I've been all over the world on my own because, as a scientist, you travel a great deal if your work is reasonably successful or published. I get invitations to go to all sorts of strange countries where I would mostly be by myself and just meet other people there, instead of having travelling companions.

Following 25 children for the TV series 'Child of Our Time' has been extraordinary. The BBC's original plan was to commemorate the new millennium. What better way than to film a number of expectant mums from across the U.K.? Coming from widely different backgrounds, all were due to give birth on January 1, 2000.

I did not study science at school until I was 13, when I was totally turned on by a seemingly dreary old teacher who suddenly, unannounced, manufactured a huge explosion in the middle of a totally boring monologue. From then on, all of his class wanted to make explosions.

However pragmatic you are, it is very demanding being a new parent.

Over the past 20 years, I have presented many science programmes on BBC1. But none is, I think, more socially important, or of more human interest, than this ongoing series of 'Child of Our Time.'

You can now modify the genes of large animals, and the largest animal we are concerned with is the human.

There were never any doctors in my family. But my grandparents and my mother had a strong social conscience that was formative.