The story of life seems to have an unsettling new plot twist. A young Chinese scientist, described by his Stanford adviser as ‘super-bright’, heads back to his homeland in 2011 and falls off the academic radar. Years later, on the eve of a global gene-editing summit in Hong Kong, he resurfaces to announce he has created the world’s first gene-edited babies.

This should be a solemn moment for both science and humankind: the beginning of an era in which we become masters of our own evolutionary destiny. We now have the power to ink permanent changes to our DNA that will join the human gene pool for ever.