Category Archives: Biology

Something is shifting out there in the ocean

Rebecca Kessler writes: ‘It’s hard to believe that a 40-ton animal can get hidden. They’re sneaky.’ Charles ‘Stormy’ Mayo was scanning the sea from the deck of the R/V Shearwater searching for omens: a cloud of vapour, a patch of white water, a fluke. A few minutes earlier someone had spotted the first North Atlantic right whales of the day. But now they were down below and out of sight in 80 feet of murky seawater. Feeding, most likely.

Finally, a whale’s head emerged briefly on the sea surface. Then a slab of black back followed by the silhouette of flukes, signaling another deep dive. The appearance lasted maybe a second and a half. Groans from the crew, who did not quite manage to snap a photo that could help identify the whale, one of an early March influx that foretold another strong season in Cape Cod Bay. ‘There’s probably a bunch of whales here but it’s going to drive us crazy,’ Mayo chimed in. ‘I’m going to say there are probably three. It’s hard as hell to tell.’

The world’s rarest whales – Eubalaena glacialis – have been visiting the bay in late winter and early spring for as long as anyone can remember. But Mayo and his team at the Center for Coastal Studies (CCS) in Provincetown documented a puzzling uptick in recent years. Not just a few dozen animals, as was typical, but hundreds were showing up and, in one year, darn-near two-thirds of the world’s entire living population of around 500 North Atlantic right whales. ‘Right Whale Kingdom’ Mayo has called the bay. Simultaneously, the whales went AWOL from their usual summer feeding grounds 300 miles to the northeast in Canada’s Bay of Fundy and elsewhere, further mystifying researchers.

The Shearwater idled, waiting. The whales remained deep down, scooping up patches of zooplankton and straining out the seawater through the long strips of baleen in their mouths. Scooping and straining, scooping and straining. A change in the location of their preferred food is the most likely explanation for the whales’ wandering itinerary, Mayo said. Something is shifting out there in the ocean. As with so much else about their lives, only the whales know what it is. [Continue reading…]

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Watching evolution happen in two lifetimes

Emily Singer writes: When Rosemary and Peter Grant first set foot on Daphne Major, a tiny island in the Galápagos archipelago, in 1973, they had no idea it would become a second home. The husband and wife team, now emeritus biology professors at Princeton University, were looking for a pristine environment in which to study evolution. They hoped that the various species of finches on the island would provide the perfect means for uncovering the factors that drive the formation of new species.

The diminutive island wasn’t a particularly hospitable place for the Grants to spend their winters. At less than one-hundredth the size of Manhattan, Daphne resembles the tip of a volcano rising from the sea. Visitors must leap off the boat onto the edge of a steep ring of land that surrounds a central crater. The island’s vegetation is sparse. Herbs, cactus bushes and low trees provide food for finches — small, medium and large ground finches, as well as cactus finches — and other birds. The Grants brought with them all the food and water they would need and cooked meals in a shallow cave sheltered by a tarp from the baking sun. They camped on Daphne’s one tiny flat spot, barely larger than a picnic table.

Though lacking in creature comforts, Daphne proved to be a fruitful choice. The Galápagos’ extreme climate — swinging between periods of severe drought and bountiful rain — furnished ample natural selection. Rainfall varied from a meter of rain in 1983 to none in 1985. A severe drought in 1977 killed off many of Daphne’s finches, setting the stage for the Grants’ first major discovery. During the dry spell, large seeds became more plentiful than small ones. Birds with bigger beaks were more successful at cracking the large seeds. As a result, large finches and their offspring triumphed during the drought, triggering a lasting increase in the birds’ average size. The Grants had observed evolution in action.

That striking finding launched a prolific career for the pair. They visited Daphne for several months each year from 1973 to 2012, sometimes bringing their daughters. Over the course of their four-decade tenure, the couple tagged roughly 20,000 birds spanning at least eight generations. (The longest-lived bird on the Grants’ watch survived a whopping 17 years.) They tracked almost every mating and its offspring, creating large, multigenerational pedigrees for different finch species. They took blood samples and recorded the finches’ songs, which allowed them to track genetics and other factors long after the birds themselves died. They have confirmed some of Darwin’s most basic predictions and have earned a variety of prestigious science awards, including the Kyoto Prize in 2009.

