Lifeboat Foundation

Researchers have achieved a new kind of chimeric first, producing sheep-human hybrid embryos that could one day represent the future of organ donation – by using body parts grown inside unnatural, engineered animals. Scientists have created the first interspecies sheep-human chimera, introducing human stem cells into sheep embryos, resulting in a hybrid creature that’s more than 99 percent sheep – but also a tiny, little bit like you and me.

Admittedly, the human portion of the embryos created in the experiment – before they were destroyed after 28 days – is exceedingly small, but the fact it exists at all is what generates considerable controversy in this field of research.