John Hoke dropped me an email pointing to this article at National Geographic News that reports on the controversy over the recent successes scientists have had in creating chimeras. Chimeras—named after the mythological creature that was composed of a lion’s head, goat’s body, and serpent’s tail— are animal-human hybrid organisms created in the laboratory for research into possible new medical treatments.
Chinese scientists are credited with the first success back in 2003 when they fused human cells with rabbit eggs which they allowed to develop for a few days before destroying them to harvest the stem cells. Then last year researchers at the Mayo Clinic in Minnesota created pigs that had hybrid pig-human blood, University of Nevada scientists have created sheep with livers that are up to 80 percent human, and over at Stanford University in California there are mice with brains that are 1% human. Needless to say all of this fusing of genetic material between species is raising some big questions and sparking off some heated debates. It should be noted that chimeras of a sort have existed for awhile prior to the Chinese experiments—anyone who’s had a heart valve replaced with one from a cow or pig is technically a chimera. It’s the means and amount of blending that’s causing the ruckus:
Biotechnology activist Jeremy Rifkin is opposed to crossing species boundaries, because he believes animals have the right to exist without being tampered with or crossed with another species.
He concedes that these studies would lead to some medical breakthroughs. Still, they should not be done.
“There are other ways to advance medicine and human health besides going out into the strange, brave new world of chimeric animals,” Rifkin said, adding that sophisticated computer models can substitute for experimentation on live animals.
“One doesn’t have to be religious or into animal rights to think this doesn’t make sense,” he continued. “It’s the scientists who want to do this. They’ve now gone over the edge into the pathological domain.”
David Magnus, director of the Stanford Center for Biomedical Ethics at Stanford University, believes the real worry is whether or not chimeras will be put to uses that are problematic, risky, or dangerous.
For example, an experiment that would raise concerns, he said, is genetically engineering mice to produce human sperm and eggs, then doing in vitro fertilization to produce a child whose parents are a pair of mice.
“Most people would find that problematic,” Magnus said, “but those uses are bizarre and not, to the best of my knowledge, anything that anybody is remotely contemplating. Most uses of chimeras are actually much more relevant to practical concerns.”
This debate has been ongoing for awhile already. I came across practically the same news item at at the Washington Post from back in November. In that article they go a little more in-depth into some of the possible scenarios that could arise from this sort of research:
Imagine, said Robert Streiffer, a professor of philosophy and bioethics at the University of Wisconsin, a human-chimpanzee chimera endowed with speech and an enhanced potential to learn—what some have called a “humanzee.”
“There’s a knee-jerk reaction that enhancing the moral status of an animal is bad,” Streiffer said. “But if you did it, and you gave it the protections it deserves, how could the animal complain?”
Unfortunately, said Harvard political philosopher Michael J. Sandel, speaking last fall at a meeting of the President’s Council on Bioethics, such protections are unlikely.
“Chances are we would make them perform menial jobs or dangerous jobs,” Sandel said. “That would be an objection.”
Irving Weissman, the man who created the mice with 1% human brains, is considering an experiment sometime this year that would create mice with brains that are 100% human in part so he can study Parkinson’s and Lou Gehrig’s disease, but what would be the result? Is it possible that these mice could end up as sentient creatures? It’s likely the smaller size of the mouse brain would make that unlikely, but it’s not impossible. Experiments by Evan Balaban over a decade ago showed the potential research potential of chimeras when she took small sections of brain from developing quails and transplanted them into the developing brains of chickens:
The resulting chickens exhibited vocal trills and head bobs unique to quails, proving that the transplanted parts of the brain contained the neural circuitry for quail calls. It also offered astonishing proof that complex behaviors could be transferred across species.
There’s a much bigger difference between a human and mouse brain than there is between a quail and chicken brain, but it still raises some potentially troublesome questions. Weisman feels he has a solution to that problem. Granted, it’s not a very elegant solution, but it is a practical one:
He proposes keeping tabs on the mice as they develop. If the brains look as if they are taking on a distinctly human architecture—a development that could hint at a glimmer of humanness—they could be killed, he said. If they look as if they are organizing themselves in a mouse brain architecture, they could be used for research.
Which side of the debate you come down on probably has a lot to do with how different you view humans and animals. The more religiously inclined naturally tend to see this as a “very bad thing” in part because of the cliche about the dangers of encroaching on God’s turf and in part because they feel it in some way destroys the dignity inherent in being human. Not that there aren’t scientists who feel this may be pushing boundaries too far toward the escapades of the fictional Dr. Moreau, but the differences in opinion tend to fall along the lines you’d expect them to with the more scientifically inclined less opposed. John has mixed feelings on the issue. Me, not so much. I’m for the research as long as careful consideration over what is being done and what its potential ramifications might be is kept forefront.
The more interesting aspect of this research for me is how it helps to prove the Theory of Evolution. This research wouldn’t be possible if Evolution and its implications weren’t true. I’d really love to hear a Creationism or Intelligent Design advocate explain how these hybrids are possible in the confines of their “theories.” The ID folks at least will own up to micro-evolutionary processes within a species because there’s no other reasonable way to explain how viruses develop new strains, but they maintain that macro-evolution isn’t possible. Yet if we are not basically the end product of a long line of evolutionary changes as is proposed by the theory of Evolution then how is it possible for scientists to create such hybrids? Prayer?