Song of the Rifleman

As an avid birdwatcher, I've learned many of the vocalizations of our local species.  Some, especially the migratory species we only hear from May to September, I have to relearn every year, but a few of them are so distinct that my ears perk up whenever I hear them.  One of my favorites is the whirling, ethereal song of the Veery (Catharus fuscescens):

Another lovely one, often heard in the same sorts of deep-woods habitats as the Veery, is the Wood Thrush (Hylocichla mustelina):

By far the strangest bird songs I've ever heard, though, we came across when we visited the lowlands of eastern Ecuador about twenty years ago.  There were two we heard but never saw -- first, the aptly-named Screaming Piha (Lipaugus vociferans), which can be heard for miles:

And second, the Great Potoo (Nyctibius grandis), which is cryptically-colored and nocturnal, so they're almost never seen.  But when they sing at night... holy crap.  Imagine being out in the jungle, alone, at night, and hearing this:

It's no wonder the locals thought there were monsters out there.

Bird songs serve two main purposes.  They're territorial defense signals and mate attractants.  (Which led a former student of mine to say, in some astonishment, "So birds only sing when they're mad or horny?")  Songs are usually only done by males, and mostly during the breeding season.  Calls, on the other hand, are done by both males and females, at any time of the year, and can mean a variety of things from "there's food over here" to "watch out for the cat" to "hey, howsyamommaandem?"  (The latter mostly from birds in the southeastern United States.)  Those of you in the eastern half of North America certainly already have heard the difference; our local Black-capped Chickadee (Poecile atricapillus) has a call, the familiar "chicka-dee-dee-dee-dee" that gives the species its name, and a song -- a two-note whistle with the second note a whole step below the first.  Listening to them, you'd never guess it was the same bird.

There's an interesting distinction in how animals vocalize.  Some vocalizations seem to be innate and hard-wired; the barking of dogs, for example, doesn't need to be learned.  A great many bird species, however, including songbirds and parrots, learn vocalizations, and deprived of examples to learn from, never sing.  (This includes the amazing mimicry of birds like the Australian Superb Lyrebird (Menura novaehollandiae), which can learn to imitate not only birdsongs but a huge variety of other sounds as well):

The topic comes up because of a study that came out this week in the journal Communications Biology about the Rifleman (Acanthisitta chloris), a tiny species from New Zealand that is one of only two surviving species in the family Acanthisittidae, the New Zealand wrens, which are only distantly related to the more familiar and widespread true wrens.  (If you're curious, its odd common name comes from the cheerful colors of the plumage, which someone decided looked like a military uniform:

[Image licensed under the Creative Commons digitaltrails, Lake Sylvan - Rifleman (5626163357) (cropped), CC BY-SA 2.0]

The Rifleman is not a songbird, and (if the preceding distinction holds) should be unable to learn vocalizations; any sounds it makes should be instinctive and fixed, like the clucking of a chicken.  But the study found that there were variations in the vocalizations of different individuals, and those variations were independent of how closely related they were; what mattered was how nearby they lived to each other, implying that the alterations in sound were learned, not innate. 

"The vocal behavior that we were unravelling in this study is very similar to what is known as vocal accommodation in human linguistics," said Ines Moran, of the University of Auckland, who led the research.  "It's similar to our ability to adjust our ways of speaking in different social, dialectal, or hierarchical settings -- modulating our voices to better fit in certain social groups."

So bird vocalizations may not be as simple as we'd thought.  Like most things, I suppose.  It brings up the silly distinction that I heard over and over again from students, that there's a split between "human" and "animal."  We're clearly animals; and, conversely, what we call "animals" share a great deal more with us than we often realize.  We have a lot to learn from the other species we whom we cohabit the planet.  It's nice that we're beginning to pay more attention.

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Flocking together

One of the most mesmerizing sights in nature is the collective motion of large groups of animals.

I remember watching films by Jacques Cousteau as a kid, and being fascinated by his underwater footage of schools of fish swimming along and then turning as one, the light flickering from their silvery sides as if they were each reflective scales on a giant single organism.  Murmurations of starlings barely even look real; the flocks swirl and flow like some kind of weird, airborne fluid.  But the most astonishing example of collective motion I've ever seen was when Carol and I visited Bosque del Apache Wildlife Refuge, in central New Mexico, a few years ago, during the migration of snow geese through the region.

"Get there early," we were told.  "At least a half-hour before sunrise.  You'll be glad you did."

We arrived just as the light was growing in the eastern sky.  The wetland was full of tens of thousands of snow geese, all moving around in a relaxed sort of fashion, calling softly to each other.  The brightness in the sky grew, and then -- without any warning at all...

... BOOM.

They all exploded into the air, seemingly simultaneously.  We have wondered many times since what the signal was; there was nothing we could discern, no handful of birds that launched first, no change in the vocalizations that a human would interpret as, "Now!"  One moment everything was calm; the next, the air was a hurricane of flapping wings.  They whirled around, circling higher and higher, and within ten minutes they were all gone, coursing through the sky toward their next destination.

[Image licensed under the Creative Commons CrunchySkies, Snow goose migration at Squaw Creek National Wildlife Refuge, Feb 2013, 25, CC BY-SA 3.0]

How animals manage such feats, moving as a unit without colliding or leaving members behind -- and seemingly without any central coordination -- has long fascinated zoologists.  Way back in 1987, computer simulation expert Craig Reynolds showed (using software called "Boids") that with only a handful of simple rules -- stay within so many wing-lengths of your nearest neighbors but not close enough to touch, match the speed of your neighbors within ten percent either way, steer toward the average heading of your nearest neighbors, give other members a chance to be in any given position in the group -- he was able to create simulated flocking behavior that looked absolutely convincing.  

