What is a living alien

What kind of life did Ata have? Was it short and painful because he was born crippled under poor conditions in northern Chile and died there after a few years? Was he stillborn? Or is it true what many UFO believers like to suspect: Did Ata flew as an elite member of an extraterrestrial civilization with his spaceship through space on a reconnaissance mission to earth, where he died under unexplained circumstances?

In any case, the corpse turned into a mummy in the bone-dry heat of the South American Atacama Desert, hence the nickname Ata. In 2003 she was found wrapped in a cloth in the ghost town of La Noria. Now researchers at Stanford University have examined the body. And as much as the owners of the mummy and the filmmakers who made Ata the star of a documentary about UFOs may have wished for scientific proof of the extraterrestrial origin - it turned out to be a human story.

"Ata is human, I have no doubt about that," says Garry Nolan of Stanford University, who examined the DNA from the mummy. Ata was a boy who died early.

Tiny body, human-like skeleton

With Nolan's data, however, the dissolute theories will certainly not end: The sight of the dried up body is too strange. It is only 15 centimeters tall, but has a very human-like skeleton, as X-rays show. Only the number of ribs is wrong, ten instead of twelve. And the head: it is disproportionately large and pointed instead of round. The forehead rises above the eyes, which look like glasses in sunglasses.

All in all, a face that Hollywood designers could have created for a science fiction film like "Men in Black", in which Will Smith and Tommy Lee Jones from a special department of the immigration service hunt down aliens living on earth undetected.

But Ata does not have an extraterrestrial migration background, as Nolan explains without reservation, although he has not yet published his analysis in a peer-reviewed journal according to the rules of science.

Nolan took Ata's DNA from a rib: "Not only is there a lot of cellular material there, it is also particularly well protected from the effects of the environment," he says.

The DNA snippets that he was able to remove from the ground sample using enzymes, a technique that was used to decipher the Neanderthals' genome, were between 100 and 150 base pairs, i.e. genetic letters, in length. When Nolan had 500 million such molecular chains compared with a current human genome, 91 percent of the DNA pieces matched. The remaining nine percent is not non-human, but was sorted out by the evaluation software because the sequencing machines or the software made mistakes, according to the Stanford researcher.

Such scrap always arises even when human genetic material is unequivocally sequenced. "Even if you prepare the DNA very well, you have to reckon with five to ten percent rejects," says Nolan. According to him, the 91 percent human genome gives no indication that Ata could be an extraterrestrial life form. Nevertheless, Nolan wants to analyze the discarded nine percent of the DNA snippets more closely.

"One would have to argue that there is something like a 24th chromosome in there if you want to mistake the mummy for an alien. Humans have 23 chromosomes. But if Ata had a 24th chromosome, the first 23 would not be like that either look like humans. "

Gateway for alien supporters

The statement of 91 percent agreement is now expected to become the gateway for alien supporters and is discussed extensively on the Internet. Some commentators on websites question Nolan's conclusion that Ata was human, after all, primates like chimpanzees have a genome that is only one percent different from that of humans.

Nolan tries to refute this comparison wherever he can, for example in the discussion column under an online report from the magazine Science. The nine percent were most likely sorted out because of technical problems, not because it has been proven that they do not match the human reference genome. "Everything we could compare is completely human."