On meditation and the birth of the universe.

On meditation and the birth of the universe.

This is part of a series of essays prepared to discuss in jail.

Our bodies are chaos engines. 

In our nearby environment, we produce order.  We form new memories.  We build things.  We might have sex and create new life.  From chaos, structure.

As we create local order, though, we radiate disorder into the universe. 

The laws of physics work equally well whether time is moving forward or backward.  The only reason we experience time as flowing forward is that the universe is progressing from order into chaos.

In the beginning, everything was homogeneous.  The same stuff was present everywhere.  Now, some regions of the universe are different from others.  One location contains our star; another location, our planet.  Each of our bodies is very different from the space around us.

This current arrangement is more disorderly than the early universe, but less so than what our universe will one day become.  Life is only possible during this intermediate time, when we are able to eat structure and excrete chaos. 

Hubble peers into a stellar nursery. Image courtesy of NASA Marshall Space Flight on Flickr.

Sunlight shines on our planet – a steady stream of high-energy photons all pointed in the same direction.  Sunshine is orderly.  But then plants eat sunshine and carbon dioxide to grow.  Animals eat the plants.  As we live, we radiate heat – low-energy photons that spill from our bodies in all directions.

The planet Earth, with all its life, acts like one big chaos engine.  We absorb photons from the sun, lower their energy, increase their number, and scatter them.

We’ll continue until we can’t.

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Our universe is mostly filled with empty space. 

But empty space does not stay empty.  Einstein’s famous equation, E equals M C squared, describes the chance that stuff will suddenly pop into existence.  This happens whenever a region of space gathers too much energy.

Empty space typically has a “vacuum energy” of one billionth of a joule per cubic meter.  An empty void the size of our planet would have about as much energy as a teaspoon of sugar.  Which doesn’t seem like much.  But even a billionth of a joule is thousands of times higher than the energy needed to summon electrons into being.

And there are times when a particular patch of vacuum has even more energy than that.

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According to the Heisenberg Uncertainty Principle, time and energy can’t be defined simultaneously.  Precision in time causes energy to spread – the energy becomes both lower and higher than you expected.

In practice, the vacuum energy of a particular region of space will seem to waver.  Energy is blurry, shimmering over time.

There are moments when even the smallest spaces have more than enough energy to create new particles.

Objects usually appear in pairs: a particle and its anti-particle.  Anti-matter is exactly like regular matter except that each particle has an opposite charge.  In our world, protons are positive and electrons are negative, but an anti-proton is negative and an anti-electron is positive.

If a particle and its anti-particle find each other, they explode.

When pairs of particles appear, they suck up energy.  Vacuum energy is stored inside them.  Then the particles waffle through space until they find and destroy each other.  Energy is returned to the void.

This constant exchange is like the universe breathing.  Inhale: the universe dims, a particle and anti-particle appear.  Exhale: they explode.

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Our universe is expanding.  Not only are stars and galaxies flying away from each other in space, but also empty space itself is growing.  The larger a patch of nothingness, the faster it will grow.  In a stroke of blandness, astronomers named the force powering this growth “dark energy.”

Long ago, our universe grew even faster than it does today.  Within each small fraction of a second, our universe doubled in size.  Tiny regions of space careened apart billions of times faster than the speed of light.

This sudden growth was extremely improbable.  For this process to begin, the energy of a small space had to be very, very large.  But the Heisenberg Uncertainty Principle claims that – if we wait long enough – energy can take on any possible value.  Before the big bang, our universe had a nearly infinite time to wait.

After that blip, our universe expanded so quickly because the vacuum of space was perched temporarily in a high-energy “metastable” state.  Technically balanced, but warily.  Like a pencil standing on its tip.  Left alone, it might stay there forever, but the smallest breath of air would cause this pencil to teeter and fall.

Similarly, a tiny nudge caused our universe to tumble back to its expected energy.  A truly stable vacuum.  The world we know today was born – still growing, but slowly.

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During the time of rapid expansion, empty vacuum had so much energy that particles stampeded into existence.  The world churned with particles, all so hot that they zipped through space at nearly the speed of light. 

For some inexplicable reason, for every billion pairs of matter and anti-matter, one extra particle of matter appeared.  When matter and anti-matter began to find each other and explode, this billionth extra bit remained.

This small surplus formed all of stars in the sky.  The planets.  Ourselves.

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Meditation is like blinking.  You close your eyes, time passes, then you open your eyes again.  Meditation is like a blink where more time passes.

But more is different.

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Our early universe was filled with the smallest possible particles.  Quarks, electrons, and photons.  Because their energy was so high, they moved too fast to join together.  Their brilliant glow filled the sky, obscuring our view of anything that had happened before.

As our universe expanded, it cooled.  Particles slowed down.  Three quarks and an electron can join to form an atom of hydrogen.  Two hydrogen atoms can join to form hydrogen gas.  And as you combine more and more particles together, your creations can be very different from a hot glowing gas.  You can form molecules, cells, animals, societies.

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When a cloud of gas is big enough, its own gravity can pull everything inward.  The cloud becomes more and more dense until nuclear fusion begins, releasing energy just like a nuclear bomb.  These explosions keep the cloud from shrinking further.

The cloud has become a star.

Nuclear fusion occurs because atoms in the center of the cloud are squooshed too close together.  They merge: a few small atoms become one big atom.  If you compared their weights – four hydrogens at the start, one helium at the finish – you’d find that a tiny speck of matter had disappeared.  And so, according to E equals M C squared, it released a blinding burst of energy.

The largest hydrogen bomb detonated on Earth was 50 megatons – the Kuz’kina Mat tested in Russia in October, 1961.  It produced a mushroom cloud ten times the height of Mount Everest.  This test explosion destroyed houses hundreds of miles away.

The fireball of Tsar Bomba, the Kuz’kina Mat.

Every second, our sun produces twenty billion times more energy than this largest Earth-side blast.

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Eventually, our sun will run out of fuel.  Our sun shines because it turns hydrogen into helium, but it is too light to compress helium into any heavier atoms.  Our sun has burned for about four billion years, and it will probably survive for another five billion more.  Then the steady inferno of nuclear explosions will end.

When a star exhausts its fuel, gravity finally overcomes the resistance of the internal explosions.  The star shrinks.  It might crumple into nothingness, becoming a black hole.  Or it might go supernova – recoiling like a compressed spring that slips from your hand – and scatter its heavy atoms across the universe.

Planets are formed from the stray viscera of early stars.

Supernova remains. Image by NASA’s Chandra X-Ray Observatory and the European Space Agency’s XMM-Newton.

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Our universe began with only hydrogen gas.  Every type of heavier atom – carbon, oxygen, iron, plutonium – was made by nuclear explosions inside the early stars.

When a condensing cloud contains both hydrogen gas and particulates of heavy atoms, the heavy atoms create clumps that sweep through the cloud far from its center.  Satellites, orbiting the star.  Planets.

Nothing more complicated than atoms can form inside stars.  It’s too hot – the belly of our sun is over twenty million degrees.  Molecules would be instantly torn apart.  But planets – even broiling, meteor-bombarded planets – are peaceful places compared to stars.

Molecules are long chains of atoms.  Like atoms, molecules are made from combinations of quarks and electrons.  The material is the same – but there’s more of it.

More is different.

Some atoms have an effect on our bodies.  If you inhale high concentrations of oxygen – an atom with eight protons – you’ll feel euphoric and dizzy.  If you drink water laced with lithium – an atom with three protons – your brain might become more stable.

But the physiological effects of atoms are crude compared to molecules.  String fifty-three atoms together in just the right shape – a combination of two oxygens, twenty-one carbons, and thirty hydrogens – and you’ll have tetrahydrocannibol.  String forty-nine atoms together in just the right shape – one oxygen, three nitrogens, twenty carbons, and twenty-five hydrogens – and you’ll have lysergic acid diethylamide.

The effects of these molecules are very different from the effects of their constituent parts.  You’d never predict what THC feels like after inhaling a mix of oxygen, carbon, and hydrogen gas.

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An amino acid is comparable in scale to THC or LSD, but our bodies aren’t really made of amino acids.  We’re built from proteins – anywhere from a few dozen to tens of thousands of amino acids linked together.  Proteins are so large that they fold into complex three-dimensional shapes.  THC has its effect because some proteins in your brain are shaped like catcher’s mitts, and the cannibinoid nestles snuggly in the pocket of the glove.

Molecules the size of proteins can make copies of themselves.  The first life-like molecules on Earth were long strands of ribonucleic acid – RNA.  A strand of RNA can replicate as it floats through water.  RNA acts as a catalyst – it speeds up the reactions that form other molecules, including more RNA.

Eventually, some strands of RNA isolated themselves inside bubbles of soap.  Then the RNA could horde – when a particular sequence of RNA catalyzed reactions, no other RNA would benefit from the molecules it made.  The earliest cells were bubbles that could make more bubbles.

Cells can swim.  They eat.  They live and die.  Even single-celled bacteria have sex: they glom together, build small channels linking their insides to each other, and swap DNA.

But with more cells, you can make creatures like us.

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Consciousness is an emergent property.  With a sufficient number of neuron cells connected to each other, a brain is able to think and plan and feel.  In humans, 90 billion neuron cells direct the movements of a 30-trillion-cell meat machine.

Humans are such dexterous clever creatures that we were able to discover the origin of our universe.  We’ve dissected ourselves so thoroughly that we’ve seen the workings of cells, molecules, atoms, and subatomic particles.

But a single human animal, in isolation, never could have learned that much.

Individual humans are clever, but to form a culture complex enough to study particle physics, you need more humans.  Grouped together, we are qualitatively different.  The wooden technologies of Robinson Crusoe, trapped on a desert island, bear little resemblance to the vaulted core of a particle accelerator.

English writing uses just 26 letters, but these can be combined to form several hundred thousand different words, and these can be combined to form an infinite number of different ideas.

More is different.  The alphabet alone couldn’t give anyone insight into the story of your life.

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Meditation is like a blink where more time passes, but the effect is very different.

Many religions praise the value of meditation, especially in their origin stories.  Before Jesus began his ministry, he meditated for 40 days in the Judaean Desert – his mind’s eye saw all the world’s kingdoms prostrate before him, but he rejected that power in order to spread a philosophy of love and charity. 

Before Buddha began his ministry, he meditated for 49 days beneath the Bodhi tree – he saw a path unfurl, a journey that would let travelers escape our world’s cycle of suffering. 

Before Odin began his ministry, he meditated for 9 days while hanging from a branch of Yggdrasil, the world tree – Odin felt that he died, was reborn, and could see the secret language of the universe shimmering beneath him. 

The god Shiva meditated in graveyards, smearing himself with crematory ash.

At its extreme, meditation is purportedly psychedelic.  Meditation can induce brain states that are indistinguishable from LSD trips when visualized by MRI.  Meditation isolates the brain from its surroundings, and isolation can trigger hallucination.

Researchers have found that meditation can boost our moods, attentiveness, cognitive flexibility, and creativity.  Our brains are plastic – changeable.  We can alter the way we experience the world.  Many of our thoughts are the result of habit.  Meditation helps us change those habits.  Any condition that is rooted in our brain – like depression, insomnia, chronic pain, or addiction – can be helped with meditation.

To meditate, we have to sit, close our eyes, and attempt not to think.  This is strikingly difficult.  Our brains want to be engaged.  After a few minutes, most people experience a nagging sense that we’re wasting time.

But meditation gives our minds a chance to re-organize.  To structure ourselves.  And structure is the property that allows more of something to become different.  Squirrels don’t form complex societies – a population of a hundred squirrels will behave similarly to a population of a million or a billion.  Humans form complex webs of social interactions – as our numbers grew through history, societies changed in dramatic ways.

Before there was structure, our entire universe was a hot soup of quarks and electrons, screaming through the sky.  Here on Earth, these same particles can be organized into rocks, or chemicals, or squirrels, or us.  How we compose ourselves is everything.

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The easiest form of meditation uses mantras – this is sometimes called “transcendental meditation” by self-appointed gurus who charge people thousands of dollars to participate in retreats.  Each attendee is given a “personalized” mantra, a short word or phrase to intone silently with every breath.  The instructors dole mantras based on a chart, and each is Sanskrit.  They’re meaningless syllables to anyone who doesn’t speak the language.

