Adaptation
An essay by ecologist, writer, and Mississippi transplant Christopher Norment on adapting to a new age and environment.
There’s a joke about summers in Mississippi that I like: try not to go outside between 11:00 am and October first. There’s a kernel of truth there, but because I am an outdoors person and Mississippi is now my home, I need to be happy in its summer sweat-farm outside world of here and now. But there’s a problem with my goal: at seventy-three, I’m not well adjusted, physically and psychologically, to Mississippi’s summer weather. I spent the first seven decades of my life in more benign climates, where the heat and humidity rarely double-teamed me into lassitude, dehydration, and maybe a touch of heat exhaustion, and there’s no way that I can stare down 90°F-plus air temperatures when they’re combined with relative humidity levels that often rise above 90%. I prefer my heat very dry; otherwise, I’m likely to become shaken and stirred.
What the Mississippi summer demands of me, then, is one form of biological adaptation: short-term adjustments in behavior, physiology, or structure to become more suited to a particular environment. The second biological definition of adaptation is “a heritable behavioral, physiological, or morphological trait that has evolved through the process of natural selection, which maintains or increases the fitness of an organism under a given set of environmental conditions.” The first form of adaptation occurs in individuals, over relatively short chunks of time. The second form is a population-level process that requires much longer (i.e., evolutionary) time periods. My successful adjustment to summers in Mississippi mostly involves the first form of adaptation, although the second also plays a role—but more on that later.
Fortunately, I’m an early morning person, because that’s when Mississippi’s summertime blues play most softly upon my body and soul, whether I’m watching the day come on, running, walking our cat, or doing yardwork. I’m often up at 5:00 and out on the screened-in porch with hot black tea at first light, listening to birdsong as the dawn chorus builds. On alternate days, I follow porch time with an early run at a local park. Although I’m no longer an eager morning runner, the heat and humidity mandate this behavioral adaptation. There are a few midday, mad-dogs-and- Englishmen-type summer runners around Jackson, but they’re pushing physiological and mental limits that are beyond me. And they rarely look happy, which is what I want to be when I run. So off I go, well in advance of the day’s worst heat:
It’s 6:30 am; the air temperature is 82°F with a relative humidity of 94%. My glasses fog when I leave the airconditioned car and wade into a viscous mix of water and air. After a few gentle stretches I walk a few hundred yards to loosen up and then begin jogging. “Slow” is the order of the morning as I slip into my post-modernist “running” pace of roughly 13-minute miles. I’d like to maintain a pulse in heart rate zone 2 (easy) or 3 (steady aerobic) and stay fully present in the somnolent summer morning, in the riot of vegetation and bird-noise that surround me as I wind through the shrubby green canopy that envelops my trail.
Night heron calls drift up from the Pearl River and prothonotary warbler songs float through a cypress swamp. There’s a scatter of red-and-yellow honeysuckle flowers along my route and the massive white blossoms of swamp rose-mallow rise along the banks of turbid Mayes Lake, where the alligators drowse. Easy pace, watching my pulse, not wishing to be anywhere else: no yearning for faraway mountain meadows allowed on this muggy morning. The air is heavy and at times almost fetid; after a mile my shirt is sweat-soaked, but my pulse holds steady.
I focus on breathing, but after another mile my pulse begins to rise—mostly because my circulatory system is working to offload heat from its core to my surface. But evaporative cooling is a terribly inefficient process in the almost-saturated air. Sweat pools on my skin and by mile three, I am mostly done. There will be no long outside runs for me in Mississippi’s summer heat, even though Jackson offers up an annual, late July Big Butts ultramarathon with 100-kilometer and 50-kilometer options. Thank you very much, but five summertime kilometers is as much as the market can bear—and these days I’m mostly experiencing a senescent bear market.
Of course, out on the running trail it's not always harmonic sweat and sweetness. Although I’d like to become a better friend with sweat, our relationship remains uneasy, and on some mornings running metamorphoses into a sluggish and sticky dissonance. I never find an easy rhythm and feel like I’m drawing each oxygen-impoverished breath from inside a soggy plastic bag—appropriately so, because saturated air contains less oxygen than does dry air. And on the most oppressive days, when the NOAA website promises a heat index above 100° Fahrenheit, I opt for the ersatz mountain country near Davos, Switzerland, courtesy of a YouTube trail running video, treadmill, and air-conditioned gym. This is the province of caged hamsters, but still: those beautiful mountain trails, that cool and crystalline air, even if they’re of the virtual variety. One can always dream.
