One day, not too long ago, a British museum curator retrieved a dead preserved specimen of a crusty lichen from the museum collection and walked back to his lab when--oops!--he spilled liquid on the herbarium sheet. (I suspect it was British tea, but the research paper doesn't say.) Now, fluids are not good for century-old specimens, so he inspected it for damage under the microscope.
And there, right under his eyes, some little flat organisms slowly plumped up and began moving! These little critters, lodged in the cracks in the lichens, were "tardigrades." They had been dried-up and totally inactive for over 120 years!
Now, that is a problem in biology. Living organisms aren’t supposed to die and then return to life. So that starts biologists asking “what is life”? Movement? Growth? Reproduction maybe? or response to the environment. But the critical requirement is probably metabolism, that organized chemistry that keeps our cells operating. In plant seeds, this chemistry is slowed down, but it is still going on in the moist cells. But in these 120-year-old tardigrades, the water is lost and the metabolism has stopped completely! At least for tardigrades, biologists now have to define life as just the “organization” necessary to support cell chemistry. Tardigrades are one of a few organisms we know that can completely stop their body chemistry...and then completely start it up again much later. It only takes water to resurrect them from the dead, but there is no mystery about how it happens.
Do we have tardigrades in Kansas? Yes we do. And they can be found in the crusty lichens and patches of moss on the sides of trees and rocks. And that explains the tardigrades need for an on-again, off-again lifestyle. Part of the year, lichens and moss are moist little jungles. And part of the year they dry out.
And do we have any tardigrade experts in Kansas? With only a handful in the world, you wouldn't expect any here. Yet, some years ago a Dr. William Miller came to Winfield, KS after finishing his research on tardigrades in Australia and Antarctica. Tardigrades, it seems, are one of the best-adapted animals for life in Antarctica. With just a short time of above-freezing weather each year–the tardigrades can live during the very brief thaw and then completely shut down for the long cold night. They are one of the few critters that can survive the Antarctic.
While in Kansas, Dr. Miller worked with Kansas science teachers and students to get them searching tree bark and rocks and moss banks. There is no reason why there couldn't be a dozen new species found in our state. Although he now teaches at a college in Pennsylvania, but he uses his internet website to still help Kansas students find new species here.
Meanwhile, if you're asking "What good are they?", you might consider this.
For centuries, humans have dreamed of traveling to distant stars. But there is a problem. That distance is so far, we would grow old and die long before we got there. We can't make that long a journey unless we learn how to shut off all of our body chemistry–something we can’t do yet. Perhaps we will have to learn to do that from the tardigrades.
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John Richard Schrock is Editor of the Kansas School Naturalist. The issue on "Tardigrades" is available free upon request from the Biology Department, Box 4050 at Emporia State University, Emporia, KS 66801
