The National Institutes of Health (NIH) announced last year that it was lifting the ban on the creation of human-animal hybrids, or chimeras.
A chimera is an animal that possesses cells from two or more different zygotes. It's basically multiple animals rolled into one. A chimera can thus have features such as both male and female organs, two different blood types, or other characteristics. The creation of a human-animal chimera thus entails introducing human cells into non-human embryos.
The NIH banned funding on chimera research in order to give scientists the time to consider the ethical ramifications of creating chimeras. Scientists currently use chimeras to study early human development and to study human diseases. In the future, scientists aim to grow human organs in animals for organ transplants.
The term “chimera” has roots in ancient Greek mythology. The mythological chimera is a monster that has the body parts of different animals. Chimeras of modern times aren't monstrous, but they do spark a debate about their controversial role in scientific research. There are worries that scientists might grow human-like embryos in animal wombs, or that chimeras will display human characteristics or features.
Some animal rights groups are also wary of the use of animals to grow organs for transplants. To them, it sounds too much like organ farming if animals are meant to grow only to provide organs. Thus, these groups worry about the possibility of another source of animal suffering.
The NIH announced in September of 2015 that it will be suspending funding for any research that involved the introduction of human cells into animal embryos. The agency then held a workshop in November 2015 to gather insight into the matter. Eventually, the workshop ended with a general consensus that human-animal hybrids are valuable to scientific research.
Though the NIH lifted the ban, it did replace it with some strict guidelines that regulate research using chimeras. The new guidelines disallow the insertion of human cells into animal embryos before the development of a central nervous system. This will prevent the human cells from ending up in the animal's brain.
Scientists also cannot breed two chimeras. Breeding two chimeras can result in human-like offspring, of which many critics of the use of chimeras have been wary. This stipulation will also prevent the birth of a chimera that has more human features than its parents.
These new restrictions will make it easier for research proposals to make it through to funding. However, there is also the risk of having to create new research guidelines that have to include a third kind of research subject. Currently, there are only two kinds of research subjects: human and non-human. Chimeras may need a new set of research guidelines, or they can fall under the category of non-human subjects.
In any case, there are still a number of questions that need answering, which isn't surprising. Controversial topics such as the use of human-animal hybrids in research often generate a lot of talk. Hopefully, scientists will be able to make sense of the noise in time.
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