Humans

Plaque fossilises while we are still alive. Now, dental calculus is giving up the secrets of our ancient ancestors, from what they ate to how they interacted and evolved

Humans

15 September 2021

By Graham Lawton

Spencer Wilson
IT IS the only part of your body that fossilises while you’re still alive,” says Tina Warinner at the Max Planck Institute for the Science of Human History in Jena, Germany.
To see what she is describing, stand in front of a mirror and examine the rear surfaces of your lower front teeth. Depending on your dental hygiene, you will probably see a thin, yellowish-brown line where the enamel meets the gum. This is plaque, a living layer of microbes that grows on the surface of teeth – or, more accurately, on the surface of older layers of plaque. If … More

By Simon Ings

An argument abouthow to read has been raging for millenniaSTR/AFP via Getty Images
Index
A History of the Dennis Duncan
Allen LaneAdvertisement

EVERY once in a while a book comes along to remind us that the idea of the internet isn’t new. Authors like Siegfried Zielinski and Jussi Parikka have written handsomely about their adventures in “media archaeology”, revealing the arcane delights of the 18th-century electrical tele-writing machine of Joseph Mazzolari or Melvil Dewey’s decimal system of book classification of 1873.
It is a charming business, to discover the past in this way, but it does have its risks. It is all too easy to fall into complacency, congratulating the thinkers of past ages for having caught a whiff, a trace, a spark of what was to come.
So it is always welcome when an academic writer – in this case Dennis Duncan, a lecturer in English at University College London – takes the time and trouble to tell this story straight, beginning at the beginning and ending at the end.
Index, A History of the is his story of textual search, told through portrayals of some of the most sophisticated minds of their era, from monks and scholars shivering among the cloisters of 13th-century Europe to server-farm administrators sweltering behind the glass walls of Silicon Valley.
It is about the unspoken and always collegiate rivalry between two kinds of search: the subject index – which is a humanistic exercise, largely un-automatable, that requires close reading, independent knowledge, imagination and even wit – and the concordance, an eminently automatable listing of words in a text and their locations.
Hugh of Saint-Cher is the father of the concordance: his list of every word in the Bible and its location, begun in 1230, was a miracle of miniaturisation, smaller than a modern paperback. It and its successors were useful, too, for clerics who knew their Bible almost by heart.
But the subject index is a superior guide when the content is unfamiliar to the reader. It is Robert Grosseteste, born in Suffolk in around 1175, who we should thank for turning the medieval distinctio – an associative list of concepts, handy for sermon-builders – into something like a modern back-of-book index.
Reaching the present day, we find that with the arrival of digital search, the concordance is once again ascendant (the search function, Ctrl-F, whatever you want to call it, is an automated concordance), while the subject index and its poorly recompensed makers are struggling to keep up in an age of reflowable screen text.
Running under this story is a deeper debate, between those who want to access their information quickly, and those (especially authors) who want people to read books from beginning to end.
This argument about how to read has been raging for millennia, and with good reason. There is clear sense in Socrates’s argument against reading itself, as recorded in Plato’s Phaedrus in 370 BCE: “You have invented an elixir not of memory, but of reminding,” his mythical King Thamus complains.
Plato knew a thing or two about the psychology of reading, too: people who just look up what they need “are for the most part ignorant”, says Thamus, “and hard to get along with, since they are not wise, but only appear wise”.
Anyone who spends too many hours a day on social media will recognise that portrait – if they haven’t already come to resemble it.
Duncan’s arbitration of this argument is a wry one. Scholarship, rather than being timeless and immutable, “is shifting and contingent”, he says, and the questions we ask of our texts “have a lot to do with the tools at our disposal”.

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By Davide Abbatescianni

Karmalink is set in a near-future version of Phnom Penh, CambodiaRobert Leitzell
Film
Karmalink
Jake WachtelAdvertisement
THAT Jake Wachtel’s Karmalink is the opening title of Venice International Film Critics’ Week is a good sign of promise. It is an enigmatic sci-fi drama that will leave you with many things to ponder.
The story follows a 13-year-old boy, Leng Heng (the late Leng Heng Prak), who claims to see glimpses of his past lives through his dreams. He and his family live in a poor district of a near-future version of Phnom Penh, the capital of Cambodia, and his community is set to relocate 15 kilometres away to make space for a new railway connection to Beijing.
Leng Heng convinces his friends that finding a golden Buddha that he has seen in his dreams may save their homes, and they seek out help from a street-smart girl, Srey Leak (Srey Leak Chitth).
Through accurate production design and well-crafted special effects, the world depicted by Karmalink is populated by drones, gigantic QR codes, simultaneous translation devices and the widespread use of virtual reality. It is a place where the rich can avail of advanced nanotechnology and the poor still live in slums, surrounded by dirt and waste.
To record Leng Heng’s dreams and discover the secrets of his past lives, Srey Leak steals Leng Heng’s sister’s AUGR (short for “augmented reality”), a sort of forehead microchip that works through the injection of special “nanobugs”. During his oneiric explorations, Leng Heng meets Vattanak Sovann (Sahajak Boonthanakit), a neuroscientist and the inventor of the Connectome, a mysterious device containing “a digital replica of one’s consciousness” that can open “a path to enlightenment” through neural connections with the user’s past lives.
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Despite the many interesting parts of this engaging premise, cracks start to appear towards the end of the first half. The search for the golden Buddha, which is mostly carried out by the two young lead characters, sees them having little trouble in accessing information and breaking into abandoned or inhabited places.
They travel in and around the city and meet many adults on their way, none of whom ever questions their actions or asks why the children are buying nanotech. They even manage to sneak into Vattanak and his assistant Sofia (Cindy Sirinya Bishop)’s lab, which it isn’t properly guarded and so is easily accessed by two teens. The whole search is generally too smooth, with few obstacles to overcome. One hint comes after the other until the ending.
“The world of Karmalink is populated by drones, gigantic QR codes and simultaneous translation devices”
The cinematography in the film really is stunning, and the grim score backs this up. The two young leads – who speak Khmer throughout – are particularly impressive actors. By comparison, the English-language cast – Boonthanakit and Bishop – deliver rather flat performances, sounding a bit too cold-hearted in some of the most tense scenes.
Altogether, Karmalink had the potential to be a gem. Yet the narrative’s weaknesses overshadow much of the second half, leaving it as more of a rock in need of a good polish. The idea of intertwining Buddhist reincarnation and nanotech is certainly original and the striking contrast between a hyper-technological world and some of the poorest people in society is interesting to watch, but these strengths aren’t enough to make Karmalink as compelling as it should be.

