Scientists solve the riddle of why precariously balanced rocks near the San Andreas fault have never been toppled by earthquakes - revealing crucial interactions between faultlines.

Dr Hugh Lewis examines the threat posed by growing amounts of space junk, and outlines some possible solutions.

The decline of the Hainan gibbon - the world's rarest primate - has been revealed by a trawl through historical Chinese documents.

Allegations of widespread doping in athletics are "a declaration of war" on the sport, says IAAF vice-president Lord Coe.

Lab-based experiments produce the first evidence of the characteristics of individual fish that leave them at greater risk of getting caught.