Any two-syllable word or phrase should work equally well, but you’re best off carving something uplifting into your brain.  “Make peace” or “all one” sound trite but are probably more beneficial than “more hate.”  The Sanskrit phrase “sat nam” is a popular choice, which translates as “truth name” or more colloquially as “to know the true nature of things.”

The particular mantra you choose matters less than the habit – whichever phrase you choose, you should use it for every practice.  Because meditation involves sitting motionless for longer than we’re typically accustomed, most people begin by briefly stretching.  Then sit comfortably.  Close your eyes.  As you breathe in, silently think the first syllable of your chosen phrase.  As you breathe out, think the second.

Repeating a mantra helps to crowd out other thoughts, as well as distractions from your environment.  Your mind might wander – if you catch yourself, just try to get back to repeating your chosen phrase.  No one does it perfectly, but practice makes better.  When a meditation instructor’s students worried that their practice wasn’t good enough, he told them that “even on a shallow dive, you still get wet.”

In a quiet space, you might take a breath every three to six seconds.  In a noisy room, you might need to breathe every second, thinking the mantra faster to block out external sound.  The phrase is a tool to temporarily isolate your mind from the world.

Most scientific studies recommend you meditate for twenty minutes at a time, once or twice a day, each and every day.  It’s not easy to carve out this much time from our daily routines.  Still, some is better than nothing.  Glance at a clock before you close your eyes, and again after you open them.  Eventually, your mind will begin to recognize the passage of time.  After a few weeks of practice, your body might adopt the approximate rhythm of twenty minutes.

Although meditation often feels pointless during the first week of practice, there’s a difference between dabbling and a habit.  Routine meditation leads to benefits that a single experience won’t.

More is different.

On domestication and Sue Burke’s ‘Semiosis’

On domestication and Sue Burke’s ‘Semiosis’

In Sue Burke’s Semiosis, humans reach an alien world with intelligent plants.

The settlers find themselves afflicted by inexplicable infertility.  Most women are able to bear children, but many men are sterile.  The settlement develops a culture in which women continue to marry based on the vagaries of affection, but from time to time, a woman will kiss her spouse goodnight before venturing off for an evening’s energetic tussle with a fertile man.

The human settlement has established itself at the base of a single plant.  This plant has ocular patches and can recognize individual humans.  The plant provides fruit that seems exquisitely tailored to each person’s nutritional needs.  In return, the humans carefully tend the plant – irrigating its groves, clearing away competitors, and fertilizing new growth.

The plant manipulates its human caretakers.  By tweaking the composition of their food, it controls the humans’ health.  Selectively instilling infertility or fecundity allows the plant to direct human evolution.  Among the fourth generation of human settlers, more than half of all children were sired by a placid man who was so contemplative and empathetic that he learned to communicate with the host plant.

The plant domesticated its human caretakers.

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Here on Earth, flowering plants also co-evolved with animals. 

Plants could very well consider themselves the dominant species in these relationships – after all, plants use animals to do their bidding.  Plants offer tiny drips of nectar to conscript insects to fertilize their flowers.  Plants offer small fruits to conscript mammals to spread their seeds.  And plants far outlive their servants – thousands of generations of animals might flit by during the lifetime of a single tree.

Some plants directed the evolution of their helpers so well that the species are inextricably linked – some insects feed on only a single species of plant, and the plant might rely on this single species of insect to fertilize its flowers.  If either the plant or insect disappeared, the other would go extinct.

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In Semiosis, the alien plant changes its attitude toward humans over the generations.  At first it was concerned only with control and utility.  The motile beasts were a tool that it could manipulate with pleasing colors and psychoactive fruits. 

Eventually, though, the plant develops an affection for its human wards.  Of course, these humans are markedly different from the people who first arrived on this planet.

The plant’s affections changed in the same way that our own attitude toward wolves softened as we manipulated the species.  Many humans are still reflexively afraid of wolves.  We tell children stories about Little Red Riding Hood; when I’m walking in the woods, sometimes I find myself humming the refrain from “Peter and the Wolf.”  The ecosystem of Yellowstone Park was devastated when we murdered all the wolves during the 1920s; willow and beaver populations have rebounded since wolves were reintroduced in the 1990s (most likely because wolves mitigate the damage done by uncontrolled elk populations); now that Yellowstone’s wolf population isn’t critically endangered, states surrounding the park are letting human hunters shoot wolves again.

And yet, we giggle at the antics of domesticated dogs.

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Among wild animals, the most aggressive individuals are often the most fecund.  Wolves who can fight for and hold the alpha rank get to breed; the others don’t.

During domestication, breeding patterns are altered.  To create dogs, we selected for the most docile individuals.  If you could expand your temporal horizons wide enough, all populations might seem as mutable as clay.  A species flows through time, ever changing, evolving such that the traits that best lead to viable children become more common.  In the wild, a speedy rabbit might have the most children, because it might survive for more breeding seasons than others.  On a farm, the most docile rabbit might have the most children, because its human handlers might give a docile male more time among the females.

Domestication seems to change animals in stereotyped ways.  Zoologist Dmitry Belyayev designed an experiment with wild foxes.  Only the foxes that were least fearful of humans were allowed to breed; over the course of some dozen generations, this single criterion resulted in a large number of behavioral and morphological changes.  The domesticated foxes produce less adrenaline; they have narrower faces; they have floppier ears.  This suite of traits seems to be present in almost all domesticated species.

Cats still have pointy ears.  As it happens, cats are barely domesticated.

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Humans seem to be self-domesticated. A few hundred thousand years ago, our ancestors lived in very small groups, maybe one or two dozen individuals.  After humans diverged from the last common ancestor that we shared with bonobos and chimpanzees, most human species still lived in groups of about this size.  Neanderthals may have lived in groups as small as six.

Eventually, Homo sapiens drove all other human species to extinction.  A major competitive advantage was that Homo sapiens lived and worked in groups as large as a hundred.  With so many people cooperating, they could hunt much more efficiently.  A violent conflict between six Neanderthals and a clan of a hundred Homo sapiens would not go well for the Neanderthals.

In the modern world, the population densities of urban areas force humans to be even more docile than our recent ancestors.  But even with our whole evolutionary history promoting cooperation, many people struggle to be calm and kind within the crowded confines of a city.  Some can do it; others feel too aggressive.

When a person’s disposition is ill-suited to the strange environment we’ve made, we punish.  We shunt people to high school detention, or jail.

In Semiosis, the plant overlord reacts by limiting fertility.

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As in Richard Powers’s Overstory, the perspective of a long-lived, immobile plant would be markedly different from ours.  Human generations flit by as a plant continues to grow.

The bamboo forest/grove in Arashiyama, Kyoto, Japan. Photograph by Daniel Walker on Flickr.

Domestication takes generations – in Belyayev’s fox experiment, twenty generations passed before a third of the population was tame – but an intelligent plant could wait.  By selecting which individuals get to pass on their genes, huge changes can be made.  From wolves, we created Great Danes and Chihuahuas.  From a scruffy grass we evoked buxom ears of corn, as though by glacial magic.

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In particularly dark eras of our past, humans have tried to direct our own evolution.  Social Darwinists in the United States forcibly sterilized people whom they disliked.  Politicians in Nazi Germany copied the legal language of the United States when they sought philosophical justification for the murder of entire religious and ethnic groups.

By putting the motivation inside the mind of a plant, Burke is able to explore the ramifications of directed human evolution without alluding to these evil regimes.

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In jail, somebody said to me, “I heard that humans were evolving to have really long fingers, so we could type real fast, and big-headed hairless bodies.”

“Yeah, yeah,” somebody added, “I saw this thing on the Discovery channel, it was like, you know the way they show all those aliens on the X-Files?  That humans were gonna be like that, like the aliens were just us coming back to visit from the future.”

Illustration of “future humans” by Futurilla on Flickr.

I murmured in disagreement. 

“Humans are definitely still evolving.  But evolution doesn’t have a goal.  It just selects for whichever properties of a creature are best for making copies of itself.”

“With modern medical care, we don’t die so easily.  So the main driver of evolution is the number of kids you have.  If you have more kids than I do, then you’re more fit than I am.  Future humans will look more like you than me.”

“There’s not much data yet, because evolution happens over such a long time, but the one study I’ve seen recently showed that humans in the United States are evolving to be shorter.”

“But it’s not like we’re getting shorter so that we’ll fit better inside spaceships.  It’s just that shorter people have been having more kids.”

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Plants have directed the evolution of bees.  Of bats – there’s a bat species that fertilizes agave, another that fertilizes mangoes, and so on. 

Photo by Marlon Machado on Flickr.

Plants directed our evolution, too.  We owe our color vision to our history as fruit eaters – we needed to see the difference between ripe reds and green buds.

And, like all populations, we are changing.  Evolution isn’t done.

What might a clever plant want us to become?

On birds watching.

On birds watching.

In jail recently, we were talking about birds.

“Yeah, my grandfather had something like a thousand chickens, had them running all through the yard,” somebody said.  “And there was this one chicken, he was a mean one.  I was kind of afraid of it, strutting around like he owned the place.  So my grandfather, he told me to kick it.”

“Well, I did, but that only made things worse.  I didn’t make him scared, I just made that chicken hate me.  So after that, anytime we went to visit my grandfather’s place, that chicken would be there, waiting for me.”

“My parents, my brothers and sisters, everybody would get out of the car, but the chicken wouldn’t bother them.  He’d be sitting there, staring, just waiting for me.  And when I finally got out I had to run, every time, sprinting to my grandfather’s front door before that chicken got me.”

“They live a long time, too!  I had, like, five or six years of that!  And still to this day, anytime my mom sees a video or a picture of somebody running from a chicken on Facebook, she’ll tag me in it.  Like, ha ha ha, remember that?”

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“Maybe you didn’t kick him hard enough,” somebody suggested.  “Cause we used to have chickens, and I had to go into the coop sometimes, and the roof of it was real low to the ground, so I had to crouch in there like this, and one chicken would always strut up to me like it was going to start something.”

“Well, it did that every time for a few months, till one day it got in my face and I just went BOOM, and I wrestled that little fucker to the ground.  And that chicken never messed with me again.”

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Birds can recognize individual humans. 

Biologist John Marzluff noticed that crows became wary of particular researchers after the crows had been captured and tagged.  In an experiment where researchers captured a half dozen crows while wearing a caveman mask, they found that the whole flock learned to respond to that mask as a threat.  Several years later, even crows who hadn’t seen the caveman’s initial misbehavior would shriek a warning when they saw that mask.  They’d been trained by their flockmates.

The caveman mask is on the left. On the right: a control mask.

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Between their intelligence and acute eyesight, birds can serve as passable oncologists.  Pigeons were trained with a set of slides from biopsies – a pigeon had to inspect each image and then choose a button for “cancer” or “not cancer”.  If the pigeon chose correctly, the computer would dispense a pellet of food.

(Human medical students are often mistreated during their training, forced to work grueling hours with few breaks.  The pigeon trainees were also mistreated – to ensure that they valued each food pellet, the pigeons were starved during the experiment.  I’m 6 feet tall and about 150 pounds, but if I were participating in this study, I’d be kept at 127 pounds – eighty-five percent of my “free feeding” weight.)

Pigeons learned to diagnose biopsies with 80% accuracy.  A team of eight pigeons voting together could diagnose biopsies with 99% accuracy

The team of pigeons was just as good as a human oncologist, and far better than computerized image analysis.

You can buy 50 pounds of pigeon pellets for under $10.  That’d give you enough rewards for a flock of half-starved pigeons to diagnose thousands of patients.

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We used to think that an entire class of vertebrates had gone extinct – the dinosaurs.  But we now know that birds are dinosaurs. 

Several species of dinosaurs/birds are gone – millions of years have passed since tyrannosaurs or velociraptors roamed the earth.  But their lineage has continued.

When I was growing up, people often remarked that dinosaurs were clearly dim-witted creatures because they have such small cranial cavities.  There was not much room for brains in their skulls! 

But contemporary dinosaurs/birds have small brains, too, and many are extremely intelligent.  They can chase kids who’ve crossed them.  They can diagnose cancer.  They can make tools, solve logic puzzles, and guess what other animals are thinking.

All with minuscule brains!

