For the first time in the U.S., scientists have genetically modified human embryos. The technique could help screen out heritable diseases, but many worry where it might ultimately lead.
As rumors spread in advance of the publication, the story sparked comparisons with films like Gattaca and books like Brave New World, with their themes of genetic discrimination, DNA-as-destiny and the social dangers of tampering with human heredity.
But the research’s most important — and, to some, troubling — aspect lies in the fact that it alters the hereditary DNA known as the germline.
Stable, nontoxic refrigerants changed the world, transforming food storage, expanding Sun Belt populations, even helping early movie theaters succeed. But they also wrecked the ozone layer — Earth’s shield against harmful ultraviolet radiation.
Today, as stockpiles dwindle — and prices rise — due to phase-outs set by the Montreal Protocols 30 years ago, the future of Freon and its successors remains in doubt.