Also, justifying the use of nonhumans for organs as being ethical simply because of our membership into the human species is misguided and superficial. In any case, the ethics balance of proponents for the use of animals would still outnumber the opponents if it weren't for the long-term irreversible evolutionary changes described next. More importantly, these specialized farms will probably make use of the complex genetic knowledge that we have acquired in the last decade to modify these animals so that the compatibility of their organs to those of humans will become greater. The increased resemblance of the animals' organs to those of humans will make it more and more unethical to use them simply for organs. Even more problematic is the increased compatibility of the genetic make-up of humans and genetically altered animals which will transform the boundary between humans and nonhumans into a chaotic blur.
Arguments also arise regarding the difference between different animals.
I can identify two parties that differ in their approaches to the ethical use of animals for xenotransplantation. The evolutionists, on the other hand, will view the use of chimpanzees as ethically unacceptable as opposed to pigs, and they base their views on the degree of genetic similarities between the animals and the human. The advantage of this view is that it establishes a framework whereby closely related species are respected, but drawing the line is problematic because there are so many factors that can used as segregating factors. In addition, one may be decreasing the potential for the use of the most compatible organ if such limitations are put in place. In retrospect, the ethical considerations of the use of animal organs for xenotransplantation in order to save a human life could only be approached through a holistic examination of all the different actors in such a practice.