When biologist Suzana Herculano-Houzel investigated the brains of various species, she found that the number of neurons in a brain typically correlates with cognitive capacity.  More neurons makes for a smarter critter!

The physical size of a brain doesn’t tell you how many neurons will be in a brain, though.  A bigger brain might just have bigger neurons

As it happens, birds’ brains are constructed better than our own.  Crows and parrots pack neurons into a brain more densely than we do, like the difference between old IBM mainframes and modern telephones.  Pigeon brains are better than ours at parallel computing, like the difference between a hypothetical quantum computer and your current laptop.

We can outsmart crows, parrots, and pigeons, but only because our raw neuron counts are so high that we’ve not been surpassed by their superior designs.

We don’t know when dinosaurs/birds evolved their high neuron densities – well-designed brains might be recent innovations, or they might be millions of years old.  Ancient dinosaurs may have been far more intelligent than we thought.

Yes, they still went extinct, but you can’t blame them for succumbing to climate change.  And it’s not like they caused the climate change that killed them.

Future archaeologists might judge humans to be more foolish than any stegosaurus.

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We humans have huge numbers of neurons in our cerebral cortex.  We are blisteringly clever.  We’ve made all variety of tools, languages, and complex social structures.  Yes, crows also have tools, language, and complex social structures, but in each category, human achievements are even more complex.

A crow tool is typically a hooked piece of stick.  We built telephones.

Well, humans collectively built telephones.  I couldn’t sit down and build one from scratch.  If I were to make a tool while out hiking, it’d probably be a hooked piece of stick.

Still, our best achievements are pretty incredible. 

But we’ve also brought our species to the brink of extinction.  Through overpopulation and excessive exploitation of the planet’s trapped resources, we’re making our world less habitable. 

Tyrannosaurus ruled this planet for a few million years.  Humans have been a dominant species for only a hundred thousand years – a few percent of T-Rex’s reign.  With the current pace of climate change, scientists soberly discuss the possibility that we’ll reap apocalypse within a hundred more years.

Measured by reign, we might prove 20-fold less successful than those giant birds.

On the study of naked mole-rats.

On the study of naked mole-rats.

This is a riff on an essay from several years ago.

In 1974, evolutionary biologist Richard Alexander gave a lecture describing the conditions that might spawn eusocial vertebrates. 

Alexander was a bug guy – “eusocial” refers to extremely cooperative animals like bees, ants, and termites. Individuals sacrifice themselves for others.  Non-breeders help with childcare.  The colony seems more intelligent than its members.

Alexander proposed that a eusocial mammal could evolve if the animals were small compared to their food sources, and if they lived in underground burrows that could be expanded easily and defended by a small percentage of the colony.

After the lecture, an audience member mentioned that this “hypothetical eusocial mammal” sounded a lot like the naked mole-rat.  Alexander was introduced to Jennifer Jarvis, who had studied individual naked mole-rats but not their social lives.  Alexander and Jarvis collaborated to write The Biology of the Naked Mole-Rat.

Eliot Weinberger condensed this 500-page textbook into his 3-page essay, “Naked Mole-Rats.”

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Like us, naked mole-rats are both good and bad.  They are cooperative.  They are affectionate.  They are always touching.  When they meet strangers, they fight to the death.  When a breeding female dies, many other females regain fertility and the colony erupts into civil war.

Weinberger wrote that naked mole-rats “are continually cruel in small ways.”  But they are outdone by naked apes. 

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For a research paper published in 2008, Thomas Park and colleagues found that being pinched by tweezers causes naked mole-rats pain, but injection with caustic acid does not.

“We tested naked mole-rats in standard behavioral models of acute pain including tests for mechanical, thermal, and chemical pain.  We found that after noxious pinch or heat, the mole-rats responded similarly to mice.”

“In contrast to the results using mechanical and thermal stimuli, there was a striking difference in responses to strong chemical irritants.  Two chemicals were used – capsaicin from hot peppers and hydrochloric acid – which normally evoke very intense pain in humans and other animals.  Injection of either rapidly evoked intense licking and guarding behaviors in mice.”

“In contrast, naked mole-rats showed virtually no response.”

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Perhaps you worry that acid-resistant naked mole-rats could conquer the world.  Fear not.  A form of kryptonite exists.  Injection of an 11-amino-acid signaling peptide allows acid to hurt naked mole-rats just as much as it hurts mice.  Or us.

Half a dozen animals were subjected to each treatment.

#

Naked mole-rats don’t die from cancer. 

They should.  Their cells, like ours, are copied from copies of copies.  Errors compound.

Some errors are particularly deadly.  Our cells are supposed to stop growing when they touch.  They are supposed to commit suicide when old.  But the instructions telling a cell when and how to kill itself can be lost, just like any other information.

This is cancer.

In cancer, a single cell proliferates at the expense of others.  A cancer cell claims more than its fair share of space.  It commandeers nutrients.  This cell, and its progeny, and its progeny’s progeny, will flourish. 

Then the scaffolding creature dies.  Then the cancer cells die, too. 

But every cell that isn’t an egg or sperm is terminal anyway.  In the colony of our body, most cells are non-breeding members.  From a cancer cell’s perspective, it has nothing to lose.

#

We develop cancer often.  With each passing day, we produce about 100 billion new cells.  Each time we produce a new cell, all 3 billion letters of our genome must be copied. 

The enzymes that copy our genome make one mistake every billion letters.  Each cell division: three new mutations.  Each day: three hundred billion new mutations.

Some mutants are trouble. 

#

Our bodies kill cancer.  Your immune system – the same mess of mucous, inflammation, and goo that goes haywire during the flu – seeks and destroys renegade cells.  Your body is a fascist enterprise; white blood cells, its militarized police.

Chemotherapy does not kill cancer.  Chemotherapy means flooding the body with poisons that stop all cells from reproducing.  With luck, if the spread of cancer is slowed, your immune system can kill it before it kills you.

In naked mole-rats, cancers always grow as slowly as if the rodents were receiving chemo, allowing their immune systems to squelch cancers at a leisurely pace.  Their cancers are slowed by a heavy sugar called “hyaluronan,” which is packed so tightly into the space between cells that there is no room to grow.

In 2013, biologist Xiao Tian and colleagues wrote that “naked mole-rats may have evolved a higher concentration of hyaluronan to provide the skin elasticity needed for life in underground tunnels.  This trait may have then been co-opted to provide cancer resistance and longevity.”

They became impervious to cancer almost by mistake.

#

The record lifespan for a naked mole-rat in captivity is 28 years, 4 months.  The record-holder was nicknamed James Bond.  He was senior consort to his queen and continued rutting – and siring pups – up until the day he died.

Bond was dissected.  His cells showed extensive oxidative damage in their lipids, proteins, and DNA.  Bond should have been hobbled by age.  But time did not slow him down.

Science writer David Stipp described him as “a little buck-toothed burrower who ages like a demigod.”

#

Humans typically cease breeding long before we die.  From an evolutionary perspective, as soon as we stop having children, our fitness drops to zero.

And yet, we have long lifespans.  The dominant theory is an offshoot of “the grandmother hypothesis” – because we often care for grandchildren, there may have been evolutionary pressure to maintain good health until our grandchildren also reach reproductive age. 

With twenty-year generations, there’d be an incentive to survive until our sixties.

After that, perhaps our ancestors were no longer helpful.  And so we’ve inherited a propensity to decay.  Expensive medical interventions can preserve us longer, but once we pass our natural lifespans, brains and bodies weaken.

#

When scientists starve animals in the lab, it’s called “caloric restriction.”  This protocol extends lifespan in a wide variety of species.  Monkeys, mice, flies, and worms.  Ten-fold increases in lifespan have been observed.

Caloric restriction should extend the lives of humans, too.

There are unpleasant side effects.  Caloric-restricted mice spend their time staring at empty food bowls.  They are listless: barely moving, barely sleeping.  They live longer, but worse – and if they are fed slightly less, they die of malnutrition.

Frequent starvation in the wild may have caused naked mole-rats to evolve their prodigious longevity.

Naked mole-rats expand their colonies outward, searching for edible roots.  When they find a good root, they gnaw it carefully, attempting to keep the plant alive as long as possible.  But a colony of naked mole-rats eats faster than any plant can grow.  When the plant dies, the colony plunges into famine. 

#

Most eusocial animals carefully ventilate their homes.  Termites build giant pylons in the desert.  Although temperatures outside careen from 35 degrees at night to over 100 during the day, the interior of the mound remains a constant 87 degrees.  And the termites do not asphyxiate.  Their exhalations are swept away by circulating air.

Naked mole-rats burrow with less care.  They sleep in piles, hundreds of bodies lumped together underground.  Those near the center soon run out of oxygen.

We would die.

Most animals, deprived of oxygen, can’t fuel their brains.  Thoughts are expensive.  Even at rest, our brains demand a constant influx of energy or else the neurons “depolarize” – we fall apart.

Since the death penalty was reintroduced in the United States in 1976, we have killed eleven prisoners in gas chambers.  During the 1983 execution of Jimmy Lee Gray in Mississippi, officials cleared the observation room after eight minutes.  Gray was still alive, gasping for breath.  His attorney said, “Jimmy Lee Gray died banging his head against a steel pole in the gas chamber while reporters counted his moans.”

Gas chambers are pumped full of cyanide gas, carbon monoxide, or carbon dioxide.  Carbon dioxide is cheapest. 

#

With each breath, we inhale oxygen, burn sugar, and exhale carbon dioxide.  When we drive, our cars intake oxygen, burn gasoline, and exhaust carbon dioxide. 

In small amounts, carbon dioxide is beneficial.  Carbon dioxide allows plants to grow.  But when you put too much inside a chamber, somebody dies.  Put too much in the air worldwide and we all die.

The planet Venus was habitable, once.  Humans could have lived there.  Venus had a deep ocean and mild weather.

Through some fluke, Venus experienced a temporary bump in the amount of carbon dioxide in the air.  Carbon dioxide traps heat, which caused water to evaporate.  Clouds formed, which trapped more heat.  The cycle continued. 

Venus is now a fiery inferno.  The ground is bare rock.  Sulfuric acid rains from the sky.

#

Lab mice die in gas chambers.  Sometimes one mouse is set inside the plexiglass box; sometimes several mice inside a Chinese-food takeout container are gassed together.  A valve for carbon dioxide is opened; the mice lose consciousness; they shit; they die.

A naked mole-rat would live.  Unless a very determined researcher left the gas flowing for half an hour.  Or so found Thomas Park and colleagues – the same team that discovered that naked mole-rats dislike being pinched.  As they reported in 2017:

Human brains drink sugar.  We are like hummingbirds that way.  And our brains are very fussy eaters.  We are fueled exclusively by glucose.

Naked mole-rats are less particular.  Their minds slurp fructose to keep from dying.

#

Naked mole-rats are the most cooperative of mammals.  They are resistant to cancer.  Unperturbed by acid.  They age with the libidinous gracelessness of Hugh Hefner. 

They are able to withstand the horrors of a gas chamber.

And yet, for all these talents, naked mole-rats are easily tormented by human scientists.

.

.

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Featured image from Wikimedia Commons.

On Darwin and free love.

On Darwin and free love.

For the moment, let’s set aside the question of why I was reading a review titled “Plants Neither Possess nor Require Consciousness.”  Instead, I’d like to share a passage from the end of the article:

Plant neurobiologists are hardly the first biologists to ascribe consciousness, feelings, and intentionality to plants.

Erasmus Darwin, [Charles] Darwin’s grandfather and a believer in free love, was so taken with the Linnaean sexual system of classification that he wrote an epic poem, The Loves of Plants, in which he personified stamens and pistils as ‘swains’ and ‘virgins’ cavorting on their flower beds in various polygamous and polyandrous relationships.

Maybe you were startled, just now, to learn about the existence of risqué plant poetry.  Do some people log onto Literotica to read about daffodils or ferns?

But what caught my attention was Erasmus Darwin’s designation as a believer in free love. 

In a flash, an entire essay composed itself in my mind.  Charles Darwin’s grandfather was a polyamorist!  Suddenly, the origin of The Origin of the Species made so much more sense!  After all, exposure to polyamory could help someone notice evolution by natural selection.  An essential component of polyamory is freedom of choice – during the 1800s, when nobody had access to effective birth control, people might wind up having children with any of their partners, not just the one with whom they were bound in a legally-recognized and church-sanctioned marriage. 

