Try picturing a 600 lb grizzly bear floating through space without the protection of a handy space suit. Unfortunately for our furry friend, let’s call them Oswald, they would definitely die within minutes due to hypoxia or from the loss of external pressure. Also, Oswald would probably get some gnarly burns from the cosmic radiation. You could imagine that life is just not possible in the vacuum of space for a bear or any organism, due to the extreme conditions.
Well as it turns out, that isn’t exactly true. Scientist have discovered a certain little microscopic animal that can survive in space called a water bear!
What the heck is a water bear?!
Waterbears, also known as Tardigrades or moss piglets, are microscopic, aquatic or terrestrial animals found just about everywhere on earth including: moss, lichen, freshwater, and saltwater. In fact, water bears are present on every continent, in every climate, and every latitude. They get their name from the fact that they look like 8-legged microscopic pandas. They are even kind of weirdly cute! Perhaps what they are best known for is their ability to survive extreme environments. They have been found to exist in extreme temperatures, at high levels of radiation, at high pressures, and even in outer space!!! In addition to all the extreme conditions that water bears can endure, cryobiologists have published findings in the past year showing that these little guys can survive being frozen at -20°C for more than 30 freaking years and then were able to produce more little water bears either sexually or asexually (say what?!). These things are seriously incredible!
So how do these little guys survive these extreme conditions?
Tardigrades combat stresses of the world by pretending to be dead (pretty melodramatic). They literally slow down their metabolic processes to a state, in which they seem to be dead, called cryptobiosis. The mechanisms water bears use to initiate cryptobiosis are not well understood. The best understood mechanism is anhydrobiosis– the change they undergo when when water is not present.
They launch the process of anhydrobiosis by tucking their eight legs and head into a ball (just like I do when I’m stressed!). Then they remove around 95% of the water from their body by withering up into a micro-blob, known as a tun. They replace lost water with a sugar that protects their internal structures from destruction and their metabolism goes down to 0.01 % of their normal activity level until external stress is gone. Just add water and the tuns turn back into water bears (sort of like the sea monkeys we had as kids). Watch the whole process here!
The seemingly deceased tuns are resistant to nearly anything nature can throw at them. In this state of suspended animation, water bears can endure extreme temperatures, pressure, and high concentrations of toxic gasses. In 2007, tardigrades hitched a ride on the FOTON-M3 mission and became the first animal to survive the harsh conditions of open space without the protection of a NASA grade spacesuit.
How did water bears become so bad-ass?
One theory on how Tardigrades got these Bear Grylls-level survival skills is by uptaking DNA from bacteria, archaea, plants and fungi in a process called horizontal gene transfer (learn about it here). It was estimated that almost 20% of Tardigrade DNA is foreign which would be the highest amount of foreign DNA in any animal. However, this data is hotly contested and most likely to be the result of some bacterial contamination.
Honing the Water Bear’s Bad-Assery
Whether or not they contain that much foreign DNA, these little guys are total badasses and should be studied more. The studying of cryptobiosis has lead to some interesting possible uses for the future. One example of ongoing research, using tardigrades for inspiration, is work to make a stable form of platelets for transfusions, which currently are only stable for 3-5 days. This break-through would be life-saving for patients undergoing massive blood loss. It also has been shown that a protein found in the Tardigrade can help shield human DNA from x-ray radiation. Water bears are bad-ass, micro-animals that need further studying to find how we can use some of their unique traits in practical research applications. Who knows maybe the study of water bear cryptobiosis will lead to scientists figuring out how to achieve suspended animation in humans!
Also, check out this how-to video of how to find water bears near you!
|Katherine Kruckowis a graduate of the University of Georgia with a Bachelor’s degree in Microbiology. She is looking for a PhD program to further her passion of studying microbes. When not in the lab she loves hiking, cooking, going to all the concerts she can afford, and reading a good book in her hammock. She also plans on visiting every national park at some point in time during her life. Contact her at firstname.lastname@example.org.More from Katherine Kruckow.|