On a spring evening along the banks of the River Thames, thousands of mayflies can be seen engaging in what may be one of the world’s oldest dances. In the fading light, the males make a steep vertical climb, flip over and float back to Earth – wings and tail outstretched in a skydiving posture so as to drop slowly through the sky.

Mayflies are among the world’s oldest winged insects, emerging roughly 300m years ago – long before dinosaurs walked the Earth. Even the Mesopotamian poem the Epic of Gilgamesh, one of the oldest pieces of literature, makes reference to the short-lived mayfly. Over the epochs, the insect’s basic design has changed very little compared with the fossils of their ancestors.

“They have retained these odd characteristics and we can probably assume that they’ve been doing this [dance] for hundreds of millions of years, and yet we don’t really know why,” says Samuel Fabian, a research fellow at the University of Oxford who studies the aerial behaviours of insects.

Now, Fabian and his colleagues at Imperial College London think they finally have an answer. In new research published in the Journal of Experimental Biology, the scientists reconstructed the flight behaviour of the common mayfly, filming large swarms in the London borough of Richmond in 3D and analysing the insects’ flight paths.

In further simulations, the scientists found that male mayflies would stop their pursuit of any target that dropped beneath the horizon

“The problem is that the males have almost no filter,” Fabian says. “You can give them a beach ball – which, as far as I’m concerned, looks quite different from a female mayfly – and males will go right up to that much larger object and try to mate with it.”

Things get even trickier in low-light conditions, as females look almost identical to males even at close range. By staying below the females, males ensure their romantic energy is well spent. This is especially critical because mayflies do not have much time, only living from a few hours to a few days, during which they must pass on their genes.

Acing such reproductive goals is crucial to the species’ long-term survival. There are more than 3,000 mayfly species living in the world’s freshwater creeks, rivers, ponds and lakes. But many of Britain’s 51 species are now in a state of decline – another victim of what scientists call the “insect apocalypse”.

A 2019 global review estimated that 40% of the world’s insects were declining, while another study suggests more than 1 in 10 species could be lost by the end of the century.

From 2015 to 2021, the nonprofit conservation group WildFish carried out a riverfly census of Britain’s chalk streams. These streams are some of the cleanest waterways, fed by cool springs that flow from aquifers through chalk, a form of limestone. The species that live here are often very sensitive to pollution.

The census found that Britain’s chalk streams had lost 41% of their mayfly species on average compared with 1998. “In many lowland catchments, the spectacular hatches that once defined early summer have diminished dramatically, reflecting decades of mounting pressure on freshwater ecosystems,” says Janina Gray, head of science and policy at WildFish. “Pollution, sediment runoff, reduced river flows and rising water temperatures are all eroding the conditions these insects depend on.”

Other research suggests that even modest pollution in many English rivers may be enough to kill up to 80% of mayfly eggs, laid in riverbeds.

For now, Fabian encourages Britons to relish the ancient spectacle while they still can.

“This behaviour is something that pretty much everyone, at certain times of the year, should be able to see,” he says.

“These are quite urban places with lots of traffic, but they’re still hanging on and they’re still doing this dance that they have probably been doing since before Britain was separated from mainland Europe.”

The Guardian

It’s an increasingly popular idea: “boosting” testosterone with diet tweaks – increasing foods rich in zinc and magnesium – hoping to build muscle faster. But the reality is more nuanced.

Testosterone is an androgen hormone that plays a key role in development, particularly in boys during puberty. Its effect on muscle isn’t simply about how much of it you have, but how your body responds to it.

“There are two key factors,” says Prof Leigh Breen, a muscle physiology specialist from the University of Leicester. “The amount of testosterone in your system, and the number of androgen receptors in your muscles.” These act like docking sites, allowing the hormone to exert its effects on muscle mass. The number you have is largely determined by genetics, but how well they work can be influenced by lifestyle factors such as exercise.

For most people, natural variations in testosterone don’t make much difference to muscle mass. “For most of our adult life, natural fluctuations, or changes we see with exercise and diet, are subtle,” Breen says.

Testosterone does have a clear impact at the extremes. The most obvious example is anabolic steroid use. These drugs flood the body with testosterone at levels far beyond what would occur naturally. “The effect on muscle mass is significant,” says Breen. “People have been reported to gain muscle even without training.”

At the other end of the spectrum are medical conditions that drastically reduce testosterone, such as hypogonadism in older men. Severely low levels are associated with muscle loss and weakness, which is why some people are prescribed testosterone replacement therapy (TRT).

