Is it possible to clone a Neanderthal? In theory, maybe.
Last year the scientific community was outraged when the Daily Mail published an article claiming that George Church, from Harvard, was trying to clone a Neanderthal. What a nonsense! I wrote a blog post concerning the scientific illiteracy of the Daily Mail editors and wondering what to do about the problem. Don’t take it personally Mr Dacre; your paper is still worth a guilt-ridden roaming, especially on Sundays.
The Daily Mail claim was -of course- false; professor Church was not trying to clone Neanderthals. But could it be possible to clone one? Back then, I said no. Now however, it may be time to give it a second thought.
Recently, Svante Paabo and colleagues have sequenced the entire genome of one of our late relatives, a big achievement. They found that Neanderthals differed from us in only 87 genes and the differences between those genes were indeed small, just one or two substitutions. Differences in what used to be called “junk” DNA were bigger: around 31000 (but that represents just a 0.001% of our entire genome, still pretty close).
True, a present-day Neanderthal will never be generated like Dolly the sheep was; that would require a Neanderthal’s healthy cell. However, now it could be possible to use a “Jurassic Park” approach: The small number of genes that separate us from them may allow the use of gene editing techniques -such as CRISPR/cas9- to transform human embryonic stem cells into Neanderthal-like embryonic stem cells.
From embryonic stem cells an embryo can be generated, and from embryos grown up individuals can be produced.
Generating adult mice from mouse embryonic stem cells is more or less a routine procedure. Nobody has yet succeeded in producing a higher primate from embryonic stem cells. Creating embryos that are viable and able to implant is clearly more difficult with primates. To the best of my knowledge nobody serious has ever tried with humans nor have I any reason to believe that anybody will want to clone a human or a Neanderthal any time soon. Even if nutty professor –just a caricature from popular culture- were willing to do it, this kind of research is extremely expensive. With no governmental agency ever going to finance it that leaves only the three richest Saudi princes in a position to try cloning a hominid, and they are not scientists.
It is an interesting proposition nonetheless that Neanderthal-like stem cells can be generated. These cells could be used to study basic mechanisms such as metabolic pathways and neurogenesis. These studies could in turn shed light into what really separated our ancestors from our primitive cousins.