Cloning became a hot issue in this year's presidential race after scientists in South Korea announced that they had created human embryos by cloning, and former first lady Nancy Reagan urged President Bush to reconsider his policies on so-called therapeutic cloning and embryonic stem-cell research. Some scientists think embryonic stem-cell research could someday produce cures for Parkinson's disease, diabetes and other maladies that afflict millions of people, including Alzheimer's disease, which killed President Ronald Reagan. Others say the procedure offers more hype than hope. Still others, including President Bush, say the research is grossly unethical because it destroys human embryos. They also fear that therapeutic cloning could lead to human cloning and even the creation of human clones as organ sources. Presidential candidate Sen. John Kerry opposes human cloning but has vowed to quadruple federal funding for embryonic stem-cell research.

Brian Hansen, a freelance writer in Boulder, Colo., specializes in educational and environmental issues. He previously was a staff writer for The Researcher and a reporter for the Colorado Daily in Boulder and Environment News Service in Washington. His awards include the Scripps Howard Foundation award for public service reporting and the Education Writers Association award for investigative reporting. He holds a B.A. in political science and an M.A. in education from the University of Colorado.