In prehistoric times, Homo sapiens was deeply endangered. Early humans were less fleet of foot, with fewer natural weapons and less well-honed senses than all the predators that threatened them. Moreover, they were hampered in their movements by the need to protect their uniquely immature young - juicy meals for any hungry beast.

Nearly all inventions are not recognised for their positive side either when they're made. So, for example, scientists didn't go out to design a CD machine: they designed a laser. But we got all sorts of things from a laser which we never remotely imagined, and we're still finding things for a laser to do.

A young woman in her teens has about 300,000 eggs in her ovaries. By the time she is menopausal, none are left.

Robots may cut down on infection and mean a consultant can see more patients, but wouldn't you rather meet the doctor than a machine?

I was born with my moustache and, no, I've never been tempted to shave it off. I don't spend a lot of time worrying about my face and, like Gilbert and Sullivan's Katisha, my best feature is my left shoulder-blade.

The trouble with climate change is it's an extraordinarily diverse and complex issue, but for example if the BBC would let me make some of the programmes I'd like to make on climate change, I bet you there would be a change of emphasis.

In prehistoric times, Homo sapiens was deeply endangered. Early humans were less fleet of foot, with fewer natural weapons and less well-honed senses than all the predators that threatened them. Moreover, they were hampered in their movements by the need to protect their uniquely immature young - juicy meals for any hungry beast.