Nobel prize-winning geneticist and director of the Francis Crick Institute Sir Paul Nurse OM CH FRS FRSE addressed a packed house at The Royal Society of Edinburgh this week, giving the President’s Signature Lecture on a fundamental question of science – the nature of life itself.

The event, chaired by fellow geneticist Professor Sir Adrian Bird FRS FRSE, Buchanan Chair of Genetics at the University of Edinburgh, sought to address a central, and as yet unanswered, question in biology: What is life?
Sir Paul said ahead of giving his talk: “It is the most fundamental question in biology, I would say.”
The answer to this question may vary, as Sir Paul has said previously, depending on your point of view. While Sir Paul says he would prefer the answer to be clearer, he added that the fact that it remains unanswered means that it keeps being revisited, time and again.
Sir Paul said: “For me I’d like it to be clearer, to be honest. It can continually attract attention over decades. Though as a practitioner I am not so keen. You can keep asking the question, and the form of the answer may change, and there have been many people who have provided answers to it and they all are a bit different.”
“The ideas that I talk about are, in some respects ‘boring’, by which I mean I’m not looking over the horizon. Often when people write popular books, they are looking over the horizon, and then when you pick it up ten years later it looks a bit old hat because it didn’t go anywhere. Whereas these ideas will still be important in a hundred years, I would say.”

This fundamental question is still attractive to many, it seems, as tickets for the event sold out rapidly, leaving a lengthy waiting list of hopeful attendees despite the event being expanded to increase capacity.
But is the question unanswerable?
Professor Bird doesn’t think so: “It’s one of those questions that you sort of assume will never be answered, but I have a hunch that it might now. With all the improved knowledge, we’re in a better position to at least reconsider it. As Sir Paul says it’s not one of those questions that you ask, and then fail to get an answer and that’s it, you just keep on coming back to it.
“I think one of the most interesting things about it is how difficult it is to answer, despite the fact that is an extremely simple, monosyllabic question.”
Sir Paul’s talk covered similar themes to those in his book What Is Life? Understand Biology in Five Steps. Beginning with the discovery of the cell, Sir Paul talked his audience through the elegance of the DNA molecule and then to the interconnectedness of life on Earth.
The evening attracted a diverse and engaged audience, with standing room only left, and despite the gravity of the question at hand there was plenty of laughter during a lively Q&A session after Sir Paul’s remarks. One question asked “When does life end?”

Sir Paul’s response: “If you wanted to ask me an easier question you’d have asked when does the life of a cell end, but I don’t suspect you did,” brought laughter from the auditorium.
The audience were left gripped and inspired by the central message of the evening. That all life on earth is fundamentally connected due to the fact that our basic building blocks are the same, and that we have a special responsibility for life on this planet.