ROBERT SIEGEL, HOST:
Twenty years ago today, a woolly little farm animal named Dolly was born. And she forever changed our sense of the possibilities of science.
(SOUNDBITE OF ARCHIVED BROADCAST)
SIEGEL: It is a rare event to unfold the morning paper, peruse the front page and see depicted there an astonishing and unsettling face of the future. It is rarer still that the face should belong to a sheep.
Who was that? Anyway, that tape was actually from several months after Dolly the sheep was born. When scientists finally took the news public, it was the first successful cloning of an adult mammal.
ARI SHAPIRO, HOST:
It was an exciting moment that also made a lot of people uncomfortable. Like Ron from Buffalo, who called in to NPR's Talk of the Nation and struggled with the idea of cloning humans.
(SOUNDBITE OF ARCHIVED BROADCAST)
UNIDENTIFIED MAN: One young man turned out to be an amazing soldier. He fights well, he's strong, he thinks well. I'm not quite sure where I would stand, if it would be right or wrong to make an army of the perfect soldier. On the other hand, if somebody could really build a house like nobody's business, would it be bad to have the entire building community filled with Bob Vilas? You could make houses for nothing.
SIEGEL: Well, Dolly the sheep was euthanized in 2003 after she came down with a lung disease.
SHAPIRO: So here we are 20 years later. And where is that clone of Bob Vila?
SIEGEL: We put that question to NPR health correspondent Rob Stein.
ROB STEIN, BYLINE: Like many things in science, it turned out to be way, way, way harder than anybody had thought. And basically, nobody's been able to do it as far as we know. There have been claims over the years of people trying to do it. There's even been claims that people did do it. But there's been no evidence that that's true.
SIEGEL: Rob says the technique used to create Dolly did help kick-start the field of stem cell research with the hope of growing organs for people in need.
STEIN: They haven't been able to do this yet, but there's still a lot of promise and hope that someday that'll be possible. None of this would've been possible without this first step of cloning Dolly.
SHAPIRO: Who, by the way, is still on display at a museum in Scotland. Happy 20th, Dolly. Transcript provided by NPR, Copyright NPR.