Evolution occurs because some individuals produce more offspring than others, and then their offspring produce more offspring, and so on.  Each lineage is constantly tested by nature – those that are less fit, or less fecund, will dwindle to a smaller and smaller portion of the total population.

Similarly, in relationships where choice is not confined by religious proscription, the partners are under constant selective pressure if they hope to breed.  When people have options, they must stay in each other’s good graces.  They must practice constant kindness, rather than treating physical affection as their just desserts.

I felt proud of this analogy.  To my mind, Erasmus Darwin’s belief in free love had striking parallels with his grandson’s theory.

And it’s such a pleasure when essays basically write themselves.  All I’d need to do was skim a few biographies.  Maybe collect some spicy quotes from Erasmus himself.  And I’d try to think of a clever way to explain evolution to a lay audience.  So that my readers could understand why, once I’d learned this juicy tidbit about Erasmus, his connection to Charles Darwin’s theory seemed, in retrospect, so obvious.


My essay failed.

I wish it hadn’t, obviously.  It was going to be so fun to write!  I was ready to compose some sultry plant poetry of my own.

And I feel happy every time there’s another chance to explain evolution.  Because I live in a part of the United States where so many people deny basic findings from science, I talk about this stuff in casual conversations often.  We regularly discuss evolutionary biology during my poetry classes in jail.

But my essay wasn’t going to work out.  Because the underlying claim – Erasmus Darwin believed in free love! – simply isn’t true.


Maybe you have lofty ideals about the practice of science.  On the children’s record Science Is for Me, Emmy Brockman sings:

I am a scientist

I explore high and low

I question what I know

Emmy is great. Find her at emmybrockman.com.

That’s the goal.  A good scientist considers all the possibilities.  It’s hard work, making sure that confirmation bias doesn’t cause you to overlook alternative explanations.

But scientists are human.  Just like anybody else, we sometimes repeat things we’ve heard without considering whether any evidence ever justified it.

In The Human Advantage, neuroscientist Suzana Herculano-Houzel describes how baffled she felt when she began reading scientific papers about the composition of our brains. 

Although the literature held many studies on the volume and surface area of the brain of different species, and various papers on the densities of neurons in the cerebral cortex, estimates of numbers of neurons were scant.  In particular, I could find no original source to the much-repeated “100 billion neurons in the human brain.”

I later ran into Eric Kandel himself, whose textbook Principles of Neural Science, a veritable bible in the field, proffered that number, along with the complement “and 10-50 times more glial cells.”  When I asked Eric where he got those numbers, he blamed it on his coauthor Tom Jessel, who had been responsible for the chapter in which they appeared, but I was never able to ask Jessel himself.

It was 2004, and no one really knew how many neurons could be found on average in the human brain.

Unsatisfied with the oft-repeated numbers, Herculano-Houzel liquified whole brains in order to actually count the cells.  As it happens, human brains have about 86 billion neurons and an equal number of glial cells.

Or, consider the psychology experiments on behavioral priming.  When researchers “prime” a subject, they inoculate a concept into that person’s mind.

The basic idea here is relatively uncontroversial.  It’s the principle behind advertising and paid product placement – our brains remember exposure while forgetting context.  That’s why political advertisements try to minimize the use of opponents’ names.  When people hear or see a candidate’s name often, they’re more likely to vote for that candidate.

Facebook has also demonstrated again and again that minor tweaks to the inputs that your brain receives can alter your behavior.  One shade of blue makes you more likely to click a button; there’s a size threshold below which people are unlikely to notice advertisements; the emotional tenor of information you’re exposed to will alter your mood.

When research psychologists use priming, though, they’re interested in more tenuous mental links.  Study subjects might be primed with ideas about economic scarcity, then assessed to see how racist they seem.

The first study of this sort tested whether subconsciously thinking about elderlies could make you behave more like an elderly person.  The researchers required thirty undergraduate psychology students to look at lists of five words and then use four of these words to construct a simple sentence.  For fifteen of these students, the extra word was (loosely) associated with elderly people, like “Florida,” “worried,” “rigid,” or “gullible.”  For the other fifteen, the words were deemed unrelated to elderlies, like “thirsty,” “clean,” or “private.”

(Is a stereotypical elderly person more gullible than private? After reading dozens of Mr. Putter and Tabby books — in which the elderly characters live alone — I’d assume that “private” was the priming word if I had to choose between these two.)

After completing this quiz, students were directed toward an elevator.  The students were timed while walking down the hallway, and the study’s authors claimed that students who saw the elderly-associated words walked more slowly.

There’s even a graph!

This conclusion is almost certainly false.  The graph is terrible – there are no error bars, and the y axis spans a tiny range in order to make the differences look bigger than they are.  Even aside from the visual misrepresentation, the data aren’t real.  I believe that a researcher probably did use a stopwatch to time those thirty students and obtain those numbers.  Researchers probably also timed many more students whose data weren’t included because they didn’t agree with this result.  Selective publication allows you to manipulate data sets in ways that many scientists foolishly believe to be ethical.

If you were to conduct this study again, it’s very unlikely that you’d see this result.

Some scientists are unconcerned that the original result might not be true.   After all, who really cares whether subconscious exposure to words vaguely associated with old people can make undergraduates walk slowly?

UCLA psychology professor Matthew Lieberman wrote,

What we care about is whether priming-induced automatic behavior in general is a real phenomenon.  Does priming a concept verbally cause us to act as if we embody the concept within ourselves?  The answer is a resounding yes.  This was a shocking finding when first discoveredin 1996.

Lieberman bases this conclusion on the fact that “Hundreds of studies followed showing that people primed with a stereotype embodied it themselves.”  Continued success with the technique is assumed to validate the initial finding.

Unfortunately, many if not most of those subsequent studies are flawed in the same way as the original.  Publication biases and lax journal standards allow you to design studies that prove that certain music unwinds time (whose authors were proving a point) or that future studying will improve your performance on tests today (whose author was apparently sincere).

Twenty years of mistaken belief has given the walking speed study – and its general methodology – an undeserved veneer of truth.


Erasmus Darwin didn’t believe in free love.  But he did have some “radical” political beliefs that people were unhappy about.  And so, to undermine his reputation, his enemies claimed that he believed in free love.

Other people repeated this slander so often that Erasmus Darwin is now blithely described as a polyamorist in scientific review articles.


So, why did conservative writers feel the need to slander Erasmus Darwin?  What exactly were his “radical” beliefs?

Erasmus Darwin thought that the abject mistreatment of black people was wrong.  He seems to have thought it acceptable for black people to be mistreated – nowhere in his writings did he advocate for equality – but he was opposed to the most ruthless forms of torture. 

Somewhat.  His opposition didn’t run so deep that he’d deny himself the sugar that was procured through black people’s forced labor.

And, when Erasmus Darwin sired children out of wedlock – which many upper-class British men did – he scandalously provided for his children.

In British society, plenty of people had affairs.  Not because they believed in free love, but because they viewed marriage as a fundamentally economic transaction and couldn’t get a divorce.  But good British men were supposed to keep up appearances.  If a servant’s child happened to look a great deal like you, you were supposed to feign ignorance. 

Even worse, the illegitimate children that Erasmus Darwin provided for were female.  Not only did Darwin allow them to become educated – which was already pretty bad, because education made women less malleable spouses – but he also helped them to establish a boarding school for girls.  The contagion of educated women would spread even further!

This was all too much for Britain’s social conservatives.  After all, look at what happened in France.  The French were unduly tolerant of liberal beliefs, and then, all of a sudden, there was murderous revolution!

And so Erasmus Darwin had to be stopped.  Not that Darwin had done terribly much.  He was nationally known because he’d written some (mediocre) poetry.  The poetry was described as pornographic.  It isn’t.  Certain passages anthropomorphize flowers in which there are unequal numbers of pistils and stamens.  It’s not very titillating, unless you get all hot and bothered by the thought of forced rhymes, clunky couplets, and grandiloquent diction.  For hundreds of pages.


While reading about Erasmus Darwin, I learned that some people also believe that he was the actual originator of his grandson’s evolutionary theories.  In a stray sentence, Erasmus Darwin did write that “The final course of this contest between males seems to be, that the strongest and most active animal should propagate the species which should thus be improved.”  This does sound rather like evolution by natural selection.  But not quite – that word “improved” hints at his actual beliefs.

Erasmus Darwin did believe all life had originated only once and that the beautiful variety of creatures extant today developed over time.  But he thought that life changed from simple to complex out of a teleological impulse.  In his conception, creatures were not becoming better suited to their environment (which is natural selection), but objectively better (which isn’t).

I’m not arguing that Charles Darwin had to be some kind of super genius to write The Origin of the Species.  But when Charles Darwin described evolution, he included an actual mechanism to rationalize why creatures exist in their current forms.  Things that are best able to persist and make copies of themselves eventually become more abundant. 

That’s it.  Kind of trivial, but there’s a concrete theory backed up by observation.

Erasmus Darwin’s belief that life continually changed for the better was not unique, nor did it have much explanatory power. 

In the biography Erasmus Darwin, Patricia Fara writes that,

By the end of the eighteenth century, the notion of change was no longer in itself especially scandalous.  For several decades, the word ‘evolution’ had been in use for living beings, and there were several strands of evidence arguing against a literal interpretation of the Bible.  Giant fossils – such as mammoths and giant elks – suggested that the world had once been inhabited by distant relatives, now extinct, of familiar creatures. 

Animal breeders reinforced particular traits to induce changes carried down through the generations – stalwart bulldogs, athletic greyhounds, ladies’ lapdogs.  Geological data was also accumulating: seashells on mountain peaks, earthquakes, strata lacking fossil remains – and the most sensible resolution for such puzzles was to stretch out the age of the Earth and assume that it is constantly altering.

Charles Darwin thought deeply about why populations of animals changed in the particular way that they did.  Erasmus Darwin did not.  He declaimed “Everything from shells!” and resumed writing terrible poetry.  Like:

IMMORTAL LOVE! who ere the morn of Time,

On wings outstretch’d, o’er Chaos hung sublime;

Warm’d into life the bursting egg of Night,

And gave young Nature to admiring Light!

*

Erasmus Darwin didn’t develop the theory of evolution.  You could call him an abolitionist, maybe, but he was a pretty half-hearted one, if that.  By the standards of his time, he was a feminist.  By our standards, he was not.

He seems like a nice enough fellow, though.  As a doctor, he treated his patients well.  And he constantly celebrated the achievements of his friends.

Patricia Fara writes that,

After several years of immersion in [Erasmus] Darwin’s writing, I still have a low opinion of his poetic skills.  On the other hand, I have come to admire his passionate commitment to making the world a better place.


And, who knows?  If Erasmus Darwin was alive today, maybe he would be a polyamorist.  Who’s to say what secret desires lay hidden in a long-dead person’s soul?

But did Darwin, during his own lifetime, advocate for free love?  Nope.  He did not.  No matter what his political opponents – or our own era’s oblivious scientists – would have you believe.

Header image from the Melbourne Museum. Taken by Ruth Ellison on Flickr.

On the ethics of eating.

On the ethics of eating.

Every living thing needs energy.  But our world is finite.  Energy has to come from somewhere.

Luckily, there’s a lot of potential energy out there in the universe.  For instance, mass can be converted into energy.  Our sun showers us with energy drawn from the cascade of nuclear explosions that transpire in its core. A tiny difference in mass between merging hydrogen atoms and the resultant helium atom allows our sun to shine.

Our sun radiates about 10^26 joules per second (which is 100,000 times more than the combined yearly energy usage from everyone on Earth), but only a fraction of that reaches our planet.  Photons radiate outward from our sun in all directions, so our planet intercepts only a small sliver of the beam.  Everything living here is fueled by those photons.

When living things use the sun’s energy, we create order – a tree converts disordered air into rigid trunk, a mouse converts a pile of seeds into more mouse, a human might convert mud and straw into a house.  As we create order, we give off heat.  Warming the air, we radiate infrared photons.  That’s what night vision goggles are designed to see.  The net effect is that the Earth absorbs high-energy photons that were traveling in a straight beam outward from the sun … and we convert those photons into a larger number of low-energy photons that fly off every which way.

