"Global warming isn't the only vexing issue the world wrestled with this week."

"While delegates gathered in Paris to discuss climate change, the International Summit on Human Gene Editing convened in Washington, D.C., to debate another conundrum: How far should scientists go when editing human DNA?"

"The main focus was whether scientists should be allowed to use powerful new genetic engineering techniques to edit genes in human eggs, sperm or embryos — an extremely controversial step that raises a host of thorny safety and ethical issues."

"At the end of the meeting Thursday, conference organizers concluded it would be "irresponsible to proceed" with any attempt to create a pregnancy or a baby from human eggs, sperm or embryos that have been altered, because of safety and ethical concerns."