Human microbes. Who is the host?

Imagine New York City with the lights all on, but nobody home — indeed, nobody anywhere. A city fully intact and yet uninhabited. Would it still be a city, or would we refer to it as the place formerly known as New York City?

The image I’m conjuring up is not meant to represent the aftermath of some catastrophe, but rather, if we were to think of NYC as representing a human body, what that body would be like if it was stripped of its microbial life.

When the human body is described as being a host to a multitude of microbial organisms, by implication those organisms are viewed as guests. We might have some sense that we need these guests — even that we cannot survive without them — but they belong to us rather than us to them.

Why?

The “I” that stands at the center, possessed — or so it imagines — with some kind of regal authority over this domain called a person, is really a fiction.

Life in the city which is the body, continues just the same whether the monarch is awake or unconscious.

Jane Brody writes: We may think of ourselves as just human, but we’re really a mass of microorganisms housed in a human shell. Every person alive is host to about 100 trillion bacterial cells. They outnumber human cells 10 to one and account for 99.9 percent of the unique genes in the body.

Katrina Ray, a senior editor of Nature Reviews, recently suggested that the vast number of microbes in the gut could be considered a “human microbial ‘organ’” and asked, “Are we more microbe than man?

Our collection of microbiota, known as the microbiome, is the human equivalent of an environmental ecosystem. Although the bacteria together weigh a mere three pounds, their composition determines much about how the body functions and, alas, sometimes malfunctions.

Like ecosystems the world over, the human microbiome is losing its diversity, to the potential detriment of the health of those it inhabits.

Dr. Martin J. Blaser, a specialist in infectious diseases at the New York University School of Medicine and the director of the Human Microbiome Program, has studied the role of bacteria in disease for more than three decades. His research extends well beyond infectious diseases to autoimmune conditions and other ailments that have been increasing sharply worldwide.

In his new book, “Missing Microbes,” Dr. Blaser links the declining variety within the microbiome to our increased susceptibility to serious, often chronic conditions, from allergies and celiac disease to Type 1 diabetes and obesity. He and others primarily blame antibiotics for the connection. [Continue reading...]

Want to diversify your own ecosystem?

It’s easier than you might imagine. Just start making your own kefir — a fermented milk drink. There’s very little skill required.

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When we were fish

Nautilus: Neil Shubin has been going backward his whole life. “I teach anatomy but I want to understand why things look the way they do,” says the paleontologist and professor of organismal biology and anatomy at the University of Chicago. “And to understand the fundamental questions you have to go ever deeper into history. So I have gone backward from humans to fish to planets.”

Shubin, 53, is referring to his two books, Your Inner Fish and The Universe Within, which detail the atoms and molecules, genes and cells, sculpted by evolution into the common bonds of life. In 2004, on Ellesmere Island in the Arctic, Shubin discovered one of the key links in animal evolution, the fish known as Tiktaalik, that, he writes, “was specialized for a rather extraordinary function: it was capable of doing push-ups.”

Shubin and his team learned from Tiktaalik fossils that the big fish with the flat head had a shoulder, elbow, and wrist composed of the same bones in a human’s upper arm, forearm, and wrist. Tiktaalik used those bones to navigate shallow streams and ponds “and even to flop around on the mudflats along the banks.” Here was the creature from the lagoon that revealed how animals evolved from fish to us. [Continue reading...]

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Systemic pesticides pose global threat to biodiversity, harming bees, butterflies, fish and birds

AFP reports: Neurotoxic pesticides blamed for the world’s bee collapse are also harming butterflies, worms, fish and birds, said a scientific review that called Tuesday for tighter regulation to curb their use.

Analysing two decades of reports on the topic, an international panel of 29 scientists found there was “clear evidence of harm” from use of two pesticide types, neonicotinoids and fipronil.

And the evidence was “sufficient to trigger regulatory action”.

“We are witnessing a threat to the productivity of our natural and farmed environment,” said Jean-Marc Bonmatin of France’s National Centre for Scientific Research, co-author of the report entitled the Worldwide Integrated Assessment.

Far from protecting food production, these nerve-targeting insecticides known as neonics were “imperilling the pollinators, habitat engineers and natural pest controllers at the heart of a functioning ecosystem.”

The four-year assessment was carried out by The Task Force on Systemic Pesticides, which advises the International Union for Conservation of Nature, the world’s watchdog on species loss.