We the living are chaos machines.  We make the universe messier.  Indeed, that’s the only way anything can live.  According to the Second Law of Thermodynamics, the only processes that are sufficiently probable so as to occur are those that make the world more random.

We’re lucky that the universe started out as such a bland, orderly place – otherwise we might not even be able to tell “before” from “later,” let alone extract enough energy to live.

Dog!

The earliest living things took energy from the sun indirectly – they used heat, and so they were fueled by each photon’s delivery of warmth to the Earth.  (Please allow me this little hedge – although it’s true that the earliest life was fueled only by warmth, that warmth might not have come from the sun.  Even today, some thermophilic bacteria live in deep sea vents and bask in the energy that leaks from our Earth’s molten core.  The earliest life might have lived in similar nooks far from the surface of the Earth.  But early life that resided near the surface of the seas seems more likely. Complicated chemical reactions were necessary to form molecules like RNA.  Nucleic acids were probably first found in shallow, murky pools pulsed with lightning or ultraviolet radiation.)

Over time, life changed.  Organisms create copies of themselves through chemical processes that have imperfect fidelity, after all.  Each copy is slightly different than the original.  Most differences make an organism worse than its forebears, but, sometimes, through sheer chance, an organism might be better at surviving or at creating new copies of itself.

When that happens, the new version will become more common. 

Over many, many generations, this process can make organisms very different from their forebears.  When a genome is copied prior to cell division, sometimes the polymerase will slip up and duplicate a stretch of code.  These duplication events are incredibly important for evolution – usually, the instructions for proteins can’t drift too far because any change might eliminate essential functions for that cell.  If there’s a second copy, though, the duplicate can mutate and eventually gain some new function.

About two billion years ago, some organisms developed a rudimentary form of photosynthesis.  They could turn sunlight into self!  The energy from our sun’s photons was used to combine carbon dioxide and water into sugar. And sugar can be used to store energy, and to build new types of structures.

Photosynthesis also releases oxygen as a biproduct.  From the perspective of the organisms living then, photosynthesis poisoned the entire atmosphere – a sudden rise in our atmosphere’s oxygen concentration caused many species to go extinct.  But we humans never could have come about without all that oxygen.

Perhaps that’s a small consolation, given that major corporations are currently poisoning our atmosphere with carbon dioxide.  Huge numbers of species might go extinct – including, possibly, ourselves – but something else would have a chance to live here after we have passed.

In addition to poisoning the atmosphere, photosynthesis introduced a new form of competition.  Warmth spreads diffusely – on the early Earth, it was often sheer chance whether one organism would have an advantage over any other.  If you can photosynthesize, though, you want to be the highest organism around.  If you’re closer to the sun, you get the first chance to nab incoming photons.

That’s the evolutionary pressure that induced plants to evolve.  Plants combined sugars into rigid structures so that they could grow upwards.  Height helps when your main goal in life is to snatch sunlight.

Animation by At09kg on Wikipedia.

Nothing can live without curtailing the chances of other living things.  Whenever a plant absorbs a photon, it reduces the energy available for other plants growing below.

Plants created the soil by trapping dirt and dust, and soil lets them store water for later use.  But there is only so much desalinated water.  Roots reach outward: “I drink your milkshake!”, each could exclaim.

For a heterotroph, the brutality of our world is even more clear.  Our kind – including amoebas, fungi, and all animals – can only survive by eating others.  We are carbon recyclers.  Sugar and protein refurbishers.  We take the molecular machines made by photosynthesizing organisms … chop them apart … and use the pieces to create ourselves.

Some heterotrophs are saprophages – eaters of the dead.  But most survive only by destroying the lives of others.

For the earliest heterotrophs, to eat was to kill.  But, why worry?  Why, after all, is life special?  Each photosynthesizing organism was already churning through our universe’s finite quantity of order in its attempt to grow.  They took in material from their environment and rearranged it.  So did the heterotrophs – they ingested and rearranged. Like all living things, they consumed order and excreted chaos.

The heterotrophs were extinguishing life, but life is just a pattern that repeats itself.  A living thing is a metabolic machine that self-copies.  From a thermodynamic perspective, only the energetics of the process distinguish life from a crystal.  Both are patterns that grow, but when a crystal grows, it makes matter more stable than its environment – life makes matter less stable as it’s incorporated into the pattern.

Your ability to read this essay is a legacy of the heterotrophs’ more violent descendants.  The earliest multicellular heterotrophs were filter feeders – they passively consumed whatever came near.

But then, between 500 and 600 million years ago, animals began to hunt and kill.  They would actively seek life to extinguish.  To do this, they needed to think – neurons first arose among these hunters.

Not coincidentally, this is also the time that animals first developed hard shells, sharp spines, armored plates – defenses to stop others from eating them.

The rigid molecules that allow plants to grow tall, like cellulose, are hard to digest.  So the earliest hunters probably began by killing other animals.

With every meal, you join the long legacy of animals that survived only by extinguishing the lives of others.  With every thought, you draw upon the legacy of our forebear’s ruthless hunt.

Even if you’re vegan, your meals kill.  Like us, plants have goals.  It’s a matter of controversy whether they can perceive – perhaps they don’t know that they have goals – but plants will constantly strive to grow, to collect sunlight and water while they can, and many will actively resist being eaten.

But it makes no sense to value the world if you don’t value yourself.  Maybe you feel sad that you can’t photosynthesize … maybe you’d search out a patch of barren, rocky ground so that you’d absorb only photons that would otherwise be “wasted” … but, in this lifetime, you have to eat.  Otherwise you’d die.  And I personally think that any moral philosophy that advocates suicide is untenable.  That’s a major flaw with utilitarianism – rigid devotion to the idea of maximizing happiness for all would suggest that you, as another organism that’s taking up space, constantly killing, and sapping our universe’s limited supply of order, simply shouldn’t be here.

At its illogical extreme, utilitarianism suggests that either you conquer the world (if you’re the best at feeling happy) or kill yourself (if you’re not).

We humans are descended from carnivores.  Our ancestors were able to maintain such large brains only by cooking and eating meat.  Our bodies lack an herbivore’s compliment of enzymes that would allow us to convert grass and leaves into the full compliment of proteins that we need.

And we owe the very existence of our brains to the hunts carried out by even more ancient ancestors.  If they hadn’t killed, we couldn’t think.

Just because we were blessed by a legacy of violence, though, doesn’t mean we have to perpetuate that violence.  We can benefit from past harms and resolve to harm less in the present and future.

Writing was first developed by professional scribes.  Scientific progress was the province of wealthy artisans.  None of the progress of our culture would have been possible if huge numbers of people weren’t oppressed – food that those people grew was taken from them and distributed by kings to a small number of privileged scribes, artisans, philosophers, and layabouts. 

When humans lived as hunters and gatherers, their societies were generally equitable.  People might die young from bacterial infections, dehydration, or starvation, but their lives were probably much better than the lives of the earliest farmers.  After we discovered agriculture, our diets became less varied and our lives less interesting.  Plus, it’s easier to oppress a land-bound farmer than a nomadic hunter.  Stationary people paid tribute to self-appointed kings.

This misery befell the vast majority of our world’s population, and persisted for thousands of years.  But the world we have now couldn’t have come about any other way.  It’s horrific, but, for humans to reach our current technologies, we needed oppression.  Food was taken from those who toiled and given to those who hadn’t. 

Mostly those others created nothing of value … but some of them made writing, and mathematics, and rocket ships.

Although the development of writing required oppression, it’s wrong to oppress people now.  It was wrong then, too … but we can’t go back and fix things.

Although the origin of your brain required violence, I likewise think we ought to minimize the violence we enact today.  We can’t help all the animals who were hurt in the long journey that made our world the place it is now.  And we can’t stop killing – there’s no other way for heterotrophs like us to live.

To be vegan, though, is to reckon with those costs.  To feel a sense of wonder at all the world pays for us to be here.  And, in gratitude, to refrain from asking that it pay more than we need.

On sexuality and freedom of choice.

On sexuality and freedom of choice.

Among worms, there is equality.  When worms entwine, each could become a mother, a father, or both.  Neither worm has grounds to bemoan the fundamental unfairness of our universe – not while fooling around, at least.

Later, the worms might drown, or be eaten by birds, or be mutilated and held captive by a mole.  That all must feel horrible.  But while mating, each worm should feel as though it’s been given a fair deal.

Among emperor penguins, both parents make huge sacrifices for their young.  Each parent will huddle over the egg for months without food, staving off the Antarctic chill.  When it’s time to trade places, the parents must pass the egg using only their webbed feet – if they make even a small mistake, the egg will roll away and freeze, killing the chick inside.

Because each parent puts forth such a huge amount of effort to raise a chick, each must feel quite choosy during the mating season.  When a pair of penguins flirt, neither seems to have the upper hand.

Most animals’ reproduction is more asymmetric.  For them – for us – differing roles can feel unfair.

Often, one partner gets to be pickier than the other. 

Among smooth guardian frogs, fathers are deeply invested in raising their young; mothers hop away after mating, providing no help.  Female smooth guardian frogs seem as though they’d be perfectly happy to make babies with anyone.  They can always have another fling while a past paramour is protecting the last batch of eggs.

For a male, mating is a serious commitment.  He’ll carefully consider his options. And so each female sings to woo him.  A common strategy: knowing that males are choosier when it comes to sex, she’ll sing her heart out, hoping to sway his decision.

Among many other species of frogs, males’ songs serve the same purpose.  Hoping to woo womenfolk, male bowerbirds build.

Female ducks raise their young.  They have the freedom to choose their mates.  Male ducks would have more leverage during courtship if they planned to contribute as parents.  But they don’t.

Male ducks are the natural world’s equivalent of violent incels.  Aggrieved by their lack of choice, they rape.  This has been going on so long that female ducks’ anatomy has evolved – they can trap unwanted sperm with labyrinth passageways inside their bodies, and are able to straighten the path to fertilization during consensual sex – allowing them to maintain mate choice despite the constant threat of assault.

From an evolutionary perspective, animals that put forth an effort as parents have earned their choices.  They generally get to indulge their desires … and, even more importantly, should be safe from those whom they do not desire.

Among many species, we can see evidence of this push and pull between devoted parents and the absentees who loudly sing, “Choose me!  Choose me!”

For instance, we can learn a lot about the sex lives of our closest relatives by comparing the males’ genitalia.  No, not your uncle – that’d be weird.  I mean the great apes.  A traditional comparison of gorillas, chimpanzees, and humans is shown below.

Male gorillas claim a territory, and then the dominant male within each territory feels reasonably certain that every female living there will mate with him and only him.  Although he makes minimal contributions toward parenting – which means the females should feel free to shop around for sexual partners – he sways their decision through physical violence.  Mostly he’ll direct aggression at other males, hoping to stave off their competition, but he’s occasionally rough with “his” females as well.

For male gorillas to control female sexuality without helping as parents, they had to become huge.  As it happens, this evolutionary pressure caused their brains to shrink.  They have almost 90% fewer neurons than we’d expect for a primate of that size.  If gorillas were egalitarian, they would’ve been more intelligent than humans.  But there simply weren’t enough calories for gorillas to have large brains and sufficient brawn to indulge in violent sexual coercion.

Image by Ryan Poplin on Flickr.

There’s less difference in size between male and female chimpanzees, but male chimpanzees also use violence to sway mate choice.  A male chimpanzee might attack and kill a mother’s babies in order to impregnate her … but he won’t if he thinks that they might be his own children. 

The safest plan for a mother, then, is to distribute her sexual favors widely.  Her children will safe from everyone with whom she shared a dalliance.  Maybe she’d like to be choosier, but each male will only last a few seconds, so the cost must not seem like too much to bear.

From an evolutionary perspective, then, male chimpanzees are not competing to be the most beautiful.  Nor to be the greatest artists.   They don’t sing.  They do battle, but they tend to battle in cooperative gangs, with the outcome being that each male among the upper echelon will have the chance to get it on.   A friendless, low-ranking male might be chased off every time he attempts to mate, but many others will have an occasional opportunity.

That’s why male chimpanzees produce so much sperm.  The chance to fertilize a mother’s egg comes down to probability.  If a chimp ejaculates prodigiously, he’s more likely to sire offspring.

