Humans

By Jake Buehler

The piles of faeces made by rock hyraxes hold clues to our own pastNatalia Kuzmina / Alamy
Fossilised piles of faeces, called middens, have revealed that a desert valley in Yemen was once a tropical oasis, which may have lasted in the dry region because of human land management practices.
Today, Wadi Sana is a dry, rocky desert. We knew that between 11,000 and 5000 years ago, the Arabian peninsula and Sahara desert were wetter than they are now, and some lake-bed deposits suggested that grasslands and trees may have grown elsewhere in the interior … More

Many of us aim for “recommended dailies” such as 10,000 steps, 2000 calories or 2 minutes of tooth brushing. But where do these figures come from and are they supported by evidence?

Humans

8 September 2021

By Amelia Tait

Shutterstock
FOR as long as I can remember, certain numbers have inhabited my head: Five fruit and veg a day, 8 hours of sleep, 2000 calories, 2 minutes of tooth brushing, eight glasses of water, 10,000 steps.
For want of a better term, these are the “recommended dailies”: numbers that are etched onto our brains as the ones we should live by. But for all their influence, it is unclear whether sticking dutifully to them actually makes a difference to our health. So I decided to get to the bottom of things, attempting to live my own life by the numbers (see “Living the dream”, page 41) while also digging into some critical questions about them: who came up with these figures in the first place? How solid is the scientific basis for these magic numbers? More to the point, is sticking to them really worth the effort?
Brush your teeth for 2 minutes, twice a day
Keeping your teeth clean isn’t just a way to avoid the dentist’s drill (and bill) – the bacteria that cause gum disease have also been linked to an increased risk of developing Alzheimer’s. People with gum disease also have a two to three times greater risk of having a stroke or heart attack, and while a causal link hasn’t been shown, there are suggestions that gum disease increases markers of inflammation in the blood.
The benefit of brushing is that as it removes thin films of plaque bacteria from the teeth, it breaks up bacterial communities, disrupting the opportunity for social evolution. This essentially stops them evolving into super bacteria that are experts at … More

By Tiffany O’Callaghan

A herd of wild Asian elephants strolls through a village in ChinaVCG via Getty Images
Book
Fuzz: When nature breaks the law Mary Roach
WW NortonAdvertisement

MARY ROACH has a knack for choosing subjects for her books that won’t have necessarily crossed your mind and convincing you that you must now know everything about them. She has covered the logistics of strapping cadavers into cars to use as human crash test dummies (Stiff), how studying what orgasms look like in the brain requires people to get busy in an MRI scanner (Bonk), pondered the literal ins and outs of what competitive eating does to your digestive tract (Gulp) and contemplated how astronauts poop in space (Packing for Mars, a rare deviation from her single word titles).
In her new book, Fuzz: When nature breaks the law, her subject is the unfortunately now familiar issue of human-wildlife conflict. But she hasn’t decided to switch gears and approach her subjects from a place of earnest lamentation, in this case about the perils of our encroachment on wild habitats. Instead, with her characteristic dry wit, she brings an intense fascination to the seldom discussed details and the at times absurd miscellany in the unexplored corners of unappreciated research.
The opening chapter finds her at a wildlife forensics conference, where she learns about what happens after a human is mauled by a wild animal. The focus of the Wildlife-Human Attack Response Training conference is mainly bears in the Pacific Northwest. We learn that very often the culprit is identified and killed, but occasionally the backwoods whodunnit turns up a surprise: a “gnawed on corpse” is no smoking gun. An opportunistic omnivore does occasionally stumble on a human already dead from other causes.
Each chapter explores a new type of conflict, from elephants that stomp their way across crops (and people) to albatrosses that get sucked into jet engines, leopards that attack people to deer that collide with aircraft (yes, you read that right).
Along the way you pick up plenty of helpful tips. The best makes of car if you plan to survive crashing into a moose? Saab or Volvo. The most cost-efficient way to keep birds from eating your harvest on a small farm? Humans regularly chasing them off.
As to whether you should stay still or fight back in a hostile bear encounter, it largely depends on what kind of bear it is, “black fight back, brown lie down” as the ditty goes. The trouble is, as Roach points out, some brown bears’ fur can be black, and some black bears look pretty brown.
“It’s impossible not to smirk, chortle and sometimes outright belly laugh as you read the many wry asides”
“A more reliable way to distinguish the two is by the length and curvature of their claws,” she says, before conceding that, “by the time you’re in a position to make that call, the knowledge will be of limited practical use.”
It is impossible not to smirk, chortle and sometimes outright belly laugh as you read her many wry asides and funny but fascinating footnotes.
A particular favourite for me has to do with the surprisingly persistent myth that birds will explode if they eat the rice tossed at weddings: “Some churches ban the practice anyway, not because it’s perilous for birds but because it’s perilous for guests, who could slip on the hard, round grains and fall and then fly off to a personal injury lawyer.”
She provides an ample supply of factoids to regale your friends with. Did you know that it is our “looming sensitivity” that helps us and other animals anticipate how fast something is coming at us, so we can get out of the way? (Or not, see the earlier mention of deer and aircraft.)
But the real trick Roach pulls off is to keep you laughing while at the same time making sure the earnest points come across. Among the many that stuck with me is that before the 1980s, wildlife and wilderness were conserved in the US to provide good hunting and fishing. It is only recently that “conservation” has been about protecting these areas and creatures for their own sake.

