Author: Star

Academic symposium on how space technologies can help tackle major climate change issues

Written by Star on October 21, 2021. Posted in news. No Comments on Academic symposium on how space technologies can help tackle major climate change issues

“We have to work together to truly preserve our planet for the future,”
says Jewish-American trailblazer.

NASA astronaut Dr. Jessica Meir on Thursday addressed Tel Aviv University’s 2021 Board of Governors Meeting, discussing her missions to space, life under extreme environmental conditions, and the relationship between her research and combating climate change.

Meir, who is also a marine biologist and physiologist, delivered her remarks by live broadcast at the Yehiel Ben-Zvi Academic Symposium, entitled “Between Climate Change, Space Research and Life under Extreme Conditions,” held on the TAU campus. This year’s symposium topic highlights TAU’s prioritization of climate change research. As part of this campus-wide effort, TAU recently launched the Center for Climate Change Action.

Big Brains Helped Large Animals Survive Extinction

Written by Star on May 19, 2022. Posted in Newsroom.

What do an elephant, a rhino and a hippopotamus all have in common? All three, along with other large animals, survived the mass extinction that took place for a period of about 120,000 years, starting from the time the last Ice Age began. In contrast, other huge animals, such as giant armadillos (weighing a ton), giant kangaroos and mammoths went extinct.

Researchers at Tel Aviv University and the University of Naples have examined the mass extinction of large animals over the past tens of thousands of years, and found that those species who survived extinction had, on average, much larger brains than those who did not. The researchers conclude that having a large brain (relative to body size) indicates relatively high intelligence and helped the surviving species adapt to changing conditions and cope with potential causes of extinction, such as human hunting.

The study was led by doctoral student Jacob Dembitzer of the University of Naples in Italy, Prof. Shai Meiri of Tel Aviv University’s School of Zoology and The Steinhardt Museum of Natural History, and Prof. Pasquale Raia and doctoral student Silvia Castiglione of the University of Naples. The study was published in the journal Scientific Reports.

Heavy Weight – No Guarantee

The researchers explain that the last Ice Age was characterized by the widespread extinction of large and giant animals on all continents on earth (except Antarctica). Among these:

America: Giant ground sloths weighing 4 tons, a giant armadillo weighing a ton, and mastodons
Australia: Marsupial diprotodon weighing a ton, giant kangaroos, and a marsupial ‘lion’
Eurasia: Giant deer, woolly rhinoceros, mammoth, and giant elephants weighing up to 11 tons

Other large animals, however, such as elephants, rhinos, and hippos, survived this extinction event and exist to this day.

The researchers also note that in some places, the extinction was particularly widespread:

Australia: The red and grey kangaroos are today the largest native animals
South America: The largest survivors are the guanaco and vicuña (similar to the llama, which is a domesticated animal) and the tapir, while many of the species weighing half a ton or more have become extinct

Brains over Body

Jacob Dembitzer: “We know that most of the extinctions were of large animals, and yet it is not clear what distinguishes the large extant species from those that went extinct. We hypothesized that behavioral flexibility, made possible by a large brain in relation to body size, gave the surviving species an evolutionary advantage – it has allowed them to adapt to the changes that have taken place over the last tens of thousands of years, including climate change and the appearance of humans. Previous studies have shown that many species, especially large species, went extinct due to over-hunting by humans that have entered their habitats. In this study, we tested our hypothesis for mammals over a period of about 120,000 years, from the time the last Ice Age began, and the time that modern man began to spread all over the world with lethal weapons, to 500 years before our time. This hypothesis even helps us explain the large number of extinctions in South America and Australia, since the large mammals living on these continents had relatively small brains.”

The researchers collected data from the paleontological literature on 50 extinct species of mammal from all continents, weighing from 11 kg (an extinct giant echidna) up to 11 tons (the straight-tusked elephant, which was also found in the Land of Israel), and compared the size of their cranial cavity to that of 291 evolutionarily close mammal species that survived and exist today, weighing from 1.4 kg (the platypus) up to 4 tons (the African elephant). They fed the data into statistical models that included the weighting of body size and phylogeny between different species.

