In the beginning, it was a news conference like any other.

A few minutes after 9 Friday morning, a woman stepped up to a podium in a South Florida hotel meeting room and began to speak.

Then things got weird. Brigitte Boisselier, a striking French woman with haphazardly dyed red hair, talked about the origins of life. She discussed her beliefs as a member of a religion, the Raelian sect, that preaches that we were all created by extraterrestrials. She bitterly accused the international press of unfairly labeling her a fraud and repeatedly pronounced it “my day.”

Then Boisselier claimed that with the Cesarean delivery of a baby girl Thursday to undisclosed parents in an undisclosed location, one of the most incredible feats in the history of science had been achieved: the birth of a cloned human.

This is not how science usually gets done. Accustomed to getting their news from staid, peer-reviewed scientific journals and monotonal meeting presentations, cloning experts had no idea how to evaluate Boisselier’s claim.

“One has to be really skeptical at this point. One has to see real, clear, independent verification,” said Ronald M. Green, a Dartmouth College bioethicist who advises Massachusetts biotech company Advanced Cell Technology on ethical matters.

Boisselier, a former chemistry professor, said she had expected that objection. So she told the throng of reporters that she had engaged one of their own to arrange for DNA testing of the mother and her alleged clone.

Michael Guillen, a former science correspondent for ABC’s “Good Morning America,” stepped forward and explained that in about a week he would have DNA evidence of the genetic relationship between mother and alleged clone.

Most major scientific advances do not come from laboratories headed by people who believe that little green aliens came to Earth to tell a former auto-racing journalist, Rael founder Claude Vorilhon, that they had created the human race through genetic engineering. And they usually aren’t revealed at Holiday Inn press conferences in Hollywood, Fla., about 25 miles down the coast from the headquarters of the National Enquirer.

For example, when Advanced Cell Technology developed a way last year to clone human embryos as a source of tissue for transplantation, it reported the advance in the Journal of Regenerative Medicine.

When Ian Wilmut of the Roslin Institute in Scotland kicked off the cloning frenzy by creating Dolly the sheep in 1997, he told the world in the British journal Nature.

Even when they do convene news conferences, triumphant scientists usually hold them on university campuses or at the headquarters of scientific societies.