Last week, a paper out of the Max Planck Gesellschaft showed there's another factor that's important in modeling collective motion, and this has to do with the fact that flying or swimming animals have a rhythm.  Look, for example, at a single fish swimming in an aquarium; its motion forward isn't like a car moving at a steady speed down a highway, but an oscillating swim-glide-swim-glide, giving it a pattern a little like a Slinky moving down a staircase.

Biologist Guy Amichay, who led the research, found that this gives schools of fish a pulse; he compares it to the way we alternate moving our legs while walking.  "Fish are coordinating the timing of their movements with that of their neighbor, and vice versa," Amichay said.  "This two-way rhythmic coupling is an important, but overlooked, force that binds animals in motion.  There's more rhythm to animal movement than you might expect.  In the real world most fish don't swim at fixed speeds, they oscillate."

The key in simulating this behavior is that unlike the factors that Reynolds identified, getting the oscillating movement right depends on neighboring fish doing the opposite of what their nearest neighbors are doing.  The swim-glide pattern in one fish triggers a glide-swim pattern in its friends; put another way, each swim pulse creates a delay in the swim pulse of the school members around it.  

"It's fascinating to see that reciprocity is driving this turn-taking behavior in swimming fish, because it's not always the case in biological oscillators," said study co-author Máté Nagy.  "Fireflies, for example, will synchronize even in one-way interactions.  But for humans, reciprocity comes into play in almost anything we do in pairs, be it dance, or sport, or conversation,"

"We used to think that in a busy group, a fish could be influenced by any other member that it can see," said co-author Iain Couzin. "Now, we see that the most salient bonds could be between partners that choose to rhythmically synchronize."

So zoologists have taken another step toward comprehending one of the most fascinating phenomena in nature; the ability of animals to move together.  Something to think about next time you see a school of fish or a flock of birds in flight.  Getting it right requires rapid and sophisticated coordination we are only now beginning to understand.

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Going to the dogs

I understand dogs a great deal better than I understand my fellow humans.

Dogs are straightforward.  They interact with their world in a direct way, whether it be motivated by love, anger, curiosity, hunger, enthusiasm, or fear.  There's nothing feigned about a dog's emotions or the way they express them.  I've sometimes misinterpreted one of my dogs' signals, but that's on me; the signals were there, even if I only recognized them in retrospect.  Once you grok dog behavior, it's much less fraught than the complex, confusing morass of human interaction.

This is why when I'm invited to social events, I'm always hoping the host will have a dog so there'll be someone for me to have a conversation with.

The dogs we've had have nearly all been rescues, and came with all the baggage and bad backstories that rescue dogs have, but one and all were and are wonderful companions, and enriched our lives tremendously.  This latter part is the only possible explanation for why during the holidays, my wife and I were looking around and thinking, "Wow, our house sure has a lot of clutter and dirt and chaos.  We never seem to be able to keep up with the housekeeping.  Hey, I know... let's get a puppy!"

So, without further ado, allow me to introduce to the Skeptophilia readership...

... Jethro.

Jethro is -- and I say this with all modesty and restraint -- the cutest puppy in the whole entire world.  He's five months old, has the sweetest, happiest disposition ever, and soft, silky hair that gathers burs, mud, and debris like some sort of bizarre magnet.  Like many puppies, he has two settings -- "Full Throttle" and "Off."

He's currently set at "Off" and is sleeping at my feet, which is the only way I'm able to write this.  Otherwise I would be engaged in the essential task of Playing With Jethro.

We got him from the amazing Stay Wild Rescue and Wildlife Rehabilitation Center on New Year's Eve.  If you are looking for a wonderful and deserving place to make a donation, please consider Stay Wild.  They do fantastic work on a shoestring budget, and the owners -- Jane George and Dan Soboleski -- work tirelessly to help find rescue pets forever homes, and to rehabilitate wild animals for re-release.  Please check out their website and consider supporting them.

In the few days we've had Jethro, he's already bonded with our other two dogs, Guinness and Rosie.  Rosie is an Australian Cattle Dog mix who pretty much loves everyone, so she was easy.

Guinness is a big galumphing American Staffordshire Terrier/Husky/Chow cross who can be cranky and gets jealous easily, especially when it comes to sharing Carol's attention with anyone, because he's a big ol' Mama's Boy.  He is, however, a very natty dresser. 

But yesterday, all three of them were romping around together in the back yard, and Guinness was letting Jethro chase him like they'd been best friends forever instead of just three days.  Guinness even responded with the doggie "play-bow" before they took off running again.

Like with most rescues, we're not sure what kind of a mix Jethro is.  Jane at Stay Wild said she thought he had some Golden Retriever in him, which makes sense given his silky coat and general head shape, but his striking and beautiful black face and brindle coloration have to come from somewhere else.  He's got huge paws, indicating he's got some serious growing to do, but whether he'll turn out to be long and lanky or barrel-chested and stocky is anyone's guess.  Dog-loving friends of mine have speculated a lot of possible contributions to his ancestry -- suggestions have included various spaniels and setters, Border Collie, Boxer, German Shepherd, even Saint Bernard -- but we won't be sure until we have him DNA-tested.  (The kit has already been ordered.)

