Eagles take down drones

The New York Times reports: Its wings beating against a gathering breeze, the eagle moves gracefully through a cloudy sky, then swoops, talons outstretched, on its prey below.

The target, however, is not another bird but a small drone, and when the eagle connects, there is a metallic clunk. With the device in its grasp, the bird of prey returns to the ground.

At a disused military airfield in the Netherlands, hunting birds like the eagle are being trained to harness their instincts to help combat the security threats stemming from the proliferation of drones.

The birds of prey learn to intercept small, off-the-shelf drones — unmanned aerial vehicles — of the type that can pose risks to aircraft, drop contraband into jails, conduct surveillance or fly dangerously over public events.

The thought of terrorists using drones haunts security officials in Europe and elsewhere, and among those who watched the demonstration at Valkenburg Naval Air Base this month was Mark Wiebes, a detective chief superintendent in the Dutch police.

Mr. Wiebes described the tests as “very promising,” and said that, subject to a final assessment, birds of prey were likely to be deployed soon in the Netherlands, along with other measures to counter drones. The Metropolitan Police Service in London is also considering using trained birds to fight drones. [Continue reading…]

This has been described as a “a low-tech solution for a high-tech problem” but, on the contrary, what it highlights is the fact that in terms of maneuverability, the flying skills of an eagle (and most other flying creatures) are vastly superior to any form of technology.

In this, as in so many other instances, technology crudely imitates nature.

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What the songs of wolves reveal about language

Holly Root-Gutteridge writes: Dialects, or regional differences in the form and use of vocalisations, have been observed in birds, bats, chimpanzees and now an increasingly long list of other species. This has been most beautifully heard in whales, where the songs of humpbacks are transmitted across hundreds of miles, telling a listener which part of the ocean the whale lives in, and tracing its family group by the influences on song formations. The bioacousticians Katharine Payne and Roger Payne first listened to the whales on underwater microphone recordings in the 1960s, and used musical notation to explore the changes that occurred in each male’s song, year on year. Whalesong, heard by humans as long ago as Aristotle, became the subject of intense study and public interest. Their research showed that there were geographic differences in humpback whale songs and that we could tell apart populations just by using those songs, which change throughout their lives. So the whales were controlling their singing and subject to cultural influences. The Paynes had found dialects in whale song. Would we find the same for canids?

Despite their cultural popularity, wolf howls haven’t been the subject of focussed research until recently. Now, following the lead of marine biologists and ornithologists, and with improved sound recording equipment and analysis programs, researchers can study them in depth. The first step in understanding what animals are saying to one another is to figure out what aspects of the voice are functional and what parts are formed by the structure of the throat and mouth, or what is the piano and what is the tune. Studies since the 1960s have shown that the howls that have haunted our dreams for centuries can tell us a lot about the particular wolf vocalising. Like humans, each wolf has its own voice. Each pack also shares howl similarities, making different families sound distinct from each other (wolves respond more favourably to familiar howls). This much we knew. What we didn’t know was whether the differences seen between packs were true of subspecies or of species, and if an Indian wolf howl would be distinct from a Canadian one.

More questions follow. If howls from different subspecies are different, do the howls convey the same message? Is there a shared culture of howl-meanings, where an aggressive howl from a European wolf means the same thing as an aggressive howl of a Himalayan? And can a coyote differentiate between a red wolf howling with aggressive intent and one advertising the desire to mate? Even without grammar or syntax, howls can convey intent, and if the shape of the howl changes enough while the intent remains constant, the foundations of distinctive culture can begin to appear. [Continue reading…]

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The ex-anarchist construction worker who became a world-renowned scientist

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Daniel Gumbiner writes: “See these lichens here? I don’t know how you see them but, to me, I see them as a surrealist.”

I am sitting in the UC Riverside herbarium, speaking to Kerry Knudsen, Southern California’s only professional lichenologist. We are looking at his collection of lichens, which consists of over 16,000 individual specimens, all of them neatly organized in large green file cabinets. Knudsen has published over 200 peer-reviewed scientific papers on lichens, and discovered more than 60 species that are new to science. It is an extraordinary output, for any scientist, but Knudsen has achieved it in only fifteen years. Science is his second career. For more than two decades he worked in construction. Before that, he was a teenage runaway living in an anarchist commune in Chicago.

“He’s amazing,” said Shirley Tucker, a retired professor of botany at LSU. “He came out of nowhere and became an expert in the most difficult genera.”

A lichen is a fungus in a symbiotic relationship with an algae or a cyanobacteria. The fungus essentially farms the algae or cyanobacteria, who are able to harvest energy from the sun through photosynthesis. In return, the fungus provides the algae or cyanobacteria with protection, but the relationship is a little one-sided.

