NEW GENETIC technologies are exhilarating and terrifying.Society might overcome diseases by tweaking individual genomes or selecting specific embryos to avoid health problems.But it may also give rise to "superhumans" who are optimised for certain characteristics (like intelligence or looks) and exacerbate inequalities in society.What is certain is that people will be able to make decisions about their lives in ways that were impossible in the past, when we relied more on random evolution than deliberation.In the words of Jamie Metzl, we are "Hacking Darwin," the title of his latest book.It is a thoughtful romp through new genetic technologies, with insights on what it means for individuals, society and even great-power politics.The theme draws together discrete strands of Mr Metz's diverse background.He's worked for the United Nations on humanitarian issues in Cambodia and served on America's National Security Council under President Bill Clinton.He's been an executive at a biotechnology company, a partner at large investment fund in New York and a candidate for Congress from Missouri.