Pet cloning is a terrible idea -  and, we now know, an extremely unpopular one. Cloning endangered species is equally foolish. Re-creating extinct species is an absurd concept, whose worst extreme is the proposal to re-make a Neanderthal. Taken together, they represent a triumph of reckless technological tinkering, and of adolescent curiosity over meaningful ethics.

The idea of cloning pets immediately followed the 1997 announcement of the first mammal cloned from a somatic cell. John Sperling, a multi-billionaire, was reading about Dolly the sheep when he whimsically wondered if it would be possible to clone his girlfriend's dog, Missy. He delegated the project to his girlfriend's son, Lou Hawthorne, who ran with it for the next decade.

A dozen laboratories are said to have been interested, but the initial contract went to Texas A&M. They estimated that the project might cost a million a year and take five years. Sperling could afford it - and the A&M team got an entree to the intriguing world of mammalian cloning.

That was a hot new field in the late 1990s, and a...