“The algae is trapped,” Knudsen explained. “It has a lot of tubes going into it. It’s controlled by chemical signals … The first time I saw it under the microscope, I wanted to join the Algae Liberation Front. I mean, it looked bad.”

Scientists believe that lichen evolved over 500 million years ago, about the same time as fish. Although lichen make up 8 percent of the world’s biomass, they are rarely considered by the amateur naturalist, and therefore have very few common names. [Continue reading…]

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Animals are us

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Tania Lombrozo writes: Researchers have studied how people think about humans in relation to the natural world, and how the way we reason about humans and other animals changes over the course of development and as a function of education and culture.

The findings from this body of work suggest that by age 5, Western children growing up in urban environments are anomalous in the extent to which they regard humans as central to the biological world. Much of the rest of the world — including 3-year-olds, 5-year-olds in rural environments and adults from indigenous populations in South America — are more inclined to think about humans as one animal species among others, at least when it comes to reasoning about the properties that human and non-human animals are likely to possess.

To illustrate, consider a study by Patricia Herrmann, Sandra Waxman and Douglas Medin published in the Proceedings of the National Academy of Sciences in 2010. In one experiment, 64 urban children, aged 3 or 5, were asked a series of questions that assessed their willingness to generalize an unknown property from one object to another. For instance, they might be told that people “have andro inside,” and would then have to guess whether it’s right or wrong to say that dogs “have andro inside.”

The findings with 5-year-olds replicated classic work in developmental psychology and suggested a strong “anthropocentric” bias: The children were more likely to generalize from humans to non-humans than the other way around, consistent with a privileged place for humans in the biological world. The 3-year-olds, by contrast, showed no signs of this bias: They generalized from humans to non-humans and from non-humans to humans in just the same way. These findings suggest that an anthropocentric perspective isn’t a necessary starting point for human reasoning about the biological world, but rather a perspective we acquire through experience.

So what happens between the ages of 3 and 5 to induce an anthropocentric bias?

Perhaps surprisingly, one influence seems to be anthropomorphism in storybooks. [Continue reading…]

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The birth and death of a landscape

Justin Nobel writes: To reach the youngest land in the United States you need a boat. Robert Twilley still vividly remembers the first time he made the trip. The Louisiana State University coastal ecologist piled into a 24-foot Boston Whaler with a bunch of geomorphologists from Minnesota and motored out to an arc of spongy islands along the central coast of Louisiana called the Wax Lake Delta. It was the best place to learn about how a delta develops. The way the land eventually stabilizes and becomes home to a unique ecosystem that changes as the delta gets older is a process that ecologists call succession. “Succession is one of the most fascinating concepts in ecology,” said Twilley, “though one of the hardest to study. But in the Wax Lake Delta you can see it all. Biologic communities link up A to Z; it is the holy grail of ecosystem succession.”

What is remarkable for scientists like Twilley is that with good muck boots, a small boat, and a non-aversion to intense sun, freak thunderstorms, biting insects, and devastating humidity, the aging process of this new land can be studied in a human lifespan. In just over 40 years, the Wax Lake Delta has grown from nothing to an area twice the size of Manhattan. Meanwhile, since the European settlement of North America, the Mississippi River Delta has lost approximately one-third of its original wetland area. A delta that was once about twice the size of Delaware and on maps resembled a head of cauliflower now looks more like a string bean. The slow death of the Mississippi River Delta has severe consequences, including reduced hurricane protection for cities like New Orleans. Not only an important food source for humans and wildlife, this rich habitat also helps filter pollutants and absorb excess nutrients that would deplete the oxygen in the Gulf of Mexico’s water.

As one delta dies, another one grows. The budding Wax Lake Delta has allowed Twilley and his team of researchers to study how a delta ages. First, the nascent delta takes shape as lobes of sediment accumulate below the water. The delta is born when it breaches the surface of the water. Colonized by plants that gradually enhance the soil’s organic content and raise its elevation, it rolls through childhood. And eventually, it grows into a landscape able to support large shrubs and black willow trees. “The delta is almost like an organism,” says Twilley, “There is a birthing, there is an aging process, and there is a death.” [Continue reading…]

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Missing mitochondria show life doesn’t relentlessly pursue complexity

Sarah Kaplan writes: Life on Earth used to be simple.

Once upon a time, every organism on the planet was a single, simple cell. Scientists call them prokaryotes. They are about as basic as a living thing can be — just little balloons of DNA and protein, with no grander goals in life than to swim around, eat and occasionally duplicate themselves to produce more swimmers and eaters.

