When geneticist George Church talked about cloning Neanderthals in his book and subsequent interview with Der Spiegel news weekly, it sounded like something out of Michael Crichton's "Jurassic Park" coming to life. But experts say that safety and ethical hang-ups mean the first Neanderthal birth in 30,000 years is probably fiction, too.
"I understand what George is saying. It's interesting. But I don't think it will ever happen," said Arthur Caplan, a bioethicist at the NYU Center for Bioethics. "It lurches too close to exploitation. It rubs up too closely as starting to turn into bringing somebody into existence just as an object of other people's interest."
Fragments of Neanderthal DNA have been found in fossils throughout in Europe, and Church said they could be put together to create an embryo for implanting into a human surrogate.
Ideally, he said, people would be able to learn from Neanderthals, which are humans' closest extinct predecessors, because their enlarged craniums hint at different thought processes from humans. He said Neanderthals' presence could also create more genetic diversity, but Caplan said it's unclear whether it would be possible for humans to breed with Neanderthals.
Also, Caplan said, creating a human-like being in a lab for study could be exploitative.
The theoretical Neanderthal family (because Church told Der Spiegel he doesn't think a lone Neanderthal would have a good sense of identity without a cohort) would live under extreme scrutiny even if they didn't have to live within the confines of a lab, Caplan said. He compared the re-creation of Neanderthals to Frankenstein, noting that the fictional Victor Frankenstein created his monster to prove that he could do it. But the monster struggled with his own identity and dignity much like a modern-day Neanderthal family would.
Caplan said there's also insufficient knowledge about whether Neanderthals would be too aggressive to flourish in society or whether they would die of an extreme unforeseen allergy. He compared the latter to the way Europeans accidentally killed the Native Americans by giving them small pox.
And, of course, the United Nations banned human cloning in 2005, although the guidance wasn't as binding as a treaty, Caplan said. Some states have banned the practice as well, but a few, including California, allow it for research purposes.
"The reasoning behind that is because human cloning, to many, seems to violate the way in which people are created," Caplan said. "It makes people nervous to make someone from an existing person. There's a repugnance factor about that."
Whether a Neanderthal counts as "human" is also debatable if states or local laws specify a ban on "human cloning."
Ethics aside, cloning a Neanderthal would be a safety issue, said Ron Crystal, a geneticist at Weill Cornell Medical College in New York City.
"Technically, putting together fragments of DNA is feasible," Crystal said. "Are we putting it together correctly? We know that one letter in the wrong place can be fatal."
One-letter deformities, called monogenic disorders, include cystic fibrosis, sickle cell anemia, Fragile X syndrome, Huntington's disease, and thousands of other life-threatening problems, Crystal said.
Single-gene mistakes are possible when scientists are cloning an organism for which they have a model of completed DNA, Crystal said. But a Neanderthal clone would involve much more guesswork because scientists don't have any reference to tell them that they're about to make a fatal mistake.
"It's a problem for whether you're trying to put together a dinosaur or trying to put together a Neanderthal," Crystal said. "There's nothing to compare to. There's no gold standard."
Caplan added that it's possible many Neanderthal stillborns and Neanderthals born with extreme disabilities would precede a healthy Neanderthal baby.