Science: Update

MAKING BULLET-PROOF vests from spider's silk has come a step closer thanks to scientists at Nexia Biotechnologies, a Quebec-based company which has managed to transfer the gene for spider silk into the udders of goats. The company aims to extract the silk protein from goat's milk to make extra-strong "biosteel", which can be used in a wide range of applications where light-weight yet super-strong material is needed. Scientists have compared the ability of a spider's web to trap a fly in mid-flight to a steel mesh strong enough to stop a fighter aircraft flying faster than the speed of sound. Attempts to produce spider silk in genetically- engineered bacteria have not been successful because of differences in the way microbes make silk proteins compared to higher animals. Nexia Biotechnologies believes goats will be better at mimicking the way the silk proteins are made naturally.

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WHY DO bats hang upside down? One theory is that they evolved from a tree mammal, such as a lemur-like animal, which had already adapted to this inverted way of life.

Nancy Simons, of the American Natural History Museum in New York, suggested three years ago that bats probably evolved from one such tree dweller which had subsequently learnt how to glide and then how to fly from one tree to another - but there was no fossil evidence to support the theory.

However, Mark Hamrick, of Kent State University in Ohio, has found that a mouse-sized, flightless animal called Phenacolemur, which lived about the same time as the first bats, hung upside down from its rear legs. He believes that the animal and bats must have shared a common ancestor.

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SOME OF the most pristine mountains in the world are polluted with man- made chemicals, according to a study led by David Schindler of the University of Alberta, in Edmonton, Canada. The scientists report in Nature that snow from the mountains of western Canada had higher-than-expected levels of dangerous organochlorine compounds, which increase by up to 100-fold between the altitudes of 770 and 3,100 metres. They believe the pollutants are likely to become concentrated on high slopes because of cold condensation, when volatile substances vaporise in warm climates and condense once they reach somewhere cooler.

THE PATENT Office will turn down patent applications which relate to protecting the intellectual property rights of new types of land-mines, according to New Scientist. The move comes after the Landmines Act, which makes it an offense to assist, encourage or induce anyone to produce land- mines.

The Patent Office has interpreted this to mean that allowing people to file patents on land-mines would be assisting in their production. ``Britain's Chartered Institute of Patent Agents is now warning patent lawyers that they risk prosecution under the Landmines Act if they try to get round the British ban by dressing up land-mine invention as an innocent application," the magazine says.

Steve Connor