Several human cultures believed that babies are formed from sperm, and that mothers required repeated infusions during pregnancy in order for the child to form correctly.  Among the Bari of Venezuela, each man who contributed sperm was treated as a biological father – the child was presumed to inherit virtues from each.

Under these beliefs, polyamory was the best strategy for raising a capable child.  A mother needed to consider which qualities would help her children most in life, then spend time astride the men who possessed each.  The best singer, the most nimble climber, the most astute tracker – each trait was an evening’s lay away.

And her strategy surely worked.  Fooling around with the best singer would probably lead to singing lessons.  If the best hunter also shared an orgasm with this child’s mother, he’d make an effort to explain the sights and sounds and rhythms of the forest.  Honestly, it makes no difference whether talents come from nature or nurture if fathers are willing to teach every child that their sperm might’ve helped create.

The Bari culture, like that of most other human hunter gatherers, was quite egalitarian compared to our own.  But even among hunter gatherers, human fathers were typically shabbier parents than mothers.  For instance, fathers who hunted typically claimed to be the ones feeding their families, even in places where the “women’s work” of gathering fruits, nuts and seeds provided more nutrition than meat.  But an occasional dead deer confers more bragging rights than a sackful of nuts each day, and human males have long loved to brag.

As humans began to practice agriculture, our societies became less equitable.  More and more of the childrearing was done by women.

According to the basic principles of evolution, this means that women should have had more and more leverage during courtship.  More and more control over their sexuality.  In cultures where mothers do basically everything – feeding the family, teaching children, cuddling them through the night – women should have had close to free reign in choosing their partners.

And there’s biological evidence that human women used to be in control.  For instance, many women’s sexual preferences seem to cycle rhythmically.  Relatively effeminate, helpful partners are favored most of the time, but ultra-masculine brutes suddenly seem sexy during temporary bursts of hormones.  In the past, human women probably made out with multiple different men each year.

That’s why human males – unlike gorillas or chimpanzees – have a strong incentive to provide a rollicking good time in bed.  Or in the back of a cave, on the forest floor, alongside the riverbank, wherever.  Although there’s been intense debate about the degree of correlation between male penis size and female sexual pleasure, most people seem willing to admit that there’s a link.

When women buy sex toys … well, usually they buy external vibrators.  These don’t always resemble the genitalia of any biological organism.  Many are designed to look like lipstick tubes or other innocuous objects, for modesty’s sake.

But toys that are designed for penetration?  These tend to be much longer and thicker than either a gorilla’s inch-long erection or a chimpanzee’s three-inch, slender shaft.  Human males tend to be well endowed because it’s a way to sway women’s choices.  By giving her a good time, a man might have the chance to fool around again.

But in addition to huge cocks (relative to other primates – as Jeffrey Yang wrote in his poetry collection An Aquarium: The barnacle has the longest penis / of any animal in proportion / to its body size.  Happiness / and proportion: / never be ashamed of evolution), humans also have huge brains.  Instead of evolving better and better ways to deliver consensual pleasure, human males invented stories to subvert female mate choice.

Human males aren’t as horrible as ducks, but we’re close.

Around the world, human males have used religion as a tool to constrain female choice.  We teach that the natural inclination toward polyamory is evil.  A woman needs to devote herself to one man.  In many cultures, women are not even allowed to choose who that man will be.

Even in contemporary experiments on U.S. college students, the presence of sexual competitors leads people to espouse more strident religious experiments.  If you can’t win with your looks, or with your charming personality, why not tell her that it’d be immoral to make eyes at that other guy?

Human men could have made art like bowerbirds.  We could’ve sung like frogs.  Hell, we could’ve capitalized on the promise of our large genitalia to deliver such sweating shaking shuddering good fun that our sexual partners would remain dazzled forever.

Instead, we invented deities, spirits, and purity laws.  We taught that women who dallied should be stigmatized, or stoned, or murdered by God with a rain of burning sulfur.

If emperor penguins learned about our sex lives, they’d be appalled.  “Dude,” a penguin father might say, “you don’t need to coerce her with a sky ghost!  Just be a good parent.  Then you’ll get to choose, too.”

That’s sound advice, Mr. Penguin.  I am trying to be a good parent.  Even when the kids are fussing, I try.

Featured image by Property#1 on Flickr.

On the evolution of skin color.

On the evolution of skin color.

Our criminal justice system ensnares people from all walks of life.  Occasionally we’ll hear about the arrest of a wealthy sociopath with a penchant for child abuse, like Jared Fogel or Jeffrey Epstein.

But, let’s face it.  Justice in this country isn’t applied fairly.  If you’re wealthy, your behavior has to be a lot more egregious for you to reap the same punishments as a poor person.  If you look white, your behavior has to a lot more egregious for you to reap the same punishments as a black person.

There’s abundant statistical evidence to back up these claims.  But the Supreme Court won’t allow any particular individual to petition for reduced punishment based on the statistical evidence.  After all, prosecutors, judges, and juries ostensibly came to their decisions based on the unique details of each individual case.  Just because people who resemble you are often treated unfairly doesn’t mean that you were treated unfairly, too. 

Or so ruled our Supreme Court.

Because we apply punishment so inequitably, our jails and prisons are full of people who’ve been treated poorly by the world.  Compared to the average citizen, people in prison grew up with less money, received less education, experienced more trauma.  And, no matter what people’s earlier lives were like, if they’re in prison, they’re not being treated well now.

So they have a lot of justifiable grievances against the dominant political, cultural, and religious beliefs of our country.  Punished unfairly by their fellow Christians, people sour on Christianity.  Inside walls where the demographics make it blatantly obvious that our laws are enforced in a malignantly racist way, racial tensions boil.

At Pages to Prisoners, an organization that sends free books to people inside, we get requests for stuff about Norse mythology, Odinism, and Asatru.  Lots of folks ask for material to learn foreign languages – people want to feel like they’ve accomplished something during their time in prison – but I always feel skeptical when somebody wants help learning Icelandic.

Not that there’s anything wrong with Icelandic.  And Norse mythology is cool!  Unfortunately, a gaggle of violent white supremacists decided that Norse mythology should be the basis for their religion.  Starting in the 1970s, a right-wing racist from Florida began sending “Odinist” publications into prisons.

A photograph showing a book page in Icelandic.

During the thirteenth century, Christian scholars transcribed many of the old Norse myths so that they could better understand the literary allusions of old Icelandic poetry.  But they didn’t record anything about ancient religious practice.  We barely have any information about most ancient pagan beliefs.  Anyone who wants to adopt a pre-Christian European religion now – whether it’s Wicca, Druidism, Odinism, or Celtic polytheism – is basically forced to make things up.

I have nothing against religious invention.  All religions were made by human beings – there’s no a priori reason why a religion created long ago, by people who understood much less about the world than we do now, would be better than something you invent today.  Sure, ancient religions have been tested by time, suggesting that they possess virtues that their practitioners found helpful over the years, but most ancient religions have their problems, too.  Inaccurate cosmologies, scattered hateful passages in their texts, that sort of thing.

So I like the idea of neo-paganism.  You want to find a clearing in the woods and do some moonlit dancing?  You’d rather worship a feminine generative force than a norm-enforcing patriarchal deity?  You want to exalt nature as a hearth to be protected rather than a resource to be exploited?  Go right ahead!  All of that sounds pretty great to me.

A Wiccan-style gathering of artifacts including a statue of a seated green goddess, her pregnant belly painted as the earth; mums; a chalice; a string of green beads; a stoppered rectangular prism bottle; and a candleholder appearing to be carved of wood, again of a pregnant woman with hands holding her belly.

Unfortunately, neo-paganism as it’s currently practiced in prison tends to be pretty hateful.

That’s why I’ve been working on a set of anti-racist pamphlets about Norse mythology.  Currently, when people ask for The Poetic Edda or whatever, we send a friendly letter saying that we don’t have it, and also that we generally don’t stock that sort of thing because it runs afoul of our anti-hate policy. 

But the Norse myths are certainly no more hateful than Biblical myths, and we send plenty of those.  The main difference is that centuries of continued Christian practice have created a scaffolding of gentler beliefs around the stories in the Bible. 

The text of Psalm 137 states that “Happy shall he be, that taketh and dasheth thy little ones against the stones.”  But the text is a tool, not the entirety of the religion.  The practice of Christianity frowns upon the murder of any human infant.  Whether you like the kid’s parents or not.

A sun-dappled photograph of a page of the Bible.

We’d be better off if Pages to Prisoners could send warm-hearted material about Norse mythology to people.  Sure, you can interpret the Norse myths as endorsing a war-mongering death cult.  You can interpret the Old Testament that way, too.  But you can also interpret the Norse myths as environmentalist.  Feminist.  Supporting the pursuit of knowledge.  Judging strangers based upon their merits, not their appearance.

Because contemporary Odinism is so entangled with white supremacy, though, our pamphlet will have to address skin color and genetic heritage directly.  It’s a fraught topic.  Lots of people in the U.S. don’t like any discussion of evolution.  Some people feel squigged out when they learn that contemporary birds evolved from the same set of common ancestors as the dinosaurs.  And that’s far less emotionally charged than a description of human evolution. 

A photograph of a model dinosaur, complete with feathers.

Plus, skin color still has huge implications for how people are treated in the United States.  Consider, um, those prison demographics I cited above. And so discussions about the evolution of epidermal melanin concentrations are especially tense.  Although the underlying biology is simple – some places have more sunlight than others! – because people think it matters, it does.

I’ve found that these conversations are actually a decent way to get people interested in the study of archeology and biology, though.  After we’ve discussed this in jail, people have asked me to bring research papers and textbooks so that they could learn more.

Whenever two groups of an organism stop mating with each other, they’ll slowly drift apart.  This rift might occur because the groups became physically separated from each other.  Maybe one group migrated to an island.  In contemporary times, maybe the groups were separated when humans built a new highway bisecting a habitat. Maybe two sets of similar-looking insects mate apart because they’re eating fruits that ripen at different times.

Or the groups might stop mating with each other because a chance mutation caused members of one group to want their sexual partners to smell a certain way.  Various species of stickleback are able to interbreed – they identify other members of their kind based on smell.  But water pollution has overwhelmed the fishes’s senses, leading the fish to mate indiscriminately.

A photograph of a three-spined stickleback fish.

If humans hadn’t polluted their waters, though, these sticklebacks would have drifted farther and farther apart until it became impossible for them to interbreed.  No matter how many sense-suppressing chemicals we dumped.

We don’t know what caused the initial rift between our ancestors and the ancestors of contemporary chimpanzees.  About 4 million years ago, though, these groups stopped having children together.  By 2 millions years ago (at least 100,000 generations later), these groups looked quite different from each other.  Although it’s possible that these organisms could have still mated with each other and raised viable progeny, they rarely did.

One group of these creatures, which included our ancestors, had a tucked pelvis and mostly upright posture.  This allowed for a good vantage while scavenging and, eventually, hunting.  The other group, which includes chimpanzees’ ancestors, mostly moved on all fours.  This body plan results in fewer mothers dying during childbirth.  As ever, there are trade-offs to be made.

Image shows the upright skeletal postures of gibbons, humans, chimpanzees, gorillas, and orangutans.

Up until about 2 million years ago, all our ancestors lived in Africa.  But then they began to migrate.  Over the next million years, they explored much of the globe.  By about 500,000 years ago, half a dozen different types of humans lived in Africa, Europe, and Asia.  The difference between one population to the next was not like the racial differences among contemporary humans, but more like the difference between lions and tigers, or between polar bears and brown bears.  Scientists describe them as distinct species.  Although they were similar enough that they could have sex and raise children together, they rarely did – they lived in distinct parts of the world and had begun to evolve adaptations to their specific environments.

Evolution isn’t easy.  Nor is it quick.  Just because a certain trait would be advantageous doesn’t mean that creatures will acquire it.  In the desert, it would help to have adaptations for water retention like camels, or long ears like jackrabbits to cool the blood.  But a trait can only spread after a random mutation creates it.  And, even if a trait is very helpful, if only one individual is born with the adaptation, there’s no guarantee that it will have enough children for the benefit to spread through the population. 