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Josie Ford
Branson pickle
The world was agog in July as two grown men squared off about who would be the first to reach space on their own rocket. Amazon founder Jeff Bezos looked set to win when he announced his Blue Origin take-off for 20 July – only to see Virgin Galactic founder Richard Branson pip him to the post with an 11 July flight.
That wasn’t the end of the cockpit fighting, though. As the Virgin Galactic trip wouldn’t be quite high enough to meet the international definition of space flight, Blue Origin cast aspersions on the size of Branson’s, ahem, trajectory.
Feedback had to watch coverage of the missions through our fingers, because space flight isn’t the kind of endeavour that should be rushed. It wasn’t just safety on our mind, but also what Branson might do in front of cameras. He has been known to demonstrate his manliness by picking up the nearest woman and brandishing her aloft like a human trophy, as documented on a blog called “Richard Branson picking up women”. We were glad to see he didn’t attempt this stunt with his two female fellow crew members.Advertisement
Hardly rocket science
Thankfully, both missions were successful, but it has emerged that Branson’s flight didn’t go entirely smoothly. During the ascent, first a yellow warning light came on, to signal that the rocket-plane was going off-course, then a red one, indicating a need to take corrective action or to abort the mission, it has been reported.
While a company spokesperson said the flight was never in danger, anonymous company sources told The New Yorker that the safest response would have been to abort. And a Virgin Galactic pilot has previously said such a red light should “scare the crap out of you”.
In the meantime, the US Federal Aviation Administration has grounded the company’s space flights until the incident has been investigated. The reduction in emissions from keeping the rocket-planes in their hangars is something the planet can be grateful for, if not Branson.
Just a minute
Talking of living dangerously, a colleague sent us a press release from a new flavoured water brand using “retronasal technology” – translation: it smells nice – which claims that every soft drink we consume cuts our lifespan by 12.5 minutes. Can this be true?
Feedback is sceptical. Putting aside the fact that different studies regularly assert that the worst dietary sin is, by turns, sugar, fat, starch, meat or, indeed, any major food group depending on what day of the week it is, the press release has an implausible level of precision over our allotted time on Earth. It seems unlikely that a 20-year-old innocently quaffing a can of cola today is condemning themselves to die, not 60 years hence, but instead in 59 years, 11 months, 29 days, 23 hours and 47.5 minutes. Still, we have come to expect such unscientific pronouncements from press releases.
An apple pie a day…
Except… what’s this? A paper in respectable, peer-reviewed journal Nature Food, which calculates the same implausibly precise lifespan metric for food items ranging from chicken wings to macaroni cheese. A hot dog, for instance, takes 36 minutes off your life, while apple pie lengthens it by 1.3 minutes.
Sadly, when one of the authors announced their findings on Twitter, the reception was… impertinent. One respondent said that they had eaten so many hot dogs that they should have died 56 years ago, while others used unkind terms such as “pseudoscience”, “garbage” and other words that shouldn’t be repeated in a family publication.
Taking the results at face value, though, a quick calculation suggests that if you must have a hot dog, just follow it with 27.7 apple pies and there will be no net change. Incidentally, the most life-lengthening food, according to this study, is peanut butter and jam sandwiches, each one making you live half an hour longer. Eat nothing but these and you would presumably live forever – or perhaps it would only feel like that.
Horsing around
One item not in that paper’s catalogue of life-extending substances is ivermectin, the horse dewormer that is a covid-19 wonder drug, according to conspiracy theorists. Judging by their communications on social media, it seems to be the same people who don’t trust coronavirus vaccines – tested in tens of thousands in carefully monitored randomised trials – who are placing their faith in a drug that is untested and unlicensed for covid-19.
While ivermectin is used in people to treat parasitic worms and head lice, most doctors won’t prescribe it for covid-19, so conspiracy theorists are resorting to buying the veterinary version of the drug. This comes in a more concentrated form, though, so is sadly leading to overdoses, causing vomiting, diarrhoea and seizures.
Veterinary stores are now quizzing prospective ivermectin buyers on their horse breed and insisting on production of a horse selfie. The US Food and Drug Administration has a diplomatically written advice sheet on why it is inadvisable for people to take animal medicines, but whoever runs their Twitter account was more succinct, saying simply: “You are not a horse. You are not a cow. Seriously, y’all. Stop it.” Words to live by – literally.
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By Bethan Ackerley

