appeared recently in the Stupid Republicans forum regarding conservative’s fear mongering about mad scientists bringing the the island of Dr. Moreau to life. While pointing and laughing may be the appropriate response to that particular set of fears, the idea of human animal hybrids should not be so cavalierly cast aside. Unlike other proposed legislation that are solutions in search of a problem (such as laws asserting the right of clergy to choose not preside over gay marriages) that can be ignored as irrelevant, the debate over chimera’s is more akin to the stem cell debate.
Genetic manipulation of animals with theinsertion of human DNA, and xenografts of human cells onto animals, hold great promise in medical research and possibly even in a clinical setting. So far only the anti side is working to get its message out, in this way it may be that the war is lost even before the pro-science side even realizes this was an issue.
So as I see it there are really two debates: First, what if any restrictions should be placed on this sort of research. Second if we decide that this sort of research should be allowed in some form (as I think it should) what steps should the supporters of this research take to fight against those who are attempting to legislate a complete ban.
To start things off, I have no problem with xenografts of any sort, with the possible exception of large scale brain tissue which seems beyond the level that is currently proposed. As far as gene editing, I feel that limited gene editing of animal cells and embryos with human DNA is acceptable but should probably be limited to no more than say 1% of the full genetic material. I would impose similar restrictions in the opposite direction (animal DNA inserted into human cells) provided that no experiments progress beyond the embryonic level.
As far as what we should do, I think waiting until after the election makes sense. It will take some time to properly educate the public on this issue and until then, supporting research of this sort can be easily be portrayed as wanting half human half cats walking around. After the election I think that we need to do more than simply point and laugh at such legislation proposals but instead point out the promise that such research could engender, so that people really understand what the debate is about.
The 1% was unthinkingly thrown out as a more or less random number on the low side. But you are right, more probably I would want something like 0.05% of coding sequences. Effectively I would be willing to add a few genes but not the re-writing of large sections of the genome.
I think the correct response to the scientifically illiterate idiots in Kansas is to point and laugh, not to engage them in debate.
Seeking to impose a crude blanket limit on genetic manipulation in the way that you describe is analogous to watching the Terminator movie and then seeking to impose legislation to limit computer processing power to prevent AIs becoming sentient and destroying the world.
What is the perceived problem that you think needs to be addressed? What is the evidence that it is really a problem?
What value system are you seeking to impose on genetic research, and why?
There was a story on NPR recently (I don’t remember which show) about a chimera farm, I want to say in the Pacific Northwest. This guy was inserting human stem cells into pig and sheep embryos, hoping they would grow human organs suitable for transplant. It sounded like he was literally just doing it to see what happened, with the promise that all resulting animals would be destroyed before they could reproduce. But the story made it sound very haphazard. I’m not necessarily opposed that line of research, but it obviously needs very tightly controlled regulations. Nobody, I hope, wants a creature that is 50% or 70% human.
But it is important to note that that 5% isn’t present as solid blocks of new material, it’s millions of tiny changes spread out all over the genome, most of which have subtle individual effects. Furthermore, most of the changes between human and chimp occur in regulatory regions (which control when and where a protein is made), not coding regions (which determine the exact sequence of the resulting protein). Even for mice, swapping the coding sequence of human and mouse genes usually doesn’t have that much of an effect (the exceptions are a Hot Research Topic).
Currently we can insert large pieces of DNA into mice relatively easily (using YAC/BAC/PAC transgenics), but we don’t have the technology to individually engineer more than a handful of targeted changes at a time. (Admittedly these “large pieces” are on the order of a couple of hundred kilo-base-pairs, so only a handful of genes at best.)
It should also be noted that you can make hybrid cells without genetic engineering; there are techniques that will cause cells in culture to fuse, and if you start with a mixture of cells from two different species (typically mouse and human) you will get a small fraction of cells combining one of each. These hybrid cells are usually very unhealthy and frequently kick out most of the chromosomes from one or the other of the species; the resulting cells can be useful for biochemical analysis if they end up with an assortment of chromosomes such that they only have the human version of a given gene (in fact, this was one of the major tools for studying human-mouse gene differences before the development of genetic engineering).
Mice and humans are different enough in the arrangement of the genome that a clean replacement of a non-XY chromosome isn’t possible (although most of our DNA sequence matches up quite nicely to mouse DNA, the way that DNA is arranged into chromosomes is quite different), so these fusion-hybrid cells are abnormal and not capable of making anything much more complex than a tumor. Chimps are close enough that it might be feasible to cleanly replace a chromosome with the human version and get a healthy embryo out of it (using a more sophisticated method than the direct fusion mentioned above), which would be a Quite Interesting experiment. Chimps are very slow breeders, difficult to genetically manipulate and expensive to raise, so even aside from any ethical problems this sort of experiment isn’t likely to be done in anything other than cultured cells at the moment.
We have some very useful chimeras in the form of the bacteria that have been engineered with human genes to produce things like insulin and erythropoietin which have saved lives and reduce suffering.
While I think some caution is needed in any form of genetic engineering so far the results have been positive.
I think anyone wanting to make human-animal hybrids should be ready and willing to justify their goals when asked, but I don’t think a blanket ban is the best thing long term.
As long as you don’t create an environment to breed cross-species infectious diseases, the main thing is to not make anything like a human nervous system. Proteins or other organs are fine.
Not if you want to actually have stem cell therapy. The point is that I don’t care if the conservatives go ahead and pass a law that prohibits clergy from being forced to preside over gay marriages, because that law will have no effect. But we need to pay attention to conservatives outlawing any biological human and animal integration.
These objections are based on complete ignorance. There is really not all that much difference between humans and any other mammal at the genetic level, and scientists have for years been moving genes around between different species. With lots of good results and no bad ones. A lot of the drugs currently keeping cancer victims alive are being produced by human-other species chimeras. Many of the laboratory tests people rely on depend on mouse-human chimeras that produce “humanized” antibodies. Hopefully at some time in the near future pigs with “humanized” organs will become available for transplants. It doesn’t affect the basic nature of the animal, it just alters a few minor biochemical features.
Point and laugh is the correct response.
I think what they’re really afraid of is a situation where a hybrid creature has enough human genetic content that the question of whether it has a soul becomes meaningful (and if not, how much more human content could be added before the answer is “maybe”).
Is this an attempt to dismiss their concerns? Because it’s got nothing to do with whether you call it a “soul” or not - deliberately creating a humanlike intelligence knowing that you cannot give it the quality of life it deserves is reprehensible.