What are Tardigrades?
Our universe is filled with the strangest and most incomprehensible phenomena in the world. As humans, our home is small. We are, in every conceivable way, a planet of mindless brutes floating on a tiny blue speck of nothingness in a cold, unfeeling, uncaring universe. Nihilism notwithstanding, physicists, chemists, and biologists will disagree with my assessment. Our planet—and only our planet as far as we can tell—is populated with some of the most diverse assortments of creatures in the universe.
We live in a planet where, over the span of a week, one can find themselves staring down the snout of an angry wildebeest, petting the soft fur of an alpaca, and attempting to outrun an angry hippopotamus. However, there are fewer animals more interesting—and more bewildering—than a tiny, barrel-shaped microorganism with four pairs of stubby legs.
The tardigrade—or water bear—is a microscopic organism part of the kingdom Animalia. It has eight legs, lives primarily in water, and is—to the knowledge of the world’s leading scientists—one of the only animals in the universe capable of surviving a temperature range between -272 degrees Celsius and 150 degrees Celsius.
How do Tardigrades work?
One must inspect and admire the shear ridiculousness of the tardigrade. These animals can survive normal terran conditions. They can survive pressures about six times greater than those found in the deepest ocean trenches. They can withstand doses of radiation so catastrophically cataclysmic that the human species could annihilate itself, and tardigrades would still survive. Most importantly, tardigrades can survive without food or water—drying out to the point where they are only three per cent water—for 10 years. Then, they can rehydrate, gather sustenance, and reproduce.
Tardigrades are more than some of the universe’s most resilient organisms—they’re creatures that sound so absurd that only a comic book writer could have reasonably envisioned their existence. Yet, tardigrades are very much real and they’ve been sighted everywhere from mountaintops, to the deep sea, to tropical rain forests, to Antarctica.
There are approximately 1,150 individual species of tardigrade that have been classified. Interesting is that tardigrades are eutelic—all adults of a single tardigrade species have the same number of cells. Tardigrade species can eat plants and bacteria, while some species are carnivores that eat smaller species of tardigrade.
Why are Tardigrades important?
There exists a classification for animals capable of surviving and thriving in extreme environmental conditions. Extremophiles are organisms capable of thriving in extreme conditions considered to be detrimental to every other species on the planet. Thermophiles, organisms that thrive in temperatures between 41 and 122 degrees Celsius, are considered extremophilic.
Sadly for the resilient tardigrade, the species is not considered extremophilic because the species does not thrive in absurd environmental conditions—it simply doesn’t die. This distinction should not bother converts to the side of the tardigrades; the tiny creatures are fully capable of surviving the hot burns of a human diss. After all, these are the same creatures that survived the open vacuum of space—complete with the customary accompanying solar radiation—for at least 10 days.
Tardigrades, however, are more than just hobby pets for sadistic human scientists—though it’s important to note that tardigrades are fully capable of surviving the extreme cold of almost absolute zero. Tardigrades are an opportunity for human scientists to better understand precisely why the living things of Earth as so incredibly disposable. For instance, tardigrades are able to survive lethal doses of solar radiation because of their impressive ability to repair DNA damage resulting from such radiation. Answering how tardigrades are able to do what they do is more than just a Nobel Prize-worthy solution—it’s the discovery of the fountain of youth.
What is the future of Tardigrades?
For a single moment, I’d like to shy away from discussing the future of tardigrades. After all, they’re clearly not going anywhere. Science often faces a public relations problem, and the fascination generated by tardigrades might possibly be a step in a dynamic reimagining of science in the public sphere.
It has been said that science is an old boy’s club and that one must pass a significant initiation process before one is welcome in the clubhouse. These sympathies hold true, but it’s equally true that federal governments treat science much like academia treats the humanities—as passing fads ultimately unworthy of research or respect. Organisms like tardigrades can serve the public as fascinating introductions into an inexplicable world of mystery and wonder.
One day, two young elementary school students will stumble across an article on Planet Earth’s tiniest organisms. One student will read on, simply because they love science. The other—a student who’s already given up on science and math—might just click ahead, simply to learn how an organism so tiny can be so resilient in a world so hostile.
As always, I’m excited for the truly absurd possibilities.