Scientists in the US have successfully corrected a disease-causing gene mutation by altering the genetic structure of a human embryo. This can prevent those who carry the disease from passing it on to their children. From a scientific standpoint, this is a big development. But this brings to the fore, again, questions about the ethics of gene editing. Experiments to change the human germ line are banned in much of Europe but are legal in the US and China. In particular, ill-informed reports of how the experiment could pave the way for ‘designer babies’ has sparked furious debates.

That particular concern is premature. Gene editing is still in its infancy. That said, there are long-term issues worth debating. For instance, there are the unknowable implications of introducing modified genomes into the human gene pool. More prosaically, the debates within the scientific community prefigure inevitable legislative conundrums as more advances are made. And the power of public opinion should never be overlooked—as the fierce resistance to genetically modified crops has shown.