Humans are not extremophiles: let’s act accordingly
I just started reading Paul Hawken’s Carbon: The Book of Life, and became intrigued by his mention of extremophiles, a term I had never heard before. It turns out extremophiles were discovered in 1969, and that, in fact, I was familiar with some of them, such as the giant tube worms that live in a lightless environment of extreme heat and pressure on the ocean floor near hydrothermal vents, where the water is hot enough to melt lead and is full of a cocktail of toxic chemicals; I was just not familiar with the term.
Extremophiles thrive in environments that are hostile to much of life on earth. They can survive, and, in some cases, have actually adapted to require conditions such as extreme temperatures, high pressure, chemicals that are toxic to other beings, extremes of pH, extreme drought, high radiation, and high salinity.
When I learned that one of my favorite creatures, the tardigrade, who I knew to be an important contributor to soil health, was an extremophile, I had to explore more. I knew tardigrades keep soil healthy by eating microorganisms and making nutrients such as nitrogen, carbon and phosphorus necessary for the survival of other creatures in the soil, but I found there was a lot more to know about them.
Hawkens describes tardigrades as “micro-animals known colloquially as ‘water bears’ or ‘moss piglets’. . . .Tardigrades have existed for over five hundred million years and can withstand nuclear radiation, starvation, oxygen deprivation, and bone-crushing pressure. When completely desiccated, they look like sesame seeds, with no legs. Decades later, if you sprinkle them with water, stumpy little legs re-emerge and they waddle away” (Hawkens 32).
I was surprised to find that tardigrades are actually aquatic creatures, but like other creatures that originally came from the sea, they developed a way to survive outside the water. They need a film of water surrounding their bodies in order to breathe in oxygen and breathe out carbon dioxide, and they can get this in moist soil. But when the soil dries out, they shut down their metabolism and curl up into a dried-up version of themselves, a state in which they can remain and still be revived from for many years.
Because they can survive in extreme conditions, they often are one of the first multicellular organisms on the scene to help get a recovering ecosystem off the ground after a life-changing event such as a volcanic eruption or a wildfire.
Many extremophiles are single-celled organisms, but some are multicellular. Our very own resurrection fern, that grows on oaks, is considered a form of extremophile because it can lose up to 97% of its water and sit for many years appearing dead and shriveled on the side of an oak tree, then immediately perk up at the first drop of rain. “After just one hour, its water content can increase by more than 50%, and it can return to full physiological activity in a matter of hours.” https://pmc.ncbi.nlm.nih.gov/
When I told my husband I was writing an article about extremophiles, he asked, “Isn’t that kind of a misnomer?” What he was getting at is that the word is a combination of a Latin word meaning “extreme’”and a Greek word meaning “lover,” which, when put together, means “lover of extremes.” He ,of course, was questioning whether these creatures, some of them single-celled, were capable of “love” or any sort of judgment of their circumstances, but also, bringing up the point that just because a creature has adapted to challenging environmental circumstances, doesn’t necessarily mean they “love” those circumstances.
And for me, that last is the point. No species, even humans, are capable of evolving at the rate of change caused by human accelerated climate change. Humans are not extremophiles — we are adapted to survive in a very limited temperature and pressure. If you dry us out, we will not spring back to life when sprinkled with a few drops of water.
But some have suggested that humans are extremophiles because our ability to develop technology that allows us to survive extremes is an adaptive feature. It is the case that the only way humans could adapt fast enough to survive a much hotter world would be through the use of technology, but even if we could use technology to survive on a planet where we have killed off a vast majority of all the other life, a planet ravaged by extreme storms, droughts, floods, wildfires and heat, where, for much of the year, in many places, it would be impossible to be outside, would we want to? I know I wouldn’t. I am no extremophile.
Collectively, however, we are behaving as lovers of the extreme as we recklessly continue disrupting the climate we depend on to survive. We need to stop driving ourselves into a situation where we might become extremophiles because our technology allows us to survive the extreme conditions we have created, but we are not lovers of those conditions.
I suppose if we don’t figure it out in time, extremophiles such as the tardigrade will make it through to the other side to start the recovery. But I’m hoping we do figure it out. I love this planet and all the creatures on it. I enter each day with the premise that we will take action to protect it for ourselves, other creatures, and future generations.
Resources and References:
Hawken, Paul. Carbon: The Book of Life. NY: Viking- Penguin Random House, March 18, 2025. Kindle.
https://carnegiescience.edu/
https://ocean.si.edu/ocean-
https://www.amnh.org/learn-
https://frontlinegenomics.com/
https://www.shapeoflife.org/