 | Slither: How Nature’s Most Maligned Creatures Illuminate Our World is a comprehensive exploration of snakes—for their own sakes and as cultural bellwethers of human attitudes. The author describes the “push-pull” he experiences of “a relationship [toward snakes] built of equal parts fascination, fear, admiration, and perhaps a secret sentimentality of a particularly wise and despised form of Otherness.” He provides ample evidence that we’re biologically wired to react to the quick movement of snakes, “yet culturally wired to channel that reaction in a particular emotional direction.” Hence why snakes have been revered as sacred in some cultures and despised as evil in others. |
As “cold-blooded” animals, snakes use the environment to control their body temperature. One scientist commented, “I really want to know what it’s like to crawl out from under the rock on a cold morning and feel your body warm up and feel your organ systems start to switch on and your brain start to work. That must be an amazing sensation.”
 | Asklepios is a Greek god of healing, closely associated with snakes. In healing centers dedicated to him, known as Asklepions, “free-ranging non-venomous snakes may have been allowed to slither unrestrained throughout the gymnasium-like dormitory while the patients slept. In the morning, patients would recount their dreams to the attendant physician-priests, who interpreted the dreams and translated them into a strategy for healing.” The snake was viewed as an “incarnation of the god.” Archeologists have uncovered more than 903 of these snake-centric healing sanctuaries. The author notes, “The cult of Asklepios—with its reputation of healing and its essential association with snakes—permeated all levels of Greco-Roman culture for nearly a millennium.” |
Snake venom kills tens of thousands of people each year. These toxins “wreak four main types of havoc: breaking down cells and tissues (known as cytotoxins), breaking down muscle to thwart movement and get a jump start on digestion (myotoxins), disrupting the ability of blood to behave properly, either clotting too much or too little (hemotoxins), or short-circuiting the function of nerve impulses that affect motor control and breathing (neurotoxins).”
Scientists have been able to repurpose these toxins into drugs used to dissolve blood clots or block hemorrhaging. Ace inhibitors such as Lisinopril are derived from the venom of a South American pit viper.
Scientists have been able to repurpose these toxins into drugs used to dissolve blood clots or block hemorrhaging. Ace inhibitors such as Lisinopril are derived from the venom of a South American pit viper.
 | Snakes “curing” cancer. Snakes like pythons, who may only eat one giant meal a year, transform from a prolonged fasting cycle into an intense digestive machine in a matter of hours. They do this by activating approximately two thousand genes that enlarge and accelerate the metabolism of multiple organs: the heart enlarges to pump more blood, the liver and kidneys similarly move into high gear, and they grow more intestines. |
After the meal is digested, all of these organs turn off and shrink back down to their fasting size. “These changes—dramatic growth and shrinkage, rapid cell proliferation and targeted cell death—were driven at the cellular level by well-known molecular processes that build and eliminate cells.”
“It’s almost like the snakes create a short-lived form of cancer to meet the extraordinary demands of digesting a huge meal, then ‘cure’ the cancer by cutting it out once digestion is complete.”
“It’s almost like the snakes create a short-lived form of cancer to meet the extraordinary demands of digesting a huge meal, then ‘cure’ the cancer by cutting it out once digestion is complete.”
 | Snakes smell in 3-D through their tongues. The molecules collected by each tine of the tongue are interpreted by two organs on the roof of their mouths. Per the author, “the two separate tines of a snake’s tongue gather molecular ‘data’ with such precision that the difference between left and right tine provides a chemosensory gradient that [creates] a three-dimensional perception of space.” |
Snakes with pit organs can detect infrared radiation. “They can discern variations in temperatures to a level of precision as small as 0.003 degree Celsius—three one-thousandths of a degree.” By studying how a snake’s sense of vision, heat, and smell interact in the brain, scientists believe snakes combine all of these inputs to create a single “somatosensory map” of their environment in a type of sensory synesthesia.
 | Snake Sex. Some snakes can reproduce by parthenogenesis (without male sperm) and there are “a confounding percentage of intersex individuals—snakes that possess the anatomical features of both males and females.” Snake mating has an Otherworldly beauty, and can incorporate elaborate rituals between the two parties. Or can be communal: garter snakes in central Manitoba “congregate in massive copulatory orgies known as mating balls.” |
Female snake reproduction was ignored for decades. Patty Brennan (whose research into duck genitalia was highlighted in The Salmon Cannon and the Levitating Frog) also studied female snake reproduction. Her collaborator, Megan Folwell, was the first scientist to discover and document a female snake clitoris. They demonstrated “that female serpents have evolved incredibly cunning mechanisms to exercise reproductive choice—even after copulation. They can constrict vaginal muscles to squeeze out [male penises]. They can close the gate to their oviducts, preventing insemination of their eggs. They can create a more acidic genital microenvironment that effectively kills unwanted sperm.”
