David White, director, Institute of Food Research, Norwich, UK

Biologists are used to life cycles, and David White can look back on some of his own. “My life goes in seven-year spells,” the new director of the Institute of Food Research notes. “At the end of that time I feel I've done everything I'm going to be able to do.”

An early change came as soon as he completed his physics BA at Oxford: a bursary from the Nuffield Foundation helped him swap to zoology. Why the change? Growing up on the edge of a country town, he had been fascinated by biology and butterflies. But he noticed that ‘high flyers’ at his school took physics, mathematics and chemistry. So he did, too. “That turned out to be a useful background for biology,” he says. (see CV).

Inspired by John Pringle, head of Oxford's zoology department, he turned his interest in movement into a DPhil on insect flight muscles. Meanwhile, his colleague, John Thorson, taught him “most of what being a scientist is about”, not only in the lab but during evenings with colleagues, when the conversation flowed over every aspect of science.

White continued to work on contractility and motility at York, but his interests were shifting. “I was drying up by the end of the 1970s,” he says. “I was getting invited to all the right conferences, but it wasn't going anywhere.”

So he began a series of collaborations using physical tools to study biological phenomena. A phone call in 1990 persuaded one of his former students, Justin Molloy, back from Vermont to use optical tweezers to study molecules instead of whole muscles. They went on to develop a molecular-force transducer.

“It's easier to take risks later in your career,” White admits. “When I went into optical tweezers, I thought it would be the last thing I'd do scientifically, and if it failed it wasn't a disaster.”

A seven-year stint as head of biology at York ended when White joined the UK Biotechnology and Biological Sciences Research Council. Due to retire last year, he moved on instead to head the council's Institute of Food Research, a chance he found “too much fun to resist”.

It also meant a move to the fens of Norfolk, nurturing his passion for wildlife photography, which he'd once thought of making “more than a hobby”. When the urge to move hits again, the next cycle may be ready to begin.