a serious, intentional or reckless interference with another’s property without consent”. This more closely aligns with the core wrong of theft, and is easier to understand for police, prosecutors and juries trying to decide if someone is guilty of theft.
The study, published in Criminal Law Review, raises concerns about the counter-intuitive consequences of the current law. Currently changing labels on supermarket goods, or taking more money than is due from a proffered wallet, or buying with a forged cheque would be classed as theft.
The new definition, proposed as part of a study by Dr. Nathan Tamblyn from the University of Exeter Law School, suggests theft should be taking and keeping, when currently something as trivial as touching can suffice. This would make the law more explicit that borrowing can be theft.
Under the current law a person is guilty of theft if they “dishonestly appropriate property belonging to another with the intention of permanently depriving the other of it”. Someone can be guilty of theft even if the property never leaves the owners possession, for example if someone tries to sell something belonging to another person.
Current theft law can cover actions which are ordinary and acceptable. For example, picking up a can of beans from a supermarket shelf to put in a shopping basket technically constitutes an appropriation of property belonging to another with an intention of permanently depriving the supermarket.
Professor Tamblyn said: “The law regarding theft needs reform because it is producing strange results. Partly the problems stem from the fact that the current definition of theft involves an “appropriation” of property, which can be as trivial as merely touching property. Instead, I suggest that theft should be reserved for serious interference with property, like taking and keeping.
“Partly the problems stem from the fact that so much of the work done in defining theft turns upon the need for a person to act dishonestly.
“The courts have struggled to find a helpful explanation of what it means to act dishonestly, advancing different tests over the years. The most recent test is still unhelpfully circular, in effect defining dishonest behaviour as whatever an ordinary decent, honest person would think is dishonest.
“That approach can fail to provide much guidance in advance as to whether contemplated behaviour is dishonest or not. It is unfair to convict a person for behaviour which they could not tell in advance was dishonest. It also means that the law fails to discourage such behaviour, for lack of any clear advance prohibition.”
Dr. Tamblyn’s definition is more similar to that of other offences. It is a crime to damage another’s property intentionally or recklessly or commit violence intentionally or recklessly.
The current law is based on a statute which could be replaced. Courts could also revisit their interpretation of that statute, to construe “appropriation” as involving serious interferences with property, and “dishonestly” as meaning without belief that the owner consents.
Chameleons are famous for their color-changing abilities. Depending on their body temperature or mood, their nervous system directs skin tissue that contains nanocrystals to expand or contract, changing how the nanocrystals reflect light and turning the reptile’s skin a rainbow of colors.
Inspired by this, scientists at the Pritzker School of Molecular Engineering (PME) at the University of Chicago have developed a way to stretch and strain liquid crystals to generate different colors.
By creating a thin film of polymer filled with liquid crystal droplets and then manipulating it, they have determined the fundamentals for a color-changing sensing system that could be used for smart coatings, sensors, and even wearable electronics.
The research, led by Juan de Pablo, Liew Family Professor of Molecular Engineering, was published July 10 in the journal Science Advances.
Stretching liquid using thin films
Liquid crystals, which exhibit distinct molecular orientations, are already the basis for many display technologies. But de Pablo and his team were interested in chiral liquid crystals, which have twists and turns and a certain asymmetrical “handedness”—like right-handedness or left-handedness—that allows them to have more interesting optical behaviors.
These crystals can also form so-called “blue phase crystals,” which have the properties of both liquids and crystals and can in some cases transmit or reflect visible light better than liquid crystals themselves.
The researchers knew that these crystals could potentially be manipulated to produce a wide range of optical effects if stretched or strained, but they also knew that it’s not possible to stretch or strain a liquid directly. Instead, they placed tiny liquid crystal droplets into a polymer film.
“That way we could encapsulate chiral liquid crystals and deform them in very specific, highly controlled ways,” de Pablo said. “That allows you to understand the properties they can have and what behaviors they exhibit.”
Creating temperature and strain sensors
By doing this, the researchers found many more different phases—molecular configurations of the crystals—than had been known before. These phases produce different colors based on how they are stretched or strained, or even when they undergo temperature changes.
“Now the possibilities are really open to the imagination,” de Pablo said. “Imagine using these crystals in a textile that changes color based on your temperature, or changes color where you bend your elbow.”
Such a system could also be used to measure strain in airplane wings, for example, or to discern minute changes in temperature within a room or system.
Changes in color provide an excellent way to measure something remotely, without the need for any sort of contact, de Pablo said.
“You could just look at the color of your device and know how much strain that material or device is under and take corrective action as needed,” he said. “For example, if a structure is under too much stress, you could see the color change right away and close it down to repair it. Or if a patient or an athlete placed too much strain on a particular body part as they move, they could wear a fabric to measure it and then try to correct it.”
Though the researchers manipulated the materials with strain and temperature, there’s also the potential to affect them with voltage, magnetic fields, and acoustic fields, he said, which could lead to new kinds of electronic devices made from these crystals.
