The Animal Made Human

From Merriam-Webster: Chimera - b : an imaginary monster compounded of incongruous parts

The Chimera is a monster of ancient Greek mythology, said to be made of parts of three different animals; the lion, the goat, and the serpant. It was a creature to be feared and hated. In modern times, "chimera" has taken on another, related meaning. Again from Merriam-Webster:

Chimera - an individual, organ, or part consisting of tissues of diverse genetic constitution

This article in the NY Times magazine made me aware of the disturbing reality that not only are we well on our way to creating creatures composed of various parts of animals, but we are also already making what the ancient Greeks considered the most horrifying of monsters, those that were part man and part animal. Everyone probably remembers the story of the mouse with the human ear growing on it's back, but scientists are going far beyond that experiment, to creating animals that are being changed on the genetic level, such that their fundamental architecture is altered.

The writer describes an sheep altered by having human stem cells injected into it when it was still a fetus:

According to Zanjani, when he examined the sheep he discovered that the human cells had traveled with their lymphatic system throughout the sheep's body, developing into blood, bone, liver, heart and assorted other cells, including some in the brain. While some scientists are skeptical of his findings, Zanjani told me that some have livers that are as much as 40 percent humanized, with distinct human structural units pumping out uniquely human proteins.

Some researchers are prepared to go beyond even this. The writer describes the work of another scientist, who is seeking to inject human stem cells in fetal mice, to allow them to differentiate through the embryo in such a way as to alter the mouse even moreso then the sheep mentioned above. Such an experiement could, if successful, lead to the very real possibility that mice treated in such fashion-if allowed to come to term-could have mostly human reproductive systems that are capable of creating a human fetus...in a female mouse.

Many people would be repulsed by this idea...but why? Why is there a sense of revulsion associated with the infusing of human features into animals, or in combining animal features? Dr. Leon Kass, the chairman of the President's Council on Bioethics, characterizes this as the "yuck" factor. At a certain point, this sense of unease regarding an experimental creature is a signal that perhaps there is something morally wrong with what's going on. But what is "morally" wrong with a creature with a human liver? Or lungs? Or reproductive organs?

One researcher in particular, Irving Weissman, has in the works an experiment in which human neural stem cells are transplanted into the brains of fetal mice whose own brain cells are genetically programmed to die, so that-if allowed to come to term-the mouse would have a brain composed almost entirely of human neurons, through structured-most likely-as a mouse's brain would be. What kind of creature would this be? What degree of human-ness would this impart on the mouse?

The most unfortunate aspect of this article is that it addresses these experiments only through the lens of human ethics. Beyond how all of this is offensive to our own sense of dignity and morality, there is the question of how offensive this is to the dignity of the animals the experiment is being performed on. Most people are willing to accept that some measure of pain and suffering must be inflicted upon animals for the sake of human progress, and human life. But are these people aware of, and willing to accept, mice with human brains? Animals with human organs that can be harvested for transplant? Animals that could possess human consciousness? At what point is it a violation of our own ethical standards concerning animal experimentation to inflict not only pain and suffering on animals, but human intelligence and emotion?

This is certainly an issue that needs to be explored in greater detail, especially by everyday laymen such as ourselves, who ultimately decide what our society's standards are. Read the article, do some research, and see what you think.