The Anti-Sam Brownback Blog

MMMmmmm.  Manimals.  Josh over at Thoughts from Kansas has an excellent discussion of Senate Bill S 1373 which would ban the creation of human - animal chimeras.

Properly speaking, a chimera is a mixture of cells from two sources. CSI fans will remember a case in which a man had two genetically distinct sets of cells in his body, so a DNA test wrongly excluded him as a suspect. That’s a naturally forming human-human chimera (strictly a mosaic, but let’s not get too caught up in terminology). For research purposes, one can put cells from one species (say a sheep) into the embryo of another (say a goat). The product will look like the little cutey right here, a so-called “geep.”

Scientists use these chimeras to study the development of mammals, improving our understanding of our own growth and development, as well as that of commercially important species.

Since Josh is the biologist, I will defer to his knowledge.  Go read his post.