Prof. Meiri: “We found that the surviving animals had brains 53% larger, on average than evolutionarily closely related, extinct species of a similar body size. We hypothesize that mammals with larger brains have been able to adapt their behavior and cope better with the changing conditions – mainly human hunting and possibly climate changes that occurred during that period – compared to mammals with relatively small brains.”

How are the Birds Coping with Climate Change?

Written by Star on April 25, 2022. Posted in news.

Researchers at Tel Aviv University have found changes in the morphology of many birds in Israel over the past 70 years, which they interpret to be a response to climate change. The body mass of some species decreased, while in others body length increased – in both cases increasing the ratio between surface area and volume. The researchers contend that these are strategies to facilitate heat loss to the environment: “The birds evidently changed in response to the changing climate. However, this solution may not be fully adequate, especially as temperatures continue to rise.”

Relying on the vast bird collection preserved by The Steinhardt Museum of Natural History at TAU, the researchers looked for changes in bird morphology over the past 70 years in Israel. They examined approximately 8,000 adult specimens of 106 different species – including migratory birds that annually pass through Israel (such as the common chiffchaff, white stork, and black buzzard), resident wild birds (like the Eurasian jay, Eurasian eagle-owl, and rock partridge), and commensal birds, that live near humans. They built a complex statistical model consisting of various parameters to assess morphological changes – in the birds’ body mass, body length and wing length – during the relevant period.

The study was led by Prof. Shai Meiri and PhD student Shahar Dubiner of the School of Zoology, The George S. Wise Faculty of Life Sciences, and the Steinhardt Museum of Natural History at Tel Aviv University. The paper was published in the scientific journal Global Ecology and Biogeography.

Cooling Down

Prof. Meiri explains that according to Bergmann’s rule, formulated in the 19th century, members of bird and mammal species living in a cold climate tend to be larger than members of the same species living in a warmer climate. This is because the ratio of surface area to volume is higher in smaller animals, permitting more heat loss (an advantage in warm regions), and lower in larger bodies, minimizing heat loss (a benefit in colder climates). Based on this rule, scientists have recently predicted that global warming will lead to a reduction in animal size, with a possible exception: birds living in the human environment (such as pigeons, house sparrows, and the hooded crow) may gain size due to increased food availability, a phenomenon already witnessed in mammals such as jackals and wolves.

Either Long or Slender

Shahar Dubiner: “Our findings revealed a complicated picture. We identified two different types of morphological changes: some species had become lighter – their mass had decreased while their body length remained unchanged; while others had become longer – their body length had increased, while their mass remained unchanged. These together represent more than half of the species examined, but there was practically no overlap between the two groups – almost none of the birds had become both lighter and longer. We think that these are two different strategies for coping with the same problem, namely the rising temperatures. In both cases, the surface area to volume ratio is increased (by either increasing the numerator or reducing the denominator) – which helps the body lose heat to its environment. The opposite, namely a decrease in this ratio, was not observed in any of the species.”

The researchers (from left to right): Shahar Dubiner and Prof. Shai Meiri

Global Phenomenon

Sadly, flying away from global warming is not an option. These findings were observed across the country, regardless of nutrition, and in all types of species: resident birds; commensal species living in the human environment – which, contrary to predictions, exhibited changes similar to those of other birds; and migrants.

A difference was identified, however, between the two strategies: changes in body length tended to occur more in migrants, while changes in body mass were more typical of non-migratory birds. The very fact that such changes were found in migratory birds coming from Asia, Europe, and Africa, suggests that we are witnessing a global phenomenon.

The study also found that the impact of climate change over time on bird morphology (the birds’ change in either weight or length over time, relative to the actual temperature change during that time) is ten times greater than the impact of similar differences in temperature between geographical areas (the birds’ differences in weight or length in different geographical areas, relative to the temperature differences between those areas).

What is the Limit of Evolutionary Flexibility?

Shahar Dubiner: “Our findings indicate that global warming causes fast and significant changes in bird morphology. But what are the implications of these changes? Should we be concerned? Is this a problem, or rather an encouraging ability to adapt to a changing environment? Such morphological changes over a few decades probably do not represent an evolutionary adaptation, but rather certain phenotypic flexibility exhibited by the birds. We are concerned that over such a short period of time, there is a limit to the flexibility or evolutionary potential of these traits, and the birds might run out of effective solutions as temperatures continue to rise.”