Now nearly 80, the couple have slowed their visits to the Galápagos. These days, they are most excited about applying genomic tools to the data they collected. They are collaborating with other scientists to find the genetic variants that drove the changes in beak size and shape that they tracked over the past 40 years. Quanta Magazine spoke with the Grants about their time on Daphne; an edited and condensed version of the conversation follows. [Continue reading…]

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Rewriting Earth’s creation story

Earth

Rebecca Boyle writes: Humanity’s trips to the moon revolutionized our view of this planet. As seen from another celestial body, Earth seemed more fragile and more precious; the iconic Apollo 8 image of Earth rising above the lunar surface helped launch the modern environmental movement. The moon landings made people want to take charge of Earth’s future. They also changed our view of its past.

Earth is constantly remaking itself, and over the eons it has systematically erased its origin story, subsuming and cannibalizing its earliest rocks. Much of what we think we know about the earliest days of Earth therefore comes from the geologically inactive moon, which scientists use like a time capsule.

Ever since Apollo astronauts toted chunks of the moon back home, the story has sounded something like this: After coalescing from grains of dust that swirled around the newly ignited sun, the still-cooling Earth would have been covered in seas of magma, punctured by inky volcanoes spewing sulfur and liquid rock. The young planet was showered in asteroids and larger structures called planetisimals, one of which sheared off a portion of Earth and formed the moon. Just as things were finally settling down, about a half-billion years after the solar system formed, the Earth and moon were again bombarded by asteroids whose onslaught might have liquefied the young planet — and sterilized it.

Geologists named this epoch the Hadean, after the Greek version of the underworld. Only after the so-called Late Heavy Bombardment quieted some 3.9 billion years ago did Earth finally start to morph into the Edenic, cloud-covered, watery world we know.

But as it turns out, the Hadean may not have been so hellish. New analysis of Earth and moon rocks suggest that instead of a roiling ball of lava, baby Earth was a world with continents, oceans of water, and maybe even an atmosphere. It might not have been bombarded by asteroids at all, or at least not in the large quantities scientists originally thought. The Hadean might have been downright hospitable, raising questions about how long ago life could have arisen on this planet. [Continue reading…]

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Tardigrades: The most fascinating animals known to science

 

Brian Resnick writes: Paul Bartels gets a rush every time he discovers a new species of tardigrade, the phylum of microscopic animals best known for being both strangely cute and able to survive the vacuum of space.

“The first paper I wrote describing a new species, there was a maternal-paternal feeling — like I just gave birth to this new thing,” he tells me on a phone call.

The rush comes, in part, because tardigrades are the most fascinating animals known to science, able to survive in just about every environment imaginable. “There are some ecosystems in the Antarctic called nunataks where the wind blows away snow and ice, exposing outcroppings of rocks, and the only things that live on them are lichens and tardigrades,” says Bartels, an invertebrate zoologist at Warren Wilson College in North Carolina.

Pick up a piece of moss, and you’ll find tardigrades. In the soil: tardigrades. The ocean: You get it. They live on every continent, in every climate, and in every latitude. Their extreme resilience has allowed them to conquer the entire planet.

And though biologists have known about tardigrades since the dawn of the microscope, they’re only just beginning to understand how these remarkable organisms are able to survive anywhere. [Continue reading…]

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Why neuroscientists need to study the crow

crow

Grigori Guitchounts writes: The animals of neuroscience research are an eclectic bunch, and for good reason. Different model organisms—like zebra fish larvae, C. elegans worms, fruit flies, and mice — give researchers the opportunity to answer specific questions. The first two, for example, have transparent bodies, which let scientists easily peer into their brains; the last two have eminently tweakable genomes, which allow scientists to isolate the effects of specific genes. For cognition studies, researchers have relied largely on primates and, more recently, rats, which I use in my own work. But the time is ripe for this exclusive club of research animals to accept a new, avian member: the corvid family.

