Human cloning has also been a charged issue, especially reproductive cloning—the implantation of cloned embryos into a surrogate mother to grow into a viable organism. While this type of cloning is presently legal in the United States, it is prohibited by University policy.

But Jennings stressed that the research the two Harvard teams want to pursue stops far short of the type of work that produced Dolly the cloned sheep.

“We have no idea whether [reproductive cloning] would work in humans—it would be grossly irresponsible to try, and we’re completely opposed to it,” Jennings said.

In fact, the institute supports a proposed law banning reproductive cloning to highlight the difference between reproductive cloning and human embryo cloning for stem cell research.

“It would help to have a legal ban to separate the issues,” Jennings said. “They are fundamentally different.”

Most respondents in a Virginia Commonwealth University survey released yesterday said that they support embryonic stem cell research, but oppose human reproductive cloning and human cloning for research purposes.

—Staff writer Katharine A. Kaplan can be reached at kkaplan@fas.harvard.edu.