Neonics are widely used insecticides whose effects can be instant and lethal, or chronic. Exposure can impair smell and memory in some species, curb procreation, reduce foraging, cause flight difficulties and increase disease susceptibility.

Used for insect pest management in farming, but also in pet flea control, they have been fingered in the recent decline in bees — crucial pollinators of human food crops — in Europe, the Americas and Asia.

The latest study says these pesticides, absorbed by plants, are also harming other insect pollinators, fish and birds as they leach into soil and water.

The most affected species were terrestrial invertebrates such as earthworms, which are crucial soil-enrichers, said a press statement.

Bees and butterflies were next, followed by aquatic invertebrates like freshwater snails and water fleas, then birds, and finally fish, amphibians and certain microbes. [Continue reading...]

Imidacloprid, primarily manufactured by Bayer CropScience, is not only the most widely used neonicotinoid pesticide but also the most widely used insecticide of any type in the world.

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How malnutrition affects the microbiome

The Scientist reports: The gut microbiomes of young children don’t fully recover from the trauma of early-life malnourishment, even after they are treated with more-complete diets, according to a study published in Nature. A team led by Jeffrey Gordon of the Washington University in St. Louis sampled the gut microbiomes of healthy and malnourished children in Bangladesh and found that the microbiomes of children who were underfed and whose diets lacked essential nutrients looked less like those of adults and more like those of younger, healthy children.

“This is actually a real step forward in terms of having a technique to look at development of the microbiome in children,” said Josef Neu, a pediatrician at the University of Florida who studies gastrointestinal health of neonates and was not involved in the work.

The findings present a possible explanation for the commonly observed complications that malnourished children suffer even after they are treated with a standardized food regimen, including stunted growth, cognitive delays, and immune system problems. The researchers suggested that the immature gut microbiomes of malnourished children may be partially responsible for some of these long-term impairments. [Continue reading...]

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The language of life

vegetables

Within the mechanistic worldview that shapes the way most of us view life, each human being and other living organism is seen as a discrete entity — a form that possesses and is animated by its own life.

Lives come into existence, go out of existence, and between times interact with each other, while all along retaining autonomy in varying degrees.

Human beings, as creatures whose powers have been extended and amplified through technology, supposedly possess the highest degree of autonomy, living lives steered by the exercise of our freewill.

Having become so full of ourselves we have mostly lost the sense of life forming a seamless whole. We fail to see that human being is a conceptual construct fabricated through a leap of imagination.

But this thing called life is unfathomably complex and the more we learn about it, the more we discover its interactive nature.

Just as people talk to each other and those conversations produce societies, it turns out that inside our bodies another kind of conversation — this one through molecular exchanges facilitated by exosomes — allows plant cells to “talk” to our cells and thereby regulate the homeostatic foundations of health.

GreenMedInfo reports: A groundbreaking new study published in Molecular Nutrition & Food Research titled, “Interspecies communication between plant and mouse gut host cells through edible plant derived exosome-like nanoparticles,” reveals a new way that food components ‘talk’ to animal cells by regulating gene expression and conferring significant therapeutic effects. With the recent discovery that non-coding microRNA’s in food are capable of directly altering gene expression within human physiology, this new study further concretizes the notion that the age old aphorism ‘you are what you eat’ is now consistent with cutting edge molecular biology.

This is the first study of its kind to look at the role of exosomes, small vesicles secreted by plant and animal cells that participate in intercellular communication, in interspecies (plant-animal) communication.

The study explained the biological properties of exosomes as follows:

“Exosomes are produced by a variety of mammalian cells including immune, epithelial, and tumor cells [11–15]. Exosomes play a role in intercellular communication and can transport mRNA, miRNA, bioactive lipids, and proteins between cells [16–19]. Upon contact, exosomes transfer molecules that can render new properties and/or reprogram their recipient cells.”

While most of the research on exosomes has focused on their role in pathological states such as tumor promotion, they were recently found to play a key role in stimulating regeneration within damaged cardiac tissue, and are known to be found in human breast milk, further underscoring how irreplaceable it is vis-à-vis synthesized infant formula. [Continue reading...]

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Mice run for fun

James Gorman writes: If an exercise wheel sits in a forest, will mice run on it?

Every once in a while, science asks a simple question and gets a straightforward answer.

In this case, yes, they will. And not only mice, but also rats, shrews, frogs and slugs.