“Now that we have the fundamental science to understand how these materials behave, we can start applying them to different technologies,” de Pablo said.
With the help of citizen scientists, astronomers have discovered two highly unusual brown dwarfs, balls of gas that are not massive enough to power themselves the way stars do.
Participants in the NASA-funded Backyard Worlds: Planet 9 project helped lead scientists to these bizarre objects, using data from NASA’s Near-Earth Object Wide-Field Infrared Survey Explorer (NEOWISE) satellite along with all-sky observations collected between 2009 and 2011 under its previous moniker, WISE. Backyard Worlds: Planet 9 is an example of “citizen science,” a collaboration between professional scientists and members of the public.
Scientists call the newly discovered objects “the first extreme T-type subdwarfs.” They weigh about 75 times the mass of Jupiter and clock in at roughly 10 billion years old. These two objects are the most planet-like brown dwarfs yet seen among the Milky Way’s oldest population of stars.
Astronomers hope to use these brown dwarfs to learn more about exoplanets, which are planets outside of our solar system. The same physical processes may form both planets and brown dwarfs.
“These surprising, weird brown dwarfs resemble ancient exoplanets closely enough that they will help us understand the physics of the exoplanets,” said astrophysicist Marc Kuchner, the principal investigator of Backyard Worlds: Planet 9 and the Citizen Science Officer for NASA’s Science Mission Directorate. Kuchner is also an astrophysicist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland.
These two special brown dwarfs have highly unusual compositions. When viewed in particular wavelengths of infrared light, they look like other brown dwarfs, but at others they do not resemble any other stars or planets that have been observed so far.
Scientists were surprised to see they have very little iron, meaning that, like ancient stars, they have not incorporated iron from star births and deaths in their environments. A typical brown dwarf would have as much as 30 times more iron and other metals than these newly discovered objects. One of these brown dwarfs seems to have only about 3% as much iron as our Sun. Scientists expect very old exoplanets would have a low metal content, too.
“A central question in the study of brown dwarfs and exoplanets is how much does planet formation depend on the presence of metals like iron and other elements formed by multiple earlier generations of stars,” Kuchner said. “The fact that these brown dwarfs seem to have formed with such low metal abundances suggests that maybe we should be searching harder for ancient, metal-poor exoplanets, or exoplanets orbiting ancient metal-poor stars.”
A study in The Astrophysical Journal details these discoveries and the potential implications. Six citizen scientists are listed as co-authors of the study.
How volunteers found these extreme brown dwarfs
The study’s lead author, Adam Schneider of Arizona State University’s School of Earth and Space Exploration in Tempe, first noticed one of the unusual brown dwarfs, called WISE 1810, in 2016, but it was in a crowded area of the sky and was difficult to confirm.
With the help of a tool called WiseView, created by Backyard Worlds: Planet 9 citizen scientist Dan Caselden, Schneider confirmed that the object he had seen years earlier was moving quickly, which is a good indication that an object is a nearby celestial body like a planet or brown dwarf.
“WiseView scrolls through data like a short movie,” Schneider said, “so you can see more easily see if something is moving or not.”
The second unusual brown dwarf, WISE 0414, was discovered by a group of citizen scientists including Backyard Worlds participants Paul Beaulieu, Sam Goodman, William Pendrill, Austin Rothermich, and Arttu Sainio.
The citizen scientists who found WISE 0414 combed through hundreds of images taken by WISE looking for moving objects, which are best detected with the human eye.
“The discovery of these two brown dwarfs shows that science enthusiasts can contribute to the scientific process,” Schneider said. “Through Backyard Worlds, thousands of people can work together to find unusual objects in the solar neighborhood.”
Astronomers followed up to determine their physical properties and confirm that they are indeed brown dwarfs. The discovery of these two unusual brown dwarfs suggests astronomers may be able to find more of these objects in the future.
About Backyard Worlds: Planet 9
The ongoing Backyard Worlds: Planet 9 project lets anyone join the quest to find more mysterious objects in spacecraft data. Citizen scientists using this project have discovered a wealth of astronomical treasures, including more than 1,600 brown dwarfs and the oldest, coldest white dwarf surrounded by a disk of debris.
About 150,000 people have participated so far. Check it out at backyardworlds.org.
Leading firearm violence prevention researchers are first to use data to show differences in gun culture across the country, identifying gun cultures around recreation, self-defense, and politics.
A new Boston University School of Public Health (BUSPH) study published in the Nature journal Humanities & Social Sciences Communications, shows that gun ownership means very different things in different parts of the United States.
Previous researchers have proposed two strands of gun culture: one focused on recreational use and a second on self-defense. But this study identifies a third, of people who do not view the defense of the Second Amendment as a means to an end, but as necessary to any freedom in this country. The study finds that this “Gun Culture 3.0” has increased the most in states that have strengthened their gun laws to the greatest degree, suggesting it may be grounded in fear of perceived threats by the government.