Featured image: Israeli birds have become either longer or slenderer over the past 70 years

The Ultimate Solution to Global Warming?

Written by Star on April 25, 2022. Posted in news.

Hydrogen-powered bicycles and cars have been in serial production for years. In these vehicles, the regular polluting lithium battery has been replaced by a fuel cell that converts hydrogen, a non-polluting fuel, to electricity. Most of today’s hydrogen is, however, still produced from natural gas in a highly polluting process and is therefore referred to as gray hydrogen. Not only is natural gas a non-renewable source of energy, but it also creates carbon dioxide gas when burned, damaging our environment and contributing to global warming.

Enter a new TAU discovery, which may boost the industrial transition from using polluting gray hydrogen to environmentally friendly green hydrogen: Researchers identified a mutant of a known strain of microscopic algae that allows, for the first time, the production of green hydrogen gas via photosynthesis on a scale suited to industrial requirements. Hydrogen gas can thus be produced solely through renewable energy and in a climate-neutral manner, reducing our carbon footprint and greenhouse gas emissions dramatically to stabilize global temperatures.

Humanity’s transition to the use of green hydrogen may be the ultimate solution to the problem of global warming.

The microscopic algae

Continuous Production Achieved

The study was led by doctoral student Tamar Elman, under the supervision of Prof. Iftach Yacoby from the Renewable Energy Laboratory of The George S. Wise Faculty of Life Sciences at Tel Aviv University. The study was recently published in the prestigious journal Cell Reports Physical Science.

While production of green hydrogen is possible through solar panels wired to devices that perform water breakdown into hydrogen and oxygen (electrolysers), the researchers explain that this is an expensive process, requiring precious metals and distilled water. In nature, hydrogen is produced as a by-product of photosynthesis for periods of minutes by micro-algae, unicellular algae found in every water reservoir and even in the soil. For this biological process to become a sustainable source of energy, however, humanity must engineer micro-algae strains that produce hydrogen for days and weeks.

Prof. Yacoby explains that as part of the laboratory tests, the researchers identified a new mutant in microscopic algae that prevents oxygen from accumulating at any lighting intensity, and therefore hypothesized that continuous hydrogen production could be achieved from it. With the help of bioreactor measurements in liter volumes, they were indeed able to prove that hydrogen can be produced continuously for more than 12 days.

According to Prof. Yacoby, the new mutant overcomes two major barriers that have so far hindered continuous production of hydrogen:

Accumulation of oxygen in the process of photosynthesis – As a rule, oxygen poisons the enzyme that produces hydrogen in algae, but in the mutation, increased respiration eliminates the oxygen and allows favorable conditions for continuous hydrogen production.

Loss of energy to competing processes – And this includes carbon dioxide fixation into sugar. This, too, has been solved in the mutant and most of the energy is being channeled for continuous hydrogen production.

To industrialize these results, the research team led by Prof. Yacoby is working on a pilot program of larger volumes and the development of methods that will allow the time of hydrogen harvest to be extended, in order to reduce its cost to competitive levels. “The rate of hydrogen production from the new mutant reaches one-tenth of the possible theoretical rate, and with the help of additional research it is possible to improve it even further,” concludes Prof. Yacoby.

Tamar Elman and Prof. Iftach Yacoby in the lab

Featured image: Tamar Elman and the microscopic algae

Research based on a comprehensive study of 8,000 birds in Israel

Written by Star on April 8, 2022. Posted in Newsroom.

Tel Aviv University (TAU) researchers say that climate change may be responsible for changes in the morphology of many birds in Israel over the past 70 years. The body mass of some species decreased while in others body length increased, in both cases increasing the ratio between surface area and volume. The researchers contend that these are strategies to facilitate heat loss to the environment.

“The birds evidently changed in response to the changing climate,” the researchers concluded. “However, this solution may not be fully adequate, especially as temperatures continue to rise.”

