Water horses: a mother and baby hippo swim at a zoo in Mexico City. Photo: Getty
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Michael Brooks: Hippo fossils offer clues about swimming

Fossilised guides to what the earth was like millions of years ago are rare, and understanding water tracks can make a difference.

Swimming is unlikely to be something you think about in scientific terms. If you’re doing it at the beach, it’s meant to be fun. And if you’re at a pool, it’s relaxing, or part of an exercise routine. To many scientists, though, swimming is an aide to understanding our place in the world.

Three British scientists have just published their observations of hippopotamus swimming. And not by any old hippo – they were interested in the swimming style of a now-extinct species called Hippopotamus gorgops.

Their interest was piqued by some peculiar tracks in what was once a small lake in northern Kenya. The tracks suggest that 1.4 million years ago a hippo had pushed itself off from the edge, before half walking and half swimming across the lake. It would have been the first observation of fossilised swim tracks made by mammals, so the scientists went to watch modern hippos swimming in a shallow pool to see whether the tracks made sense. They did: the observed hippos paddled through a pool, leaving similar hoof marks on the bottom.

Fossilised guides to what the earth was like millions of years ago are rare. We have to take advantage of every available clue, and understanding water tracks can make a difference. Last year, fossilised tracks that had been associated with a dinosaur stampede were reinterpreted as a river crossing.

We are unlikely ever to find out exactly how land-based dinosaurs swam, but it’s a good bet they looked nothing like we do in the pool. Most four-limbed land creatures swim doggy-paddle. When researchers took chimps and orang-utans for a swim, however, they found breaststroke was the natural instinct for staying afloat. It is probably easier for creatures built with shoulders and hips which have evolved to reach for branches to move limbs parallel to the surface of the water.

Not that our fastest swimmers use breaststroke any more. The front crawl has been in human use for thousands of years, but our observations of the natural world have made it even more efficient. Watching the swimming events at the Commonwealth Games, you’ll see several tricks copied from more natural swimmers.

At the turn, for instance, the competitors will empty their lungs, making them less buoyant. Doing this enables them to use their energy to move forward rather than maintain depth, which is why marine mammals and birds exhale deeply before diving into water.

It is important to remain streamlined when under water, so the leg kick has to be kept to no more than one-third of the body’s length – which is how much the dolphin’s tail moves naturally. Competitors are allowed to swim no more than 15 metres of each length under water and they will make the most of this, as the water there offers one-fifth the resistance of the drag just beneath the surface, research shows.

Swimmers can gain an advantage by mimicking penguins’ and dolphins’ streamlined shape and smooth surface. Hence, swimsuits are engineered to hold the human body in an optimum shape and to allow water to move past with minimal resistance.

That said, you can’t mimic everything in nature. Studies of the clawed frog showed the importance of a long push-off from the end of the pool: its pelvis actually slides along its backbone to give extra length to its legs. But not even the Olympic champion Michael Phelps could manage that. 

Michael Brooks holds a PhD in quantum physics. He writes a weekly science column for the New Statesman, and his most recent book is At the Edge of Uncertainty: 11 Discoveries Taking Science by Surprise.

This article first appeared in the 23 July 2014 issue of the New Statesman, Summer Double 2014

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Man alive! Why the flaws of Inside No 9 only emphasise its brilliance

A man we’d thought destined for certain death reappeared, alive and kicking.​ ​Even as my brain raced, I was grinning.

At the risk of sounding like some awful, jargon-bound media studies lecturer – precisely the kind of person those I’m writing about might devote themselves to sending up – it seems to me that even the dissatisfactions of Inside No 9 (Tuesdays, 10pm) are, well, deeply satisfying. What I mean is that the occasional flaws in Steve Pemberton and Reece Shearsmith’s cultish series, those unlooked-for moments when nothing quite makes sense, only serve to emphasise its surpassing brilliance.

At the end of the final episode of series three, for instance, there came a discombobulating twist. A man we’d thought destined for certain death reappeared, alive and kicking. How had this happened? Were the preceding 28 minutes only a dream? Even as my brain raced, I was grinning. That line about Ron Mueck! In a piece that seemed mostly to be paying topsy-turvy homage to the camp 1973 horror flick Theatre of Blood.

Pemberton and Shearsmith are all about homage: a bit of Doctor Who here, a touch of Seventies B-movie there. Inside No 9’s format of twisty one-offs is a direct descendant of ITV’s Tales of the Unexpected. And yet it is so absolutely its own thing. Only they could have written it; only they could ever do this much (stretch your arms as wide as they’ll go) in so little time (half an hour).

In the episode Private View, guests were invited to the Nine Gallery in somewhere Hoxtonish. This motley crew, handpicked to represent several of the more unedifying aspects of 21st-century Britain, comprised Carrie (Morgana Robinson), a reality-TV star; Patricia (Felicity Kendal), a smutty novelist; Kenneth (Pemberton), a health and safety nut; and Maurice (Shearsmith), an art critic. Hard on their heels came Jean (Fiona Shaw), a wittering Irishwoman with gimlet eyes. However, given that they were about to be bloodily picked off one by one, at least one of them was not what she seemed. “I’m due at Edwina Currie’s perfume launch later,” Carrie yelped, as it dawned on her that the pages of Grazia might soon be devoting a sidebar to what Towie’s Mark Wright wore to her funeral.

Private View satirised a certain kind of contemporary art, all bashed up mannequins and blindingly obvious metaphors. Admittedly, this isn’t hard to do. But at least Pemberton and Shearsmith take for granted the sophistication of their audience. “A bit derivative of Ron Mueck,” said Maurice, gazing coolly at one of the installations. “But I like the idea of a blood mirror.” The duo’s determination to transform themselves from episode to episode – new accent, new hair, new crazy mannerisms – calls Dick Emery to mind. They’re better actors than he was, of course; they’re fantastic actors. But in the context of Inside No 9, even as they disappear, they stick out like sore thumbs, just as he used to. They’re the suns around which their impressive guest stars orbit. They may not always have the biggest parts, but they nearly always get the best lines. You need to watch them. For clues. For signs. For the beady, unsettling way they reflect the world back at you.

What astonishes about this series, as with the two before it, is its ability to manage dramatic shifts in tone. Plotting is one thing, and they do that as beautifully as Roald Dahl (the third episode, The Riddle of the Sphinx, which revolved around a crossword setter, was a masterclass in structure). But to move from funny to plangent and back again is some trick, given the limitations of time and the confined spaces in which they set the stories. In Diddle Diddle Dumpling, Shearsmith’s character found a size-nine shoe in the street and became obsessed with finding its owner, which was very droll. But the real engine of the piece, slowly revealed, was grief, not madness (“Diddle-diddle-dumpling, my son John”). You felt, in the end, bad for having sniggered at him.

If you missed it, proceed immediately to iPlayer, offering a thousand thanks for the usually lumbering and risk-averse BBC, which has commissioned a fourth series. One day people will write learned papers about these shows, at which point, jargon permitting, I might discover just how Maurice managed to live to fight another day.

Rachel Cooke trained as a reporter on The Sunday Times. She is now a writer at The Observer. In the 2006 British Press Awards, she was named Interviewer of the Year.

This article first appeared in the 23 March 2017 issue of the New Statesman, Trump's permanent revolution