The laboratory creation of chimeras

-- animals with mixed-species heritage -- has become so advanced that scientists have drawn up regulations to prevent the production of creatures that blur the line between animal and human.
The National Academies last week outlined guidelines for scientists who want to work with certain types of chimeras.
Wired News: Careful How You Monkey With DNA
http://www.wired.com/news/medtech/0,1286,67395,00.html