The study was led by Professor Shai Meiri and PhD student Shahar Dubiner of the School of Zoology, Wise Faculty of Life Sciences, and the Steinhardt Museum of Natural History at TAU. The paper was published in the scientific journal Global Ecology and Biogeography.

Professor Meiri explains that according to “Bergmann’s rule,” an ecogeographical rule formulated in the 19th century, members of bird and mammal species living in a cold climate tend to be larger than members of the same species living in a warmer climate. This is because the ratio of surface area to volume is higher in smaller animals, permitting more heat loss (an advantage in warm regions), and lower in larger bodies, minimizing heat loss (a benefit in colder climates). Based on this rule, scientists have predicted that global warming will lead to a reduction in animal size, with a possible exception: birds living in the human environment (such as pigeons, house sparrows, and the hooded crow) may gain size due to increased food availability, a phenomenon already witnessed in mammals such as jackals and wolves.

Relying on the vast bird collection preserved by the Steinhardt Museum of Natural History at TAU, the researchers looked for changes in bird morphology over the past 70 years in Israel. They examined approximately 8,000 adult specimens of 106 different species, including migratory birds that annually pass through Israel such as the common chiffchaff, white stork, and black buzzard; resident wild birds like the Eurasian jay, Eurasian eagle-owl, and rock partridge; and commensal birds that live near humans. They built a complex statistical model consisting of various parameters to assess morphological changes — in the birds’ body mass, body length and wing length — during the relevant period.

“Our findings revealed a complicated picture,” Dubiner says. “We identified two different types of morphological changes: some species had become lighter – their mass had decreased while their body length remained unchanged; while others had become longer – their body length had increased, while their mass remained unchanged. These together represent more than half of the species examined, but there was practically no overlap between the two groups – almost none of the birds had become both lighter and longer.

“We think that these are two different strategies for coping with the same problem, namely the rising temperatures. In both cases, the surface area to volume ratio is increased by either increasing the numerator or reducing the denominator, which helps the body lose heat to its environment. The opposite, namely a decrease in this ratio, was not observed in any of the species.”

These findings were observed across the country, regardless of nutrition, and in all types of species. A difference was identified, however, between the two strategies: changes in body length tended to occur more in migrants, while changes in body mass were more typical of non-migratory birds. The very fact that such changes were found in migratory birds coming from Asia, Europe, and Africa suggests that this is a global phenomenon. The study also found that the impact of climate change over time on bird morphology is 10 times greater than the impact of similar differences in temperature between geographical areas.

“Our findings indicate that global warming causes fast and significant changes in bird morphology,” Dubiner concludes. “But what are the implications of these changes? Should we be concerned? Is this a problem, or rather an encouraging ability to adapt to a changing environment? Such morphological changes over a few decades probably do not represent an evolutionary adaptation, but rather certain phenotypic flexibility exhibited by the birds. We are concerned that over such a short period of time, there is a limit to the flexibility or evolutionary potential of these traits, and the birds might run out of effective solutions as temperatures continue to rise.”

Work created by TAU-affiliated artists can’t exist on earth

Written by Star on April 8, 2022. Posted in news.

Many think that physics is an exact science that requires the application of analytical and quantitative abilities, while art is based on emotion and creativity. A collaboration between the physicist Dr. Yasmine Meroz of Tel Aviv University (TAU) and the contemporary artist Liat Segal challenges the boundaries between the two fields. Their joint work, called “Impossible Object,” will be launched in April to the International Space Station (ISS), as part of the “Rakia” mission of the Israeli astronaut Eitan Stiva.

Dr. Meroz is a senior faculty member at the School of Plant Sciences and Food Security at TAU’s Wise Faculty of Life Sciences, whose lab studies the physics of plant systems. Segal studied Computer Science and Biology and worked in the hi-tech industry for several years, before shifting her career to arts. The special bond between the two was created when they were graduate students at the same lab at TAU.

“Impossible Object” is a sculpture made of water. The liquid’s three-dimensional form does not get its shape from any vessel and so cannot exist on earth, but only in outer space in the absence of gravity.

