Ronald Bailey: The morality of resurrecting our closest evolutionary cousins
The ancestral lines of Neanderthals and modern humans split about 800,000 years ago, making them our closest relatives on the hominid family tree. Neanderthals inhabited ice age Europe and parts of the Middle East before going extinct 30,000 years ago. A team of researchers led by geneticist Svante Pääbo at the Max Planck Institute in Leipzig, Germany announced last week that they had completed a draft sequence of the genome of Neanderthal humans. Eager evolutionary biologists believe that comparing the Neanderthal genome with our own will throw considerable light on the genetic changes that gave us our big brains, language, and the ability to create culture.
Once the Neanderthal genome is complete, could it then be used to clone an actual Neanderthal? Harvard University biologist George Church thinks so. He told The New York Times that a Neanderthal could be brought to life using present technology for about $30 million. How? Church would modify a modern human genome so that its DNA matches the Neanderthal version. To avoid ethical problems, Church tells the Times, this Neanderthal genome would not be inserted into a human cell but instead into a chimpanzee cell. This chimp cell would be reprogrammed to an embryonic state, and then introduced into a chimpanzee's womb where it would develop into a Neanderthal infant. But does this avoid ethical problems? Hardly.
Assuming that cloning is safe, would it be ethical to clone a human being? The short answer is yes. Clones are basically delayed twins—and there is nothing inherently immoral about twins. Recent polls, however, show that most Americans still oppose the use of cloning to create human babies. In addition, some religious traditions believe that human cloning is immoral. So I suspect that the proposal to use chimpanzee cells to clone a Neanderthal is an attempt to do a kind of ethical end-run around this"yuck factor" reaction to human cloning. In this case, researchers could argue that they are cloning a different species, not a human being.
But there is another problem with Church's plan to use chimpanzee cells: Neanderthals are human beings, too. The ancestral lineage that led to both Neanderthals and modern humans diverged from the chimpanzee line nearly 6 million years ago. If it is possible to clone Neanderthals using chimpanzee cells, it would also be possible to clone humans the same way. One would insert a human genome taken from, say, a skin cell, into an enucleated chimpanzee egg and then install that egg in a chimpanzee's womb where it would develop. The only genetic difference from a normal human would be that the clone's mitochondria (tiny intracellular power plants that have their own small genomes) would be chimp rather than human. Neanderthal mitochondrial DNA has around 200 differences from human mitochondrial genomes whereas chimpanzee mitochondrial DNA has about 1500 differences. I fear that using chimpanzee cells to clone Neanderthals would likely be taken as an indication from the outset that they are in some sense subhuman, and thus less worthy of moral respect. ...