Steve Connor: 14 days that make all the difference

Some people may not be happy with the idea of being given a blood transfusion made from the stem cells of spare IVF embryos, a development that could emerge from a three-year research project funded by the Wellcome Trust. But what do these ethical objections come down to?

In essence, the crux of the matter is whether you believe that an IVF embryo less than 14 days old is a potential human being with a "soul". If you believe this, which as far as I gather is what the Roman Catholic Church teaches, then you would presumably not countenance the idea of destroying a life to save a life.

The problem with this belief, however, is the unnerving fact that many, indeed most naturally conceived embryos never implant successfully into the womb. They are expelled from the body and die, leaving Catholic theologians struggling with the thought that these innocent "souls" have gone straight to heaven, which must therefore be mostly populated by people who have never existed.

Scientifically, of course, this is nonsense. The reason why it was decided to allow research on human embryos less than 14 days old was because the ball of cells within the developing embryo that actually becomes the baby – as opposed to the placenta and amniotic sac – does not itself develop until after the 14th day.

Embryologists call this tissue the "primitive streak" and its non-existence in IVF embryos younger than 14 days old was why the 14-day limit on researching and growing human embryos is enshrined in British law. We can thank the Warnock Committee, which sat more than 20 years ago, for this insight. It has proved a remarkably robust argument against those who hold the view that a human being with a soul begins at conception.

Trust in Dr Google

Ben Goldacre routinely takes his simple sword of truth to take swipes at the scientifically illiterate in the British media. Dr Goldacre has a day job as a medical doctor but he is known mostly from his highly readable Bad Science newspaper column, which almost always sprinkles some scientific sense on the fire of the latest health scare.

But his most recent column went too far by suggesting that people like me should be made redundant on the grounds that the public no longer needs science and health journalists to translate the latest research findings – they can instead get more accurate information for free from the web.

I might suggest that GPs could also be pensioned off – gold-plated of course – on the grounds that Dr Google can now tell us all we need to know about our health problems. After all, aren't GPs only there to write prescriptions and to come up with ingenious ways of preventing their patients from being referred to the real medical experts?