Then, about 1.5 billion years ago, something strange and spectacular happened. One prokaryote engulfed another, and instead of digesting it, he put the little guy to work. They established an endosymbiotic relationship: The smaller internal cell performed lots of helpful tasks — such as making energy and building proteins — and in exchange, the bigger cell kept it safe and well-fed. This lucky bit of teamwork gave rise to the complex (a.k.a. eukaryotic) cell that exists today, from curious single-celled protists to the cells that make up all plants, fungi and animals — including us.

The eukaryotes are a weird and diverse lot, but at the cellular level we’ve all got the same basic components: a nucleus to store our DNA, and mitochondria — the descendants of that ancient swallowed organism — to make energy and perform other essential functions. Other internal structures, called organelles, may vary, but those two are so universal that biologists assumed we couldn’t exist without them.

“They’re part of the definition of eukaryotic cell,” said Anna Karnkowska, an evolutionary biologist at the University of British Columbia. “If you open a biology textbook to a picture of a eukaryotic cell, that’s what you’ll see.”

Which is why she was so shocked to find a eukaryote that didn’t have any mitochondria at all: a single-celled relative of the giardia parasite called Monocercomonoides.

The discovery, which Karnkowska made with other biologists when she was a post-doctoral fellow at Charles University in Prague, seems to rip up that textbook illustration. One of her co-authors compared it to finding a city with no utilities or public works department.

“This is the first example of a eukaryote lacking any form of a mitochondrion,” the researchers write in their study, which was published Thursday in the journal Current Biology, “demonstrating that this organelle is not absolutely essential for the viability of a eukaryotic cell.” [Continue reading…]

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Ancient space dust hints at a mysterious period in Earth’s early history

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Rebecca Boyle writes: Geologists tell a pretty broad-brush narrative of Earth’s 4.5 billion-year history. For its first half-billion years, the newly formed planet was a seething ball of lava constantly pelted by giant space rocks, including a Mars-sized object that sheared off a chunk that became the moon. Things calmed down when the Late Heavy Bombardment tapered off some 3.8 billion years ago, but volcanoes ensured Earth’s atmosphere remained a toxic stew of gases with almost no oxygen to speak of. It stayed that way for another billion years, when single-celled bacteria filled the oceans. Around 2.5 billion years ago, at the end of the Archean era, algae figured out how to make energy from sunlight, and the Great Oxygenation Event gave Earth its lungs. Complex life took its time, finally exploding in the Cambrian era some 500 million years ago. Evolution moved a lot faster after that, resulting in dinosaurs, then mammals, then us.

It’s a great story, and scientists have been telling it for decades, but tiny fossilized space pebbles from Australia may upend it entirely, giving us a new narrative about Earth’s adolescence. These pebbles rained down on our planet’s surface 2.7 billion years ago. As they passed through the upper atmosphere, they melted and rusted, making new crystal shapes and minerals that only form where there is plenty of oxygen. A new paper describing the space pebbles will be published today in the journal Nature. It suggests the atmosphere’s upper reaches were surprisingly rich in oxygen during the Archean, when Earth’s surface had practically none.

“If they’re right, a lot of people have had misconceptions, or have been wrong,” says Kevin Zahnle, a planetary scientist at NASA’s Ames Research Center. Moreover, if the research holds up, geologists will have a new mystery on their hands: How did all that oxygen get there, and why didn’t it reach the ground? [Continue reading…]

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Are oxygen-depleted oceans from California to Namibia a harbinger of the next mass extinction?

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Moises Velasquez-Manoff writes: It was crabbers who first reported something amiss. In 2002, they began pulling in traps full of corpses. (Crabs should be alive when you catch them.) And they mentioned something else: Little octopuses had followed their crab lines to the surface, as if fleeing inhospitable conditions below.

Then heaps of dead crustaceans began washing ashore along a stretch of Oregon’s coast. When scientists sent a robotic submersible offshore, they discovered mile upon mile of dead crustaceans, the water brown and murky with detritus.

The killer was low oxygen, or hypoxia. Nearly all animals require oxygen to live, and, that year, dissolved oxygen had fallen so low off Oregon’s coast that whatever mobile creatures could had fled, while more-sessile life had simply suffocated.

Every year since, those hypoxic waters have appeared in late summer and early autumn. In 2006, they became anoxic, meaning they lost all their oxygen. “You didn’t see a single fish in a day,” says Jack Barth, a professor at Oregon State University, “just the piles of crab carcasses and worms that had come out of the bottom, sort of wafting in the current.” When scientists examined the roughly 50-year record of oxygen measurements from the region, they couldn’t find a single comparable event in the past. The hypoxia, it seemed, was unprecedented.

