Adult stem cell researcher Irving Weissman, M.D. of the Stanford School of Medicine wants to develop mice that have a lot of human neurons in their brains.
So Stanford asked where it should draw the line. It is the first university in the nation to tackle the philosophical question: When does a chimera stop being an animal and start becoming a person, suggesting that research should end? The report foreshadows the release of guidelines on stem-cell research, including chimeras, by the National Academy of Sciences this spring.
``We concluded that if we see any signs of human brain structures . . . or if the mouse shows human-like behaviors, like improved memory or problem-solving, it's time to stop,'' said law and genetics Professor Henry T. Greely, director of the Center for Law and the Biosciences and leader of the committee.
``We think if he takes appropriate caution -- including stopping at each step along the way, to see what's happening -- the research is ethical,'' he said.
What I find especially interesting about this report is the reticence to see animals made smarter. What is their motivation for this restriction? Is it that they do not want lab animals made intelligent because then experimentation on them would become too much like experimentation on sentient humans?
Or do they object more generally to modification of other species to make them become as smart as humans? If the latter, what are their reasons for opposing this move? Certainly one can think of reasons to oppose such a development. The human race could find its existence threatened if we genetically engineered some predator species to be as smart as we are. Imagine smart lions and tigers with no empathy for the human species hunting us down to eat. For that matter, imagine genetically engineered human psychopaths with no empathy for the human species. They already occur naturally in smaller numbers. Will some people ever choose to use biotechnology to produce offspring with little or no empathy?
Or is the objection to making smart mice with human neurons just the creepiness factor? Are the committee members either creeped out by that notion or afraid the public will be? In the longer run discoveries of which genetic variations raise intelligence will point to ways to increase the intelligence of mice without the need to use human neurons. Higher intelligence will be achievable in mice by use of genetic engineering to change the sequences of existing mouse genes.
Weissman's motivation here is that he wants better animal models of human diseases. He is not initially aiming to create mice that have 100% human nerve cell brains. He just needs enough human neuronal cells in the brains of a mouse model to recreate manifestations of human neurological disorders such as Lou Gehrig's disease (a.k.a. Amyotrophic Lateral Sclerosis or ALS), schizophrenia, stroke, and other neurological disorders. The ability to replicate human diseases outside of humans is an enormously valuable approach to investigating the mechanism that cause diseases and to test potential therapeutic approaches for treating and curing diseases.
For some interesting insights and an overview of the state of stem cell research see Weissman's July 14, 2004 testimony on adult stem cell research to the US Senatoe Committee on Commerce, Science, & Transportation.
On the subject of cross-species hybrids the US Patent Office has just rejected an attempt to patent the idea of creating a human-animal chimera hybrid.
The U.S. Patent and Trademark Office rejected the claim, saying the hybrid -- designed for use in medical research but not yet created -- would be too closely related to a human to be patentable.
Paradoxically, the rejection was a victory of sorts for the inventor, Stuart Newman of New York Medical College in Valhalla, N.Y. An opponent of patents on living things, he had no intention of making the creatures. His goal was to set a legal precedent that would keep others from profiting from any similar "inventions."
Newman does not want to see people create chimeras. So he is trying to reduce the business incentive for doing so. However, I do not believe the question of whether to create chimeras is going to be decided based on expected return on investment. Some potential projects hold sufficient allure that even absent a large chance of profit there are wealthy people who will attempt them once attempts to do so become cheap enough. For examples of this phenomenon look at the groups (some of them driven by spiritual beliefs) that are trying to clone humans. Or how about people who build airplanes and other devices for the challenge and for the fame that sometimes results.
I think the development of smarter animals and the development of chimeras are both inevitable. These developments can be delayed by regulations and restrictions on government funding. But the expense and difficulty of attempting these efforts will eventually drop to the point that the barriers in the way of attempts to do these things will fall so low that they will happen. The streets find their own uses for technology.
Supporters of stem cell research at Stanford University include the actor Michael J Fox, who suffers from Parkinson's disease. Fox provided the voice for Stuart Little, Hollywood's version of the "human mouse'', who talks, has human parents and lives in a New York apartment.
I picture a Back To The Future sequel where talking mice go along for a ride in a Delorean.
Update II: Also see my previous post Human-Mouse Hybrid Creation Debated.