IT started out 50 years ago as an alternative to buttons and zips on outdoor clothing. Today Velcro is used everywhere a good grip is needed. The material is ubiquitous. Where cars once had rivets and bolts, they now have Velcro. A short strip of the stuff held together the ventricles of the first artificial heart. It even has a place in space, where shuttle astronauts keep their ship tidy by anchoring bits of gear to patches on the wall. Yet by a strange twist that its inventor could never have foreseen, Australian botanists have discovered that Velcro's very effectiveness is posing a threat to the planet's most pristine places.

How so? Jennie Whinam, a botanist with Australia's Department of Primary Industries in Tasmania, and colleagues from the Australian Antarctic Division decided to check what sort of alien organisms might be hitching a ride on the division's expeditions to remote ...