Nothing gets the blood boiling like a manimal. For many people, the idea of breaching the human species barrier–to mingle our biology with that of an animal–seems like a supreme affront to the moral order. In his January state of the union address, President Bush called for a ban on “creating human-animal hybrids.”

These so-called chimeras, according to their opponents, devalue humanity by breaching our species barrier. “Human life is a gift from our creator, and that gift should never be discarded, devalued or put up for sale,” Bush declared. Senator Sam Brownback of Kansas expanded on this sentiment in his Human Chimera Prohibition Bill of 2005. Chimeras, according to the bill, “blur the lines between human and animal.”