The sculpture is made of interconnected brass pipes and rods, through which water is flown. In the absence of gravity, the water adheres to the rods and forms a liquid layer shaped by water tension, which envelopes the brass structure, yielding a three-dimensional shape that changes over time. The underlying brass structure is reminiscent of a wavy and directionless staircase, raising questions about shape and form in the absence of gravity and directionality. In particular, what is the shape of water? What does a “slice of the sea” or a “handful of a wave” look like?

“There is much in common between art and scientific research: Both are the result of a thought process in which creativity plays a central role and are motivated by the desire to ask interesting questions,” Dr. Meroz says. “‘Impossible Object’ is a research-based artwork, where the medium is basically the physics underpinning water behavior in the absence of gravity. I learned a lot in the process, and I have no doubt it will contribute to research in my laboratory. In this respect, this work expresses the unrealized potential of the synergy between art and scientific research.”

“I am very happy about my collaboration with Yasmine,” Segal adds. “In this collaboration we not only shared knowledge and inspiration, but we were also able to bring about a true co-creation, which could not have been realized by each one of us individually. ‘Impossible Object’ is timely, weighing the role of culture and art at an era when humanity is experiencing accelerated scientific and technological developments. Following incredible technological and scientific achievements in space, and as space tourism becomes tangible, it is important to reflect on the place of culture and arts in our lives, on earth and beyond.”

This is their second collaboration; their previous artwork, “Tropism,” has been exhibited at TAU’s Genia Schreiber University Art Gallery.

Inventive Study to Develop Biological Solutions for Agriculture

Written by Star on March 27, 2022. Posted in news.

Unravelling Recycling Practices from 500,000 Years Ago

Written by Star on March 21, 2022. Posted in Newsroom.

What drove prehistoric humans to collect and recycle flint tools that had been made, used, and discarded by their predecessors? In a first-of-its-kind study at Tel Aviv University, researchers examined flint tools from one layer at the 500,000-year-old prehistoric site of Revadim in the south of Israel’s Coastal Plain, and propose a novel explanation: prehistoric humans, just like us, were collectors by nature and culture. The study suggests that they had an emotional urge to collect old human-made artefacts, mostly as a means for preserving the memory of their ancestors and maintaining their connectedness with place and time.

The study was led by PhD student Bar Efrati and Prof. Ran Barkai of the Jacob M. Alkow Department of Archaeology and Ancient Near Eastern Cultures at TAU’s The Lester and Sally Entin Faculty of Humanities, in collaboration with Dr. Flavia Venditti from the University of Tubingen in Germany and Prof. Stella Nunziante Cesaro from the Sapienza University of Rome, Italy. The paper appeared in the prestigious scientific journal Scientific Reports, published by Nature.

Prehistoric Vintage Tools

Bar Efrati explains that stone tools with two lifecycles have been found at prehistoric sites all over the world, but the phenomenon has never been thoroughly investigated. In the current study, the researchers focused on a specific layer at Revadim – a large, open-air, multi-layered site in the south of Israel’s Coastal Plain, dated to about 500,000 years ago. The rich findings at Revadim suggest that this was a popular spot in the prehistoric landscape, revisited over and over again by early humans drawn by an abundance of wildlife, including elephants. Moreover, the area is rich with good-quality flint, and most tools found at Revadim were in fact made of fresh flint.

“The big question is: Why did they do it?” says Bar Efrati. “Why did prehistoric humans collect and recycle actual tools originally produced, used, and discarded by their predecessors, many years earlier? Scarcity of raw materials was clearly not the reason at Revadim, where good-quality flint is easy to come by. Nor was the motivation merely functional, since the recycled tools were neither unusual in form nor uniquely suitable for any specific use.”

Scars that Reveal the Past

The key to identifying the recycled tools and understanding their history is the patina – a chemical coating which forms on flint when it is exposed to the elements for a long period of time. Thus, a discarded flint tool that lay on the ground for decades or centuries accumulated an easily identifiable layer of patina, which is different in both color and texture from the scars of a second cycle of processing that exposed the original color and texture of flint.

