We can't any longer have the conventional understanding of genetics which everybody peddles because it is increasingly obvious that epigenetics - actually things which influence the genome's function - are much more important than we realised.

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.

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.'

My first vote was for a communist in east London when I was a medical student. But I've voted Tory, Labour and Lib Dem in my time.

Both in Britain and America, huge publicity has been given to stem cells, particularly embryonic stem cells, and the potential they offer. Of course, the study of stem cells is one of the most exciting areas in biology, but I think it is unlikely that embryonic stem cells are likely to be useful in healthcare for a long time.

Man is a competitive creature, and the seeds of conflict are built deep into our genes. We fought each other on the savannah and only survived against great odds by organising ourselves into groups which would have had a common purpose, giving morale and fortitude.

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.