A photo of Jethro from five minutes ago, because why not

It's tempting to say his lovable, playful temperament is indicative of his Golden Retriever genes, but a surprising study at the University of Massachusetts just last year found the contribution of breed to behavior is way smaller than most people think.  We often associate particular behavioral traits with certain types of dog -- labs are friendly and loyal, hounds laid-back but stubborn, Dalmatians nervous and prone to biting, and so on -- but the researchers found exceptions to the rule are so common that the rule isn't really a rule.  And while we've had dogs who seemed to conform to the breed expectations, all of them have their own unique characteristics and quirks.

Dogs are as varied in personality as people are, I suppose.

In any case, now we've got three dogs.  I commented yesterday that this means we're outnumbered, and that it's a good thing this is a benevolent dictatorship and not a democracy.  Although a friend of mine responded, "I'm sure your dogs would vote for you anyway."

Given the fact that Jethro is snoozing happily right next to me, I suspect my friend is right.

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Music of the heart

A couple of days ago I was in my car, listening to Sirius XM Satellite Radio's station Symphony Hall, and was delighted when one of my favorite pieces of music came on -- Beethoven's Seventh Symphony.

What has always struck me as marvelous about this symphony is the contrast between the first and second movements.  The first movement is one of the most joyous pieces of music I know, a galloping romp that never fails to make me smile.  Then... the second movement begins.  It's quiet, dark, deeply melancholic, achingly beautiful.  It brings home what a genius Beethoven was, able to take us from one emotional extreme to the other in a heartbeat.

I've always reacted to music emotionally, ever since I was four years old and begged to be allowed to put my parents' vinyl records on the turntable and play them.  My mom, not trusting my capacity to handle them carefully, at first refused, but when it became clear that I would keep asking till I got my way, she finally caved and taught me how to operate it.

To my credit, I never so much as scratched a single record.  Even at that age, I recognized that they were far too precious to me to mishandle.  I did, however, play certain records over and over and over, undoubtedly making my mother question her decision to teach me how to use the record player.  Interestingly, I never had any interest in children's music -- not that my parents had much of that in any case -- the pieces I fell in love with as a child were Rimsky-Korsakov's Scheherazade and Dvorak's Symphony #9: From the New World.  I remember being blown away when I was about twelve, and had a little portable AM/FM radio my grandmother gave me, and stumbled on the one radio station near where I lived that had a classical music program once a week.  I was idly flipping channels, and -- all of a sudden -- the opening chords of the first chorus of J. S. Bach's Magnificat in D came pouring out of the little speakers.

Three minutes later, when the piece ended, I was sitting on the floor in my bedroom with tears streaming down my face.  It was, truly, a transformative experience -- so much so that I worked it, very nearly verbatim, into my novel The Hand of the Hunter.

But I didn't know then, and still don't know, why some music resonates so strongly with me, and other pieces don't generate any emotional response at all.  I was spellbound when I discovered Stravinsky's Firebird when I was seventeen; it's still my very favorite piece of music.  On the other hand, I've heard music-loving friends rave about the symphonies of Brahms, and I can say unequivocally that I've never heard anything by Brahms that has ever generated more than a "meh" reaction from me.

Why?  I don't think anyone could answer that.

What is certain is that music is, for most of us, a deeply emotional experience.  And two studies that just came out this week support the conclusion that this response is very likely to be innate.

The first, which appeared in the Journal of Complementary and Alternative Medicine, is perhaps not that surprising.  It studied the stress levels and mood of over seven hundred volunteers, and found that listening to music improved mood and reduced stress, pretty much across the board.  Most hearteningly, the stress reduction was greatest in those who registered the highest stress levels before the study.

Like I said, nothing too earthshattering.  But the second is absolutely astonishing.  A paper in Psychological Studies showed that newborns, when played music judged by listeners as "happy" or "sad," responded differently -- and that it seems to be independent of tempo ("happy" music generally having a faster rhythm than "sad" music).  Newborns listening to the tunes judged as "happy" showed greater focus, calmer facial expressions, reduced heartbeat, and less movement of the hands and feet; "sad" music produced no such effect.

So the hallmarks of a happy piece of music -- things like being in a major key, less harmonic dissonance, and wide pitch contours -- are markers we either learn prenatally, or else are (amazing as it may seem) hard-wired into our neural network.

I said earlier that this was "astonishing," but honestly, it shouldn't be.  Like I said, I've responded emotionally to music for as long as I can recall, and although my parents had a decent collection of records, neither of them played an instrument (nor made any real efforts to expose me to music).  Whatever capacity I had for music appreciation was already there somewhere.  And the fact that the link between emotion and music is so innate is pretty incredible.  I have to wonder what evolutionary purpose it serves.  We certainly get a lot of information about others' emotional states through the pitch contours of their speech; think about what it sounds like when an actor portrays a "robotic voice," for example.  The contours flatten out, leaving behind a monotonous, mechanical stream of words.

But is this really what drives our emotional response to music?  It's only a guess.  What's certain is that the current research explains why for so many of us, music is a critical piece of our lives -- something we return to again and again for solace, comfort, and emotional release.

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Dance of life

Dancing is ubiquitous amongst human societies.