In the current study, 49 flint tools with two lifecycles were examined. Produced and used in their first lifecycle, these tools were abandoned, and years later, after accumulating a layer of patina, they were collected, reworked, and used again. The individuals who recycled each tool removed the patina, exposing fresh flint, and shaped a new active edge. Both edges, the old and the new, were examined by the researchers under two kinds of microscopes, and via various chemical analyses, in search of use-wear marks and/or organic residues. In the case of 28 tools, use-wear marks were found on the old and/or new edges, and in 13 tools, organic residues were detected, evidence of contact with animal bones or fat.

Surprisingly, the tools had been used for very different purposes in their two lifecycles – the older edges primarily for cutting, and the newer edges for scraping (processing soft materials like leather and bone). Another baffling discovery: in their second lifecycle the tools were reshaped in a very specific and minimal manner, preserving the original form of the tool, including its patina, and only slightly modifying the active edge.

Recycled Tools as Keepsakes

Prof. Ran Barkai: “Based on our findings, we propose that prehistoric humans collected and recycled old tools because they attached significance to items made by their predecessors.”

“Imagine a prehistoric human walking through the landscape 500,000 years ago, when an old stone tool catches his eye. The tool means something to him – it carries the memory of his ancestors or evokes a connection to a certain place. He picks it up and weighs it in his hands. The artifact pleases him, so he decides to take it ‘home’. Understanding that daily use can preserve and even enhance the memory, he retouches the edge for his own use, but takes care not to alter the overall shape – in honor of the first manufacturer. In a modern analogy, the prehistoric human may be likened to a young farmer still plowing his fields with his great-grandfather’s rusty old tractor, replacing parts now and then, but preserving the good old machine as is, because it symbolizes his family’s bond with the land.”

“In fact,” says Barkai, “the more we study early humans, we learn to appreciate them, their intelligence, and their capabilities. Moreover, we discover that they were not so different from us. This study suggests that collectors and the urge to collect may be as old as humankind. Just like us, our early ancestors attached great importance to old artifacts, preserving them as significant memory objects – a bond with older worlds and important places in the landscape.”

Featured image: From Left to Right: Prof. Ran Barkai & Bar Efrati

Microplastics Increase Toxicity of Organic Pollutants by a Factor of 10

Written by Star on February 20, 2022. Posted in news.

Microplastics are tiny fragments of plastic that are found almost everywhere: in wells, soil, food products, water bottles, and even in glaciers at the North Pole. A new study by Tel Aviv University researchers found that in a marine environment, microplastics encounter environmental pollutants that attach to their surface and increase their toxicity by a factor of 10, which may cause severe harm to the environment and human health.

The study was conducted by Dr. Ines Zucker of the School of Mechanical Engineering and the Porter School of the Environment and Earth Sciences at Tel Aviv University, together with Ph. D. student Andrey Eitan Rubin. The study was recently published in the prestigious journal Chemosphere.

‘Magnets’ for Environmental Pollutants

In the study, the researchers examined the entire process that the microplastic undergoes, from the interactions it has with environmental pollutants to the release of the pollutants and the creation of increased toxicity.

The researchers found that adsorption of those organic pollutants to the microplastics increases toxicity by a factor of 10 and may also cause severe impact on humans who are exposed to contaminated food and drink.

“In this study we showed that even very low concentrations of environmental pollutants, which are non-toxic to humans, once adsorb to the microplastic result in significant increase in toxicity,” says Dr. Zucker. “This is because microplastics are a kind of ‘magnet’ for environmental pollutants, concentrating them on its surfaces, ‘ferrying’ them through our digestive tract, and releasing them in a concentrated form in certain areas – thus causing increased toxicity.”

From left to right: Ph. D. student Andrey Eitan Rubin, Dr. Ines Zucker and Dr. Amit Kumar Sarkar

Not Just a Remote Problem

Ph. D. student Andrey Eitan Rubin adds: “For the first time we are presenting a complete ‘life cycle’ of microplastics: from the moment of their release into the environment, through the adsorption of environmental pollutants and up to their joint toxicity in humans.”

“The amount of waste dumped into the ocean every year is enormous – the best known example is the plastic island in the Pacific Ocean, which has an area 80 times larger than the State of Israel.”