But, for most of us, testosterone operates within a relatively narrow range. Building muscle still comes down to the fundamentals: consistent training, adequate nutrition and time.

The Guardian

In the world of magazines, when someone announces they’re leaving a job, their colleagues will traditionally present them with their own personalised mock-up of the magazine’s front cover. Perhaps their face is superimposed on the body of a previous celebrity cover star. There are probably some witty cover lines referencing memorable office moments or their favourite snacks. It’s a rite of passage – and this week, Anna Wintour was bestowed with her very own cover. But instead of a jokey imitation bidding her adieu, it was the real, glossy deal, coming to a newsstand near you on 28 April.

In a somewhat surprising effort to promote the forthcoming The Devil Wears Prada 2, Vogue’s May issue sees Wintour share the cover with Meryl Streep, whose steely Miranda Priestly, editor-in-chief of the fictional title Runway, is said to have been inspired by Wintour. “Seeing Double. When Miranda met Anna” reads the cover line. While Wintour has fronted various industry titles, including Interview in 1993 and Ad Week in 2017, it’s the first time an editor has placed themselves as the subject. In another fun twist, both Wintour and Streep are wearing Prada.

First teased via Vogue’s Instagram on Tuesday, within seconds the image had gone viral, amassing, at the time of writing, more than 1.2m likes. “Maaj” commented the model Gigi Hadid. “Just so good” added the actor Mindy Kaling, while the 10k-plus other comments from the general public span everything from “Actually groundbreaking”, in reference to Priestly’s immortal florals line from the original film, to “Getting this framed”.

Rather than just plugging the highly anticipated sequel, though, Wintour’s newsstand appearance serves as something more significant (of course it does, this is Wintour we’re talking about): it’s her own personal power move, and a klaxon for the next phase of Anna Wintour. The cover comes just 10 months after she announced she was “stepping back” as editor-in-chief of Vogue and six months after she promoted Chloe Malle to head of editorial content. What better way to affirm that she is still very much in control of the magazine she has helmed for close to four decades than by appearing on its cover?

When Wintour first revealed she was relinquishing her editor-in-chief title, many misconstrued it as a step down. Her cover appearance now hammers home that it was no such thing. Her current role as chief content officer for Condé Nast and global editorial director for the magazine allows her to retain the ultimate authority while leaving the day-to-day running to Malle.

Mark Borkowski, a press consultant and author, describes Wintour’s appearance on the cover as “a hell of a smart move”. “This is very much about Wintour not letting go of her power,” he says. “A lot of people in these types of jobs recognise they are sitting in a chair that has power. Wintour doesn’t believe that. She believes she is the power. She’s not a personality that’s going to fade away into the background.”

Even the ideation of the cover hints at the authority Wintour still wields. Writing in her editor’s letter, Malle outlines how it came about. She was in the backseat of Wintour’s personal town car (a nice power play by Wintour, and reminiscent of the first film) running ideas for the next batch of covers past her (a tacit hint that all the big decisions still need to be approved by Wintour) when Malle first suggested the idea. Wintour initially shot it down, saying: “That’s very flattering, Chloe, but it’s not really my style.” It then, so the story goes, fell to Streep to persuade her. Wintour called the Hollywood star directly (another not-so-subtle power move).

Wintour was dismissive of the first film when it came out in 2006. Although she did attend the premiere – wearing Prada, no less – she was cagey about her reaction. In 2024, at the opening of the musical version in London, she told the BBC that it was “for the audience and for the people I work with to decide if there are any similarities between me and Miranda Priestly”.

However, more recently she has seemed happier to engage, suggesting that Priestly is very much “a caricature” and a highly enjoyable and very fun one at that. The various social media videos that accompany the shoot drive this idea home. Streep stays in character, while Wintour plays herself. We see her fumble her lines and get the giggles. She is warm and witty, a sharp contrast to the icy Priestly.

We first saw her toy with the idea at the Oscars in March, where she jokingly referred to Anne Hathaway as “Emily”, a nod to Emily Blunt’s character in the film. Meanwhile, the next read in the Vogue Book Club is the novel by Lauren Weisberger that inspired the film. Borkowski suggests these stunts hint that Wintour is beginning to separate herself from brand Vogue. “Her life has been defined by Vogue,” he says. “Back in the day she was recognisable by a very distinctive haircut and a pair of dark glasses. She was a cypher. But now it’s all about the narrative of the personal brand.” She is, he says, “getting involved in the film because she sees it as something that can establish Anna Wintour, the brand”.

The Guardian