And then it spread.

In 2013, low-oxygen water showed up off the California coast just north of San Francisco. The following year, crabbers pulled in dead crabs in Half Moon Bay, just below San Francisco. Further south, the Monterey Bay Aquarium registered a decline in the oxygen content of the water it pumps in from the ocean.

“It seems like something has changed,” says John Largier, head of the Coastal Oceanography Group at the University of California-Davis. He tries to remain skeptical, but he suspects “large-scale global change.”

These suffocated patches of ocean aren’t just bad for fishermen and their catch; they represent a change in the ocean that has, at times in Earth’s past, heralded mass extinction. [Continue reading…]

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One in five of world’s plant species at risk of extinction

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Phys.org reports: The first annual State of the World’s Plants report, which involved more than 80 scientists and took a year to produce, is a baseline assessment of current knowledge on the diversity of plants on earth, the global threats these plants currently face, as well as the policies in place and their effectiveness in dealing with threats.

“This is the first ever global assessment on the state of the world’s plants. We already have a ‘State of the World’s …birds, sea-turtles, forests, cities, mothers, fathers, children even antibiotics’ but not plants. I find this remarkable given the importance of plants to all of our lives- from food, medicines, clothing, building materials and biofuels, to climate regulation. This report therefore provides the first step in filling this critical knowledge gap.” said Professor Kathy Willis, Director of Science at the Royal Botanic Gardens, Kew at the report launch on Monday.

“But to have effect, the findings must serve to galvanise the international scientific, conservation, business and governmental communities to work together to fill the knowledge gaps we’ve highlighted and expand international collaboration, partnerships and frameworks for plant conservation and use,” she added.

The status of plants outlined in the report is based on the most up to date knowledge from around the world as of 2016 and is divided into three sections; describing the world’s plants, global threats to plants and policies and international trade. [Continue reading…]

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Brainless intelligence observed in slime

Phys.org reports: What is intelligence? The definitions vary, but all infer the use of grey matter, whether in a cat or a human, to learn from experience.

On Wednesday, scientists announced a discovery that turns this basic assumption on its head.
A slime made up of independent, single cells, they found, can “learn” to avoid irritants despite having no central nervous system.

“Tantalizing results suggest that the hallmarks for learning can occur at the level of single cells,” the team wrote in a paper published in the journal Proceedings of the Royal Society B. [Continue reading…]

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The spark of life and a burst of zinc fluorescence

For some religious believers, the idea that human life has a divine origin includes the notion that the biological event of conception has a divine component: the moment at which a soul enters a developing embryo.

It is now being claimed that this belief is supported by scientific evidence.

Citing a recently published study appearing in Scientific Reports, Catholic Online says:

Researchers discovered the moment a human soul enters an egg, which gives pro-life groups an even greater edge in the battle between embryonic life and death. The precise moment is celebrated with a zap of energy released around the newly fertilized egg.

Teresa Woodruff, one of the study’s senior authors and professor in obstetrics and gynecology at the university, delivered a press release in which she stated, “to see the zinc radiate out in a burst from each human egg was breathtaking.”

It’s easy to understand why images showing a burst of light as an egg is fertilized, might appear to provide scientific validation of religious belief.

But attaching religious significance to these findings requires ignoring a key detail in what has been reported.

If the zinc spark that’s been observed — a burst of zinc fluorescence that occurs as millions of zinc atoms get dumped out of the egg — actually bore a relationship with the arrival of a soul enabling the emergence of life, then no such sparks would have been photographed. Why? Because the experiment involved staging a facsimile of fertilization using a sperm enzyme, not live sperm.

Either the experimenters fooled God into placing souls into unfertilized eggs, or these “sparks of life” can be understood as chemical events — though no less wondrous to behold.

Moreover, for those who insist these zinc sparks are triggered by souls, they might need to make some theological revisions to accommodate the evidence that mice apparently possess souls too.

To understand the science in more detail, watch this:

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Humans paid for bigger brains with energy-hungry bodies

Ed Yong writes: Evolution works on a strict energy budget. Each adaptation burns through a certain number of calories, and each individual can only acquire so many calories in the course of a day. You can’t have flapping wings and a huge body and venom and fast legs and a big brain. If you want to expand some departments, you need to make cuts in others. That’s why, for example, animals that reproduce faster tend to die earlier. They divert energy towards making new bodies, and away from maintaining their own.

