Jojo is an Ornate Box Turtle. She lives in our vegetable garden. We first encountered her about 15 years ago, minding her own business among the okra. At some point we learned she likes to eat a grub worm if you offer her one. Or a cherry tomato. She sometimes shows up for a shower when we turn on a sprinkler.
The first time we saw her, we figured she was passing through. We hung out together for a few days, and then she was gone for weeks. Then we saw her again, just about where she was the first time. Then she disappeared for the better part of a year.
They don’t call Jojo’s species “ornate” for nothing. She’s an object of elaborate beauty. The top of her shell is a network of abstract rosettes in bright yellow on a dark green background. Her face and front legs are dabbed with yellow circles, like bright little suns.
We’ve cohabited with Jojo for a decade and a half, but we don’t really know much about her. So when she appears, two or three times each summer, we’re delighted. And we’re fascinated by her mysterious life.
Just last summer my wife Carolyn witnessed, for the first time, Jojo disappearing. She found her half buried in a patch of mud, gradually descending into the muck. Box turtles in Kansas apparently spend a lot of time underground, sometimes as much as two feet deep in winter.
The species was common and widespread across the Great Plains until we started farming here. A creature that needs grass, shade and open water – and especially one that spends a great deal of time in a shallow burrow – suffers when the prairie is plowed or paved.
Lots of reptiles share our property. We see at least four species of snake regularly and several varieties of skink. A few times each summer I discover I’ve killed a snake while mowing the grass. I hate that but I haven’t figured out a way to prevent it. Even mowing very slowly I can’t seem to pick them out ahead of my mower in the grass, and they evidently don’t know how to get out of my way.
One of my horrors is that I’ll hit Jojo, buried in the garden, with the rototiller. To maintain some control over the garden weeds we have cultivated the garden several times over the course of each summer. Every time, I wonder whether I’ll crush or dismember Jojo with the machine.
Partly to minimize the tilling, we’ve been building raised garden beds from old lumber. It’s easier to control the weeds inside the beds and they can be tilled by hand with a garden fork just once or twice a year. Also, my aging gardener’s body prefers weeding on a stool, so the raised beds are at a friendlier height.
Minimizing our tilling has other benefits as well. Soil is packed with life. In a single gram (a quarter-teaspoon, roughly) of healthy soil scientists find 200 million individual bacteria; a million fungi; 100,000 algae; 10,000 protozoans; and a thousand nematodes. Tilling, just for one summer, can destroy two-thirds of those living things and then it takes years, or decades, for them to return.
Farming and gardening connect us with all these other families of living things being sustained by – and sustaining – this land. It’s sort of a group project. When I sink a trowel in the garden soil to remove a thistle my interests are obviously different than the thistle’s, not to mention the hundreds of millions of soil microbes whose lives I’m disturbing. But we’re all seeking our livelihood here, side-by-side, sometimes competing and sometimes cooperating. We all ultimately benefit from a healthy system. If we can contribute to the general well being we have a chance to improve life for everybody.
As we distribute manure and irrigate our flowers and vegetables, we try to nurture and improve the health of the soil. When we nurture the soil we are, in fact, nurturing the billions of creatures on whom the soil’s health depends.
And healthy soil creates more valuable food for us, as well. Healthier soils produce more nutritious foods.
Soil is not dirt. At least not the dirt we usually refer to when we say “dirt”. The ground beneath our feet, when it’s healthy, is a souffle of minerals, organic matter and myriad creatures. This living alchemy generates beauty, nutrition and oxygen. The health of the soil is fundamental to the health of every living thing.
Under a microscope healthy soil is revealed to contain a menagerie of tiny hyperactive denizens: bacteria like tiny grains of rice or beans; hairy protozoans and worm-like nematodes that feed on the bacteria; and predatory arthropods, relatives of lobsters and crabs, with armored bodies and powerful jaws that prey on the nematodes and protozoans.
Grubs and earthworms are the dominant leviathans of subsurface life. The pudgy, pink earthworm is an omnivorous titan of the underworld. They eat both plant material and every variety of microorganism, leaving behind slime-lined tunnels and trails of fertile waste, which in turn nourishes plant roots and new generations of microbes.
Grub worms are larvae, destined to emerge next spring as one of 350,000 species of beetle. The most iconic, and some of the most common of them, are the scarabs sometimes known as dung beetles.
As a kid growing up in the Chihuahuan Desert of southern New Mexico I was enchanted by a flying scarab known as the Green June Beetle, which we called June Bugs. Their shells appear a gorgeous, iridescent green, an effect scientists call “structural coloration” because microscopic structures on their surfaces are designed to reflect blue, turquoise and green light frequencies, so in the sunlight they offer the vivid, shifting appearance of precious stones.
More common than June Bugs in that desert was the comical ground-dweller we knew as the “stink bug,” the Pinacate Beetle perpetually stalking about the desert floor. Easily riled, the Pinacate Beetle’s defense mechanism is to raise its hind end and squirt a noxious chemical. I could never smell it, but the beetles were everywhere so it must have worked, somehow, to repel predators.
Both the glamorous June Bugs and lowly stink bugs are dung beetles. Their larvae are grub worms that feed on the feces of larger animals. The grubs will live in a pile of dung if they can find one spacious enough. Shit is their food, and often their nursery.