Everywhere you go, every culture you look at, there is some form of rhythmic movement, usually to music.  (Sometimes the dancing creates its own music.)  I love to dance; I'm not saying I'm great at it, but starting out the day by putting on some tunes and moving my body just feels good.  And it's much more fun to do daily chores like cooking dinner with my music on, rockin' to the beat while I'm chopping the vegetables.

It's an interesting question why this is.  A shrewd guess is that a lot of it is about social cohesion.  You get a bunch of people together, all moving in the same way to the same rhythm, and it's a strong symbol of unity and common purpose.  

There's some biochemical support for this contention.  A series of studies a few years ago found that dancing releases four of the most important feel-good and bonding hormones -- dopamine, oxytocin, serotonin, and endorphin.

No wonder we feel better after we dance.

[Image licensed under the Creative Commons Ramesh lalwani, Revanta Sarabhai Male Dancer, CC BY-SA 4.0]

For me, one of the most wonderful -- and difficult -- things about dancing is that it requires you to forget about yourself.  To dance fluidly, you need to be immersed in the music and the movement, and overcome the self-consciousness we all seem to carry around with us, to greater or lesser degrees.  I'm plagued with more than my fair share of it, and it's only been fairly recently that I've been willing to dance with other people around.  Which, of course, is missing a good part of the fun of it -- sharing the experience of moving your body in synchrony to the music.

What brings all this up is a fascinating study from the University of Tokyo released last week showing that humans aren't the only ones who feel like shakin' their tails when the music comes on.

Rats do it, too.

Rats were fitted out with tiny helmets containing wireless accelerometers, and then exposed to varying types and speeds of music.  Sure enough -- they began to move their heads in time to the beat.

"Rats displayed innate — that is, without any training or prior exposure to music — beat synchronization most distinctly within 120-140 bpm (beats per minute), to which humans also exhibit the clearest beat synchronization," said Hirokazu Takahashi, of the Graduate School of Information Science and Technology, who co-authored the paper.  "The auditory cortex, the region of our brain that processes sound, was also tuned to 120-140 bpm, which we were able to explain using our mathematical model of brain adaptation...  Music exerts a strong appeal to the brain and has profound effects on emotion and cognition.  To utilize music effectively, we need to reveal the neural mechanism underlying this empirical fact."

I find this absolutely astonishing, given that rats don't have music in their natural environments (well, except for the rats that sometimes end up cohabiting with us).  What possible purpose can this serve?  It's interesting, but it seems to me to raise as many questions as it answers.

Which, of course, is the hallmark of good science.

Whatever the reason, it's pretty cool that this impulse to move to the music has a long evolutionary history.  And there's no doubt that it does a body good.  I'll end with a quote from the wonderful writer Dave Barry: "Nobody cares if you can't dance well.  Get out there on the floor and dance anyway."

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The nose knows

The first few years my wife and I were married, we had a dog named Doolin.

At least I think Doolin was a dog.  The story is that she was born to the unholy union between a border collie and a bluetick coonhound, but there's credible evidence she was an alien infiltrator from the planet K-9, sent to study humans by pretending to be a humble house pet.  My observations suggested that she was far smarter than humans but had only recently mastered pretending to be a dog.  She is, far and away, the weirdest dog I've ever met, and I've had dogs pretty much my whole life.  She figured out how to unlatch our gates (and let herself out) by watching us; we ultimately had to put carabiners on the latches to stop her from going on walkies by herself.  She valiantly attempted to herd our four cats, an effort that was ultimately unsuccessful.  Of her many odd habits, one of the funniest was that she was never without her favorite toy, a plush jack that she carried around in her mouth -- always pointing the same way.  (We tested this by taking it from her and sticking it in her mouth the other way 'round.  She dropped it, looked at us as if we'd lost our minds, and picked it up from the other direction.)

Doolin, with her jack toy sticking out of the right side of her mouth, as it obviously should be

One of Doolin's most curious traits was an extraordinary sensitivity to us, particularly to Carol.  She seemed to watch us continuously for cues about what was going on, and sensed when one of us was upset or feeling unwell.  Most strikingly, Doolin always knew when Carol was about to get a migraine.  Starting about a half-hour before the symptoms began, Doolin followed Carol around like her shadow, and if Carol sat down, Doolin smushed herself right up against her.  It got to be that Carol knew when to prep for a migraine once she saw Doolin acting weird (well, weirder than usual, which was admittedly a pretty high bar).

I used to think that people claiming their dogs had a second sense about how they (the owners) were feeling was an example of people anthropomorphizing, or at the very least, exaggerating their pets' intelligence and emotional sensitivity.  Until I had lived for a while with Doolin.

After that, a lot of the stories I'd heard began to seem a good bit more plausible.

Just this week, some research supported the contention with hard evidence.  A team of scientists in Belfast studied the responses of four dogs to breath and sweat samples from thirty-six volunteers, before and after doing a stressful exercise -- counting backwards from 9,000 by intervals of 17, without using calculators or pen and paper.  The researchers laid it on thick, telling the participants that it was very important to the study to do the counting exercise quickly and accurately.  A wrong answer got a shouted "No!", followed by being told the most recent correct response and an instruction to pick up from there.  For most of us, this would be a pretty high-stress activity, and would cause stress hormones (like cortisol and epinephrine) to pour into our bloodstreams.

And the breakdown products of those chemicals end up in our breath, sweat, and urine.  What's remarkable is that the four dogs, which had been conditioned to be able to discern between samples containing those breakdown products from ones which did not, correctly distinguished the post-stress breath and sweat samples from the pre-stress ones 93% of the time.

