The only animal known to survive the extreme environment of outer space without the help of special equipment turns out to have the most foreign DNA of any species.
Water bears, also known as tardigrades, have genomes that are nearly one-sixth foreign, meaning that the DNA comes from creatures other than the animal itself, new research finds.
The discovery, published in the Proceeding of the National Academy of Sciences, adds to the evidence that tiny water bears are incredibly unique and seemingly indestructible animals. In 2007, some were even rocketed into space on the outside of a satellite.
Animals With Mad Skillz: Photos
When the satellite returned, many of the water bears were still alive. What's more, some of the females had laid eggs in space, with the young hatching healthily, as though nothing had happened.
"We had no idea that an animal genome could be composed of so much foreign DNA," co-author Bob Goldstein of the University of North Carolina at Chapel Hill said in a press release. "We knew many animals acquire foreign genes, but we had no idea that it happens to this degree."