Once a beneficial trait has a good toe-hold – present in perhaps 1% to 10% of the population – then we can expect it to flourish.  But below that amount, even great adaptations might die off due to bad luck.  That’s why it takes so many generations – tens of thousands, or hundreds of thousands – before you see organisms become drastically better suited for the environment.  Even when scientists do directed evolution experiments in the lab, it takes about this many generations for a population of bacteria to evolve ways to consume a new food source, for instance.

By 500,000 years ago, the various species of humans were recognizably different.  Denisovans lived in the mountains, and their hemoglobin genes allowed them to avoid altitude sickness.  Their blood was less likely to clot and cause strokes, and they could extract more oxygen from the thin air.  These are incredibly beneficial traits.  Even though the Denisovans went extinct about 40,000 years ago, about 40% of people currently living in Tibet have copies of the Denisovan hemoglobin gene.

Our ancestors migrated east to the Denisovans’ homeland just before the Denisovans went extinct.  To be perfectly honest, we probably killed them.  But before or during this genocide, a few of our ancestors must have had sex with the locals.  And then the bi-racial children of these Homo sapiens / Denisovan couplings must have been significantly better off for the gene to spread so widely.

The Neanderthal lived at high latitude.  Over many generations, their average skin color became paler.  In part, this was probably due to the lack of selective pressure.  Think about a dodo – there was no advantage for these birds to lose their fear of humans.  But, because the dodos were living on an island that no humans traveled to, there was also no harm in the birds becoming fearless.

A sculpture of a dodo.

Dodos lost a beneficial trait – fear – because their fear wasn’t actively needed.  It’s kind of like the airbags in an old car.  If your car’s engine goes bad, you’ll notice right away.  Turn the key, hear it sputter.  You use the engine every time you drive.  But your airbags could get worse without you noticing … and then, in the moment when they’re needed, they won’t deploy.

Humans living near the equator need epidermal melanin.  If you don’t have enough melanin, you’ll get sunburns, which exacerbate the risk of infection and dehydration; you’ll suffer radiation-induced DNA damage, which leads to skin cancer; and you’ll lose folate, which means that pregnant women will have more birth defects.

The most recent ancestors that humans and chimpanzees shared in common had pale skin.  Contemporary chimpanzees are still pale.  They can afford to be – their fur protects them from the sun.  But our ancestors lost their fur, probably so that they didn’t overheat while running, and this led to the evolution of dark skin.

High concentrations of epidermal melanin distinguished humans from the other apes.

As humans migrated to higher latitudes, though, they gradually lost this indicator of their humanity.  Because the sunlight was less intense, there was less selective pressure.  Humans could lose their epidermal melanin in the same way that dodos lost their fear – not because it was helpful to go without it, but because the trait went untested in their day to day lives.  They had no way to “realize” how important it was. 

Your airbags aren’t helpful until you crash.  And then they’ll either deploy and save you, or they won’t.

Now, it’s possible that the Neanderthal also experienced some positive selective pressure on their skin color as they migrated north.  Over thousands of generations, the Neanderthals may have benefited from paler skin because it increased their production of vitamin D.  We don’t know for certain that the Neanderthal felt any evolutionary pressure to have more vitamin D – after all, contemporary Inuit people live at very high latitudes but still have a lot of epidermal melanin – but it’s true that vitamin D deficiency is a big risk among people with crummy diets.

In the past, hunter / gatherers typically ate much healthier, more varied diets than farmers.  When humans began to farm, they would mostly eat the one type of plant that they cultivated, rather than the wide mix of plants that could be found growing wild.  And when Homo sapiens farmers migrated to northern Europe, their diets were so poor that they even developed loss-of-function mutations in a cholesterol synthesis gene, probably so that they’d have higher concentrations of vitamin D precursors.  Among these people, pale skin was probably a big advantage.  They’d be ready for the cloudless days when their homeland’s feeble sunlight was enough to make some vitamin D.

Pieter Bruegel the Elder’s The Harvesters.

Around 40,000 years ago, our planet’s most recent ice age ended.  The world began to warm, and glaciers retreated from Europe.  By then, a group of humans living in Africa were recognizably Homo sapiens.  These were our ancestors.  Every human alive today – no matter what you look like or where your family is from – is descended from this group of people from Africa.  They lived in tribes of twenty to a hundred people, had darkly pigmented skin, made art, and spoke complex languages.

As the world warmed, some of these Homo sapiens began to migrate.  These journeys occurred over many generations.  Some tribes stayed in Africa; some tribes ventured north into Europe; others moved east toward Asia.  As they traveled, they encountered the humans who already lived in those places.  As I’ve mentioned, the newcomers occasionally had sex and raised children with the natives.  They probably also killed a lot of them.  Unfortunately, we Homo sapiens don’t have the best reputation for treating strangers well. 

Interbreeding happened rarely enough that most people living today have about 99% Homo sapiens DNA.  Some people, especially if their families are from Africa, have essentially 100% Homo sapiens DNA.  At other extreme, even people whose families are from Europe have 96% or more Homo sapiens DNA.

Among people living in Tibet, the Denisovan hemoglobin gene is common, but most other Denisovan genes are gone.

Everyone living today is human.  We are all Homo sapiens, all the same species.  But some of us do carry vestiges of the other human populations whom our ancestors killed.

Like the Neanderthal before them, the Homo sapiens who ventured north into Europe began to lose their epidermal melanin.  People who hunted and fished probably became paler simply because there was less risk of sun damage.  Remember, this didn’t happen all at once.  Average skin color would change only over the course of hundreds or even thousands of generations, not during the course of a single journeying Homo sapiens’s lifetime. 

Our ancestors spent almost all their time outdoors, which is why even dark-skinned people could probably synthesize plenty of vitamin D.  Among contemporary humans, vitamin D deficiency is such a big problem because we spend too much time inside.  As I type this, I’m sitting at a table in the YMCA snack room, lit up by flickering fluorescent bulbs.  This low-quality light won’t help me make vitamin D.

Instead, I take a daily supplement.  But that doesn’t come near matching the health and psychological benefits of time outdoors.

Perhaps it’s worth mentioning that people in jail – places not known for providing a rich, high-quality, varied diet – typically get to go outside no more often than once a week.  At our local jail, their hour of “outdoor rec” occurs in a little courtyard at the top of the jail, a cement space covered with a chain-linked fence.  Outdoor rec often happened at night – a friend who was recently released told me that “This was still nice.  You could see some stars.  And there’s that restaurant, Little Zagrib, down the street?  Sometimes we’d smell foods from their kitchen.”

Treating people that way is unlikely to help them get better.

Blue sky and white cirrus clouds as viewed through coiled razor wire atop a barbed-wire fence.

But back to our migrants!  Descendants of these pale-skinned Homo sapiens continued to explore new territories.  Some reached North America about 12,000 years ago, and some of their descendants continued farther, all the way to South America. 

As people traveled – journeys that lasted many generations – they continued to evolve.  Indeed, skin color was a trait that came repeatedly under selective pressure.  As people migrated south into the Americas, they were living progressively closer and closer to the equator.  Compared to their grandparents, they were bombarded by more intense sunlight.  They needed more epidermal melanin.

This is a process that takes a long time.  A family might have six kids; maybe the two palest kids get sunburned, which makes it more likely that they’ll develop skin infections and die before they have children of their own.  If this happens again and again, among many different families, then eventually the whole population will wind up with slightly darker skin.

A prediction for the distribution of human skin colors based on the intensity of ultraviolet light present at each latitude. Figure from Nina Jablonski & George Chaplin, “The Evolution of Human Skin Color,” in Journal of Human Evolution, 2000.
This figure depicts the (limited) data we have on the distribution of human skin colors before the modern era’s horrific set of forced migrations. In this image, white-colored regions indicate an absence of data, not low concentrations of epidermal melanin among a region’s prehistoric population. Figure from Nina Jablonski & George Chaplin, “The Evolution of Human Skin Color,” in Journal of Human Evolution, 2000.

Because human skin color has changed during each of the many prehistoric migrations, it isn’t correlated with other traits.  As we entered the modern era, people’s skin color was lighter or darker based on how close to the equator their recent ancestors lived.  But human populations migrated so often that there were many different groups, each with unique cultural and genetic heritages, living at every latitude.  Because skin color is so closely linked to latitude, this means many different groups shared similar concentrations of epidermal melanin.  And there’s no evolutionary pressure linking a trait that protects skin to brain size or intelligence.

As it happens, there are major events known to have caused a decrease in human brain size (and probably intelligence).  After all, human brains are costly.  Even though there’s a benefit to being clever, there’s also been constant evolutionary pressure against large brains.

Large brains kill mothers.  Because humans walk upright, childbirth is riskier for human mothers than for other primates.  Our posture constrains the width of our hips – both male and female – but a baby’s whole head has to pass through that narrow passageway.

Having children is so risky that we evolved to give birth about 3 months prematurely.  Human gestation takes about a year, but most mothers give birth after only 9 months.  This allows a baby’s head to continue to grow outside the mother’s body, but human babies are totally helpless at birth.  We have to be very devoted parents to keep them alive.

Also, our brains require a lot of fuel.  Human evolution occurred over such a long, long time that our ancestors lived through many droughts and calamities.  During the hard years, our ancestors would struggle to get enough to eat, and a large brain makes that struggle harder. 

A person with a smaller brain requires fewer calories, making that person less likely to starve in lean times.  And, again, it’s worth remembering that evolution happens over so many generations, among so many families, that even small changes can add up.  If mothers who have small-headed children can survive a dozen pregnancies, but mothers with large-headed children die after only a few, then the trend will be to have people with smaller brains.  Intelligence has to be extremely beneficial to overcome this sort of evolutionary pressure.

Similarly, if people with small brains are more likely to survive and raise children during droughts, then, after hundreds of generations of people who have survived dozens of extended droughts, you’d expect to see more people with small brains.

Many of us have the bad habit of reflexively thinking about evolution as the gradual development of more and more complexity.  But that’s not what it is.  Evolution is the process by which things that are better suited for their environment become more abundant.  If the environment is a hard place to live in, then evolution tends to push for more and more simplicity.  When it’s hard to get enough calories, why waste calories on anything that you don’t really need?

Starfish are descended from organisms that had brains.  But starfish are brainless.  The ancestral starfish that weren’t wasting energy thinking were more likely to survive.

Which should make you feel pretty good about your own brain, actually.  Your ability to think is so fabulous that your ancestors evolved larger and larger brains … even though these brains were sometimes causing us to starve to death, or kill our mothers.

That’s a valuable thing you’ve got inside your skull.  It cost our ancestors so much for you to be able to have it.

But, right.  Because the cost was so high, human brains did shrink sometimes.  Like when we first domesticated dogs.  Our ancestors began living with dogs about 30,000 years ago.  Dogs were willing to do some thinking for us – they’d sniff out prey and listen for predators at night.  Based on the behavior of my family’s dogs, I bet that they licked the faces of screaming children.  Maybe that doesn’t seem essential for survival, but I certainly appreciate every time our dogs calm the kids down.

Because we could slough off a few mental tasks – I don’t need to be so observant if the dog will help me hunt – our brains could shrink, making childbirth less deadly and reducing the caloric cost of maintaining our minds each day.

Pottery shard depicting a boar hunt in ancient Greece.

When humans switched from hunting and gathering to agriculture, our brains shrunk further.  A hunter / gatherer has to know so much about every plant and animal living nearby; the work asks more of a person’s brain than farming.  This evolutionary trend was exacerbated by the fact that people’s diets became way worse when they began to farm.  Instead of getting nutrition from a wide variety of different plants and animals, a farmer might eat meals consisting mostly of a single type of grain. 

There’s nothing we can do now about these evolutionary trends.  Dogs and farming swayed our ancestors’ evolution toward smaller brains, but it’s not as though you can get those neurons back by deciding to take up hunting, or never living with a pet.

But, honestly, our brains are so plastic that our genetic heritage matters less than how we choose to spend our time.  By nature, neither gorillas nor parrots will speak human language.  But individuals from both these species have been able to learn to communicate with us after we taught them.

Nobody is born with an innate understanding of mythology, religion, science, or mathematics.  None of that can be encoded in your genes.  If you want to understand this stuff, you’ll have to make an effort to learn it.

Neuron count only suggests a brain’s potential.  You could do incredible things with a low number – consider, by ways of analogy, the feats that 1960s NASA accomplished using computers much smaller than a contemporary telephone.  And, conversely, sensory deprivation will make it much harder to get things done, no matter what your innate potential.