“The NRA has been spreading insurrectionist rhetoric for the past few decades, undermining Americans’ trust in their legislators and the federal government, while passing for a patriotic organization. The result is a few million people who are convinced that any genuine firearm violence prevention effort is the first step in a scheme to take away all of their rights and disenfranchise them,” says study lead author Claire Boine, a research scholar in community health sciences at BUSPH.
Using data on gun-related behaviors including hunting, NRA membership, magazine subscriptions, handgun and long gun purchases, and certain gun laws, the researchers show that American gun owners vary widely in the symbolic meaning they find in firearms and how they use them.
Over the last 20 years, at the national level, firearm recreation has dwindled and self-defense has expanded, even as a distinct culture of Second Amendment political advocacy has sprung up, the researchers found.
They also identified wide variation between states. Certain states, such as New York and Massachusetts, have very low recreational and self-defense gun cultures but very high Second Amendment activism. In contrast, states such as South Dakota have high recreational and self-defense cultures and little Second Amendment activism. Other states, such as Florida, have a high degree of self-defense gun culture and less recreational and Second Amendment gun culture.
The researchers found more emphasis on recreation in politically conservative states with large rural areas, little racial diversity, and few firearm regulations, while emphasis on self-defense is more common in politically conservative states that have enacted few new firearm laws in the last 20 years, have large rural areas, and are experiencing higher unemployment levels. The Second Amendment-focused “Gun Culture 3.0” is most common in liberal states, states where more of the population lives in an urban setting or is Hispanic, and states with stronger firearm regulations.
The researchers explain that the study shows only a marginal part of American gun culture is political, and the ability to measure gun culture empirically, as demonstrated by this study, will help better account for this variation in future studies of how gun policy affects gun use and violence.
“No longer can we speak about gun culture as if it is a single entity. There are positive aspects to gun culture that bring recreation, enjoyment, or a feeling of security to many people, and there are also some negative elements,” says Dr. Michael Siegel, professor of community health sciences at BUSPH.
“Those of us in public health must acknowledge the positive aspects of that culture and stop blaming law-abiding gun owners for the problem of firearm violence,” he says. “Instead, we need to address one very specific aspect of gun culture that the NRA has created that does not represent the overwhelming number of gun owners in this country.”
Venus flytraps catch spiders and insects by snapping their trap leaves. This mechanism is activated when unsuspecting prey touch highly sensitive trigger hairs twice within 30 seconds. A study led by researchers at the University of Zurich has now shown that a single slow touch also triggers trap closure—probably to catch slow-moving larvae and snails.
The Venus flytrap (Dionaea muscipula) is perhaps the most well-known carnivorous plant. It catches its prey, mostly spiders and insects, using a sophisticated trapping mechanism. Its distinct leaves have three highly sensitive trigger hairs on each lobe. These hairs react to even the slightest touches—e.g. when a fly crawls along the leaf—by sending out an electrical signal, which quickly spreads across the entire leaf. If two signals are triggered in a short time, the trap snaps within milliseconds.
New trigger for trapping mechanism
The physiological reactions on which this trapping mechanism is based have been studied for over 200 years. The consensus has been that every sufficiently strong touch of a trigger hair causes an electrical signal, and that two signals within 30 seconds result in the closing of the trap. A new study from the University of Zurich (UZH) and ETH Zurich has now found another triggering mechanism. “Contrary to popular belief, slowly touching a trigger hair only once can also cause two signals and thus lead to the snapping of the trap,” says co-last author Ueli Grossniklaus, director of the Department of Plant and Microbial Biology at UZH.
First, the interdisciplinary team of researchers determined the forces needed to trigger the plant’s trapping mechanism. They did this by using highly sensitive sensors and high-precision microrobotic systems developed by the team of co-last author Bradley J. Nelson at the Institute of Robotics and Intelligent Systems at ETH Zurich. This enabled the scientists to deflect the trigger hairs to a precise angle at a pre-defined speed in order to measure the relevant forces. These experiments confirmed the previous theory. If the chosen parameters approximate the touch of regular prey, it takes two touches for the trap to snap.
From the collected data, the researchers at the ETH Institute for Building Materials developed a mathematical model to determine the range of angular deflection and velocity thresholds that activate the snapping mechanism. “Interestingly, the model showed that at slower angular velocities one touch resulted in two electrical signals, such that the trap ought to snap,” says Grossniklaus. The researchers were subsequently able to confirm the model’s prediction in experiments.
Catching slow prey
When open, the lobes of the Venus flytrap’s leaves are bent outwards and under strain—like a taut spring. The trigger signal leads to a minute change in the leaves’ curvature, which makes the trap snap instantaneously. The electrical signals are generated by ion channels in the cell membrane, which transport atoms out of and into the cell.
“We think that the ion channels stay open for as long as the membrane is mechanically stretched. If the deflection occurs slowly, the flow of ions is enough to trigger several signals, which causes the trap to close,” explains co-first author Hannes Vogler, plant biologist at UZH. The newly discovered triggering mechanism could be a way for the Venus flytrap to catch slow-moving prey, such as larvae or snails.