I know that our current dogs are pretty sensitive as well (although nowhere near the level of acuity that Doolin had).  Cleo, our Shiba Inu rescue, is really keyed in to me especially.  I had a couple of seriously high stress things happen in the last couple of months, and whenever I was really in freak-out mode, Cleo followed me around with a very worried expression on her face.  Her curly tail is like a barometer; the tighter the curl, the happier she is.  And when I was struggling, her tail was sagging.  Clearly an unhappy dog.

Cleo the Wonder Floof

So I guess all this stuff isn't our imagination.  Dogs really do sense our emotional states, not by some kind of canine telepathy, but because of plain old biochemistry coupled with an extraordinary sense of smell.

Although I wonder about Doolin.  I still think she was an alien spy, and was relaying information about us back to the Mother Ship.  Maybe the jack toy was some kind of transmitter, I dunno.

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What's bred in the bone

A friend of mine was chatting with me about irritating situations at work, and she mentioned that she'd really lost her cool with a supervisor the previous week who apparently is notorious for being a bit of an asshole.  I mentioned that I tend to put up with such nonsense and later wish I'd spoken up for myself -- that it has to be pretty bad before I'll blow up (at a supervisor or anyone else).

She laughed and said, "Of course I have a quick temper.  My family's Italian.  It's in our genes."

She was joking, of course, no more serious than my father was when he quipped that our family was "French enough to like to drink and Scottish enough not to know when to stop."  But it's a common enough view, isn't it?  We get our personality traits from some nebulous genetic heritage, despite the fact that a great many of us are pretty thorough mixtures of ancestry, and that all humans regardless of race or ethnicity are well over 99.9% similar anyhow.  As geneticist Kenneth Kidd put it, "Race is not biologically definable.  We are far too similar."

Ha.  Take that, racists.

[Image is in the Public Domain]

The whole thing gets complicated, however, because race and ethnicity certainly have a cultural reality, and that can certainly affect how your personality develops as you grow up.  If you're raised in a family where arguments are regularly settled through shouting and waving your arms around (apparently true in my friend's case), then you learn that as a standard of behavior.  (Or, sometimes, decide, "That was a miserable way to live, I'm never going to treat people that way," and swing to the opposite extreme.)  All of this is just meant to highlight that teasing apart the genetic components of behavior (and there certainly are some) from the learned ones is no simple task.

All of this just gained an additional complication with a study last week in the journal Social Cognition that looked at another factor contributing to our behavior -- how our notions about our genetic makeup influence how we think we should be acting.

The study, by Ryan Wheat and Matthew Vess (of Texas A & M) and Patricia Holte (of Wake Forest University), was simple enough.  What they did was to take a group of test subjects, gave them a (bogus) saliva test, and split the group in two.  They were then given the "results," regarding what the sample said about their genetic makeup for a variety of characteristics.  The salient part, though was that half were told that their genetic sample showed they had an unusually high propensity for risk-taking, and the other half were told their genes said they tended to avoid risk.

Afterward, they were given a personality test, and only one thing was important; the questions that evaluated them for risk-tolerance.  Across the board, the people who were told their genes predisposed them to taking risks scored higher on the risk-tolerance questions than did the people who were told their genes made them risk-averse.

So not only do we have how we were raised complicating any sort of understanding of the genetic component of human behavior, we have our subconscious conforming to our perception of how people with our genetic makeup are thought to behave.

So even if there is no Italian gene for quick temper, maybe my friend's short fuse comes from her belief that there is.

Coupled, of course, with having been raised in a shouty family.  The "nurture" side of "nature vs. nurture" is not inconsequential.  All the more reason that question of whether behavior is learned or innate has been going on for a century and still hasn't been decisively settled.

In any case, I better wrap this up.  I think I'm going to go get another cup of coffee.  It's a little early for a glass of red wine, and you know us people with French blood.  It's either one or the other.

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Living crystals

Starfish are odd creatures in just about every respect.

They belong to a phylum called Echinodermata, which is Greek for "spiny skin" and also includes such weird animals as sea urchins, sand dollars, brittle stars, sea cucumbers, and crinoids (also called "sea lilies" or "stone lilies" because they look more like some kind of weird undersea plant than they do animals).  One of the big surprises for my AP Biology students, during the unit on zoology, was that echinoderms are our closest non-vertebrate relatives.  The old distinction of vertebrate versus invertebrate turns out to reflect less of a real genetic and evolutionary split than the distinction between protostome and deuterostome; the former includes insects, crustaceans, arachnids, mollusks, annelids (e.g. earthworms), and nematodes (roundworms), while the latter is just the echinoderms and vertebrates such as ourselves.

The names protostome and deuterostome, if you're curious, are also Greek; they mean (respectively) "first mouth" and "second mouth," referring to the order in which the openings of the digestive tract form.  In protostomes, when the beachball-shaped early embryo forms an inpocket that will lead to the formation of the gut, that first opening will eventually become the mouth; the anus forms when the inpocket tunnels its way through and comes out of the other side.  In deuterostome, it happens the other way around, but early embryologists evidently thought that "mouth second" sounded more genteel than "ass first," and that's how we ended up called "deuterostomes."  (I remember the shocked look on one of my students' faces when I told the class about this fun feature of embryonic development.  She said, wide-eyed, "So, at some point, all humans are just... a butthole?"  I deadpanned back, "Yup.  Unfortunately, some people never get past that stage.")