Corvids, such as crows, ravens, and magpies, are among the most intelligent birds on the planet — the list of their cognitive achievements goes on and on — yet neuroscientists have not scrutinized their brains for one simple reason: They don’t have a neocortex. The obsession with the neocortex in neuroscience research is not unwarranted; what’s unwarranted is the notion that the neocortex alone is responsible for sophisticated cognition. Because birds lack this structure—the most recently evolved portion of the mammalian brain, crucial to human intelligence—neuroscientists have largely and unfortunately neglected the neural basis of corvid intelligence.

This makes them miss an opportunity for an important insight. Having diverged from mammals more than 300 million years ago, avian brains have had plenty of time to develop along remarkably different lines (instead of a cortex with its six layers of neatly arranged neurons, birds evolved groups of neurons densely packed into clusters called nuclei). So, any computational similarities between corvid and primate brains — which are so different neurally — would indicate the development of common solutions to shared evolutionary problems, like creating and storing memories, or learning from experience. If neuroscientists want to know how brains produce intelligence, looking solely at the neocortex won’t cut it; they must study how corvid brains achieve the same clever behaviors that we see in ourselves and other mammals. [Continue reading…]

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1.5 billion birds missing from North American skies, ‘alarming’ report finds

The Canadian Press reports: North American skies have grown quieter over the last decades by the absent songs of 1.5 billion birds, says the latest summary of bird populations.

The survey by dozens of government, university and environmental agencies across North America has also listed 86 species of birds — including once-common and much-loved songbirds such as the evening grosbeak and Canada warbler — that are threatened by plummeting populations, habitat destruction and climate change.

“The information on urgency is quite alarming,” said Partners In Flight co-author Judith Kennedy of Environment Canada. “We’re really getting down to the dregs of some of these populations.”

The report is the most complete survey of land bird numbers to date and attempts to assess the health of populations on a continental basis. It concludes that, while there are still a lot of birds in the sky, there aren’t anywhere near as many as there used to be. [Continue reading…]

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Forget ideology, liberal democracy’s newest threats come from technology and bioscience

John Naughton writes: The BBC Reith Lectures in 1967 were given by Edmund Leach, a Cambridge social anthropologist. “Men have become like gods,” Leach began. “Isn’t it about time that we understood our divinity? Science offers us total mastery over our environment and over our destiny, yet instead of rejoicing we feel deeply afraid.”

That was nearly half a century ago, and yet Leach’s opening lines could easily apply to today. He was speaking before the internet had been built and long before the human genome had been decoded, and so his claim about men becoming “like gods” seems relatively modest compared with the capabilities that molecular biology and computing have subsequently bestowed upon us. Our science-based culture is the most powerful in history, and it is ceaselessly researching, exploring, developing and growing. But in recent times it seems to have also become plagued with existential angst as the implications of human ingenuity begin to be (dimly) glimpsed.

The title that Leach chose for his Reith Lecture – A Runaway World – captures our zeitgeist too. At any rate, we are also increasingly fretful about a world that seems to be running out of control, largely (but not solely) because of information technology and what the life sciences are making possible. But we seek consolation in the thought that “it was always thus”: people felt alarmed about steam in George Eliot’s time and got worked up about electricity, the telegraph and the telephone as they arrived on the scene. The reassuring implication is that we weathered those technological storms, and so we will weather this one too. Humankind will muddle through.

But in the last five years or so even that cautious, pragmatic optimism has begun to erode. There are several reasons for this loss of confidence. One is the sheer vertiginous pace of technological change. Another is that the new forces at loose in our society – particularly information technology and the life sciences – are potentially more far-reaching in their implications than steam or electricity ever were. And, thirdly, we have begun to see startling advances in these fields that have forced us to recalibrate our expectations.[Continue reading…]

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Fish can recognize human faces, study shows

archerfish

CNN reports: Can your pet fish recognize your face?

A new study says, Yes, it probably can.

Researchers studying archerfish found the fish can tell a familiar human face from dozens of new faces with surprising accuracy.

