A year after Dolly, the immaculately conceived sheep, burst upon the world's consciousness, scientists and ethicists gathered here to discuss the rights and wrongs of animal cloning.

The conference, held March 2 and organized by the Center for the Interactions of Animals and Society in the School of Veterinary Medicine and by the Center for Bioethics, is one in a series examining peoples' relationships with animals.

Addressing a crowd of about 50 in the Penn Tower Hotel, four featured speakers took theoretical and practical approaches. They talked about cloning for science and cloning for sentiment.

Sentimentally speaking, the theologian, the philosopher, the ethicist and the scientist all seemed comfortable with the idea of cloning a pet.

"Are you morally obligated to clone your dog?" asked philosopher Gary Varner, Ph.D., from Texas A & M University, an expert in animal rights philosophy and ethics. "No. Is it morally permissible to clone your dog? Yes."

He considered one of his own cats. "I would find it fascinating to watch a clone of it grow up." He expressed interest in seeing how different the clone would be from the original."

But how comfortable would the pet owner who wants to clone a beloved dog be with that difference? wondered ethicist Art Caplan, Ph.D., of Penn's Center for Bioethics.

"When you clone your pet Dolly-style, you won't get the same pet," he said.

Theologian Gary L. Comstock, Ph.D., the coordinator of Iowa State University's bioethics program, discussed whether cloning was "natural." "The language comes from our religious tradition, and that gives us what's natural and unnatural. It's a way to end thinking about it." His conclusion: Cloning is natural.

But Comstock objected to some of the transgenic animals produced for research -- obese mice, mice that exhibited symptoms similar to multiple sclerosis -- conditions that prevented the mice from behaving as a normal mouse might.

Alan Shaw, a scientist from Merck Pharmaceuticals, wondered if the discussion should center on something other than dogs. "I think you ought to go after something like racehorses," he said, where cloning would have a frivolous -- but lucrative -- purpose.

In research, Shaw said it was difficult to weigh the risks against the benefits, because they were unpredictable until after the results come in. "You try to do this economically in terms of the number of animals used," he said.

While multiples from an assembly line might be useful in science, they might be counterproductive in pets beloved for their uniqueness. "Others can have your pet." Caplan mused.

Introducing and moderating were James Serpell of the Center for the Interactions of Animals and Society and Glenn McGee of the Center for Bioethics.

The next conference in the series is "Beastly Kids: The Role of Animals in the Development and Education of Children," March 27. For information, contact Yuying Hsu at yuying@vet.upenn.edu. Register by e-mail at serpell@vet.upenn.edu. The series is supported by the provost's Interdisciplinary Seminar Fund.