Why stop here on our evolution from the ape

There was a time when the use of animal organs in medicine gave many of us an attack of the moral heebie-jeebies. It was considered bestial, degrading and, well, rather yucky. No longer. Even the conservative Senator Jesse Helms, suffering from a coronary condition in the 1990s, gratefully consented to having a pig’s heart valve, and I suspect most of us, offered a choice of a synthetic or animal part for transplantation, would plump for whatever works best, without giving the ethics a second thought.

It is curious, then, that controversy continues to swirl around other types of animal-human fusion. Last week the Human Embryology and Fertilisation Act, which permits the creation of animal-human embryos, received Royal Assent. The legislation forbids scientists from developing these embryos beyond 14 days (when they are about the size of a full stop) but that has not stopped opponents banging on about “the crossing of an ethical Rubicon”.