A vital part of science is the compulsion to ask questions, even if, like Darwin, we cannot always find an answer. I admit to being surprised, almost offended, when people claim not to be interested in animals, what animals do, and why they do it. I don't care at all if someone isn't interested in my other preoccupations – jazz, exhibition poultry – why should they be? But somehow I can't accept that it is possible not to have an interest in the evolution of behaviour – the evolution of our own behaviour, and ultimately why we are what we are. Indeed, it seems impossible to gain insight about ourselves without considering the diversity of animal life, and our place in it all.

Maybe that, and my fascination for natural history, was why I changed almost immediately from medicine to zoology as a student at Bristol University in 1962. Medicine would have offered affluence and security, but when ‘push came to shove’, I opted for the risk and adventure of following my obsession. Biology – indeed science itself – offers a philosophy and insight into the nature of life that applied science and technology does not.