Yardwork comes after running, breakfast, and a backyard walk with Young Darwin the cat. Unless it’s raining or brutally hot, Darwin also is eager for the outside world, although he must suffer the indignity of a harness and leash, lest he vanish into the wilds of our Jackson neighborhood or hone the hunting skills that make him a natural-born killer. Minus a firm check on his inclinations our yard would be littered with songbird feathers and macerated lizards. Walks with Darwin last at least 40 minutes, although by his standards that’s rarely adequate and we often are out for an hour or more. The rules for our walks are straightforward. The cat decides where we go, as long as he avoids roads and doesn’t roam far into a neighbor’s yard. He also can choose his activity, if he doesn’t climb more than ten feet up a tree, lead me into thorny bushes, or kill a vertebrate. Stalking prey is acceptable; the leash prevents his final pounce, although imperfect supervision means that our yard is now The Home for Tailless Lizards.
Darwin’s (the man’s, not the cat’s) “descent with modification” means that humans share a common ancestor with all organisms. In the case of cats (carnivores) and human (primates), their evolutionary lineages diverged about 87 million years ago. Our two species are close relations, sharing placenta and fur, milk and sensory neurons, and remarkably similar genomes. Although the sensory details of our Mississippi worlds undoubtedly differ, they turn in similar ways, and his walks are rich, varied, and involve all his senses. He’s certainly visually oriented: a robin foraging on our lawn elicits a predator’s crouch: front paws extended, body linear and tense with electric energy, utterly engaged. Quivering. His tail twitches repeatedly and he utters a rapid series of “eh-eh-eh”s. For Simone Weil, "Absolute, unmixed attention is prayer," and so Darwin's intense focus just might be a form of predatory prayer. But he’s an olfactory being, too, and sniffs just about everything he encounters—much more often than when he’s inside. He’s also tactile (dipping his front paws in water, stirring the dirt in his favorite excavation), and auditory (loud sounds startle him, while the chatter of an alarmed gray squirrel draws his attention). And he’s a taste-oriented botanist, sampling many different plants during his daily rambles, from grasses to blueberry shrubs. Cat puke often follows. In all this I can watch, closely, as he moves through the world, and his focused attention allows me to focus my attention, too—and by doing so, better adapt to the Mississippi world that we share.
In the botanically profligate Mississippi summer, “yardwork” for me mostly means mowing and keeping the weeds at bay—a plant war that I’ll never win. Nor will I break even, because my work is limited by the summer sun. Once I finish circumnavigating our yard, it’s back to the start, where the weeds are again running riot: Sisyphus had his boulder, while I have my weeds. Although “weed” is a matter of definition and perspective, I am no fan of invasive plants. Alas, but we’re far from a mythical Garden of Eden; according to Answers in Genesis, before Adam and Eve made their poor dietary choice, “weeds” were a non-issue. But here in sinful Mississippi, here they are—and because Monsanto’s poisons are not a broad-scale option I hand-pull the suckers. The odd thing is, though, that I have come to enjoy weeding. A decade ago, I would not have embraced such a quotidian and perverse pleasure—but then, a decade ago I never would have imagined living in Mississippi. But I like the rhythm of the work and unlike with many chores, it’s easy to measure my progress, despite the futility of my task.
Whatever I do outside, I drink plenty of liquids—and I’m not talking mint juleps. One product of human senescence, including mine, is an increased susceptibility to dehydration and its debilitating effects. A newborn is about 70% water by weight, while in older people like me (sigh) that value falls to about 50%, which reduces the body’s buffering capacity against dehydration and thermal stress. Aristotle proclaimed that “Old age is dry and cold,” but he never spent a summer in Mississippi, where old age is dry, hot, and sweaty. So, bring on the water, seltzer, electrolyte replacements, more water, and an occasional soda.
But there are limits to what wise temporal scheduling, a slow and steady pace, and hydration will do for a body (and mind). This brings me to the second form of biological adaptation, which occurs over evolutionary time. Although both kinds of adaptation help us adjust to demanding environmental conditions, the second form (I’ll call it selective adaptation) also constrains our ability to adjust. Selective adaptation means that endothermic mammals—ones that mostly use metabolic heat to maintain their body temperature—have evolved three main strategies for dealing with their thermal environments: avoidance, tolerance, or regulation. Whatever mix of strategies is present in a species probably has to do with its phylogeny (evolutionary history), body size, and the habitats it occupies (or once did).
