A ban will be lifted on federal funding of experiments that use human stem cells to create part-human, part-animal embryos.

The embryos, known as chimeras, include sheep, pigs and cows, and would use stem cells to create human organs that could be used as transplants or to study diseases inside the animals. But this has some critics worried about the ethical implications of these experiments.

Though the NIH has put forth restrictions such as closely watching and reviewing cases on embryos that develop human brain cells, there is a chance that human reproductive organs could also develop and precautions would have to be taken to keep the chimeras from breeding.

Patt Morrison speaks to two experts today, to weigh in on the ethics of creating chimeras. What do you think of these experiments? Have these experiments gone too far?

Guests:

Ronald Bailey, Science Correspondent at Reason magazine and Reason.com; Author of the new book "The End of Doom: Environmental Renewal in the Twenty-first Century”

Stuart A. Newman, Ph.D, Professor of Cell Biology and Anatomy at New York Medical College