This is a big, big deal. It’s the first time fish have demonstrated this ability.

Think about it: All faces have two eyes sitting above a nose and a mouth. And for us to be able to tell them apart, we need to be able to pick up the subtle differences in features.

We’re good at this because we are smart, i.e. we have large and complex brains. Other primates can do this too. Some birds as well.

But a fish? A fish has a tiny brain. And it would have no reason in its evolution to learn how to recognize humans.

So this study, published in the journal “Scientific Reports,” throws on its head all our conventional thinking. It was done by scientists at University of Oxford in the U.K. and the University of Queensland in Australia. [Continue reading…]

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Magpies challenge bird-brain myth

magpie

GrrlScientist writes: Birds have been disparaged publicly as “bird brains” for so long that most people have lost the ability to view them as intelligent and sentient beings. However, a group of researchers in Germany have conducted a series of studies with several captive European magpies, Pica pica, that challenge the average person’s view of birds and their cognitive abilities.

It is widely accepted in the scientific community that self-awareness is prerequisite for the development of consciousness. Previously, only mammals — humans and several of their cousins, chimpanzees and orangutans, as well as dolphins and elephants — were observed to have self-awareness by demonstrating that they could recognize themselves in a mirror.

However, a new study by a research group in Germany reveals that birds apparently also evolved self-recognition.

“[Our research] shows that the line leading to humans is not as special as many thought,” pointed out lead researcher Helmut Prior of the Institute of Psychology at Goethe University in Frankfurt, Germany.

To do their research, Prior and his colleagues carried out a series of tests with five hand-raised European magpies. [Continue reading…]

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The strange case of the butterfly and the male-murdering microbe

Ed Yong writes: Hurbert Walter Simmonds had only been in Fiji for a year before he was appointed as Government Entomologist in 1920. It was an unusual role, but an important one. The island was repeatedly threatened by agricultural pests, and so Simmonds would spend the next 46 years searching for predators and parasites that could bring these crop-destroyers to heel.

In his downtime, he collected butterflies. There are thousands of species in Fiji, and the blue moon butterfly (Hypolimnas bolina) is among the most beautiful of them. The name comes from the males, whose black wings have three pairs of bright white spots, encircled by blue iridescence. They are stunning, and all males look the same. The females are more varied: they are clothed in a wide range of spots, stripes and hues, many of which mimic other local butterflies. Simmonds wanted to know how these patterns are inherited, so he started capturing and breeding the insects.

That’s when he noticed that most of the females only gave birth to females.

Some 90 percent of them would produce all-female broods. They laid large clutches of eggs and around half the embryos died — presumably, the male ones. Simmonds didn’t know why. [Continue reading…]

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Ancient Venus may have been much like Earth

The Washington Post reports: For a 2-billion-year-long span, ending about 715 million years ago, Venus was likely a much more pleasant spot that it is today. To observe Venus now is to witness a dry and toxic hellscape, where the planet heats up to a scorching 864 degrees Fahrenheit. A super-strong electric wind is believed to suck the smallest traces of water into space. With apologies to Ian Malcolm, life as we know it could not find a way.

But travel back in time a few billion years or so. Ancient Venus, according to a new computer model from NASA, would have been prime solar system real estate, to the point it may have been downright habitable.

That life would find Venus amenable hinges on two main factors. Venus would have needed much balmier temperatures, and it also would have needed a liquid ocean — which is a significant if, although elemental traces such as deuterium indicate water existed on Venus at one point. As Colin Wilson, an Oxford University planetary physicist, told Time in 2010, “everything points to there being large amounts of water in the past.”

Venusian temperatures, too, appear to have been far cooler when the solar system was younger. NASA’s Goddard Institute for Space Studies, in a report published Thursday in the journal Geophysical Research Letters, calculated that the average surface temperature 2.9 billion years ago was about 50 degrees Fahrenheit. Such temperature would have made Venus, surprisingly for a planet closer to the Sun, a bit chillier than Earth was at the time. [Continue reading…]

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Cricket’s famous ‘legover’ moment and why getting the giggles is so contagious

By Sophie Scott, UCL

It is 25 years since cricket commentators Brian Johnston and Jonathan Agnew famously got the uncontrollable giggles on live radio, while reporting on that day’s Test Match between England and the West Indies. The pair were commentating on the wicket of England’s Ian Botham, when he stumbled on to his stumps and, as Agnew put it: “Didn’t get his leg over”.

