Science!
Why Water Bears Are Practically Immortal
By Daniel Starkey 08.01.2017 :: 7:00AM EST 08.01.2017
@dcstarkey
Source: http://www.mikro-foto.de/ by Frank Fox Used under Creative Commons License 3.0
Tardigrades are well-known as one of the hardiest creatures on earth. Also known as the water bear (or, more rarely, the moss piglet), tardigrades can take enormous amounts of radiation, survive in the vacuum of space and endure just about anything else we can throw at them
That's bizarre because they don't really… Need all of that. Evolution tends to only select for traits that a creature can use, because most advantages or adaptations take energy to grow and maintain. If it isn't useful, it gets cut because it's a waste. Since these cute little animals just sort of nibble on moss and algae, it's a bit unusual for them to be tougher than the Hulk on a rough day.
To better understand how tardigrades survive all these extreme environments, a group of researchers gathered DNA from two different species and compared. Previously, it seemed, that water bears were one of the few multicellular organisms to transfer genetic material horizontally. That's a bit like trading eye color with just about anyone you meet. Instead of being bound by the genes you're born with, you could actually change your DNA partway through life.
This ability really only works with very simple organisms like bacteria. The more complex anything gets, the easier it is to muck up. It wouldn't be a very good idea to randomly swap out genes in humans based on what we wanted. There's no telling what kinds of systems or organs or traits it could spill over to, which could mean a very rough time for us.
New findings, however, contradict this early assumption. These extremophiles have indeed swapped DNA with other basic organisms, but that's been rather limited. Researchers found that less than 2% of their genes originated from bacteria, for example. But those that did were responsible for some of the creatures' most important survival tactics.
For example, water bears, as their name implies, live in water. Even those that wander about on land do so in a thin film of liquid to keep themselves hydrated. If conditions change, however, and it starts getting a bit too dry, they can form a rigid internal, cellular skeleton made out of specialized proteins. These molecules don't evaporate like water, and they help the creature maintain its shape, putting it into a specialized type of hibernation until it can get to water again.
The species studied also had two different methods for protecting themselves. One was able to prepare almost immediately, with very little forewarning. The other would die unless it had time to produce the special proteins.
Studying these little animals is an important first step in understanding one of Earth's most mysterious creatures. In an interview with Wired, one of the study's authors, Mark Baxter, mentioned that we might one day be able to manufacture these special proteins ourselves so that we could preserve things like vaccines for far longer than we would otherwise be able to. This would, Baxter argues, dramatically increase our ability to get medical supplies that need to be refrigerated out to people in remote areas.
It's even conceivable (though many, many decades off) that we could eventually apply our understanding of water bear physiology to ourselves and dramatically increase our own lifespans. For now, though, more study is needed. But with genetic sequencing getting cheaper and more accessible all the time, it's likely we'll be getting a flurry of new insights into the complex inner world of these awesomely cute microbes.
long-lived
microscopic
tiny animals
water bears
More in Science!
01.17.2020 :: 9:48AM EST :: Stephanie Mlot
Female Lion Dies Days After Losing Her Mate at Chicago Zoo