Science: Update

WOMEN RESPOND to pornographic films in a similar way to men, according to a study that casts doubt on the commonly held view that sexual arousal in males and females depends on different physical signals. Astrid Jutte, at the Ludwig Boltzmann Institute for Urban Ethology in Vienna, asked 10 men and 10 women to watch a 15-minute pornographic film and found there was a significant increase in testosterone levels in both males and females. The average increase for men was 100 per cent and for women 80 per cent, reports New Scientist magazine. Other studies have shown that the more testosterone a woman produces in her monthly cycle, the more sexually active she tends to be, but little is known about short-term increases. ``Maybe it changes her motivation for sex,'' Dr Jutte said.

BEES USUALLY come to mind when it comes to pollinating flowers, but scientists in South Africa have found an unusual relationship between a member of the milkweed family of plants and the lesser double-collared sunbird, Nectarina chalybea. Although many plants are pollinated by birds, the mechanism tends to rely simply on pollen getting stuck to the feathers as the birds feed on the nectar. But in the case of the milkweed plant, Microloma sagittatum, the pollen is precisely clipped on to the ends of the bird's tongue. According to research published in the journal Nature, by Anton Pauw of the University of Cape Town, the plant's tightly closed flowers are finely adapted to make it difficult for insects to sip nectar, but provide welcome access for the sharp beaks of the birds.

SCIENTISTS HAVE launched a campaign to save some viruses, bacteria and fungi that risk being eliminated without people realising how important they can be to a balanced ecosystem. Though these microbes can cause disease in plants and animals, the microbiologists attending the seventh International Congress on Plant Pathology want them to be treated with the same respect as rare animals and plants. David Ingram, president of the British Society for Plant Pathology and Regius Keeper for the Royal Botanic Garden in Edinburgh, is spearheading the campaign to ``preserve the pathogen''. He says: ``For every plant that becomes extinct, 30 other species go with it, and many of these will be plant pathogens. With the rapid loss of habitats and ecosystems world-wide, the increased use of fungicides, pesticides and herbicides in agriculture, and the release of genetically modified organisms, the threats to pathogen diversity in the wild are immense.''

STEVE CONNOR