Chimeras #1

Oh, the pressures Science creates for those who are attached to traditional identities and perspectives! Everyone knows something about artificial fertilization and implantation that now occurs daily in the US. The so-called ethical dilemmas around abortion and raised by the tens of thousands of frozen embryos stored in freezers only start to hint at the confrontation biology is bringing society with its exploration of genetics and stem cells. And of the stem-cell issues causing social distress, the least appreciated is experimentation with placing human stem cells into animals.

The reasons for these experiments are numerous, and (again) the so-called ethical issues of constructing hybrids of animals and human stem cells (called chimeras) present challenges for people whose view of self (and perhaps others) has not included an appreciation of the limits of our conventional definitions of beingness and humanity. Think about it: there are ways to combine cells from two different creatures, methods already known and used, that yield creatures no longer of one species. This has been done already, but at this point these creatures bear only a trace of another species. But for how much longer will that limit remain?

Experimenters are working on making creatures that grow human organs, even though they are otherwise some other creatures. The reason for these experiments? To test whether organs suitable for transplantation might be so created.

Of the most provocative studies, none perhaps exceeds those involving the placement of human cells into the brains of other creatures. So far these experiments are like all the other chimera studies -- limited to adding only a small fraction of the total number of cells in the area receiving these foreign cells -- but it seems certain some scientists are wondering what would happen if greater numbers of cells were used. What for instance would occur if a creature's brain were "boosted" with an equal number of human cells?

Now of course so little is known about brain functioning, just what increasing the number of cells might accomplish is at best poorly understood. Still such explorations introduce into people's minds the often unnerving possibility of human-animal hybrids-of-the-mind. Few people know that quite a number of humans are already hybrids of a sort -- having cells with two (or sometimes more than two) human genetic patterns within their bodies. In effect these folks are merged people. Usually these hybrids are mostly one person genetically, with only a bit of someone else "on board". Mothers often are of this sort, with residual cells from past pregnancies in circulation. Once a mother, always a mother, as they say...

And I'll bet you thought the changes a woman goes though when she bears a child was just hormonal plus something that happens when one becomes responsible for a child! I jest of course, but it's true: a not small number of women do carry vestiges of their pregnancy as cells in their circulation (and elsewhere). Rarely does this have any significance physically or medically.

Then there are people who are hybrids because when they were developing, their body formed from the fusion of two embryos. Mmmmm. And I'll bet you think you'd know whether you might be one of these people. Not likely.

This is a world science is no longer willing to understand only because sometimes nature creates hybrid creatures. So now our experiments and explorations into this world initiate yet another ethical problem, particularly for those who see science as threatening the bases of their ethics.