ALEX CHADWICK, host:
This is DAY TO DAY. I'm Alex Chadwick.
The journal Science, published by the American Association for the Advancement of Science, normally carries articles about research findings in various fields. The Policy column in the latest issue raises this question: What are the moral issues in transplanting developing human brain cells into non-human primates, monkeys and apes? Could that procedure make these creatures more human in some way, and would that change how we should think about them? Professor Mark Greene of the University of Delaware is the lead author on the article with more than a dozen co-authors.
Professor Greene, welcome to DAY TO DAY. What would be the purpose of this research, and is it currently under way?
Professor MARK GREENE (University of Delaware): Yes, it is currently under way. The first reported case of it was actually reported in Science a couple of years ago. And my colleagues in the neuroscience field tell me that other research is currently going on in that field. We can expect other versions to be published probably in the near future.
CHADWICK: And what is the goal?
Prof. GREENE: There's a lot we still need to find out about the basic behavior of cells, the cell biology, right down at the submolecular level, finding out basically how these things work in mammals and in particular in our closest related mammals, like other primates. Then, as we look forward to perhaps using stem cell or other cellular treatments in the treatment of diseases like Alzheimer's, we might want to be able to test potential treatments in other animals before we go to human trials. So that might be another motivation to go forward.
CHADWICK: These are neural stem cells developing human brain cells. Here's a sentence in the article that stopped me: `One conceivable result of human/non-human primate neural grafting is that the resulting creature will develop humanlike cognitive capacities relevant to moral status.' Do you mean an ape or a monkey would develop the ability to think like a human?
Prof. GREENE: People will guarantee you that the monkeys won't start quoting Shakespeare or writing or talking. And nobody disputes that; that's not the issue at all. What we can't rule out, though, is that there might be some changes which would have an effect. So consider, just for example, how rich our social lives are and how much that impacts on our own welfare. Now we know that other primates have very complex social interactions, as well. If you start putting human neural cells into the brains of other primates, we could find that it changes the way they're able to interact or the kind of social needs they may have in a way that makes them completely unable to get sort of social interactions from each other or even from ourselves. So they'd be in this kind of horrible between land.
So that's just one example of something which doesn't remotely come close to thinking like us, which is what none of us expect, but nevertheless can make important changes in what it's like to be that animal in a way that makes it able to suffer in new and different ways that we should be concerned about.
CHADWICK: There's a Greek term from mythology for a creature that is made up of parts of other creatures, chimera. But you say this really no longer mythical; these creatures already exist. And you pretty much reject the idea of speciation. That is you can't just say you have to keep everything within a species because you can't really tell what the boundaries of species are.
Prof. GREENE: That's right, Alex. And there is, indeed, chimerism that already happens within the natural world and as part of science and part of medical treatments. But it is not the Greek kind. The precise medical meaning is that there's a mixture of cells from different genetic lines that are within the one creature. So, for example, we don't think of Trent Lott as a freak of nature just because he has pig heart valves, for example, which he does, I'm told.
CHADWICK: This is the noted senator from Mississippi, I'll say. But go on.
Prof. GREENE: That is, indeed, the noted senator from Mississippi, yes.
The worries about these kind of procedures--and there are such worries--tend to focus on animal welfare. A lot of animal rights activists are very concerned about these kinds of procedures because of the necessity, obviously, of killing the animal that supplies the parts. But to say that the being that has these parts in them is of some lower or abhorrent moral status just because of that is, I think, absurd.
CHADWICK: But does the creature that has developing human brain cells implanted into it, grafted onto it, is it raised to a higher status? That's the question.
Prof. GREENE: Whether we'd actually elevated other primates to something close to human status, I think, is fabulously unlikely. But it also just doesn't matter that we can't do that because we can fall far short of that and still have made a difference that makes a huge moral difference.
CHADWICK: Made a difference in the animal, you mean?
Prof. GREENE: In the animal, yes. That's crucial, that the difference will be in the animal. It's not just because it's a mixture; it's because of the different kind of mental life it might have as a result.
CHADWICK: This creature would--I think you imply, would know that it was different from other apes. Is that what you're saying?
Prof. GREENE: I don't think I could say that. And certainly at this point, I doubt ever we could say that. One of the great problems with working out what's going on with other minds is that we don't have direct access to them. We don't really even have direct access to each other's minds. We have to infer stuff from what we say to each other, how we behave, what we observe in each other. And the same is going to be true when we look at ingrafted animals that have had these human cells put into them. We're going to have to look at their behavior. We're going to have to test them on various cognitive experimental tasks, see what they can do, see how they can manipulate symbols, that kind of thing, and try and infer from that what we can about what their mental life might be, and from that infer something about how we should be treating it morally.
CHADWICK: You might give this creature--put it through a series of tests, and if it performed, say, significantly better or even identifiably better than other apes, then you would conclude that you had created a more humanlike ape?
Prof. GREENE: That would be a flag, yes. One of the things, I think, going into this that I expected and I think some of my colleagues did as well, was that really this probably isn't going to happen. And we surprised ourselves. I went in thinking that the neuroscientists and the cell biologists would be able to tell why this couldn't happen, and I'd go away thinking, `OK, it was interesting to think about, but there's no real deep moral problem here.' But that's not what happened. What actually happened was that the neuroscientists and the cell biologists and the primatologists couldn't fill in those details. Nobody could give us a good reason why this might not happen. So we concluded that we have to be alive to this possibility; we have to look for this possibility.
Now we still think that it might well not happen, it might not be something that is raised as an actual plausibility once the research is done. Yet we should be alive to it since right now, given what we know, we cannot rule out the possibility that we could make changes that make the creatures more humanlike and, therefore, should be considered morally.
CHADWICK: Professor Mark Greene is a bioethicist who teaches philosophy at the University of Delaware. His paper in the new issue of Science is Moral Issues of Human-Non-Human Primate Neural Grafting.
I'll just note, Professor Greene, that among the authorities you site in your paper are the Abrahamic tradition of Genesis, Immanuel Kant and John Stuart Mill. Those are unusual citations in a scientific paper.
Prof. GREENE: Yes, some heavy hitters there.
CHADWICK: Thank you for being with us.
Prof. GREENE: Thank you very much.
(Soundbite of "Monkey Man")
CHADWICK: I'm Alex Chadwick. DAY TO DAY continues in just a moment. Transcript provided by NPR, Copyright NPR.