You might wonder how echinoderms can look so different from vertebrates if we're actually on the same branch of the animal family tree.  In fact, echinoderm larva are clearly bilaterally symmetric, just like vertebrates are; they largely lose that symmetry as they mature, although the apparent pentaradial symmetry of a starfish is kind of an illusion, because they do have organs (like the water intake organ, or sieve plate) that are offset to one side.  But they lose more than their symmetry; the adults have no true circulatory system (all they end up with is a set of what are essentially water pipes), no central nervous system (just a nerve ring and branched peripheral nerves), and the simplest of digestive tracts.  This despecialization seems to underlie their wild ability to regenerate lost or damaged limbs -- a capacity that has been under intensive study because of the possible applications to medical science.

[Image licensed under the Creative Commons Copyright (c) 2004 Richard Ling, Blue Linckia Starfish, CC BY-SA 3.0]

The reason all this comes up is because of yet another bizarre and beautiful feature of starfish, just discovered at MIT.  When they're still very early in embryonic development, and resemble spherical glass beads, they exhibit a peculiar behavior -- they spin, creating tiny vortices in the water and drawing other nearby embryos in.  Eventually they self-assemble into a living crystal -- a regular, tightly-packed lattice of embryos all spinning in the same direction.  They undergo peculiar ripples that the researchers call "odd elasticity" -- odd because the oscillations aren't damped down by the water's drag, but continue to propagate through the entire crystal, like some sort of biological standing wave pattern.

"The spontaneous, long-lasting ripples may be the result of interactions between the individual embryos, which spin against each other like interlocking gears," said Alexander Mietke, who co-authored the paper on the phenomenon that appeared last week in Nature.  "With thousands of gears spinning in crystal formation, the many individual spins could set off a larger, collective motion across the entire structure."

The benefit to this behavior isn't known.  One possibility is that the formation of these crystals makes it less likely that the embryos will be eaten by predators, but that's just speculation.  At the moment, though, it's enough to wonder at the intricacy and beauty of these odd creatures, our distant cousins on the evolutionary family tree.

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Nice smile!

Back in December, I completely skeeved out some of my readers with a discussion of parasites, more specifically the protist Toxoplasma gondii.  Toxoplasma causes the disease toxoplasmosis, and a number of mammalian species are hosts, most notably cats, humans, and rats.  It's the cat/human connection that is why you've probably heard that pregnant women shouldn't clean cat litter boxes; contact with an infected cat's urine can transmit the parasite to a human, and Toxoplasma is associated with birth defects in human infants.

More interesting, though, are its behavioral effects.  In December's post, I described how toxoplasmosis alters the behavior of all three of its main hosts -- it makes cats more affectionate, humans more neurotic, and rats more fearless, all three of which serve the evolutionary function of increasing the likelihood that the pathogen will jump to another host.  (The cats seek out human company; the humans crave the comfort that pets can give; and the rats become unafraid of predators.  In fact, some studies have even shown that infected rats are actively attracted to the scent of cat urine.)

Which is creepy enough.  The idea that a brain parasite is, at least in some respects, in the driver's seat of our emotional state is a little unsettling.  Or maybe I'm only saying that because I've got it myself, having had cats off and on for pretty much my entire adult life.  But I'm not indulging in hypochondria, here; if you've ever owned a cat, especially one allowed outdoors, your chances of having a Toxoplasma infection is nearly 100%.  Kevin Lafferty, a microbiologist who is one of leading experts on Toxoplasma, estimates that there are three billion people in the world who have it.

Yes, that's "billion" with a "b."  As in just shy of 40% of the world's population,

But now another filigree of "holy shit, that is freaky" has been added to this already bizarre pathogen.  A team made up of Javier Borráz-Léon and Markus Rantala (of the University of Turku), Indrikis Krams (of the University of Latvia), and Ana Lilia Cerda-Molina (of the Instituto Nacional de Psiquiatría of Mexico City) found out that not only does Toxoplasma change our personalities, it changes our appearance.

The idea came from the fact that in other mammals, Toxoplasma can be spread through sexual contact, so there was no reason to believe the same couldn't be true of humans.  The researchers wondered if -- given that the parasite is pretty damn good at engineering its hosts to do things that pass it on -- there might be some way that being Toxoplasma-positive increased your likelihood of having sex.

And hoo boy, what they found.

They took a large test sample of infected and uninfected individuals, and rated them (or had others rate them, as the case may be) for a variety of features -- attractiveness (both self-perceived and as perceived by others), perception of healthiness, number of sexual partners, number of minor ailments, body mass index, mate value, handgrip strength, facial fluctuating asymmetry (i.e. asymmetry in features that change, such as how you smile), and facial width-to-height ratio, all of which could feasibly connect to sexual attractiveness.  

Some of the features (like handgrip strength and minor ailment susceptibility) showed no statistically significant difference.  But... well, let me quote you directly from the paper, so you don't think I'm making this up:

[We] found that infected men had lower facial fluctuating asymmetry whereas infected women had lower body mass, lower body mass index, a tendency for lower facial fluctuating asymmetry, higher self-perceived attractiveness, and a higher number of sexual partners than non-infected ones.  Then, we found that infected men and women were rated as more attractive and healthier than non-infected ones...  The present study offers novel evidence supporting the idea that some sexually transmitted parasites such as T. gondii may produce changes in the appearance and behavior of the human host, either as a by-product of the infection or as a result of the manipulation of the parasite to increase its spread to new hosts.