A complex network called the Gleaming watches over the town of Ora via a huge inverted treeShutterstock/Tithi Luadthong
Book
In the Watchful CityAdvertisement
S. Qiouyi Lu Tordotcom

MODERN life is built around the accumulation of objects: some valuable, some not, and most entirely unnecessary. But which, if any, of your possessions could represent the core of who you are? In S. Qiouyi Lu’s debut novella, each item in a mismatched collection of curios is a window into a defining moment of another person’s life.
In the Watchful City is set in Ora, an isolated metropolis at the heart of a cloud forest. Ora’s society is vibrant, comprising people of many cultures, genders and even mythical species, but its citizens are monitored via the Gleaming, a complex network that integrates qì – the vital force of all living things – with vast amounts of data. The Gleaming is channelled through the Hub, an enormous, inverted tree that acts as a database for the all-encompassing surveillance state.
Yet neither Ora’s governance nor the lives of its citizens is the focus of In the Watchful City. It instead follows the inner turmoil of Anima, a “node” who is rooted to the Hub’s inner sanctum, who can manipulate the Gleaming by slipping into a Minority Report-style amniotic bath. It is Anima’s job to watch over the city, be that by scouring for evidence of financial crimes or by borrowing the bodies of animals to chase down fugitives.
Anima – who uses the non-binary neopronouns ae/aer – has always lived in Ora and has been both unable and unwilling to physically leave the Hub since ae became a node as a child. All that changes when a mysterious stranger called Vessel arrives at the Hub with a qíjìtáng, a cabinet of curiosities from far-flung places; the items range from rarities like a bone marionette and a mermaid’s scale to a simple bundle of letters.
In the Watchful City is a mosaic novella: for every object in the qíjìtáng that Anima observes, we get a glimpse of another story from the lands outside Ora. Some of these tales feel relatively disconnected from the main narrative, like A Death Made Manifold, in which a man goes to extraordinary lengths to resurrect his late brother. Others may help explain why Ora’s society is so isolated. This Form I Hold Now, for instance, reveals more about the cultural imperialism of the Skylanders, a federation in the clouds that has colonised many nations on the planet’s surface.
Though the novella takes a little time to show its full potential – the opening pages bombard you with details about Anima and Ora, while the first of the qíjìtáng’s tales is the weakest – Lu has crafted an impressive mythos that draws from the traditions and legends of a variety of cultures, especially Chinese folklore. Take The Sky and Everything Under, a bittersweet tale that describes an imperial duarchy based on Chinese myths of one-winged birds, dependent on each other for flight. But these lofty allusions are leavened by rich, joyful descriptions of everyday life; a lengthy depiction of an outdoor food market viewed through the eyes of a hungry dog is a particular highlight.
It comes as little surprise, then, that Anima grows more and more intrigued by life outside the confines of Ora. Readers expecting a thorough analysis of the city’s surveillance culture will be disappointed; Lu is more concerned with the psychological effects of Anima’s isolation than the system that necessitates aer physical confinement.
Such details could have been fleshed out in a longer narrative, and more than once I found myself wishing that certain events, like Anima witnessing the death of a stranger, had been given more room to breathe. But I suspect that, much like the effect the tales of the qíjìtáng have on Anima, In the Watchful City will linger all the more for being an incomplete picture.