The ancient Egyptians revered dung beetles as symbols of transformation and resurrection. In their hieroglyphs a beetle literally meant “to become,” or “to transform.” Some scarabs form balls of dung and roll them across the ground. The beetle-faced Egyptian god Khepri, in identical fashion, rolled the sun across the sky every day, literally equating the source of all life – the sun – with a ball of shit. The ancient Egyptians seem to have understood soil health and its importance to living things pretty well.
Now we have science to help demonstrate that the soil, and the dung that fortifies it, are as important as the sun to energizing earthly life.
From first-hand observation the Egyptians knew, 5,000 years ago, that dung nourished the soil, and soil continuously recycled waste into new vitality. This cycle remains as important today as it was during the reign of the Pharaoh Wazner.
The soil’s vital efficiency is reliant on the diversity of its resident species. Soil microbes facilitate biochemical reactions in a critical chain of events that is interrupted by the absence of diversity. When we kill off a percentage of the living things in a field, the plants grown there are less successful and the food we harvest from them is less nutritious.
A bunch of stuff we’ve been doing lately – plowing, applying pesticides, applying industrial fertilizers – has negative effects on the living diversity of our soil, and its fertility.
Like the soil, our bodies also contain a surprisingly diverse cast of characters. More than half the cells in your body are not human. Only a little over 40 percent of the cells inside your skin carry human DNA. And because human DNA is relatively simple, with fewer genes than other organisms, if we add up all the genes in a human body the microbial genes can outnumber the human genes a thousand to one. The total number of non-human living creatures in a normal adult human being’s digestive system is said to be between 10 trillion and 100 trillion.
Healthy soil, by volume, contains just about the same number of microorganisms as a human body. But recently our bodies and the soil have both been depleted of their microbial diversity by modern lifestyles and industrial agricultural practices. Our homes, bodies, pastures and fields have become dramatically less hospitable environments for microorganisms, lately. It’s becoming more and more clear that the health and diversity of the soil biome is most likely related to what’s going on in our bodies. We’re beginning to suspect that health of the soil is necessary to the health of our bodies, including our brains.
We’re just beginning to study myriad health effects of changes in the populations of microorganisms in human bodies, which are generally referred to as the human “ biome.” We know quite a bit about specific gut organisms that can make us sick – Typhoid, Shigella, Salmonella, etc. – but very little about the thousands of species that peacefully share the space within our skin. However, there’s a bunch of new evidence that the health and diversity of a person’s biome has a profound effect on individual health and studies have connected a lack of biome diversity to obesity, heart disease and, astonishingly, a number of psychiatric diseases.
The longest nerve in your body is the vagus, or pneumogastric nerve that connects your brain to your heart, lungs and digestive system. It also branches off to the laryngeal nerve to control speech; and to sensitize parts of your ears. It creates your gag reflex. If the vagus nerve is stimulated by something perceived as harmful in your stomach, it makes you vomit. It controls hunger. When it’s damaged, a person may eat uncontrollably or not feel like eating at all. It can carry the sensation of orgasm from your sexual organs to your brain. If you are frightened suddenly, it’s the vagus nerve that causes you to pee yourself.
Artificially stimulating the vagus nerve can help patients with severe depression. A damaged vagal nerve can cause tiredness, dementia and paranoia.
Parkinson’s Disease is believed to start in the gastrointestinal system and spread, via the vagus nerve, to the brain. Scientists are investigating the possibility that microorganisms in the gut, when they are injured, may be sending messages through the vagus nerve that have a negative effect on the dopamine reward system, and that this negative effect could eventually induce Parkinson’s Disease.
We don’t yet have an understanding of the biome’s role in all this. We know that most of the non-human living things within our bodies are in the gut. We know our biggest neural pathway, the vagus nerve, carries information from the digestive system to the brain.
So just how many of our thoughts and moods are influenced – or dictated – by the microbes? That, we don’t know. Maybe a lot of them.
Unhealthy soil can create an unhealthy gut, which may create an unhealthy mind.
Some scientists are suggesting that we should view human beings and their microbial inhabitants; the soil; the plants; the bacteria in the air and in our food as one “superorganism” connected through a microbiome that transcends the barriers between species. The trillions of living things that share our bodies migrate in and out through our food, drink and air. When you pick up a bell pepper at the farmer’s market, put it down and then rub your eye, you’ve most likely distributed some of your biome to the environment, and some of the biome’s environment to your body. And so, with each passing moment, your body transforms with the introduction or depletion of new residents.
This might be disturbing. We have, after all, been trained to avoid “contamination” by “germs.” But from another perspective I sometimes feel thrilled by the notion that my existence isn’t conscribed by my skin, my brain or even my species. It feels like a great thing to be part of the “superorganism” that inhabits this planet, carrying on its immense, communal life around the globe for eons.
Compassion, in that context, is also self-interest. The health of the planet and its myriad creatures can’t really be meaningfully separated from the health of our own bodies.
We accuse narcissists of “navel-gazing,” or living in a state of preoccupation with themselves. So it’s ironic, and maybe amusing, that to contemplate our own navels, stomachs, intestines and organs is, in fact, to contemplate a vast menagerie of creatures that live there, and influence our lives in profound and mysterious ways.
We’re building garden beds and retiring the roto-tiller because, in part, we were worried about Jojo. We don’t want to kill her with our machine. That sentimental concern has led to the contemplation of many layers of cause and effect, from a turtle, to grub worms, to soil microbes, to dung beetles, to vegetables, to our stomachs and back to our own minds.