Leading article: Ignore this tired ethical debate

This is greatly encouraging. Both these techniques have the potential to lead to a reduction in human suffering. The objective behind creating a embryo with two genetic mothers - a process in which the nucleus of a human embryo is transplanted into another woman's unfertilised egg - is to prevent the transmission of mitochondrial disease from a mother to her children. This is a terrible affliction that damages the cells of the brain, heart, liver and kidney. Meanwhile, the purpose of creating an embryo with no genetic father is to produce stem cells. This is another avenue scientists hope will lead them to a supply of those versatile "master cells" of the human body with such potential to alleviate suffering.

These exciting developments have been greeted with outrage from the usual quarters. Josephine Quintavalle from something called "Comment on Reproductive Ethics" condemns scientists for "playing around with early human life". But these complaints are unjustified.

The process of transplanting the nucleus of a human embryo into another woman's unfertilised egg is not all that different from a surrogate mother carrying another couple's child. The child would not have "two mothers" in any meaningful sense in either case. And in respect of the embryos with no fathers, there is no intention of allowing these bundles of cells to develop into a foetus.

Rather than getting bogged down in this tired ethical debate, we should concentrate on the big picture. What these experiments demonstrate is that our reproductive cells and embryos might be much more flexible than was initially thought.

The renowned fertility expert Lord Winston is right to argue that the potential benefits of stem cell research should not be "oversold". But this is a field of biology that is moving astonishingly quickly. And there is real prospect that one day, embryo research will yield a cure to some debilitating genetic diseases. It is imperative that it is not held up by those who find this area distasteful, either in principle or practice.