Now this is going to stir up the faithful . . .

A team at Stanford has inserted human stem cells into a sheep embryo. This is actually the second time scientists have successfully created what this article calls an "animal-human hybrid." That is not technically correct. A hybrid is a result of cross breeding such that every cell has DNA from each species. Examples are mules and Ligers. Humans cannot be hybridized with any living species (although Neanderthals are now known to have bred with Homo Sapiens).

This is actually what's called a chimera, having some sheep cells and some human cells, not a hybrid. The purpose of this research is to grow human organs for transplant inside non-human animals. That's still quite a bit far off, if not far fetched. The team destroyed these embryos after a few days. But I definitely predict this work will cause a shit storm if it gets much more publicity. This article does not say what kind of human stem cells were used -- it's going to create an even bigger shit storm if they were embryonic stem cells -- but you may remember that George Bush the Second actually spoke against this line of research in a State of the Union speech. So a lot of people don't like it.

However, I haven't really heard anyone articulate why or how this is unethical. I am curious what people may think.

Update: Okay, here are my thoughts on this. As far as the animal welfare question, at this point we have no idea whether the quality of life of say, a pig with a human liver would somehow be impaired. But it's a pretty good bet that said pig would be much better cared for than a typical pig raised for meat. As far as animal exploitation and suffering are concerned, if you object to this, then you will have to become a vegetarian. Which, by the way, I am, but it's because of the way livestock are treated in our industrial meat production system. Eating meat is not, in and of itself, unethical, that's human nature. So anyway, assuming the animals are treated humanely it's hard to make an argument against this on animal welfare grounds given what we already tolerate.

As far as human dignity, I'm missing that too. There's no human brain involved here. The only human being affected is the patient who ultimately gets the organ. However, the technology could conceivably be used in more problematic ways. We'd have to cross that bridge when we come to it. BUT . . .

This is most likely all moot because the prospect of growing human organs in an artificial environment is probably much more imminent. So this is unlikely to become a real problem.