True, the frogs did not exactly run, and the slugs probably ended up on the wheel by accident, but the mice clearly enjoyed it. That, scientists said, means that wheel-running is not a neurotic behavior found only in caged mice.

They like the wheel.

Two researchers in the Netherlands did an experiment that it seems nobody had tried before. They placed exercise wheels outdoors in a yard and in an area of dunes, and monitored the wheels with motion detectors and automatic cameras.

They were inspired by questions from animal welfare committees at universities about whether mice were really enjoying wheel-running, an activity used in all sorts of studies, or were instead like bears pacing in a cage, stressed and neurotic. Would they run on a wheel if they were free?

Now there is no doubt. Mice came to the wheels like human beings to a health club holding a spring membership sale. They made the wheels spin. They hopped on, hopped off and hopped back on. [Continue reading...]

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Why does life resist disorder?

Addy Pross writes: Biology is wondrously strange – so familiar, yet so strikingly different to physics and chemistry. We know where we are with inanimate matter. Ever since Isaac Newton, it has answered to a basically mechanical view of nature, blindly following its laws without regard for purposes. But could there be, as Immanuel Kant put it, a Newton of the blade of grass? Living things might be made of the same fundamental stuff as the rest of the material world – ‘dead’ atoms and molecules – but they do not behave in the same way at all. In fact, they seem so purposeful as to defy the materialist philosophy on which the rest of modern science was built.

Even after Charles Darwin, we continue to struggle with that difference. As any biologist will acknowledge, function and purpose remain central themes in the life sciences, though they have long been banished from the physical sciences. How, then, can living things be reconciled with our mechanical-mechanistic universe? This is a conceptual question, of course, but it has a historical dimension: how did life on Earth actually come about? How could it have? Both at the abstract level and in the particular story of our world, there seems to be a chasm between the animate and inanimate realms.

I believe that it is now possible to bridge that gap. [Continue reading...]

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Hunter-gatherers have healthier guts than urban dwellers

Nature Communications reports: The gut microbiota is responsible for many aspects of human health and nutrition, but most studies have focused on “western” populations. An international collaboration of researchers, including researchers of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, has for the first time analysed the gut microbiota of a modern hunter-gatherer community, the Hadza of Tanzania. The results of this work show that Hadza harbour a unique microbial profile with features yet unseen in any other human group, supporting the notion that Hadza gut bacteria play an essential role in adaptation to a foraging subsistence pattern. The study further shows how the intestinal flora may have helped our ancestors adapt and survive during the Paleolithic.

Bacterial populations have co-evolved with humans over millions of years, and have the potential to help us adapt to new environments and foods. Studies of the Hadza offer an especially rare opportunity for scientists to learn how humans survive by hunting and gathering, in the same environment and using similar foods as our ancestors did.

The research team, composed of anthropologists, microbial ecologists, molecular biologists, and analytical chemists, and led in part by Stephanie Schnorr and Amanda Henry of the Max Planck Institute for Evolutionary Anthropology, compared the Hadza gut microbiota to that of urban living Italians, representative of a “westernized” population. Their results, published recently in Nature Communications, show that the Hadza have a more diverse gut microbe ecosystem, i.e. more bacterial species compared to the Italians. “This is extremely relevant for human health”, says Stephanie Schnorr. “Several diseases emerging in industrialized countries, like IBS, colorectal cancer, obesity, type II diabetes, Crohn’s disease and others, are significantly associated with a reduction in gut microbial diversity.” [Continue reading...]

Jeff Leach recently accompanied some Hadza hunters and observed the way they handled a recently killed adult Impala: Before the two Hadza men I was with jumped in to help skin and gut the Impala, I quickly took swabs of each of their hands (and 1 hour after, 3 hours after, and so on) to assess how the skin (palm) microbiota change throughout the day/week of a typical Hadza (We’ve sampled the hands [and stools] of 150+ Hadza men, women, and children so far). As they slowly and methodically dismembered the animal, they carefully placed the stomach and its still steaming contents on the fleshy side of the recently removed hide. In a separate area, they piled the fatty internal organs (which men are only allowed to eat by the way). Once the animal had been processed more or less, I was amazed to see all three men take a handful of the partially digested plant material from the recently removed stomach to scrub off the copious amounts of blood that now covered their hands and foreman’s. This was followed by a final “cleaning” with dry grass for good measure.

