Chimeras

There is a Wall Street Journal article (link good until Thu 5/12) about the existence now of chimeras — that is, combining genetics from different animal species into a new creature. They've already created a combine sheep/goat they call a "geep". They implanted brain cells from a quail into a chicken embryo, and the chicks make sounds like quail. Someone applied for a patent on a human-chimpanzee chimera, and lots of work is being done on implanting human stem cells into mice. They even talk about safeguards to prevent, say, a mouse that produces human sperm cells and a mouse that produces human eggs from copulating and producing a human embryo (which of course they'd be unable to fully gestate).

This is some seriously freaky stuff, folks. And you know given today's environment, that anything goes. The concept of ethics is just a nice though: someone will violate the ethical boundaries.

Obviously this brings up a lot of tough philosophical questions. If you graft human brain cells into a mouse, and they start to form complex human neural networks such that the mouse starts to think like a human, does the mouse become in part human? (They somewhat whimsically bring up in the article the possibility of some such mouse saying "Get me out of this body!") Under what circumstances does a chimera acquire the dignity of a human being?
I am envisioning an ethically-challenged doctor producing some sort of human-based chimera (i.e. injecting animal DNA into a human embryo), one male and one female so they can breed, raising it (it? him? her? what?) up as his own children. Not to mention the philosophical questions face by such a being: being rejected and feared by men, unless it had the fortune to have the appearance of a man.

Here is a telling quote: "But Prof. Weissman had in mind a new sort of chimera. He would start with ill-fated mice whose neurons all die just before or soon after birth. He planned to transplant human-brain stem cells into their brains just before their own neurons died off. Would that lead the human cells to turn into neurons and replace the dead-or-dying mouse neurons, producing a mostly human brain in a mouse? Such a chimera could bring important scientific benefits."

Hello? Can we say "missing the point"? Anyone who doesn't get a chill down the spine at that thought — just isn't human (sorry, couldn't resist!).

The big question is, what does the Catholic Church have to say about this? We know what she says about stem cells, or at least how they are harvested, although it is possible to get stem cells from adults. We know that IVF is out. As far as I know the church has had little to say about genetic experimentation in general. But if any pope is able to respond to this brave new world, I know it is Pope Benedict.