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?”

#

“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.”

#

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.

#

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.

#

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.

#

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 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 human uniqueness and invasive species.

On human uniqueness and invasive species.

We like to see ourselves as special.  “I am a beautiful and unique snowflake,” we’re taught to intone.

Most of the time, this is lovely.  Other than the U.S. Supreme Court, hardly anyone thinks you should be punished for being special.  Of course, the Court’s opinion does matter, since the ignorant claims of five old rich white men have an inordinate sway in determining how U.S. citizens will be allowed to live.  And they, the conservative predecessors of our lockstep quartet (soon to return to a quintet) of hate machines, oft feel that the beautiful snowflakes should melt in prison.  In McCleskey v. Kemp, the court decided that statistical evidence of injustice should not be admissible as evidence; they would only consider documentation of deliberate bias in individual cases.

snowflake
Unique when you are on trial, now orange & a number.  Photo by Joel Franusic on Flickr.

Which means, for instance, that if a police force decides to systematically harass black drivers, and winds up stopping hundreds of black drivers and zero white drivers each month, they’re in the clear as long as each black driver stopped was violating some portion of the traffic code.  At that point, each black driver is a unique individual lawbreaker, and the court sees no reason why their experiences should be lumped together as statistical evidence of racial injustice.  Adolph Lyons, after being nearly choked to death by an L.A. police officer, could not convince the courts that the L.A. police should stop choking innocuous black drivers.

Lovely, eh?

So it can hurt if others see us as being too special.  Too distinct for our collective identity to matter.

At other times, we humans might not feel special enough.  That’s when the baseless claims get bandied about.  For instance, K recently received a letter from Stanford’s Graduate School of Education pontificating that “Only humans teach.”  A specious example is given, followed by the reiteration that “Only humans look to see if their pupils are learning.”  Which simply isn’t true.

But people feel such a burning desire to be special – as individuals, as fans of a particular sports team, as people with a particular skin color, or as people who follow a particular set of religious credos – that an ostensibly very-educated someone needed to write this letter.

That’s why the occasional correctives always make me smile.  For instance, research findings showing that other animal species have some of the skills that our sapiens chauvinists oft claim as uniquely human, or other data indicating that humans are not as exceptional as we at times believe.

Consider our brains.  For many years, we thought our brains were anomalously large for the size of our bodies.  The basic rationale for this metric was that more brain power would be needed to control a larger body – this seems tenuous if you compare to robots we’ve created, but so it goes.  Recently, a research group directed by Suzana Herculano-Houzel counted how many actual neurons are in brains of different sizes.  Again comparing to human creations, computer scientists would argue that more neurons allow for more patterns of connections and thus more brainpower, somewhat comparable to the total number of transistors inside a computer.

As it happens, no one knew how many neurons were in different creatures’ brains, because brains are very inhomogeneous.  But they can be homogenized – rather easily, as it happens.  I did this (unfortunately!) with cow brains.  These arrived frozen and bloodied; I’d smash them with a hammer then puree them in a blender till they looked rather like strawberry daiquiri.  For my work I’d then spin the soupy slushy muck so fast that all the cell nuclei pelleted on the bottom of centrifuge tubes, ready to be thrown away.

brains
After a spin in the blender, all brains look the same. Photo from Wikipedia.

Alternatively, one could take a sample of the soup and simply count.  How many nuclei are here?  Then stain an equivalent sample with antibodies that recognize proteins expressed in neurons but not the other cell types present in a brain: what fraction of the nuclei were neurons?  And, voila, you have your answer!

Gabi et al. did roughly this, publishing their findings with the subtly anti-exceptionalist title “No relative expansion of the number of prefrontal neurons in primate and human evolution.”  We have more neurons than smaller primates, but only as many as you’d expect based on our increased size.

zombie-starfish(Perhaps this leaves you wondering why gorillas rarely best us on human-designed IQ tests – as it happens, the other great apes are outliers, with fewer neurons than you would expect based on the primate trends.  Some of this data was presented in a paper I discussed in my essay about the link between “origin of fire” and “origin of knowledge” myths.  In brief, the idea is that the caloric requirements of human-like brainpower demanded cooked food.  The evolutionary precursors to gorillas instead progressed toward smaller brains – which happens.  The evolutionary precursors to starfish also jettisoned their brains, making themselves rather more like zombies.)

Perhaps all these brain musings are an insufficient corrective.  After all, humans are very smart – I’m trusting that you’re getting more out of this essay than the average hamster would, even if I translated these words into squeaks.

So let’s close with one more piece of humility-inducing (humiliating) research: archaeologists have long studied the migration of early humans, trying to learn when Homo sapiens first reached various areas and what happened after they arrived.  Sadly, “what happened” was often the same: rapid extinction of all other variety of humans, first, then most other species of large animals.

All the Neanderthal disappeared shortly after Homo sapiens forayed into Europe.  There are reasons why someone might quibble with the timeline, but it seems that Homo erectus disappeared from Asia shortly after Homo sapiens arrived.  The arrival of Homo sapiens in Australia brought the extinction of all large animals other than kangaroos.  The arrival of Homo sapiens in South America presaged, again, a huge megafaunal extinction.

On evolutionary timescales, we are a slow-moving meaty wrecking ball.

27435263990_8f7566831d_b.jpg
Bad as we are, we can always get worse. My country! Picture by DonkeyHotey on Flickr.

And our spread, apparently, resembles that of all other invasive species.  This is slightly less derogatory than the summation given in The Matrix – “[humans] move to an area and … multiply and multiply until every natural resource is consumed and the only way [they] can survive is to spread to another area.  There is another organism on this planet that follows the same pattern.  Do you know what it is?  A virus.  Human beings are a disease, a cancer of this planet.” – but only slightly.

Upon the arrival of Homo sapiens in South America, we quickly filled the entire continent to its carrying capacity, and then, after the invention of sedentary agriculture – which boosts food production sufficiently for an area to support more human farmers than hunter gatherers – resumed exponential population growth.  Although the switch to an agricultural lifestyle may have been rotten for the individual actors – the strength needed to push plows makes human sexual dimorphism more important, which is why the spread of agriculture heralded the oppression of & violence against women throughout human history – it’s certainly a great technology if our goal is to fill the world with as many miserable humans as possible.

We’ll be passing eight billion soon, a population inconceivable without modern farming technologies.  And likely unsustainable even with.

Not, again, that this makes us unique.  Plenty of species are willing to breed themselves into misery & extinction if given half the chance.  Almost any species that follows r-type population growth (this jargon signifies “quantity over quality”) – which oft seems to include Homo sapiens – is likely to do so.  My home town, wolf-less, is currently riddled with starving, sickly deer.