Build a Pet Dinosaur or Your Perfect Child

If Silicon Valley has anything like a coherent philosophy, it is summed up in the idea that the best way to predict the future is to invent it. Innovation is to the technology industry in the 21st century what the Feejee Mermaid was to P.T. Barnum in the 19th—a manufactured ideal, relentlessly and hyperbolically promoted and frequently documented in credulous accounts by the technology press and popular science writers, many of whom have adopted the perpetually fawning posture of subjects backing away from a monarch.

But Silicon Valley’s second-order philosophy might be “Don’t Tread on Me.” While a libertarian approach might be harmless when it comes to the question of regulating the latest dating app, the stakes are much higher in fields such as synthetic biology, where the ambitions of private companies go far beyond increasing advertising revenue to embrace the design and construction of new forms of life.

Synthetic biology entrepreneurs want each of us to become gods of our own creations. “Anyone with a smartphone and a credit card will be able to get to creature,”...