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A 6-inch-long skeleton was found in the Atacama Desert in Chile. The skeleton showed several anomalies, including its alien-like skull, teensy body and the fact that it had just 10 ribs rather than the 12.
We've been conjecturing about life on Mars for centuries. In popular culture, the concept of intelligent life on Mars was championed by astronomer Percival Lowell in the late 1800s and his theories on the Martian canals. Science fiction writers -- always game for some reckless conjecture -- took up the banner from there.
Perhaps the most famous Martians in the history of sci-fi and popular culture, the invaders in H.G. Wells' 1898 novel "War of the Worlds," have since spawned dozens of films, TV shows, comic books and one very famous radio drama.
Telescopic observations of Mars in the late 19th and early 20th centuries appeared to show long surface lines that some believed were man-made (well, Martian-made) irrigation canals. Italian astronomer Giovanni Schiaparelli made this map of Mars from his notes on the telescope images.
Science fiction writers often depicted Martians as an advanced humanoid race intent on conquering Earth. In "Flash Gordon's Trip To Mars" (1938), Azura Queen of Mars subjugates her own Martian people. Ray Bradbury would later conceive of a kinder, gentler race in "The Martian Chronicles."
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Space explorer stories were a regular staple in the pulp fiction magazines of the early 1900s, and Edgar Rice Burroughs was another author to speculate at length on Mars' inhabitants. His Martians included the six-limbed, green-skinned Tharks and humanoid Red Martians.
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The so-called Grey Alien is a kind of archetype image of an extraterrestrial -- not necessarily from Mars -- that has arisen from fictional depictions, alleged alien abduction stories and conjecture on what an advanced race of beings would look like.
On July 25, 1976, NASA's Viking 1 orbiter captured the above image on the surface of Mars' Cydonia region. The infamous "Face on Mars" prompted decades of speculation, although scientists have long dismissed the image as an example of pareidolia; e.g. seeing shapes in the clouds, or Jesus in your toast.
Legendary Looney Tunes animator Chuck Jones created the character of Marvin the Martian in 1948 as a foil for Bugs Bunny. As devotees of Saturday morning cartoons know, Marvin is forever plotting to destroy the Earth by way of his Illudium Q-36 Explosive Space Modulator. Apparently, we obstruct his view of Venus.
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Director Tim Burton played around with B-movie tropes and pop art notions of Martians in his 1996 film "Mars Attacks!" Brian De Palma followed up a few years later with "Mission to Mars," a huge critical and commercial bomb. (Although the French critics liked it -- really.)
Bureau L.A. Collection/Sygma/Corbis
As is its eternal wont, pop culture is constantly recycling its own ideas -- Martians included. In 1999, Christopher Lloyd starred as the titular alien in director Donald Petrie's reboot of the 1960s TV show "My Favorite Martian," which was itself inspired by earlier pulp sci-fi stories.
A teensy skeleton with a squashed alien-like head may have earthly origins, but the remains, found in the Atacama Desert a decade ago, do make for quite a medical mystery.
Apparently when the mummified specimen was discovered, some had suggested the possibility it was an alien that had somehow landed on Earth, though the researchers involved never suggested this otherworldly origin.
Now, DNA and other tests suggest the individual was a human and was 6 to 8 years of age when he or she died. Even so, the remains were just 6 inches (15 centimeters) long. (See Images of the Alien-Looking Human Remains)
"While the jury is out regarding the mutations that cause the deformity, and there is a real discrepancy in how we account for the apparent age of the bones … every nucleotide I've been able to look at is human," researcher Garry Nolan, professor of microbiology and immunology at Stanford School of Medicine, told LiveScience. "I've only scratched the surface in the analysis. But there is nothing that jumps out so far as to scream 'nonhuman.'"
Analyzing the tiny human
Nolan and his colleagues analyzed the specimen in the fall of 2012 with high-resolution photography, X-rays and computed tomography scans, as well as DNA sequencing. The researchers wanted to find out whether some rare disorder could explain the anomalous skeleton -- for instance it had just 10 ribs as opposed to 12 in a healthy human -- the age the organism died, as its size suggested a preterm fetus, stillborn or a deformed child, and whether it was human or perhaps a South American nonhuman primate.
The remains also showed skull deformities and mild underdevelopment of the mid-face and jaw, the researchers found. The skull also showed signs of turricephaly, or high-head syndrome, a birth defect in which the top of the skull is cone-shaped.
The genome sequencing suggested the creature was human, though 9 percent of the genes didn't match up with the reference human genome; the mismatches may be due to various factors, including degradation, artifacts from lab preparation of the specimen or insufficient data.
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The team also looked at mitochondrial DNA, or the DNA inside the cells' energy-making structures that gets passed down from mothers to offspring. The so-called allele frequency of the mitochondrial DNA suggested the individual came from the Atacama, particularly from the B2 haplotype group. A haplotype is a long segment of ancestral DNA that stays the same over several generations and can pinpoint a group who share a common ancestor way back in time. In this case the B2 haplotype is found on the west coast of South America.
The data from the mitochondrial DNA alleles point toward "the mother being an indigenous woman from the Chilean area of South America," Nolan wrote in an email.
The jury is still out on the mutations that caused the deformities, and the researchers aren't certain how old the bones are, though they estimate the individual died at least a few decades ago. In addition, they didn't find any of the mutations commonly associated with primordial dwarfism or other forms of dwarfism. If there is a genetic basis for the deformities, it is "not apparent at this level of resolution and at this stage of the analysis," Nolan wrote in a summary of his work.
In addition, even if they found those mutations, they may not explain the anomalies seen in the skeleton. "There is no known form of dwarfism that accounts for all of the anomalies seen in this specimen," Dr. Ralph Lachman, professor emeritus, UCLA School of Medicine, and clinical professor at Stanford University, wrote in a report to Nolan.
This wouldn't be the first time alien-looking remains have been brought to the attention of science. The alienlike skulls of children were discovered in a 1,000-year-old cemetery in Mexico. Researchers who examined the skulls said they had been deliberately warped and illustrated a practice of skull deformation that was common at the time in Central America.
"It's an interesting medical mystery of an unfortunate human with a series of birth defects that currently the genetics of which are not obvious," Nolan wrote of the Atacama skeleton.
The research was featured in film "Sirius," a crowd-funded documentary that premiered on April 22 in Hollywood, Calif.
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