Which is probably why everyone finds me so dashingly handsome, and why my entire adult life I've had to fight off people trying to break down my bedroom door.

(Maybe having toxoplasmosis also makes you more sarcastic, I dunno.)

So.  Yeah.  That's not creepy at all.  Having a brain parasite causes you to look healthier and have a more attractive smile, and makes it more likely you'll get laid.  Who would have thought something that completely bizarre could be real?

Yeah, look at that smile. I bet you a hundred bucks David Tennant has toxoplasmosis. Maybe it even accounts for his amazing hair. [Image licensed under the Creative Commons Rach from Tadcaster, York, England, 2009 07 31 David Tennant smile 09, CC BY 2.0]

Interestingly, I wrote a short story called "The Germ Theory of Disease" (which you can read for free at the link provided) that riffs on this very idea -- a pathogen that makes you more social.  Unfortunately, it also turns you into a werewolf.  (C'mon, it's me we're talking about here, you had to know there'd be a paranormal twist.)

But hell's bells, I thought it was fiction.

And little did I know that I'm very likely to be carrying around a pathogen myself that does just that.  (Well, not the werewolf part.  I hope.)  Sometimes, as Oscar Wilde pointed out, life imitates art just as much as art imitates life.  Or, to quote Mark Twain, "The difference between reality and fiction is that fiction has to be believable."

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Oops, I did it again

The following is a direct transcript of how I got welcomed into a multi-person business-related Zoom call a couple of years ago:

Me: How are you today?

Meeting leader: I'm fine, how are you?

Me: Pretty good, how are you?

Meeting leader: ...

Me: *vows never to open his mouth in public again*

I think we can all relate to this sort of thing -- and the awful sensation of realizing, microseconds after it leaves our mouths, that what we just said was idiotic.  When my then fiancée, now wife, told a mutual friend that she was getting married -- after we'd been dating for two years -- the friend blurted out, "To who?"  Another friend ended a serious phone call with her boss by saying, "Love you, honey!"  Another -- and I witnessed this one -- was at a trailhead in a local park, preparing to go for a walk as two cyclists were mounting their bikes and putting on their helmets.  He said to them, "Enjoy your hike!"

The funniest one, though, was a friend who was in a restaurant, and the waitress asked what she'd like for dinner.  My friend said, "The half chicken bake, please."  The waitress said, "Which side?"  My friend frowned with puzzlement and said, "Um... I dunno... Left, I guess?"  There was a long pause, and the waitress, obviously trying not to guffaw, said, "No, ma'am, I mean, which side order would you like?"

I don't think my friend has been in that restaurant since.

This "oops" phenomenon probably shouldn't embarrass us as much as it does, because it's damn near ubiquitous.  The brilliant writer Jenny Lawson -- whose three wonderful books, Let's Pretend This Never Happened, Furiously Happy, and Broken (In the Best Possibly Way) should be on everyone's reading list -- posted on her Twitter (@TheBloggess -- follow her immediately if you don't already) a while back, "Airport cashier: 'Have a safe flight.'  Me: 'You too!'  I CAN NEVER COME HERE AGAIN.", and was immediately inundated by (literally) thousands of replies from followers who shared their own embarrassing, and hilarious, moments.  She devotes a whole chapter to these endearing blunders in her book Broken -- by the time I was done reading that chapter, my stomach hurt from laughing -- but here are three that struck me as particularly funny:

I walked up to a baby-holding stranger (thinking it was my sister) at my daughter's soccer game and said "Give me the baby."

A friend thanked me for coming to her husband's funeral.  My reply?  "Anytime."

A friend placed her order at drive thru.  She then heard, "Could you drive up to the speaker?  You're talking to the trash can."

Lawson responded, "How could you not love each and every member of this awkward tribe?"

This universal phenomenon -- particularly the moment of sudden realization that we've just said or done something ridiculous -- was the subject of a study at Cedars-Sinai Medical Center that came out last week, led by neurologist Ueli Rutishauser.  You'd think it'd be a difficult subject to study; how do you catch someone in one of those moments, and find out what's going on in the brain at the time?  But they got around this in a clever way, by studying patients who were epileptic and already had electrode implants to locate the focal point of their seizures, and had them perform a task that was set up to trigger people to make mistakes.  It's a famous one called the Stroop Test, after psychologist John Ridley Stroop who published a paper on it in 1935.  It's an array of names of colors, where each name is printed in a different color from the one named:

The task is to state the colors, not the names, as quickly as you can.

Most people find this really difficult to do, because we're generally taught to pay attention to what words say and ignore what color it's printed in.  "This creates conflict in the brain," Rutishauser said. "You have decades of training in reading, but now your goal is to suppress that habit of reading and say the color of the ink that the word is written in instead."  Most people, though, when they do make an error, realize it right away.  So this made it an ideal way to see what was happening in the brain in those sudden "oops" moments.

What Rutishauser et al. found is that there are two arrays of neurons that kick in when we make a mistake, a process called "performance monitoring."  The first is the domain-general network, which identifies that we've made a mistake.  Then, the domain-specific network pinpoints what exactly the mistake was.  This, of course, takes time, which is why we usually become aware of what we've just done a moment after it's too late to stop it.

"When we observed the activity of neurons in this brain area, it surprised us that most of them only become active after a decision or an action was completed," said study first author Zhongzheng Fu.  "This indicates that this brain area plays a role in evaluating decisions after the fact, rather than while making them."

