In our series of articles on the current Biotech Revolution, certainly the most controversial area is that of "cloning," the common vernacular for nuclear transplant techniques. The British Parliament has recently approved laws to allow research using stem cells from human embryos to develop new medical treatments, overruling opposition from those who said it was a step toward human cloning.

While there continue to be many serious hurdles yet to be overcome, after over 60 years of research on animals such as sea urchins, frogs and mice, the cloning of commercially relevant mammals finally seems feasible.