While I was fascinated by the microbe-laden stomach contents being used as hand scrubber – presumably transferring an extraordinary diversity of microbes from the Impala gut to the hands of the Hadza – I was not prepared for what they did next. Once they had cleaned out – by hand – the contents of the stomach (“cleaned” is a generous word), they carved pieces of the stomach into bite-sized chunks and consumed it sushi-style. By which I mean they didn’t cook it or attempt to kill or eliminate the microbes from the gut of the Impala in anyway. And if this unprecedented transfer of microbes from the skin, blood, and stomach of another mammal wasn’t enough, they then turned their attention to the colon of the Impala.

After removing the poo pellets (which we collect samples of as well), they tossed the tubular colon onto a hastily built fire. However, it only sat on the fire for a minute at best and clearly not long enough to terminate the menagerie of invisible microbes clinging to the inside wall of the colon. They proceeded to cut the colon into chunks and to eat more or less raw. For myself, I kindly turned down offers to taste either the raw stomach or the partially cooked colon – but did eat some tasty Impala ribs I thoroughly turned on a stick over the fire to a microbial-free state of well done.

The Hadza explained that this is what they always do, and have always done (though I suspect sushi-style eating of innards is not an every-kill ritual. But….). Whether it’s an Impala, Dik Dik, Zebra, bush pig, Kudu or any other of the myriad of mammals they hunt and eat, becoming one with the deceased’s microbes in any number of ways is common place – same goes for 700 plus species of birds they hunt (minus abundant amounts of stomach contents for hand sanitizer!). While less obvious than at the “kill site,” the transfer of microbes continued back in camp when women, children and other men handled the newly arrived raw meat, internal organs, and skin. The transfer continued as the hunters engaged (touching) other members of the camp.

The breathtaking exchange (horizontal transfer) of microbes between the Hadza and their environment is more or less how it’s been for eons until humans started walling ourselves off from the microbial world through the many facets of globalization. Rather than think of ourselves as isolated islands of microbes, the Hadza teach us that we are better thought of as an archipelago of islands, once seamlessly connected to one another and to a larger metacommunity of microbes via a microbial super highway that runs through the gut and skin/feathers of every animal and water source on the landscape (for those of you keeping up with your homework, this is Macroecology 101). The same can be said for plants and their extraordinary diversity of microbes above (phyllosphere) and below ground (rhizosphere) that the Hadza, and once all humans, interacted with on a nearly continuous basis.

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Methane-producing microbes may have triggered the largest mass extinction in Earth’s history

MIT News Office: Evidence left at the crime scene is abundant and global: Fossil remains show that sometime around 252 million years ago, about 90 percent of all species on Earth were suddenly wiped out — by far the largest of this planet’s five known mass extinctions. But pinpointing the culprit has been difficult, and controversial.

Now, a team of MIT researchers may have found enough evidence to convict the guilty parties — but you’ll need a microscope to see the killers.

The perpetrators, this new work suggests, were not asteroids, volcanoes, or raging coal fires, all of which have been implicated previously. Rather, they were a form of microbes — specifically, methane-producing archaea called Methanosarcina — that suddenly bloomed explosively in the oceans, spewing prodigious amounts of methane into the atmosphere and dramatically changing the climate and the chemistry of the oceans.

Volcanoes are not entirely off the hook, according to this new scenario; they have simply been demoted to accessories to the crime. The reason for the sudden, explosive growth of the microbes, new evidence shows, may have been their novel ability to use a rich source of organic carbon, aided by a sudden influx of a nutrient required for their growth: the element nickel, emitted by massive volcanism at just that time.

The new solution to this mystery is published this week in the Proceedings of the National Academy of Science by MIT professor of geophysics Daniel Rothman, postdoc Gregory Fournier, and five other researchers at MIT and in China.

The researchers’ case builds upon three independent sets of evidence. First, geochemical evidence shows an exponential (or even faster) increase of carbon dioxide in the oceans at the time of the so-called end-Permian extinction. Second, genetic evidence shows a change in Methanosarcina at that time, allowing it to become a major producer of methane from an accumulation of organic carbon in the water. Finally, sediments show a sudden increase in the amount of nickel deposited at exactly this time. [Continue reading...]

