One of my tasks is to teach genetics to medical students. In the first class of the previous semester, a student, who did not identify himself, had raised his hand shortly after I showed my first slide. The slide is a brilliant and beautiful diagrammatic summary of evolution from single-cell organisms to today’s incredible variety of life. Only my colleagues in the Physics Department can match the extraordinary story that it tells. I cannot comprehend why some people are more interested in the outcome of a football match or the weight of an actress.

This student belonged to another category.

‘Professor Tillman, you used the word “evolved”.’

‘Correct.’

‘I think you should point out that evolution is just a theory.’

This was not the first time I had received a question – or statement – of this kind. I knew from experience that I would not sway the student’s views, which would inevitably be based on religious dogma. I could only ensure that the student was not taken seriously by other trainee doctors.

‘Correct,’ I replied, ‘but your use of the word “just” is misleading. Evolution is a theory supported by overwhelming evidence. Like the germ theory of disease, for example. As a doctor, you will be expected to rely on science. Unless you want to be a faith healer. In which case you are in the wrong course.’

There was some laughter. Faith Healer objected.

‘I’m not talking about faith. I’m talking about creation science.’

There were only a few moans from the class. No doubt many of the students were from cultures where criticism of religion is not well tolerated. Such as ours. I had been forbidden to comment on religion after an earlier incident. But we were discussing science. I could have continued the argument, but I knew better than to be sidetracked by a student. My lectures are precisely timed to fit within fifty minutes.

‘Evolution is a theory,’ I said. ‘There is no other theory of the origins of life with wide acceptance by scientists, or of any utility to medicine. Hence we will assume it in this class.’ I believed I had handled the situation well, but I was annoyed that time had been insufficient to argue the case against the pseudo-science of creationism.

Some weeks later, eating in the University Club, I found a means of making the point succinctly. As I walked to the bar, I noticed one of the members eating a flounder, with its head still in place. After a slightly awkward conversation, I obtained the head and skeleton, which I wrapped and stored in my backpack.

Four days later, I had the class. I located Faith Healer, and asked him a preliminary question. ‘Do you believe that fish were created in their current forms by an intelligent designer?’

He seemed surprised at the question, perhaps because it had been seven weeks since we had suspended the discussion. But he nodded in agreement.

I unwrapped the flounder. It had acquired a strong smell, but medical students should be prepared to deal with unpleasant organic objects in the interests of learning. I indicated the head: ‘Observe that the eyes are not symmetrical.’ In fact the eyes had decomposed, but the location of the eye sockets was quite clear. ‘This is because the flounder evolved from a conventional fish with eyes on opposite sides of the head. One eye slowly migrated around, but just far enough to function effectively. Evolution did not bother to tidy up. But surely an intelligent designer would not have created a fish with this imperfection.’ I gave Faith Healer the fish to enable him to examine it and continued the lecture.

He waited until the beginning of the new teaching year to lodge his complaint.

In my discussion with the Dean, she implied that I had tried to humiliate Faith Healer, whereas my intent had been to advance an argument. Since he had used the term ‘creation science’, with no mention of religion, I made the case that I was not guilty of denigrating religion. I was merely contrasting one theory with another. He was welcome to bring counter-examples to class.

‘Don,’ she said, ‘as usual you haven’t technically broken any rules. But – how can I put it? – if someone told me that a lecturer had brought a dead fish to class and given it to a student who had made a statement of religious faith, I would guess that the lecturer was you. Do you understand where I’m coming from?’

‘You’re saying that I am the person in the faculty most likely to act unconventionally. And you want me to act more conventionally. That seems an unreasonable request to make of a scientist.’

‘I just don’t want you to upset people.’

‘Being upset and complaining because your theory is disproven is unscientific.’

The argument ended, once again, with the Dean being unhappy with me, though I had not broken any rules, and me being reminded that I needed to try harder to ‘fit in’. As I left her office, her personal assistant, Regina, stopped me.

‘I don’t think I have you down for the faculty ball yet, Professor Tillman. I think you’re the only professor who hasn’t bought tickets.’

Riding home, I was aware of a tightness in my chest and realised it was a physical response to the Dean’s advice. I knew that, if I could not ‘fit in’ in a science department of a university, I could not fit in anywhere.

Natalie McPhee, daughter of the late Dr Alan McPhee, potential biological father of Rosie, lived eighteen kilometres from the city, within riding distance, but Rosie decided we should travel by car. I was amazed to find that she drove a red Porsche convertible.

‘It’s Phil’s.’