Building Better Humans

A young couple having difficulty conceiving a child undergoes tests to pinpoint the problem. As they sit in the doctor's office, awaiting the results, each wonders whose reproductive system has failed.

"There's nothing wrong with either of you," the doctor tells them, at last.

"So what's the problem?" they ask.

"You're two different species. You can't interbreed."

Science fiction? Perhaps for now. But according to the eminent physicist Freeman Dyson, this is where the human genome project will inevitably lead us. He and his Princeton colleague, molecular biologist Lee Silver, say that rapidly emerging genetic technology will ultimately split humanity into many species.

They draw their conclusion from cold, complex science, but their point is simple, and frightening: Once we figure out how to safely manipulate our genes, people will start adding and deleting them to their perceived advantage. Different sorts of humans will emerge. And it's safe to assume that each will decide that it is superior.

While anyone who watched even a minute of "Britney in Hawaii" might believe that this has already occurred, rest assured it has...