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Devasting consequences of losing ‘knowledgeable elders’ in non-human cultures

bluefin-tuna

Culture — something we generally associate with its expressions through art, music, literature and so forth — is commonly viewed as one of the defining attributes of humanity. We supposedly rose above animal instinct when we started creating bodies of knowledge, held collectively and passed down from generation to generation.

But it increasingly appears that this perspective has less to do with an appreciation of what makes us human than it has with our ignorance about non-human cultures.

Although non-human cultures don’t produce the kind of artifacts we create, the role of knowledge-sharing seems to be just as vital to the success of these societies as it is to ours. In other words, what makes these creatures what they are cannot be reduced to the structure of their DNA — it also involves a dynamic and learned element: the transmission of collective knowledge.

The survival of some species doesn’t simply depend on their capacity to replicate their DNA; it depends on their ability to pass on what they know.

Scuola Internazionale Superiore di Studi Avanzati: Small changes in a population may lead to dramatic consequences, like the disappearance of the migratory route of a species. A study carried out in collaboration with the SISSA has created a model of the behaviour of a group of individuals on the move (like a school of fish, a herd of sheep or a flock of birds, etc.) which, by changing a few simple parameters, reproduces the collective behaviour patterns observed in the wild. The model shows that small quantitative changes in the number of knowledgeable individuals and availability of food can lead to radical qualitative changes in the group’s behaviour.

Until the ’50s, bluefin tuna fishing was a thriving industry in Norway, second only to sardine fishing. Every year, bluefin tuna used to migrate from the eastern Mediterranean up to the Norwegian coasts. Suddenly, however, over no more than 4-5 years, the tuna never went back to Norway. In an attempt to solve this problem, Giancarlo De Luca from SISSA (the International School for Advanced Studies of Trieste) together with an international team of researchers (from the Centre for Theoretical Physics — ICTP — of Trieste and the Technical University of Denmark) started to devise a model based on an “adaptive stochastic network.” The physicists wanted to simulate, simplifying it, the collective behaviour of animal groups. Their findings, published in the journal Interface, show that the number of “informed individuals” in a group, sociality and the strength of the decision of the informed individuals are “critical” variables, such that even minimal fluctuations in these variables can result in catastrophic changes to the system.

“We started out by taking inspiration from the phenomenon that affected the bluefin tuna, but in actual fact we then developed a general model that can be applied to many situations of groups “on the move,” explains De Luca.

The collective behaviour of a group can be treated as an “emerging property,” that is, the result of the self-organization of each individual’s behaviour. “The majority of individuals in a group may not possess adequate knowledge, for example, about where to find rich feeding grounds” explains De Luca. “However, for the group to function, it is enough that only a minority of individuals possess that information. The others, the ones who don’t, will obey simple social rules, for example by following their neighbours.”

The tendency to comply with the norm, the number of knowledgeable individuals and the determination with which they follow their preferred route (which the researchers interpreted as being directly related to the appeal, or abundance, of the resource) are critical variables. “When the number of informed individuals falls below a certain level, or the strength of their determination to go in a certain direction falls below a certain threshold, the migratory pathway disappears abruptly.”

“In our networks the individuals are “points,” with interconnections that form and disappear in the course of the process, following some established rules. It’s a simple and general way to model the system which has the advantage of being able to be solved analytically,” comments De Luca.

So what ever happened to the Norwegian tuna? “Based on our results we formulated some hypotheses which will, however, have to be tested experimentally,” says De Luca. In the’50s Norway experienced a reduction in biomass and in the quantity of herrings, the main prey of tuna, which might have played a role in their disappearance. “This is consistent with our model, but there’s more to the story. In a short time the herring population returned to normal levels, whereas the tuna never came back. Why?”

One hypothesis is that, although the overall number of Mediterranean tuna has not changed, what has changed is the composition of the population: “The most desirable tuna specimens for the fishing industry are the larger, older individuals, which are presumably also those with the greater amount of knowledge, in other words the knowledgeable elders.” concludes De Luca.

Another curious fact: what happens if there are too many knowledgeable elders? “Too many know-alls are useless,” jokes De Luca. “In fact, above a certain number of informed individuals, the group performance does not improve so much as to justify the “cost” of their training. The best cost-benefit ratio is obtained by keeping the number of informed individuals above a certain level, provided they remain a minority of the whole population.”

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We need to understand the language of nature

o13-iconMycologist, Paul Stamets, discusses the important role mushrooms play in the survival and health of the earth and human species.

