John Harris: A world without men? That's not the real ethical issue here

I cannot see a downside to research that increases the range of human possibility and choice

The end of men has always been a possibility. Women have many ways of trying to do without men. They don't need men – they just need their sperm. Sperm is a notoriously renewable resource and it is plentiful. There is always the turkey baster option for women who want to get pregnant but do not see the need to get a man.

Now, if this research is confirmed, all they will need is a very large supply of male stem cells. Might we see the George Clooney stem cell line (assuming he were to consent to it)? I can see no objection. It is no more wrong to choose the genes of your child than your reproductive partner. Indeed, we have always sought to do both, choosing our partners on the basis of our – sometimes erroneous – belief about the sort of children likely to result. I see nothing wrong with people exercising that choice using the technology as it becomes available.

If it is not wrong to wish for a bouncing brown-eyed baby girl, why would it become wrong once we had the technology to play Fairy Godmother to ourselves and grant our own wish?

If the researchers have done what they claim to have done, this is an important advance. It will mean that no man in the future will need to regard himself as infertile and for many men that will be very liberating. I cannot see a downside to research that increases the range of human possibility and choice.

But that depends on the process being practical and safe. First we have to be sure that genuine sperm have been created and that they are healthy and viable and won't cause the death of the embryo or unacceptable defects. In previous work from this group on mice, the baby mice produced died early. Safety is going to be a key factor.

This is true of all reproductive technologies. It was true of the first attempts at IVF. It is also true of normal human sexual reproduction, which has an 80 per cent failure rate (to produce a pregnancy). If sexual reproduction were introduced today it would never get a licence – the failure rate is too high.

A general feature of reproductive technologies is that they are more perfectable than normal sexual reproduction so it is possible eventually to achieve a higher success rate and a lower abnormality rate. You will be able through refinement and research to examine the sperm and eggs and embryo before implantation in a way that you can't do in normal sexual reproduction. Some of these techniques are already safer than sexual reproduction.

The real ethical issue here is that we do not foreclose the beneficial possibilities of research through prejudice or fear. We need to ensure that the science can continue and that we remain receptive to, but critical of, the opportunities it affords.

John Harris is professor of bioethics at The University of Manchester and editor-in-chief of the 'Journal of Medical Ethics'