Every so often scientists stumble on parts of nature that baffle them, for their very existence strays from the very defined and strictly followed laws of nature. The tardigrade, also known as a water bear, is one such case.
These creatures, which are only a sixteenth of an inch long, are somewhat translucent and resemble minuscule hippopotamuses or bears. Tardigrade’s can be found almost anywhere: moss and lichens, bubbling hot springs, and Antarctic ice. They’ve also been found in the Himalayan Mountains and deep-see trenches. They’ve recently become famous for becoming the only known animal able to survive the vacuum of space. Its other claim to fame is that it is the animal with the largest genetic complement (set of chromosomes contained within any one particular cell).
Discovered in 1773 by German pastor Johann August Ephrain Goeze, these microscopic creatures have continued to be intensely studied due to their unique and foreign features. Through hundreds of years of serious scientific observance, scientists have found that tardigrade’s have some truly amazing traits. They are known to be able to survive in temperatures ranging from -458°F to over 300°F. Tardigrades are able to adapt to survive without water by completely drying their body out and replacing the water in their bodies with a sugar called trehalose. They have survived all 5 mass extinctions and have been around longer than nearly every other living organism (approximately 500 million years).
In 2007, Swedish researcher K. Ingemar Jonsson and his team from Kristianstad University, sent tardigrades into space on a spacecraft to low-Earth orbit. These remarkable creatures were exposed to open space conditions, yet were able to survive cosmic rays, deadly levels of UV radiation, and the vacuum of space.
In November of 2015, researchers at the University of North Carolina at Chapel Hill released a publication on the genome of tardigrades. The sequencing of the tardigrades’ genome revealed that a massive portion of the tiny organism’s genome is of foreign origin. Nearly 17.5% of the water bear’s genome is comprised of foreign DNA, which results in about 6,000 genes.The transfer of these genes is believed to occur during the process of desiccation (the druying out described above).
So, what value do we have from studying these microscopic creatures? Their ability to travel through space can give insight on how to better prepare other organisms and possibly humans for future extended space explorations. Their unique DNA can give understanding on how organic material first traveled through the universe and arrived on Earth. Scientists believe there is much more to learn from these little guys, so their value to the scientific and real world is almost immeasurable.
Sources:
http://tvblogs.nationalgeographic.com/2014/03/19/5-reasons-why-the-tardigrade-is-natures-toughest-animal/
http://news.meta.com/2015/11/23/waterbear/
http://www.nytimes.com/2015/09/08/science/the-tardigrade-water-bear.html?_r=0
http://www.americanscientist.org/issues/pub/2011/5/tardigrades/1