I loved the idea that biology was logical.

Ageing is very exciting. But if I didn't work on ageing, I'd want to work on the brain. There are really cool techniques you can use now. And bioinformatics. The methods you can use for comparing large data sets - that's so powerful.

If I were a worm, I would rather be the long-lived mutant than the normal worm, that's for sure.

Imagine that: If you could change one of the genes in an experiment, an aging gene, maybe you could slow down aging and extend lifespan.

I eat some fruit every day, but not too much and almost no processed food. I stay away from sweets, except 80 per cent chocolate.

Generally, older people in their fifties, sixties, and seventies are running most countries and are CEOs of corporations. Which isn't to say there aren't entrepreneurs, but if the young were better in every respect, there'd be no reason for the old. Our life span reflects our particular life strategy.

In the early '90s, we discovered mutations that could double the normal life span of worms.