Gathering Moss: A Natural and Cultural History of Mosses

by Robin Wall Kimmerer

All three—mosses, waterbears, and rotifers—figured prominently in a nineteenth-century debate about revivification and the very nature of life. The behavior of these three blurs the distinction at the edge between life and death. All signs of life are extinguished when they are dry: no movement, no gas exchange, no metabolism. All enter a state known as anabiosis, or lack of life. And yet, as soon as water is returned, life suddenly is renewed. Their apparent death, followed by resuscitation, suggested that life might be stopped and then re-started. Waterbears were the subject of intense experimentation to test the limits of their endurance. In the dry state, they were subject to conditions that would kill any known organism: boiling, being held in a vacuum only 0.008 degrees above absolute zero. But, without fail, they tolerated these abuses and were revivified with a drop of water. The addition of water unlocks the chemistry of life by a mechanism that is still largely unknown, but utilized by mosses and waterbears everyday.