But humans, on the face of it, are exceptional. Compared to other apes, we reproduce more often (or, at least, those of us in traditional societies do) and our babies are bigger when they’re born and we live longer. And, as if to show off, our brains are much larger, and these huge organs sap some 20 percent of our total energy.

“We tend to have our cake and eat it too,” says Herman Pontzer from Hunter College. “These traits that make us human are all energetically costly. And until now, we didn’t really understand how we were fueling them.” [Continue reading…]

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One gene can produce many different proteins

Veronique Greenwood writes: The millimeter-long roundworm Caenorhabditis elegans has about 20,000 genes — and so do you. Of course, only the human in this comparison is capable of creating either a circulatory system or a sonnet, a state of affairs that made this genetic equivalence one of the most confusing insights to come out of the Human Genome Project. But there are ways of accounting for some of our complexity beyond the level of genes, and as one new study shows, they may matter far more than people have assumed.

For a long time, one thing seemed fairly solid in biologists’ minds: Each gene in the genome made one protein. The gene’s code was the recipe for one molecule that would go forth into the cell and do the work that needed doing, whether that was generating energy, disposing of waste, or any other necessary task. The idea, which dates to a 1941 paper by two geneticists who later won the Nobel Prize in medicine for their work, even has a pithy name: “one gene, one protein.”

Over the years, biologists realized that the rules weren’t quite that simple. Some genes, it turned out, were being used to make multiple products. In the process of going from gene to protein, the recipe was not always interpreted the same way. Some of the resulting proteins looked a little different from others. And sometimes those changes mattered a great deal. There is one gene, famous in certain biologists’ circles, whose two proteins do completely opposite things. One will force a cell to commit suicide, while the other will stop the process. And in one of the most extreme examples known to science, a single fruit fly gene provides the recipe for more than 38,000 different proteins.

But these are dramatic cases. It was never clear just how common it is for genes to make multiple proteins and how much those differences matter to the daily functioning of the cell. Many researchers have assumed that the proteins made by a given gene probably do not differ greatly in their duties. It’s a reasonable assumption — many small-scale tests of sibling proteins haven’t suggested that they should be wildly different.

It is still an assumption, however, and testing it is quite an endeavor. Researchers would have to take a technically tricky inventory of the proteins in a cell and run numerous tests to see what each one does. In a recent paper in Cell, however, researchers at the Dana-Farber Cancer Institute in Boston and their collaborators reveal the results of just such an effort. They found that in many cases, proteins made by a single gene are no more alike in their behavior than proteins made by completely different genes. Sibling proteins often act like strangers. It’s an insight that opens up an interesting new set of possibilities for thinking about how the cell — and the human body — functions. [Continue reading…]

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Why are your gut microbes different from mine?

Ed Yong writes: There are tens of trillions of bacteria in my gut and they are different from those in yours. Why?

This is a really basic question about the human microbiome and, rather vexingly, we still don’t have a good answer. Sure, we know some of the things that influence the roll call of species — diet and antibiotics, to name a few — but their relative importance is unclear and the list is far from complete. That bodes poorly for any attempt to work out whether these microbes are involved in diseases, and whether they can be tweaked to improve our health.

Two new studies have tried to address the problem. They’re the largest microbiome studies thus far published, looking at 1,135 Dutch adults and 1,106 Belgians respectively. Both looked at how hundreds of factors affect the microbiome, including age, height, weight, sleep, medical history, smoking, allergies, blood levels of various molecules, and a long list of foods. Both found dozens of factors that affect either the overall diversity of microbial species, or the abundance of particular ones. And encouragingly, their respective lists overlap considerably.

But here’s the important thing: Collectively, the factors they identified explain a tiny proportion of the variation between people’s microbiomes — 19 percent in the Dutch study, and just 8 percent in the Belgian. Which means we’re still largely in the dark about what makes my microbiome different from yours, let alone whether one is healthier than the other. [Continue reading…]

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Why it’s impossible to actually be a vegetarian

By Andrew Smith, Drexel University

In case you’ve forgotten the section on the food web from high school biology, here’s a quick refresher.

Plants make up the base of every food chain of the food web (also called the food cycle). Plants use available sunlight to convert water from the soil and carbon dioxide from the air into glucose, which gives them the energy they need to live. Unlike plants, animals can’t synthesize their own food. They survive by eating plants or other animals.

Clearly, animals eat plants. What’s not so clear from this picture is that plants also eat animals. They thrive on them, in fact (just Google “fish emulsion”). In my new book, “A Critique of the Moral Defense of Vegetarianism,” I call it the transitivity of eating. And I argue that this means one can’t be a vegetarian.

[Read more…]

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