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A Siberian giant virus and the butterfly effect

Omulyakhskaya and Khromskaya Bays lie along the northern Siberian coast, where permafrost blankets the land around the bays. Photo: NASA Earth Observatory

Omulyakhskaya and Khromskaya Bays lie along the northern Siberian coast, where permafrost blankets the land around the bays. Photo: NASA Earth Observatory

Embedded in the mud, glistening green and gold and black, was a butterfly, very beautiful and very dead.

“Not a little thing like that! Not a butterfly!” cried Eckels.

It fell to the floor, an exquisite thing, a small thing that could upset balances and knock down a line of small dominoes and then big dominoes and then gigantic dominoes, all down the years across Time. Eckels’ mind whirled. It couldn’t change things. Killing one butterfly couldn’t be that important! Could it? — Ray Bradbury, A Sound of Thunder, 1952

As one of the massive and probably irreversible consequences of climate change, the melting of the Northern Hemisphere’s permafrost is not an example of the butterfly effect. Yet the discovery of a giant virus which has come back to life after 30,000 years of frozen dormancy, suggests many possibilities including some akin to those envisaged by Ray Bradbury is his famous science fiction story.

Whereas his narrative required that the reader suspend disbelief by entertaining the idea of time travel, the thawing tundra may produce a very real kind of time travel if any viruses or other microbes were to emerge as new invasive species.

Rather than being transported geographically as a result of human activity, these will spring suddenly from a distant past into an environment that may lack necessary evolutionary adaptations to accommodate their presence.

We are assured that Pithovirus sibericum poses no threat to humans — it just attacks amoebas. But our concern shouldn’t be limited to fears about the reemergence of something like an ancient strain of smallpox.

The rebirth of a pathogen that could strike phytoplankton — producers of half the world’s oxygen — would have a devastating impact on the planet.

BBC News reports: The ancient pathogen was discovered buried 30m (100ft) down in the frozen ground.

Called Pithovirus sibericum, it belongs to a class of giant viruses that were discovered 10 years ago.

These are all so large that, unlike other viruses, they can be seen under a microscope. And this one, measuring 1.5 micrometres in length, is the biggest that has ever been found.

The last time it infected anything was more than 30,000 years ago, but in the laboratory it has sprung to life once again.

Tests show that it attacks amoebas, which are single-celled organisms, but does not infect humans or other animals.

Co-author Dr Chantal Abergel, also from the CNRS, said: “It comes into the cell, multiplies and finally kills the cell. It is able to kill the amoeba – but it won’t infect a human cell.”

However, the researchers believe that other more deadly pathogens could be locked in Siberia’s permafrost.

“We are addressing this issue by sequencing the DNA that is present in those layers,” said Dr Abergel.

“This would be the best way to work out what is dangerous in there.”

The researchers say this region is under threat. Since the 1970s, the permafrost has retreated and reduced in thickness, and climate change projections suggest it will decrease further.

It has also become more accessible, and is being eyed for its natural resources.

Prof Claverie warns that exposing the deep layers could expose new viral threats.

He said: “It is a recipe for disaster. If you start having industrial explorations, people will start to move around the deep permafrost layers. Through mining and drilling, those old layers will be penetrated and this is where the danger is coming from.”

He told BBC News that ancient strains of the smallpox virus, which was declared eradicated 30 years ago, could pose a risk. [Continue reading...]

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Can plants make choices?

a13-iconHelmholtz Centre for Environmental Research: Plants are also able to make complex decisions. At least this is what scientists from the Helmholtz Center for Environmental Research (UFZ) and the University of Göttingen have concluded from their investigations on Barberry (Berberis vulgaris), which is able to abort its own seeds to prevent parasite infestation. The results are the first ecological evidence of complex behaviour in plants. They indicate that this species has a structural memory, is able to differentiate between inner and outer conditions as well as anticipate future risks, scientists write in the renowned journal American Naturalist — the premier peer-reviewed American journal for theoretical ecology.

The European barberry or simply Barberry (Berberis vulgaris) is a species of shrub distributed throughout Europe. It is related to the Oregon grape (Mahonia aquifolium) that is native to North America and that has been spreading through Europe for years. Scientists compared both species to find a marked difference in parasite infestation: “a highly specialized species of tephritid fruit fly, whose larvae actually feed on the seeds of the native Barberry, was found to have a tenfold higher population density on its new host plant, the Oregon grape”, reports Dr. Harald Auge, a biologist at the UFZ.