That’s why I volunteer with Pages to Prisoners.  Our brains are capable of wonders.  At any age, we can learn and grow.  And yet, we lock people into prisons that seem designed to make them worse.

On bowerbirds, process, and happiness.

On bowerbirds, process, and happiness.

We recently read Donika Kelly’s “Bower” in jail. 

I love this poem.  There’s a undercurrent of darkness as the bird constructs his pleasure dome. “Here, the iron smell of blood.”  But he is undeterred.  “And there, the bowerbird.  Watch as he manicures his lawn.”

This bowerbird has themed his edifice around sparkling bits of blue.  Bower birds incorporate all manner of found objects: berries, beetles (which must be repeatedly returned to their places as they attempt to crawl away), plastic scraps.  A bowerbird has a clear vision, a dream of which colors will go where, and scours the forest to find the treasures he needs.

Will high-contrast white in front of the brown bower bedazzle guests? Our artist can only hope. Image by davidfntau on Flickr.

Female bowerbirds raise children alone, so she doesn’t need a helpful partner..  Instead, she’ll choose someone who can show her a good time.  And her pleasure will be enhanced by a beautiful dome, a splendid arch beneath which several seconds of intercourse can transpire.

A mother-to-be typically visit several bowers before choosing her favorite.  During each inspection, the male will hop and flutter during her evaluation … and then slump, dejected, if she flies away.

Kelly closes her poem with the experience of a crestfallen artist: “And then, / how the female finds him, / lacking.  All that blue for nothing.

I especially love the wry irony of that final sentence.  We create art hoping to be fawned over; it’d feel nice to know that readers enjoyed a poem so much that they responded with a flush of desire for the author. 

But this is rare.  No piece of writing will appeal to all readers; an author is lucky if it appeals to any.  The same holds true for painting, music, and bowers.  A bowerbird hopes that his magnificent edifice will soon be the site of his acrobatic, if brief, bouts of copulation.  But his life will miserable if he can’t also take pleasure in the sheer act of creation. 

Female tropical birds are free to select whichever male they want.  Their flirtations are unlikely to be turned down.  And because each intimate encounter is vanishingly brief, a single male might service every female in an area.  The other males, having assembled less glorious bowers, will die without ever experiencing erotic delights.

And so a bowerbird needs to enjoy his own arch.  To endure, to thole, even if no one wants to fool around with him.  Even if no one looks.  He needs to feel pleasure as he assembles those beautiful hues.  Every visiting female might quickly fly away, but all that blue will have served a purpose.

I love the poem “Bower,” but I also hope that Kelly enjoyed writing her poem enough that my opinion doesn’t matter.

After reading “Bower,” our class got sidetracked into a wide-ranging conversation about birds.  At first, we did talk about bowerbirds.  Most of the guys had no idea that birds like that existed – that an animal might make art – but one guy had seen a television show about them years ago, and the program made such a deep impression on him that he still remembered much of it.  “They really do,” he said.  “I’ve seen it.  And they showed the people nearby, somebody who was eating breakfast cereal with like a plastic spoon, and this bird flew right over and took it.  Later they found bits of it all broken up, in this weird ring around the bird’s nest.”

And then this man started talking about crows.

He gesticulated profusely as he talked, which was rather distracting.  One of his hands had about 1.3 fingers; his ring finger was missing entirely, and the others, including his thumb, ended after the first knuckle.  I wouldn’t have felt so puzzled – stuff happens, after all – except that one of his stories involved chasing somebody with a steak knife, and this was the hand he brandished.

Many of the people in jail have suffered severe physical injuries.  When we were discussing personality manipulation and mind control, someone told me that he’d been hit by a truck and that everything in his life had felt flat and emotionless ever since.  He showed me the thick scar at the top of his head: “When it happened, I guess I was out for almost a week, and it took another month before I really remembered my name.  Even then, for that first year I felt like I was back in eighth grade again.”  He was twenty-something when it happened.

Another time, I asked a man if he wanted to read the next poem and he said he couldn’t, that he was disabled, then thumped his leg onto the table.  He had a rounded stump where most people’s foot would be.  I didn’t quite see the connection between his injury and the poem, and it’s not as though we ever force people to read.  We have a lot of guys with dyslexia, and I go in with the goal of making their Fridays a little more pleasant; no reason for somebody to suffer unnecessarily.

“I was working in a saw mill,” he said.  “Planer caught me and, zzooomp.  Didn’t even feel anything, at first.”

He got a legal settlement – a few guys muttered that they’d trade a foot for that kind of money – but his pain script led to more opiates and eventually the money was gone and he was in jail and the only help he was getting was from a PD.

But, right, back to the man gesticulating wildly as he talked about birds.  “Real smart animals,” he said.  “Especially crows.”

I nodded.  Crows can use tools – they’ll craft hooks out of wire, cut twigs into the length they need for various tasks.  Their brains are structured differently from primates’, which lets them cram just as many neurons into a much smaller volume

Photo by Natalie Uomini on Flickr.

The guy went on: “See, I was living in a tent, and cops kept coming by, harassing me.  Cause there’d always be all this trash on the ground.  They’d say, ‘look, we know that you’re sleeping here, but you can’t just leave all this shit everywhere.’  And they’d make me clean it up.  I’d do it, but then a day or two later, there’d be trash scattered everywhere again.  I thought it must be some homeless guys or something that was doing it.”

“But it turned out these crows – they knew I was drinking, that I’d never be up before about noon – and they were raiding the dumpster out behind McDonalds.  I only found out because I actually woke up one morning to piss.  And I looked up and these crows in the tree above me, they carried tied-off garbage bags way up into that tree and were tearing them apart, looking for things to eat.  And that’s how all that trash was getting everywhere.  I’d thought it was homeless guys, and it was crows!”

Male bowerbirds can afford to be such terrible parents because they live in tropical forests where there’s an abundance of food to eat.  Crows, though, need ingenuity to survive.  Sometimes they pick apart the leavings of hairless apes below.

Because crows raise their young in much harsher environs than bowerbirds, males contribute more than just DNA.  While a mother roosts, the father will gather food.  And so he’ll try to impress a potential mate, beforehand, with his gathering prowess.  He won’t build, paint, or compose poetry, but he’ll scour the land below for tasty treats and shiny things, then leave these gifts at his beloved’s feet.

As with bowerbirds, some crows are helpful without reaping the benefits of a dalliance.  When a female crow begins to build a nest, five other crows might bring sticks and twigs.  These five won’t all be rewarded with the chance to sire her young.

With luck, the crows enjoy the sheer act of helping. 

Neither birds nor humans will be lauded for everything we do.  If we measure success based solely upon the rewards we reap, many of our lives will feel bleak.  In a world full of pyramids – bowerbird mating, corporate finance, the attention economy of social media – not everyone can be at the top.

No matter the outcome, we can all feel fulfilled if we focus on the process of what we’re doing. 

Admittedly, it’s hard to find the zen in a lot of the shitty jobs out there in the world.  But I did enjoy typing this essay.  And I will try to enjoy the irritating parts of parenting today.  Someday, my children will learn to ask for cereal politely.

On the celebration of Neanderthals.

On the celebration of Neanderthals.

I am descended from the oppressors.  My ancestors ventured from their homeland with colonial aspirations and genocidal results.

It wasn’t my fault.  I wasn’t born yet!  But, having inherited vast privilege, some measure of responsibility from the misdeeds of my people surely falls upon my shoulders.

A hundred thousand years ago, several species of humans shared our planet.  My ancestors, who would give rise to contemporary Homo sapiens, mostly lived in Africa.  They differed from other primates in that their brains were larger, their posture more upright, their epidermis darker in hue, their verbal communication more nuanced.

During a period of climate change, my ancestors left their home.  The planet was warming; glaciers receded; Homo sapiens ventured north. 

One still-popular model for how Homo sapiens spread. Image by Altaileopard on Wikimedia Commons.

Europe was already populated by humans, people who had weathered the bitter cold through the waning ice age.  But my ancestors were undeterred.  They did not respect the old territorial boundaries.  Soon they supplanted the native peoples.  Every last one of the natives died.  Their people disappeared from the face of the earth, extinct.

Every time my ancestors ventured to a new land, the old inhabitants were killed.  Nearly all of our planet’s large animals are gone now; megafauna extinction is directly correlated with human migration

Image by Uweka on Wikimedia Commons.

If it’s any consolation, Homo sapiens were not the only perpetrators of these atrocities.  Every other human species – including those whom my ancestors harried to extinction – wrought similar devastation on their environments.

In this case, no reparations are possible.  The victims are dead; their families curtailed.  My ancestors’ misdeeds against them ceased, but only because there was no one left to harm.

But I can atone through remembrance.

And so, as a descendant of the oppressors, I felt a special sympathy toward the Neanderthal.  When I was in school, these humans were consistently described as brutish, uncouth, and unintelligent.  But I recognized that sort of language.  My people have almost always maligned supposed “others” – until we took the time to learn how smart they are, all non-human animals were imagined to be unthinking automata.  Pale-skinned Europeans claimed that intelligence – or even humanity itself – was inversely correlated with epidermal melanin concentration (by which measure Pan troglodytes would be more human than any Englishman). 

Forty years ago, medical doctors implied that men who felt a sexual attraction to men differed from their peers on a cellular level, as though the human immunodeficiency virus was sensitive to a psychological preference.  Even now, many medical doctors believe that people with higher amounts of epidermal melanin experience pain differently.

My people’s negative assessment of the Neanderthal, I figured, was probably not true.  Indeed, in recent years we’ve discovered that Neanderthals made art, that they probably had spoken languages … that they were like us.  Enough so that many humans living today carry Neanderthal DNA sequences in their genomes.

A Neanderthal model at Zagros Paleolithic Museum, Kermanshah.
Photograph by ICHTO on Wikimedia Commons.

Inspired by Paul Kingsnorth’s The Wake, a first-person perspective of the apocalypse wrought upon 11th century England, I began working on a story narrated by the last of the Neanderthal.

Stray scientific findings have revealed surprising details about Neanderthal life.  Young women often left their family tribe.  All people collaborated on hunts, regardless of gender.  Homo sapiens males would fool around with either Homo sapiens or Neanderthals; Neanderthal males rarely sired children with Homo sapiens.  After Homo sapiens arrived in Europe, they ate a lot of squirrels, but the Neanderthal declined to eat rodents.

These details seemed sufficient to evoke a world.

I was still working on this story during the 2016 presidential election.  But with our 45th openly praising white supremacists, I felt suddenly less inspired to celebrate the Neanderthal.  Many of the hate mongers were extolling the virtues of humans descended from northern Europeans, and, as it happens, these are the people who have the most abundant remnants of Neanderthal DNA in their genomes.

Genetics isn’t destiny.  And there haven’t been any correlations between Neanderthal DNA and intelligence; indeed, most of the genetic sequences that have been proposed to modulate intelligence are probably false.  Neanderthal DNA has been found to correlate only with an increased risk of depression and an increased susceptibility to allergies.

I began working on my Neanderthal story as an apology to the dispossessed, but I couldn’t bring myself to finish it in an environment where some individuals might tout their Neanderthal heritage as a mark of superiority.  As though their blood conferred the right to mistreat people from other backgrounds, or the right to so thoroughly ravage our planet’s atmosphere that other people’s homes are scorched or submerged beneath the sea.

Which seems shocking to me.  Quite recently, the Neanderthal were thoroughly impugned.  As though we could declare their kind to be undeserving of existence and thereby spare ourselves a reckoning for having killed them.

Now the contemporary oppressors herald the Neanderthal as a source of greatness.  Light-skinned warrior folk, beset by dark-skinned immigrants from the south.

Who would have thought?

Then again, I would not have expected Odin or Thor to become patron deities of U.S. white supremacists.  Nor that they might switch from beer to chugging milk as a display of inner fortitude.

Hate works in mysterious ways.

Someday, perhaps, in a kinder, gentler world, I’ll feel safe to write more stories featuring the Neanderthal. For now, I’ve set my draft aside.

Image by Chapendra on Flickr.

Featured image: the National Museum of Natural History. Image by Eden, Janine and Jim on Flickr.