Throughout history, people have been fascinated by the idea of combined creatures, such as the legendary Chimera, described as being part lion, part goat, and part snake. In particular, we like to imagine fusion creatures with a human component, a classic example being Greek mythology’s centaurs and centraurides, with a human head and torso merged with the body and legs of a horse. In children’s tales in modern times, we have the mermaids, like Ariel, the Little Mermaid, a great success for the Disney Company, not only as an animated film but as inspiration for numerous dolls for little girls planet wide. It’s an exciting idea to think about human-non-human combinations, and science has actually begun experimenting in this area genetically for the sake of improving human health. Such research is not aimed at producing a centaur, nor any other being that’s anatomically part human and part something else, but the field of human-animal hybridization research scares people anyway. In our society, where genetic technology is ever more influential, the fact that people are concerned is a good thing. Ethicists and scientists say that we should be extremely careful. A few years ago, Stanford University hosted a major conference & stressed caution. That means not creating literal chimera, like a human head on a horse body. This is not something that geneticists even know how to do.
But since not all people understand this–and because there’s a paranoid, sensationalist element in some media, and, every now and then, some individual, or institution, might engage in unethical research — there’s a fear based on the belief that human-animal hybridization research could lead to making centaurs and other such fantastical beings. Taking out of context reports about research combining human and non-human cells and genes to make novel tissues and organs, some posts floating around the internet use the term “chimera” to describe what scientists are developing, and go as far as to imply that literal chimera have already been created. The only reason we do not know about it, they say, is because there is a conspiracy to keep it quiet.
Some conspiracy theory websites express concern about the insertion of a human chromosome into mouse cells and the use of human embryonic stem cells to enhance the brains of mice, making them smarter. But the key to how misconstrued the content is comes when the writer states that the human organ makes the pig “no longer fully a pig”, and then implies that somehow the recipient receiving such a graft becomes part pig. But getting a human organ that’s been engineered, enhanced, or otherwise developed in a laboratory setting, and then grown or maintained connected to the blood supply of a pig, would not prompt any of us to oink, or start rolling around in the mud, any more than a blood transfusion from LeBron James or Kevin Durant could suddenly make you a scoring terror in the NBA. Blood doesn’t improve athletic ability and neither does a transplanted kidney–whether the kidney has been maintained within a pig, or for that matter even if the kidney is literally a pig kidney, produced in the natural way within the pig’s body. The kidney’s job is to filter the blood and even in the case of xenotransplantation–getting organs directly from a non-human animal–the main issue is whether the organ can be protected from rejection by the recipient’s immune system. Researchers at the Salk Institute in La Jolla, Calif., have combined mouse-human livers to study liver disease in mice that previously were not a good model for human liver disease. No humans with tails are walking around the lab, nor are there any talking mice, but the mice are humanized when it comes to their livers. For this reason, the special mice can be infected with human hepatitis viruses, whereas naturally occurring mice cannot. Also, since the malaria parasite that kills millions of people around the world gets into the human liver, the special mice also are becoming vital in the effort to develop new malaria drugs. At Stanford University, a study involves mice, whose brains have a small percentage of human cells. The mice are not inventing warp drive, but they are helping neuroscientists to make great strides toward treating, and possibly preventing, neurodegenerative diseases, like Parkinson and Alzheimer diseases. Perhaps one of the most fascinating and potentially live saving, projects on the clinical horizon is the effort to grow human organs within non-human animals, such as pigs and rats. Such a project involving pigs is underway in Japan. The idea is that it may solve the problem of organ shortages around the planet for people needing transplants. According the US Department of Health and Human Services, more than 123,000 people in the United States currently need an organ transplant, and about 21 people die each day waiting for one.