This lack of consensus plagues us, especially in a society with such widely differing views among individuals. This implies that in every case where a human could be saved, an animal should be used because the human has more intrinsic value than the animal. Consider the case of using an animal which happens to be a member of an endangered species. Suppose it is found that the heart of the endangered white lynx is found to be compatible with people of a certain bloodtype, who make up three percent of all patients waiting for a heart transplant. This would seem to be quite unwise.
Animals clearly do have some sort of value.
Now let us look at the issue of our history. That is, the history of Americans of European descent. The term that describes this is speciesism. From this argument, it is clear that we need more than just instinct to decide how to deal with those who are 'obviously' fair game for exploitation. It can be argued that if Baby Fae was to receive any organ at all it should have been a human one.