Four Corners

The old mantra – all girls have XX chromosomes and all boys have XY – is no longer reliable. The proof lives in as many as 40,000 Australians whose chromosomes don’t match the standard.

Cartoonist Bill Leak has had depression all of his life. He is not alone. One in five Australians will suffer from depression as some stage in their lives.

US strategists are honing plans to oust Iraqi strongman Saddam Hussein, but after Saddam, what then? Who would lead Iraq? Another military dictator or a bold democrat? Might Iraq fall into chaos, even disintegrate?

A whole generation of Australians has grown up believing that smoking pot is a harmless pastime. They need to think again. The view of cannabis as a benign drug is under challenge from the science and medical community.

Outer space is open for business. It's a booming $50 billion a year industry – and growing so fast that not even the sky is the limit. Few of us give a thought to the myriad satellites bobbing around thousands of kilometres above our heads.

A 'hostess supervisor' at a Port Moresby brothel may tell clients to use a condom with his girls but sometimes he is too tired to bother. This is one of the stories of how Papua New Guinea became a hot spot for the AIDS virus.