This led scientists to examine the seeds of the Barberry more closely. Approximately 2000 berries were collected from different regions of Germany, examined for signs of piercing and then cut open to examine any infestation by the larvae of the tephritid fruit fly (Rhagoletis meigenii). This parasite punctures the berries in order to lay its eggs inside them. If the larva is able to develop, it will often feed on all of the seeds in the berry. A special characteristic of the Barberry is that each berry usually has two seeds and that the plant is able to stop the development of its seeds in order to save its resources. This mechanism is also employed to defend it from the tephritid fruit fly. If a seed is infested with the parasite, later on the developing larva will feed on both seeds. If however the plant aborts the infested seed, then the parasite in that seed will also die and the second seed in the berry is saved. [Read more...]

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Searching for the elephant’s genius inside the largest brain on land

elephant

Ferris Jabr writes: Many years ago, while wandering through Amboseli National Park in Kenya, an elephant matriarch named Echo came upon the bones of her former companion Emily. Echo and her family slowed down and began to inspect the remains. They stroked Emily’s skull with their trunks, investigating every crevice; they touched her skeleton gingerly with their padded hind feet; they carried around her tusks. Elephants consistently react this way to other dead elephants, but do not show much interest in deceased rhinos, buffalo or other species. Sometimes elephants will even cover their dead with soil and leaves.

What is going through an elephant’s mind in these moments? We cannot explain their behavior as an instinctual and immediate reaction to a dying or recently perished compatriot. Rather, they seem to understand—even years and years after a friend or relative’s death—that an irreversible change has taken place, that, here on the ground, is an elephant who used to be alive, but no longer is. In other words, elephants grieve.

Such grief is but one of many indications that elephants are exceptionally intelligent, social and empathic creatures. After decades of observing wild elephants—and a series of carefully controlled experiments in the last eight years—scientists now agree that elephants form lifelong kinships, talk to one another with a large vocabulary of rumbles and trumpets and make group decisions; elephants play, mimic their parents and cooperate to solve problems; they use tools, console one another when distressed, and probably have a sense of self (See: The Science Is In: Elephants Are Even Smarter Than We Realized)

All this intellect must emerge, in one way or another, from the elephant brain—the largest of any land animal, three times as big as the human brain with individual neurons that seem to be three to five times the size of human brain cells. [Continue reading...]

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The emotional intelligence of dogs

f13-iconThe ability to discern the emotions of others provides the foundation for emotional intelligence. How well-developed this faculty is seems to have little to do with the strength of other markers of intelligence, indeed, as a new study seems to imply, there may be little reason to see in emotional intelligence much that is uniquely human.

Scientific American: [A]lthough dogs have the capacity to understand more than 100 words, studies have demonstrated Fido can’t really speak human languages or comprehend them with the same complexity that we do. Yet researchers have now discovered that dog and human brains process the vocalizations and emotions of others more similarly than previously thought. The findings suggest that although dogs cannot discuss relativity theory with us, they do seem to be wired in a way that helps them to grasp what we feel by attending to the sounds we make.

To compare active human and dog brains, postdoctoral researcher Attila Andics and his team from MTA-ELTE Comparative Ethology Research Group in Hungary trained 11 dogs to lie still in an fMRI brain scanner for several six minute intervals so that the researchers could perform the same experiment on both human and canine participants. Both groups listened to almost two hundred dog and human sounds — from whining and crying to laughter and playful barking — while the team scanned their brain activity.

The resulting study, published in Current Biology today, reveals both that dog brains have voice-sensitive regions and that these neurological areas resemble those of humans. Sharing similar locations in both species, they process voices and emotions of other individuals similarly. Both groups respond with greater neural activity when they listen to voices reflecting positive emotions such as laughing than to negative sounds that include crying or whining. Dogs and people, however, respond more strongly to the sounds made by their own species. “Dogs and humans meet in a very similar social environment but we didn’t know before just how similar the brain mechanisms are to process this social information,” Andics says. [Continue reading...]

