Washington: A bizarre 12-centimetre-long skeleton found in a pouch in a ghost town in the Atacama Desert of Chile ten years ago has confused scientists and UFO enthusiasts.
The diminutive skeleton, named Ata, is shown in a new documentary on UFOs titled ` Sirius`.
The skeleton ended up in a private collection in Barcelona; and producers of the documentary latched onto the bizarre mummy as evidence of alien life.
Among the apparent abnormalities, that the skeleton sports are 10 ribs instead of the usual 12 and a severely misshapen skull.
To study the specimen, immunologist Garry Nolan, director of the National Heart, Lung, and Blood Institute`s Proteomics Centre for Systems Immunology at Stanford in California, sought clues in it`s genome.
He initially presumed that the specimen was tens or hundreds of thousands of years old, so he consulted experts who had extracted DNA from bones of the Denisovans, an Asian relative of European Stone Age Neandertals but it turned out that the DNA was modern, abundant, and high quality, indicating that the specimen is probably a few decades old.
To much chagrin of UFO hunters, Ata is decidedly of this world, after mapping more than 500 million reads to a reference human genome, equating to 17.7-fold coverage of the genome, Nolan concluded that the specimen`s B2 haplotype-a category of mitochondrial DNA - reveals that its mother was from west coast of South America, Chile that is, the Sydney Morning Herald reported.
After examining X-rays, paediatric radiologist Ralph Lachman, co-director of the International Skeletal Dysplasia Registry at Cedars-Sinai Medical Centre in Los Angeles, concluded that the skeletal development, based on the density of the epiphyseal plates of the knees (growth plates at the end of long bones found only in children), surprisingly seemed to be equivalent to that of a six- to eight-year-old kid.
If that holds up, there are two possibilities, Nolan said, one, a long shot, is that Ata had a severe form of dwarfism, and was actually born as a tiny human, and lived until that calendar age.
The second possibility is that Ata, the size of a 22-week-old foetus, was suffering from a severe form of a rare rapid ageing disease, progeria, and died in the womb or after premature birth.
Another possibility is a teratogen, which is a birth defect-inducing toxicant along the lines of thalidomide.
Nolan is planning to analyse tissue using mass spectrometry to look for toxicants or metabolites. But reports of a handful of other similar-sized skeletons from Russia and elsewhere has him leaning toward a genetic explanation.
William Jungers, a palaeoanthropologist and anatomist at Stony Brook University Medical Centre in New York, said that this looks to him like a badly desiccated and mummified human foetus or premature stillbirth. He noted that "barely ossified and immature elements" of the hands and feet, and the wide open metopic suture, where the two frontal bones of the skull come together down the middle of the forehead.
Nolan said that the number of ribs and epiphyseal plate densities remain a riddle; while he is open to the foetus hypothesis, he thinks that the jury is still out.
The study has been published in ScienceNOW, the online daily news service of the journal Science.