Scientists Busy Combining Human And Animal Cells To Create Hybrid Creatures

What happens when you cross a human and a mouse? Sounds like the beginning of a bad joke but, in fact, it's a serious high tech experiment recently carried out by a research team headed by a distinguished molecular biologist, Irving Weissman, at Stanford University's Institute of Cancer/Stem Cell Biology and Medicine. Scientists injected human brain cells into mouse fetuses, creating a strain of mice that were approximately 1 percent human. Dr. Weissman is actively considering a follow-up experiment that would produce mice whose brains are 100 percent human. What if the mice escaped the laboratory and began to proliferate in the outside environment? What might be the ecological consequences of mice who think like human beings, let loose in nature? Dr. Weissman says he would keep a tight rein on the mice and if they showed any signs of humanness he would kill them. Hardly reassuring. In a world where the bizarre has become all too commonplace, few things any longer shock the human psyche. But, experiments like the one that produced a partially humanized mouse at Stanford University stretches the limits of human tinkering with nature to the realm of the pathological. Some researchers are speculating about human-chimpanzee chimeras-creating a humanzee. A humanzee would be the ideal laboratory research animal because chimpanzees are so closely related to human beings. Chimps share 98 percent of the human genome and a fully mature chimp has the equivalent mental abilities and consciousness of a four-year-old human child. Fusing a human and chimpanzee embryo-a feat researchers say is quite feasible-could produce a creature so human that questions regarding its moral and legal status would throw 4,000 years of human ethics into utter chaos.