Real science, da! Baby killing, nyet!

Two teams of scientists provided the first definitive evidence yesterday that embryonic stem cells can be grown in laboratory dishes without harming healthy embryos, an advance that some scientists and philosophers believe could make the medically promising field more politically and ethically acceptable.

The work, done with mouse cells, generated several colonies of mouse embryonic stem cells without destroying any embryos that otherwise could have developed into mice.

If the new approaches were to work with human cells, as many scientists suspect, they could help defuse a moral maelstrom that has raged since human embryonic stem cells were discovered seven years ago. But the new techniques raise ethical issues of their own, leaving their ultimate value uncertain for now. (Thanks to Laura Ingraham for the heads up.)