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Read
The Dinosaurs: New Visions of a Lost World are conjured by palaeontologist Michael Benton and palaeoartist Bob Nicholls, showing how advances in technology have changed the way we see these beasts forever.
Nick Treharne/Alamy Stock Photo
Visit
How The Light Gets In festival brings deep thought to the grounds of Kenwood House in London on 18 and 19 September. Explore the temptations of rewilding, the seductiveness of memes and other hot topics. Also streamed online.Advertisement

Watch
Autism and Cinema, at London’s Barbican Centre from 16 September, hosts a series of films, including Temple Grandin (pictured), a biopic about the animal behaviour researcher and activist of the same name.

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By Simon Ings

In A New World Order, military robots have turned on humanityReel 2 Reel Films
Film
A New World Order
Daniel RaboldtAdvertisement

“FOR to him that is joined to all the living there is hope,” runs the verse from Ecclesiastes, “for a living dog is better than a dead lion.” Stefan Ebel plays Thomasz, the “living dog” in A New World Order. He is a deserter who, out of necessity, has learned to look out solely for himself.
In the near future, military robots have turned against their makers. The war seems almost over. Perhaps Thomasz has wriggled and dodged his way to the least settled part of the planet (Daniel Raboldt’s debut feature is handsomely shot in Arctic Finland by co-writer Thorsten Franzen). Equally likely is that this is what the whole planet looks like now: trees sweeping in to fill the spaces left by an exterminated humanity.
You might expect the script to make this point clear, but there is no script, or rather, there is no dialogue. The machines (wasp-like drones, elephantine tripods and one magnificent airborne battleship that wouldn’t look out of place in a Marvel movie) target people by listening out for their voices. Consequently, not a word can be exchanged between Thomasz and his captor Lilja, played by Siri Nase.
Lilja takes Thomasz prisoner because she needs his brute strength. A day’s walk away from the questionable safety of her log cabin, there is a burned-out military convoy. Amid the wreckage and bodies, there is a heavy case – and in the case is a tactical nuke. Lilja needs Thomasz’s help in dragging it to where she can detonate it, perhaps bringing down the machines. While Thomasz acts out of fear, Lilja is acting out of despair. Both are reduced to using each other. Both will have to learn to trust again.
“The film’s sound design is striking, even a car’s gear change comes across as an imminent alien threat”
In 2018, John Krasinski’s A Quiet Place arrived in cinemas – in which aliens chase down every sound and slaughter its maker. This can’t have been a happy day for the devoted and mostly unpaid German enthusiasts working on A New World Order. But such “silent” movies are no novelty, and theirs has clearly ploughed its own furrow. The film’s sound design, by Sebastian Tarcan, is especially striking, balancing levels so that even a car’s gear change comes across as an imminent alien threat.
Writing a good silent film is something of a lost art. It is much easier for writers to explain their story through dialogue than to propel it through action. Maybe this is why silent film, done well, is such a powerful experience. There is a scene in this movie where Thomasz realises not only that he has to do the courageous thing, but that he is at last capable of doing it. Ebel, on his own on a scree-strewn Finnish hillside, plays the moment to perfection.
Somewhere on this independent film’s long road to distribution – it began life on crowdfunding platform Kickstarter in 2016 – someone decided “A Living Dog” was too obscure a film title for these godless times. It is a pity, I think, and not just because A New World Order, the title picked for UK distribution, manages to be at once pompous and meaningless.
Ebel’s pitch-perfect performance drips guilt and bad conscience. In order to stay alive, he has learned to crawl about the earth. But Lilja’s example, and his own conscience, will turn dog to lion at last, and in a genre that never tires of presenting us with hyper-capable heroes, it is refreshing, on this occasion, to follow the forging of one courageous act.
Simon also recommends…
Film
The Last Battle (1983)
Another debut with no dialogue, this time by Luc Besson. This mysterious, post-apocalyptic adventure, filmed in derelict corners of Paris, conjures up a future in which humanity has lost its powers of speech.
Book
Hope Island
Tim Major
Titan Books
This horror-sci-fi hybrid unpicks the sonic mysteries of a small island in the Gulf of Maine. It is a spine-tingling tale of screams and susurration and all manner of sinister audio wizardry.

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By Clare Wilson

SJ Images/Alamy
OF ALL my garden tools, the one I have used most must be my trusty spade, a lovely small and light one with a comfortable wooden handle. But recently, it has been getting less action because I have been stepping up on the “no-dig” approach to gardening.
All gardeners need to dig sometimes, of course, such as when making holes to put plants in or rooting out weeds. Traditional advice is that we should also turn over all the soil every autumn, to aerate it, improve drainage and mix in soil improvers like manure.
For the past few years, though, … More