Brennan says females are often “portrayed as passive, as somehow victims; they’re waiting for the males to fight it out so that they can then mate with the male. That is an inaccurate portrayal of females, and complexity in females. . . . Because they’re not passive vessels. They are active evolutionary agents.”
Research has demonstrated that females in some species can store sperm for a year or more, choosing when to self-fertilize. There is also a species "native to India and Southeast Asia in which all the individuals are females and all the offspring are clones of the mother," similar to Lesbian Lizards.
Brennan says females are often “portrayed as passive, as somehow victims; they’re waiting for the males to fight it out so that they can then mate with the male. That is an inaccurate portrayal of females, and complexity in females. . . . Because they’re not passive vessels. They are active evolutionary agents.”
Research has demonstrated that females in some species can store sperm for a year or more, choosing when to self-fertilize. There is also a species "native to India and Southeast Asia in which all the individuals are females and all the offspring are clones of the mother," similar to Lesbian Lizards.
Snake Dance. Snakes “started out with legs in the deep evolutionary past” then dropped their limbs “roughly 85 million years ago.” Yet snakes can “negotiate a dizzying array of surfaces and obstacles—dirt, sand, water, mud, muck, rock ledges, poles, crevices, burrows, trees, forests, deserts, oceans, swamps. They crawl. They swim. They climb. They fly [glide]. They do all those things without limbs.”
 | Sidewinders in particular, have a unique way of moving: their forward movement “is actually at a sharp angle to the axis of the body.” Scientists studying them discovered that the key to their locomotion “was not the side-winding, but the up-and-down wave. . . . the snakes were masters at fractionally adjusting the amount of their bodies that touched the surface of the sand depending on the slope. More of a slope, more body contact with the sand; less slope, less body contacting the surface. The sidewinders made these miniscule, neuromuscular calculations on the fly, adjusting the amount of their body’s surface area that comes in contact with the sand in milliseconds. [It’s] a fully three-dimensional behavior.” |
You can watch a sidewinder in action (beware: it catches a lizard at the 2:23 mark).
 | Invasive Snakes. Snakes are incredibly diverse and successful survivalists. Pythons (released by irresponsible pet owners) have established themselves in southern Florida, but may be poised to spread into colder climes. “At a time when 40 percent of Americans do not accept the notion of evolution, the pythons that survived the [2010] Big Freeze in Florida appear to believe in it 100 percent. The [message] from the snakes is that evolution is real, it’s apparently happening at blindingly fast speed and it argues that the 2010 cold snap may have created a subset of pythons better able to survive cold temperatures—and thus better adapted to spread beyond the northern boundaries of its current range.” |
The author closes with these sobering thoughts:
“[Our] century-long embrace and promotion of the fossil-fuel economy enabled, knowingly or not, population spread, commercial and residential development, habitat destruction, climate change [and turned] all of us into invasive species.”
“[In Nature,] every ecological niche is unique, dynamic, complex. Nature celebrates diversity; all those name-brand franchises lining [the roads] reminded me that commerce and ‘civilization’ demand conformity, predictability, consistency. Development is a form of predation [where natural habitats] surrender to the number one predator on the planet, [humans].”
“Although many people believe animals relocate when their habitats are destroyed, most organisms have nowhere to go. Part of the imperial indifference of the human animal is our illusionary belief that there is always plenty of habitat left.”
Respect for snakes and “for nature itself [requires] acceptance of all the things we can’t control.”
Whether or not you’re a snake lover, Slither: How Nature’s Most Maligned Creatures Illuminate Our World is definitely worth reading.
“[Our] century-long embrace and promotion of the fossil-fuel economy enabled, knowingly or not, population spread, commercial and residential development, habitat destruction, climate change [and turned] all of us into invasive species.”
“[In Nature,] every ecological niche is unique, dynamic, complex. Nature celebrates diversity; all those name-brand franchises lining [the roads] reminded me that commerce and ‘civilization’ demand conformity, predictability, consistency. Development is a form of predation [where natural habitats] surrender to the number one predator on the planet, [humans].”
“Although many people believe animals relocate when their habitats are destroyed, most organisms have nowhere to go. Part of the imperial indifference of the human animal is our illusionary belief that there is always plenty of habitat left.”
Respect for snakes and “for nature itself [requires] acceptance of all the things we can’t control.”
Whether or not you’re a snake lover, Slither: How Nature’s Most Maligned Creatures Illuminate Our World is definitely worth reading.
Read other fascinating nonfiction books on nature and science: Sounds Wild and Broken,
If Nietzsche Were a Narwhal, The Forest Unseen, The Underworld, The Light Eaters,
An Immense World, The Hidden Life of Trees, The Salmon Cannon and the Levitating Frog
If Nietzsche Were a Narwhal, The Forest Unseen, The Underworld, The Light Eaters,
An Immense World, The Hidden Life of Trees, The Salmon Cannon and the Levitating Frog