The resulting infectious two minutes of laughter has since been voted the greatest moment of sporting commentary ever. It’s worth listening to again – see if you can help giggling along with them.

I research the neurobiology of human vocal communication, and recently I’ve been spending a lot of time looking at laughter, which is easily the most common non-verbal emotional expression which one comes across (though in some cultures laughter is rather impolite and can be less frequently encountered when out and about). There are four key features of the science of laughter that this the Botham clip illustrates.

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There are no ‘good’ or ‘bad’ microbes

microbiome

Ed Yong writes: In the 1870s, German physician Robert Koch was trying to curtail an epidemic of anthrax that was sweeping local farm animals. Other scientists had seen a bacterium, Bacillus anthracis, in the victims’ tis­sues. Koch injected this microbe into a mouse – which died. He recovered it from the dead rodent and injected it into another one – which also died. Doggedly, he repeated this grim process for over 20 generations and the same thing happened every time. Koch had unequivocally shown that Bacillus anthracis caused anthrax.

This experiment, and those of contemporaries like Louis Pasteur, confirmed that many diseases are caused by microscopic organisms. Microbes, which had been largely neglected for a couple of centuries, were quickly cast as avatars of death. They were germs, pathogens, bringers of pestilence. Within two decades of Koch’s work on anthrax, he and many others had discovered that bacteria were also associated with leprosy, gonorrhoea, typhoid, tuberculosis, cholera, diphtheria, tetanus, and plague. Microbes became synonymous with squalor and sickness. They became foes for us to annihilate and repel.

Today, we know this view is wrong – as I explain in my new book I Contain Multitudes. Sure, some bacteria can cause disease, but they are in the minority. Most are harmless, and many are even beneficial. We now know that the trillions of microbes that share our bodies – the so-called microbiome – are an essential part of our lives. Far from making us sick, they can protect us from disease; they also help digest our food, train our immune system, and perhaps even influence our behaviour. These discoveries have shifted the narrative. Many people now see microbes as allies to be protected. Magazines regularly warn that antibiotics and sanitisers might be harming our health by destroying our microscopic support system. Slowly, the view that ‘all bacteria must be killed’ is giving ground to ‘bacteria are our friends and want to help us’.

The problem is that the latter view is just as wrong as the former. We cannot simply assume that a particular microbe is ‘good’ just because it lives inside us. There’s really no such thing as a ‘good microbe’ or a ‘bad microbe’. These broad-brush terms belong in children’s stories. They are ill-suited for describing the messy, fractious, contextual relationships of the natural world. [Continue reading…]

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Your gut bacteria predates appearance of humans, genetic study finds

The Guardian reports: The evolutionary history of the bacteria in your guts predates the appearance of humans, and mirrors that of our great ape relatives, according to a genetic study.

The research suggests that microbes in our ancestors’ intestines split into new evolutionary lineages in parallel with splits in the ape family tree.

This came as a surprise to scientists, who had thought that most of our gut bacteria came from our surroundings – what we eat, where we live, even what kind of medicine we take. The new research suggests that evolutionary history is much more important than previously thought.

“When there were no humans or gorillas, just ancestral African apes, they harboured gut bacteria. Then the apes split into different branches, and there was also a parallel divergence of different gut bacteria,” said Prof Andrew Moeller of the University of California, Berkeley who led the study, published in Science. This happened when gorillas separated somewhere between 10-15 million years ago, and again when humans split from chimps and bonobos 5 million years ago. [Continue reading…]

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Biodiversity is below safe levels across more than half of world’s land, say scientists

wheat

The Guardian reports: The variety of animals and plants has fallen to dangerous levels across more than half of the world’s landmass due to humanity destroying habitats to use as farmland, scientists have estimated.

