A few weeks ago, one of my friends relayed a fascinating story about an animal that at first sounded like it was straight out of a science fiction novel because of its abilities, which frankly sounded made-up. He told me that this animal could survive in space, withstand nuclear explosions and extreme amounts of radiation, live in pressures up to one thousand atmospheres and temperatures between -200 and 150ºC, and survive for decades without food or water. Not believing a word he uttered, I logged onto the nearest computer and researched these amazing organisms, known as tardigrades, (which are now my new favourite animals), and found out that I could probably find them in my backyard.
Tardigrades, known colloquially as ‘water bears’, are microscopic water invertebrates that are less than one-millimetre-long on average and found in many habitats but are most prevalently found in mosses and lichens. On first glance, they seem like nothing special, but their unique abilities have puzzled scientists and have the potential to lead to major scientific advancements.
The secret to their superhuman abilities is a process called ‘cryptobiosis’, which is when an organism enters a state wherein all metabolic activity stops, which would kill most other animals. The most common type of cryptobiosis seen in water bears in anhydrobiosis; this is when these animals live without water by curling up into a ball, which slows down their metabolism to 0.01% the normal speed. They can remain in this water-less state for decades and be rehydrated within hours.
The reason they survive for so long both without water and under extreme conditions has been recently discovered when a team of scientists in Japan sequenced the genomes of these extraordinary animals. They discovered that during the process of anhydrobiosis, a special glass-like protein (which is different from other proteins as it does not have the usual 3-D amino acid structures) coats the tardigrade, protecting its body and preserving its cell structure.
The real-world applications of this discovery are numerous. According to researchers, the water bears’ special ability could make other organisms a hundred times more resilient. For example, if this ability is given to plants, crops could become much more drought tolerant, and it could also permit delicate vaccines to no longer not require careful refrigeration.
Another recent ground-breaking discovery about water bears is the fact that they have a radiation shield protecting their DNA. According to scientists, the protein responsible for this could be used to increase human resistance to radiation from X-rays by 40%.
So the next time you go to a park, think of how many of the world’s greatest animals are around you!