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Watch: The hidden patterns of birds and insects in motion

[Source: The Atlantic -- see more of Dennis Hlynsky's videos at Vimeo]

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Climate change is threatening the entire marine food chain

f13-iconPeter Brannen writes: At the Woods Hole Oceanographic Institution on Cape Cod, Massachusetts, snowdrifts piled up outside shuttered T-shirt shops, and wind and whitecaps lashed vessels tethered to empty piers in the harbour. The flood of sun-tanned tourists and research students that descends on this place in summer was still months away. The only visitor was a winter storm that hung over the coast, making travel in and out of the cedar-shingled town impossible. In a research building downtown, at the end of a dimly lit hallway, Peter Wiebe sat with a stack of yellowed composition notebooks, reliving a lifetime spent on the ocean. Wiebe, a grizzled scientist emeritus, is transcribing his research cruise logs, which go back to 1962. His handwritten notes archive a half-century of twilit cruises in the Antarctic and languorous equatorial days surrounded by marine life.

‘It’s quite clear to me things are changing,’ he told me, after I asked him to think back on his decades on the ocean. ‘As a graduate student on one cruise, my logs talk about a hammerhead and two whitetips following the ship the whole time. On other cruises, we would fish for mahimahi and tuna, and occasionally catch a shark. Now we hardly ever see any big fish or sharks at all.’

Indeed, in oceanography, the big story over the past half century – the span of Wiebe’s career – has been the wholesale removal of the seas’ top predators through overfishing. But the story of the oceans for the coming century may be a revolution that starts from the bottom of the food chain, not the top.

‘I won’t be around to see it,’ Wiebe told me. ‘I wish I were.’

Plankton (taken from the Greek word for wanderer) are the plants, animals and microbes that are unable to overcome the influence of ocean currents, either because they’re too small, like bacteria, or because, as in the case of the indifferent jellyfish, they can’t be bothered. Wiebe’s speciality is zooplankton, the kaleidoscopic, translucent animal world in miniature, much of which feeds on even smaller photosynthetic life called phytoplankton. To make the jump from photosynthesis to fish, birds and whales, you have to go through zooplankton first.

Wiebe is part of a body of researchers worldwide working feverishly to find out how these grazers will be affected by an increasingly unfamiliar ocean, an ocean that absorbs 300,000 Hiroshimas of excess heat every day, and whose surface waters have already become 30 per cent more acidic since the dawn of the Industrial Revolution.

‘When I first started, the idea that you could actually change the pH of the ocean just wasn’t there – no one expected us to be able to do it,’ Wiebe told me. ‘Certainly, no one expected us to be able to do it at the pace we’re doing it, at a pace that far surpasses anything natural that has ever happened.’ [Continue reading...]

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The secret language of plants

f13-iconKat McGowan writes: Up in the northern Sierra Nevada, the ecologist Richard Karban is trying to learn an alien language. The sagebrush plants that dot these slopes speak to one another, using words no human knows. Karban, who teaches at the University of California, Davis, is listening in, and he’s beginning to understand what they say.

The evidence for plant communication is only a few decades old, but in that short time it has leapfrogged from electrifying discovery to decisive debunking to resurrection. Two studies published in 1983 demonstrated that willow trees, poplars and sugar maples can warn each other about insect attacks: Intact, undamaged trees near ones that are infested with hungry bugs begin pumping out bug-repelling chemicals to ward off attack. They somehow know what their neighbors are experiencing, and react to it. The mind-bending implication was that brainless trees could send, receive and interpret messages.

The first few “talking tree” papers quickly were shot down as statistically flawed or too artificial, irrelevant to the real-world war between plants and bugs. Research ground to a halt. But the science of plant communication is now staging a comeback. Rigorous, carefully controlled experiments are overcoming those early criticisms with repeated testing in labs, forests and fields. It’s now well established that when bugs chew leaves, plants respond by releasing volatile organic compounds into the air. By Karban’s last count, 40 out of 48 studies of plant communication confirm that other plants detect these airborne signals and ramp up their production of chemical weapons or other defense mechanisms in response. “The evidence that plants release volatiles when damaged by herbivores is as sure as something in science can be,” said Martin Heil, an ecologist at the Mexican research institute Cinvestav Irapuato. “The evidence that plants can somehow perceive these volatiles and respond with a defense response is also very good.”

Plant communication may still be a tiny field, but the people who study it are no longer seen as a lunatic fringe. “It used to be that people wouldn’t even talk to you: ‘Why are you wasting my time with something we’ve already debunked?’” said Karban. “That’s now better for sure.” The debate is no longer whether plants can sense one another’s biochemical messages — they can — but about why and how they do it. [Continue reading...]

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