The unchecked loss of biodiversity is akin to playing ecological roulette and will set back efforts to bring people out of poverty in the long term, they warned.

Analysing 1.8m records from 39,123 sites across Earth, the international study found that a measure of the intactness of biodiversity at sites has fallen below a safety limit across 58.1% of the world’s land.

Under a proposal put forward by experts last year, a site losing more than 10% of its biodiversity is considered to have passed a precautionary threshold, beyond which the ecosystem’s ability to function could be compromised.

“It’s worrying that land use has already pushed biodiversity below the level proposed as a safe limit,” said Prof Andy Purvis, of the Natural History Museum, and one of the authors. “Until and unless we can bring biodiversity back up, we’re playing ecological roulette.” [Continue reading…]

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Goats, sheep and cows could challenge dogs for title of ‘man’s best friend’

By Catherine Douglas, Newcastle University

Since the evolution of dogs from wolves tens of thousands of years ago, they have been selectively bred for various roles as guards, hunters, workers and companions. But dogs are not the only animal humans have domesticated, which suggests that although dogs get all the attention, there’s reason to argue other species could also deserve the title of “man’s best friend”.

Anthrozoology, the study of human-animal relationships, has established that dogs demonstrate complex communication with humans. Charles Darwin thought that dogs experienced love, but it was only in 2015 that Japanese scientists demonstrated what we all intuitively knew. Miho Nagasawa and colleagues sprayed the “love hormone” oxytocin up dogs’ noses, measured the loving gaze between dog and human, and then measured the oxytocin levels in the humans’ urine, finding them to be higher. Rest assured, dog owners, that science has verified your bond with your faithful hound.

Horses also show intentional communicative behaviour with humans, and another recent paper published in the Royal Society’s Biology Letters from researchers at Queen Mary University of London has shown that goats also demonstrate an affinity with humans. The experiments tested goats’ intelligence and ability to communicate with humans. What the team found may come as no surprise to anyone who has worked with livestock: goats are highly intelligent, capable of complex communication with humans, and are able to form bonds with us – treating us as potential partners to help in problem-solving situations.

Our attitudes to animals tend to reflect the familiarity we have with them. Dogs score higher in perceived intelligence ratings than cows, for example, yet a study in the 1970s demonstrated that in a test cows could navigate a maze as well as dogs, and only slightly less well than children. The point was made that our perception of an animal’s ability is influenced by how we test them.

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Learning from nature: Record-efficiency turbine farms are being inspired by sealife

Alex Riley writes: As they drove on featureless dirt roads on the first Tuesday of 2010, John Dabiri, professor of aeronautics and bioengineering at the California Institute of Technology, and his then-student Robert Whittlesey, were inspecting a remote area of land that they hoped to purchase to test new concepts in wind power. They named their site FLOWE for Field Laboratory for Optimized Wind Energy. Situated between gentle knolls covered in sere vegetation, the four-acre parcel in Antelope Valley, California, was once destined to become a mall, but those plans fell through. The land was cheap. And, more importantly, it was windy.

Estimated at 250 trillion Watts, the amount of wind on Earth has the potential to provide more than 20 times our current global energy consumption. Yet, only four countries — Spain, Portugal, Ireland, and Denmark — generate more than 10 percent of their electricity this way. The United States, one of the largest, wealthiest, and windiest of countries, comes in at about 4 percent. There are reasons for that. Wind farm expansion brings with it huge engineering costs, unsightly countryside, loud noises, disruption to military radar, and death of wildlife. Recent estimates blamed turbines for killing 600,000 bats and up to 440,000 birds a year. On June 19, 2014, the American Bird Conservancy filed a lawsuit against the federal government asking it to curtail the impact of wind farms on the dwindling eagle populations. And while standalone horizontal-axis turbines harvest wind energy well, in a group they’re highly profligate. As their propeller-like blades spin, the turbines facing into the wind disrupt free-flowing air, creating a wake of slow-moving, infertile air behind them. [Continue reading…]

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