Relative to Mississippi summers, I could become an avoider and permanently retreat to an air-conditioned space. Although I give great thanks for air conditioning (and a spoiled twenty-first century me wonders how people ever lived here without it) and pray for the power to stay on, I won’t constrain my days by always retreating inside. What I can’t be, though, is a good tolerator, like a camel. Desert camels regularly experience body temperatures up to 105°F and can lose 25% of their body water without substantial impairment. Conversely, humans have evolved to be archetypal regulators and must maintain most of their physiological parameters within very narrow ranges. Unlike camels, losing just 6% of our body water leads to impairment, while a 105°F body temperature is life-threatening. From the standpoint of environmental physiology, we are partial prisoners of our evolutionary history, which affects how our body talks (RIP, Olivia Newton-John). And I’d better listen.
It’s 9 in the morning and I’m weeding the sinuous, cobble-lined ditch that facilitates drainage in our backyard. The ditch is dry and I’m in the bottom, kneeling on a small mat and attacking my least favorite weeds, carry me seed (Phyllanthus amarus) and Virginia buttonweed (Diodia virginiana). Virginia buttonweed spreads by aboveground and underground runners, while carry me seed has a tight set of fibrous roots and tends to reproduce sexually. Both species are the Devil’s spawn; they’re very good at what they do and can quickly overwhelm the rocky banks. My enmity toward these plants is unreasonably intense, a byproduct of my desire for a small measure of control in the face of the world’s chaos. (“Oh! Blessed rage for order,” wrote Wallace Stevens. He yearned for order in Key West, while here in Jackson I carry the same angry desire.) Simply plucking individual plants produces a temporary cosmetic improvement, while ignoring the root of the problem (ha), because the roots usually remain embedded in the rocks. So, my work consists of removing each rock sheltering the Devil-weeds and tearing out their roots, before replacing the rock and moving on to the next offenders. Despite the tedium of my task, I love being out in the morning. And as with running and cat-walking, I opt for slowness, pleasure, and presence: seeking the shade, downing lots of water, listening to birdsong, searching out anoles and skinks, watching light gather in the oaks, enjoying the slightest touch of a blessed breeze on my sticky skin.
After an hour of work, I find a place to sit, remove a glove, wipe the sweat from my eyes, take a long pull from my water bottle, and mark the advance of sunlight toward my shaded spot. A flock of fish crows move from south to north; their corny uh-oh calls suggest that they’ve been up to no good, which is likely true. They’re mischievous punks. A pair of cardinals issue a stream of agitated chinks as they shepherd their newly fledged young through shrubs along the eastern border of the yard. As I watch the cardinals, I realize that there’s more to my Mississippi adaptation than maintaining a constant body temperature, attending to hydration, paying close attention to the world, and cultivating slowness.
I want to adapt to this place in a way that will make it my home, despite its taxing summer climate, irritating weeds (picky, picky), infuriating politics, and blood-stained history. Most of all, though, I want to adapt to my senescence, which constrains so many aspects of my septuagenarian life, including how I interact with the hot and humid physical world of Mississippi, as well as its political and social environments. And my hoped-for adaptation is partly a matter of confronting a sweatiness more profound than what’s generated by the Southern summer: the existential variety, which flourishes as my years accumulate and senescence gnaws away at my physical suppleness and behavioral flexibility. And along with carry me seed and Virginia buttonweed, there are those psychological weeds that require my attention—anger and regret, and the tendency to indulge in some personalized version of restorative nostalgia as I yearn for an idealized past that never was.
As I age and senesce, being fully present in this world requires physical, emotional, and intellectual adaptation—a mélange of compromise, acceptance, push-back, and wisdom. The Latin root of “adaptation,” adaptare, means “to fit.” And how badly I want to fit: with this day, with the unfamiliar natural and cultural world of the Deep South, with this complex and challenging place, with the people I love here, with my aging body and less-agile mind—and with that tiny Carolina wren, singing his tiny heart out from a nearby water oak.
This is marvelous. I enjoyed every word.
What a wonderful weaving together of personal and evolutionary adaptive strategies! I love this essay, especially your description of weeding. I too struggle with Phyllanthus but I’ve (incorrectly?) identified it as P. urinaria, or chamberbitter - a name I remember by thinking of my feelings about the Supreme Court chambers. My second worst weed is Fatoua villosa, mulberry weed. Are you blessedly free of that? Thank you for this essay, and for your commitment to adapting to Mississippi!