‘Motherless babies!’ How to create a tabloid science headline in five easy steps

No, scientists have not figured out how to make “motherless babies,” nor have they gotten any closer to making an embryo without using an egg cell. A paper published yesterday in Nature Communications sparked a flurry of headlines about futuristic ways to get around the basic formula of "sperm + egg = embryo." Many stories claimed researchers had moved closer to using a skin cell, for example, instead of an egg cell, to make a baby. That, they said, could make it possible for a gay couple to have a baby by fusing sperm from one man with the skin cell of another. 

But those headlines and stories frequently left out a crucial detail: The researchers, led by Tony Perry, an embryologist at the University of Bath in the United Kingdom, most definitely needed egg cells—also called oocytes—to make the mouse pups they described. The egg cells they experimented on were past the typical “use by” date, in that they had been chemically prompted to start dividing. (Usually it is fertilization by sperm that provides that signal.) That meant that they had started...