Embryonic, fetal and post-natal animal-human mixtures: an ethical discussion.

Overview: The potential power of embryonic and fetal inter-species mixtures became clear about a decade ago in a series of dramatic experiments in which small sections of brains from developing quails were taken and transplanted into the developing brains of chickens. The resulting chickens exhibited vocal trills and head bobs unique to quails, proving that the transplanted parts of the brain contained the neural circuitry for quail calls. It also offered astonishing proof that complex behaviors could be transferred across species.1