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By Bobby Duffy

Roberto Cigna
TOO often discussion of generations descends into stereotypes and manufactured conflicts – avocado-obsessed, narcissistic millennials against selfish, wasteful baby boomers. Instead of serious analysis, we get apocryphal predictions about millennials “killing” everything from wine corks to the napkin industry.
Such discourse wouldn’t be so worrisome if it didn’t sully genuine research into generational differences, a powerful tool to understand and anticipate societal shifts. They can provide unique and often surprising insights into how societies and individuals develop and change.
That is because generational changes are like tides: powerful, slow-moving and relatively predictable. Once a generation is set on a course, it tends to continue, which helps us see likely futures. That is true even through severe shocks like war or pandemic, which tend to accentuate and accelerate trends. Existing vulnerabilities are ruthlessly exposed, and we are pushed further and faster down paths we were already on.
We tend to settle into our value systems and behaviours during late childhood and early adulthood, so generation-shaping events have a stronger impact on people who experience them while coming of age. This is why it is vitally important to heed the lessons we learn by looking at previous generations so we can understand what the covid-19 pandemic will mean for those growing up through it, and use those insights to help Generation Covid meet the unprecedented challenges ahead.
Some approaches that define swathes of the population purely on when people were born are closer to astrology than serious analysis. The type of generational analysis I use in my new book, Generations: Does when you’re born shape who you are?, however, is built … More

By Bobby Duffy

FILIPPO MONTEFORTE/AFP via Getty Images
The idea that younger generations care the most about the climate while older people downplay the issue and refuse to take action is a widespread myth, according to new research.
To better understand differences between generations, including how they perceive one another and the biggest challenges of the day, my team at the Policy Institute at King’s College London and New Scientist commissioned a survey of more than 4000 people aged 18 and over in the US and UK. Responses were collected from 2 to 9 August.
Previous research has made clear that one of the most pervasive and destructive generational myths is that older cohorts don’t care about the environment or social purpose more generally. The new survey shows how dangerously caricatured this is.Advertisement

In the UK, over three-quarters of baby boomers – who are defined as those currently aged 56-76 –  agree that climate change, biodiversity loss and other environmental issues are big enough problems that they justify significant changes to people’s lifestyles. This was as high as any other generation (see chart). Seven in 10 of this group say they are willing to make changes to their own lifestyle, completely in line with younger generations.
Older generations are also less fatalistic than the young: only one in five baby boomers say there is no point in changing their behaviour to tackle climate change because it won’t make any difference, compared with a third of Generation Z – those aged 18-25. This is an important driver of how we act: a sense that all is already lost leads to inertia.
But our study shows that people have a rather different impression of who thinks what: when we ask people which age group is most likely to say there is no point in changing their behaviour, the oldest group is the most likely to be picked out. We wrongly think they have given up. Social psychologists call this misconception “pluralistic ignorance”. It is an important effect, because it shapes our views of others.

Older people’s concern isn’t just expressed with words, but reflected in their actions. We know from other studies that it is actually baby boomers and Generation X who are the most likely to have boycotted products. But our new study shows that also isn’t the perception. The majority of the public wrongly think it is Generation Z or millennials who are most likely to boycott products, and only 8 per cent pick out baby boomers and just 9 per cent choose Gen X.
No contest
It is no surprise that the public have the wrong impression. Endless articles and analyses paint the picture of a clean generational break in environmental concern and action, with a new cohort of young people coming through who will drive change, if only older people would stop blocking them. Time magazine, for example, called Greta Thunberg “an avatar in a generational battle” when it made her its Person of the Year in 2019.

This isn’t just wrong, but dangerous, as it dismisses the real concern among large proportions of our economically powerful and growing older population.
The aftermath of the pandemic means it is set to become harder, not easier, to think about the long term, as short-term needs become more pressing: we will need all the support we can get, and creating or exaggerating generational division won’t help.
Sign up for Countdown to COP26, our free newsletter covering this crucial year for climate policy

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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

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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