No, not that cousin. I mean the real fungus, the kind that grows where light is scarce and moisture abundant. We usually think of mushrooms as populating the soil, but I remember a spidery fluorescent orange one that grew in the carpet under the drinking fountain just outside my dorm room in college. And who hasn’t joked about the new civilizations forming in the fridge?

What I didn’t know until recently was that we’re related to fungi. Literally. Animals and fungi share a common ancestor called Opisthokonta–a reclassifying that took place after a 2005 paper in the Journal of Eukaryotic Microbiology. As mycologist (fungus biologist) Paul Stamets says,

Fungi and animals share a more common ancestry than with any other group.

What this means is that humans share DNA–about 30 percent–with fungi, far more than we share with plants. Mushrooms are closer cousins than plants.

We often think of fungi as parasitic. The Urban Dictionary’s first definition of fungus is:

Someone who is lazy and does nothing all day (someone who just sits around and rots).

But Paul Stamets, who has been poring over mushroom spores for decades, says the reality is far different–just the opposite, in fact. Fungi take solid matter and turn it into soil.

Mushrooms are the grand molecular disassemblers in nature.

Fungi are doing the primal work–the very hard work–of cleaning up after other organisms. They mediate between life and death, producing more soil so that more plants and animals may grow. Stamets calls fungi “soil magicians.”

It appears that fungi may also help in the very hard work of cleaning up some messes we recently made that we have no idea how to clean up by ourselves. Stamets has had spectacular success cleaning up soils contaminated with petroleum products, as you can see in this 4-minute video:

Fungi accomplish their hardworking miracles through their very weird and wonderful structure of mycelium. Mycelium is the filamentlike strands of one-cell-wall-thick fungus laced throughout the soil. Stamets again:

There are these vast networks of mycelium everywhere in the ground. In a single cubic inch of soil, there could be more than eight miles of these cells.

The largest organism in the world, in fact, is a mycelial mat. It covers 2400 acres in Oregon and is 2200 years old. And the mat is strong:

These mycelial strands can hold 30,000 times their weight. They’re tenacious. They grip the soils. They prevent erosion. They hold water. They establish vast micro-communities for all sorts of other organisms. The mycelial network–we have five or six skin layers–the mycelium only has one. How is it that the largest organism in the world can only be one cell wall thick?

From his decades of working with fungus, Stamets has developed a respect for mycelium that goes beyond dispassionate lab work:

And I present to you the concept that the mycelium is sentient, it is intelligent, it knows that you’re there. And because of the biodiversity of fungi in the ecosystem, when you break a stick or if you’re chopping wood, there is this amazing competition of different fungal populations that reach up and try to grab that new nutrition.

Our cousins, the fungi. Turning death into life. Providing 30 percent of our DNA. Cleaning up after us. Sound like hardworking cousins. Sound like relatives to respect and cherish.

For more info, see the Bioneers program “From Kingdom to Kin-dom: Acting as if We Have Relatives.”