This is not just a remote problem. The researchers’ preliminary monitoring data show that Israel’s shores are among the most polluted with microplastic waste. “Each of the microplastic particles secreted in these areas has tremendous potential for harm, as they serve as an effective and stable platform for any pollutant that they may encounter on their way to the human body,” warns Rubin.

“This is another painful reminder of the dire consequences of polluting the marine and terrestrial environment with hazardous industrial waste, which has unfortunately been saturated with plastic in recent decades. The dangers are not theoretical but are more tangible than ever. Although there is a great deal of awareness of this problem, the preventive measures in the field are still far from imprinting a significant mark,” concludes Dr. Zucker.

Why do Locusts Form Destructive Swarms?

Written by Star on February 17, 2022. Posted in Newsroom.

Locust swarms that ruin all crops in their path have been a major cause of famine from Biblical times to the present. Over the last three years, large parts of Africa, India and Pakistan have been hard-hit by locust outbreaks, and climate change is expected to exacerbate the problem even further.

A new multidisciplinary study by experts in fields as varied as insect behavior and physiology, microbiology, and computational models of evolution, has led to valuable insights concerning locust swarming: “Locust swarms form when individual locusts, usually solitary and harmless, aggregate and begin to migrate. However, the causes for this behavior remain largely unknown, and an effective solution is yet to be found,” explains Prof. Amir Ayali from the School of Zoology at TAU’s George S. Wise Faculty of Life Sciences.

Following recent studies, indicating that microbiomes can influence their hosts’ social behavior, the researchers hypothesized that locusts’ microbiomes may play a role in changing the behavior of their hosts to become more ‘sociable’. The study was published in Environmental Microbiology.

The Bacteria that Fly with Borrowed Wings

To test their hypothesis, the researchers examined the gut microbiomes of locusts reared in the laboratory, and found a profound change when individuals reared in solitary conditions joined a large group of about 200 locusts.

Omer Lavy: “The most significant change was observed in bacteria called Weissella, almost completely absent from the microbiome of solitary locusts, which became dominant soon after their hosts joined the group.”

The researchers then developed a mathematical model that was used for analyzing the conditions under which induction of locust aggregation produces significant evolutionary advantages for Weissella, allowing these bacteria to spread to numerous other hosts. Based on these results, the researchers hypothesize that Weissella bacteria may play an important role in the locust aggregation behavior. In other words, the bacteria may in some way encourage their hosts to change their behavior and become more ‘sociable’.

Prof. Ayali concludes: “Our study contributes to the understanding of locust swarming – a leading cause of famine from antiquity to the present. Our findings do not prove unequivocally that the Weissella bacteria are responsible for the swarming and migration of locusts. The results do, however, suggest a high probability that the bacteria play an important role in inducing this behavior – a new hypothesis never previously proposed. We hope that this new understanding will drive the development of new means for combating locust outbreaks – still a major threat to countless people, animals, and plants all over the globe.”

The new study was based on a multidisciplinary collaboration of experts in fields as varied as insect behavior and physiology, microbiology, and computational models of evolution. The project was led by Prof. Amir Ayali and PhD student Omer Lavy from the School of Zoology at TAU’s George S. Wise Faculty of Life Sciences. Participants included Prof. Lilach Hadany, Ohad Lewin-Epstein and Yonatan Bendett from the School of Plant Sciences and Food Security and Prof. Uri Gophna from The Shmunis School of Biomedicine and Cancer Research, all of the Wise Faculty. They were joined by Dr. Eran Gefen from the University of Haifa-Oranim.

Author: Star

TAU researchers: more brain power helped animals adapt to changing conditions and increased chances of survival.

Heavy Weight – No Guarantee

Brains over Body

Researchers detect changes in birds’ bodies, probably caused by global warming.

Cooling Down

Either Long or Slender

Global Phenomenon

What is the Limit of Evolutionary Flexibility?

Breakthrough TAU discovery may accelerate an industrial transition to sustainable energy.

Continuous Production Achieved

TAU and ag-biotech company PlantArcBio to collaborate on development of RNAi-based products.

The urge to collect in the prehistoric world: preserving memory of ancestors and connectedness with place and time.