Humans have souls, animals don't...but what about chimeras? A chimeras "is an animal that has two or more different populations of genetically distinct cells that originated in different zygotes." The more sensational term is "animal-human hybrid." William Saletan has a very disturbing article on slate.com: http://www.slate.com/id/2168932/fr/flyout.
There's a lot of distrubing aspects of this article, but here's a good excerpt:
"Last month, ethicists from Stanford University and the University of Wisconsin detailed a proposal by a Stanford scientist to substitute human brain stem cells for dying neurons in fetal mice. "The result would be a mouse brain, the neurons of which were mainly human in origin," they reported. The payoff, if the fetuses survived, would be "a laboratory animal that could be used for experiments on living, in vivo, human neurons." Imagine that: a humanoid brain network you can treat like a lab animal, because it is a lab animal.
"The Stanford experiment wouldn't actually produce a human brain. Most brain cells aren't neurons, and the experiment called for inserting human cells after the mice had constructed their brain architecture. But last year in Developmental Biology, researchers proposed to insert human stem cells in mice before this architectural stage. The resulting "mouse/human chimeras," they argued, "would be of considerable value for the modeling of human development and disease in live animals."
"When Stanford's ethicists first heard the proposal for humanized mouse brains, they were grossed out. But after thinking it over, they tentatively endorsed the idea and decided that it might not be bad to endow mice with "some aspects of human consciousness or some human cognitive abilities." The British academy and the U.S. National Academy of Sciences have likewise refused to permanently restrict the humanization of animals."
Al Mohler responded to this today on his blog. The best part of the blog was this statement by bioethicist Dr. Nancy Jones:
"What principles may Christians invoke to guide them in formulating a response to the possibility of such animal-human chimeras? Some concern should certainly be expressed for the experimental animal's suffering; however, Christians do believe that they have been given stewardship over animals and are permitted to use them to benefit humanity. Another concern would be zoonotic transmission of disease, which occurs when pathogens cross the traditional species barriers of disease transmission. When human and animal tissues are intertwined so closely, potential mutations of once species-specific pathogens may gain a unique ability to infect organisms of other species. A more fundamental Christian concern involves violation of the divinely created order. The Bible tells us that God designed procreation so that plants, animals, and humans always reproduce after their own kind or seed. (Gen 1:11-12, 21) In the biblical view, then, species integrity is defined by God, rather than by arbitrary or evolutionary forces. The fusion of animal-human genomes runs counter to the sacredness of human life and man created in the image of God."