No more buttock-clenching exercises, girls. Why not try poop padding instead? Caroline Sarll reports
This summer the message is clear: forget aspiring to honed, toned gluts, or Kate Moss boiled-egg butt. For Madonna read Marilyn. For plum read grapefruit. It is suddenly OK to have a full, fleshy, feminine bottom. And if you are "pygally challenged" (little or no bum at all), help is on hand to cushion this anatomical blow.

Or at least that's what the style-setters would like us to believe. In the past year, the most extraordinary array of cheeky garments have wobbled down the catwalks, all designed to give the sadly sagging British bot a long overdue lift.

First there was Vivienne Westwood's bumbag, a cushion tied round the waist and resting on our natural rumps. Then came the ludicrous bumster jeans, cut low to show off "bum cleavage" (aka "builders' bum"). In recent months, we've seen the arrival of bum-pads, which Japanese women use to turn their rears into the proverbial "two boiled eggs in a handkerchief". In the spring came perhaps the cheekiest statement of all: jeans with built-in bottom support ("poop padding"); this autumn, the 13th Rear Of The Year competition will hail an unsuspecting celebrity as "Plum Bum" 1995.

The rump stakes, it would seem, have never been higher. Or bigger. Because on the whole, for women at least, these prosthetic posteriors are hailing the fuller bottom as the new shape.

This development is not before time. The Eighties and Nineties have been a sad time for the buttocks. The ubiquitous 501s heralded the death of the defined, grabbable bottom. Forget sex appeal: these jeans were about comfort and bulging bellies, a compromise for thirtysomethings whose waists had increased with their status. And as for that other Eighties uniform, leggings - a real bummer. Either the accompanying long T-shirts obscured the bottom, or the dreaded Visible Panty Line turned potential peaches into lumpy segments.

But is this return to the Bountiful Bum just another case of the wheel of fashion turning full circle? A retro-Victorian look, ie back to the bustle? No, this is about more than just fashion. We may be witnessing a subconscious hankering after our prehistoric origins. Stone Age women had massive buttocks which, it is said, sometimes stuck out at the back as much as six inches, a condition known as "steatopygia". Much later, the early Greeks revered the full bottom so much they even had a Goddess of the Buttocks, Aphrodite Kallipygos. These days the Italians are the unequivocal big-butt supporters. Forget buttock-clenching exercises or cellulite-attacking creams: Italian women are flocking to have silicone implants in their bottoms.

Worldwide, however, it is Africans who best know the value of the big bottom. Irene Banda-Beer, a Zambian who lectures at the Centre for Population Studies in Cardiff, says: "African men like their women to have very big, round bottoms, and women would never dream of trying to reduce them. The bottom is considered far more important than the breasts."

African tribeswomen still value their buttocks as a vital erotic tool. And indeed, if one wonders what the point of having buttocks is, it is worth remembering how we all got here. As anthropologist Ted Polhemus points out: "The buttocks are the main source of sexual attraction in primates, who copulate from the rear. When the female is aroused, her buttocks go bright red. As humans developed and sex became frontal, so females developed breasts as stimulators to replace the buttocks. Rear copulation can't have been easy for Stone Age men and women. Their huge buttocks must have got in the way."

Whether the designers are aware of the sexual statement they are making can only be guessed at. But many men will welcome this new Big Is Beautiful endorsement. For it is no secret that men everywhere have always appreciated a lavish rump.

And women? After being unable to ogle the 501s-clad male bottom for a decade, perhaps they will launch their own campaign for the more defined male rear. After all, as the fashion writer Colin McDowell says, they do care passionately about men's behinds: "Never mind whether a man has got a big penis or not. All a girl cares about is whether he's got a sexy bum."

One thing's for sure. Even if big bottoms make a comeback, the word that goes with them probably won't. Steatopygia hardly sounds sexy. And even less so when you know its origins. Translated from the Greek, it means, literally, "suet bum".