Do you get confused over the difference between greenhouse gases and ozone loss? Don't worry - greenhouse gases really do deplete the ozone layer, according to a team from the US space agency Nasa. A study reported in the science journal Nature says that ozone depletion over the Arctic will peak some time between 2010 and 2019, and be about as big as that now occurring over the Antarctic. The only solecism to rid yourself of now is the idea that a thinner ozone layer leads to global warming - it doesn't.

If you aren't taught evolution, you won't understand biology at all, according to American scientists, who last week released a guidebook aimed at keeping the subject from being watered down - or even eliminated - from American school classrooms. "There is no debate within the scientific community over whether evolution has occurred, and there is no evidence that evolution has not occurred," said the National Academy of Sciences, which pointed out that without understanding evolutionary pressures, you won't see why different organisms have developed as they have. It might seem amazing, but teaching evolution is still a political problem for some American schools: the Arizona Board of Education dropped the word "evolution" from its 1996 science standards and North Carolina last year passed a bill requiring that evolution be presented as theory, not fact. Which of course it is - except that many Americans think "theory" means "hunch", rather than "hypothesis which explains existing observations and has predicted other ones".

You may have suspected this: women are more sensitive to pain than men, new research on arthritis sufferers suggests. But women are better able to cope with it, recover more quickly and do not let pain control their lives.