The news on 14 June that scientists had made “synthetic human embryos” caused widespread surprise and alarm. Sounds scary, right? Perhaps even, as an editorial in the Guardian suggested, like “playing God” and paving the way towards a dystopian “brave new world”. The reality is different. For one thing, calling these “synthetic embryos” is rather misleading, even prejudicial – most scientists prefer the term “embryo models”, and they are made from ordinary human cells. And they are not new – the earliest ones were made years ago, although the scientists behind the latest work say they have been able to...