Which is kind of unfortunate, because however we rationalize those kinds of blunders as being commonplace, it's hard not to feel like crawling into a hole afterward.  But I guess that, given the fact that it's hardwired into our brains, there's not much hope of changing it.

So we should just embrace embarrassing situations as being part of the human condition.  We're weird, funny, awkward beasts, fumbling along as best we can, and just about everyone can relate to the ridiculous things we say and do sometimes.

But I still don't think I'd be able to persuade my friend to eat dinner at the restaurant where she ordered the left half of a chicken.

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Catty behavior

Ever heard of the cui bono principle?

Cui bono? is Latin for "who benefits?"  It's been used for centuries as a central question in criminal cases; to figure out who's guilty of a crime, the first thing to determine is who benefitted from it.  But it is also critical to questions of evolutionary biology.  There are behaviors in the biological world that seem unnecessarily risky, or even suicidal, and it's hard to imagine how they'd be selected for.

So... who benefits?

Take, for example, the strange behavior of certain ants.  Ground-dwelling ants, when threatened, usually have one of two responses; rush out and try to sting or bite whatever's threatening them, or move downward (and underground) to hide.  But some ants were observed to have a third, and bizarre, response: faced with a threat, they climb upwards on plant stems, and then just docilely sit there -- and, frequently, get eaten (along with the plant) by herbivorous animals.

The reason for this weird behavior is positively grotesque.  It turns out that the seemingly-suicidal ants were infected with a brain parasite called a lancet worm (Dicrocoelium dendriticum) that, in order to complete its life cycle, has to pass through the digestive tract and liver of a ruminant (sheep, cow, or goat).  So the worm reprograms the ant's brain to make it do something that will ultimately end up with its being turned into lunch.  

Too bad for the ant.  But cui bono?  The worm, of course.  It hijacked the ant's brain to make it an unwilling participant in the worm's life cycle.

This is hardly the only example of the cui bono principle, and far from the creepiest one.  Ready to get completely skeeved out?

You may know of the pathogen Toxoplasma gondii in its connection to the recommendation by doctors that pregnant women not clean cat litter boxes.  The pathogen, which is neither a bacteria nor a virus but a protist, is carried by cats and excreted with the urine; and a pregnant woman who contracts toxoplasmosis risks birth defects in her unborn child.

Toxoplasma, however, is found in other animals besides cats, and in fact it was some recent research into hyenas that brought it to mind today.  A study out of the University of Colorado that appeared in Nature Communications a few months ago showed that wild populations of hyenas have a high rate of infection, and the weirdest result is seen in infected hyena cubs.  They, like the unfortunate ants, have a behavioral consequence of infection; they become bold, and seem to lose their perception of lions and other predators as dangerous.  They're far more likely to be killed than healthy, uninfected hyena cubs -- which, of course, benefits the pathogen because it then passes on to the lion.  The pathogen, in essence, is programming its host to engage in behavior that will make it more likely to jump to another host.

[Image licensed under the Creative Commons New Jersey Birds, Spotted hyena cubs in Limpopo, CC BY-SA 2.0]

So, a weird and gruesome outcome of being infected with a tropical disease, right?  Nothing for us humans to worry about, right?  Well, what you may not know is that there is a significant likelihood that you have toxoplasmosis right now.  In fact, if you have ever owned a cat, the probability stands close to 100%.

A study done a while back by Kevin Lafferty, of the University of California, suggests that as many as three billion people may have a dormant Toxoplasma infection.  Yes, dear readers, you read that right; that's three billion with a "b," as in a little less than half of the human population.  Turns out that Lafferty's research indicated that when you get toxoplasmosis, you get flu-like symptoms for a couple of days, and then the symptoms abate -- but for most of us, the protist goes dormant, and we carry around the parasite for life.

This is creepy enough, but wait'll you hear what it does to you.

Lafferty's research showed that in mammalian hosts, the Toxoplasma organism invades, and becomes dormant in, the host's brain cells.  Not only hyenas become bolder around predators; mice and rats do, as well, aiding in the passage of the germ between rodents and domestic cats.  Lafferty's study, though, goes a step further, and looks at what latent Toxoplasma infection does to humans -- and he found  it seems to cause significant personality changes.

Now, it doesn't make us have a high affinity for cats, which would make sense, and would explain Crazy Cat Lady Syndrome, in which some people think it's normal to own thirty cats, and somehow seem immune to the truly cataclysmic odor that their houses attain.  No, what actually happens is more subtle.  Apparently, if you have Toxoplasma, you're more likely to be neurotic.  People who tested positive for antibodies for Toxoplasma scored far higher on personality assessments in the areas of guilt-proneness, anxiety, and risk of depression.  These effects were so pronounced that Lafferty speculates that it could account for certain differences between cultures.

"In some cultures, infection is very rare," Lafferty said, "while in others, virtually everyone is infected.  The distribution of Toxoplasma gondii could explain differences in cultural aspects that relate to ego, money, material possessions, work, and rules."

I find this speculation fascinating.  The idea that my neuroses might not be due to my genes or upbringing, but because I'm carrying around a parasite in my brain, doesn't create the level of Icky-Poo Factor that you might expect.  Of course, I'm a biologist, and so I'm at least on some level accustomed to thinking about creepy-crawlies.  But the idea that some sort of a microorganism could affect my behavior strikes me as weirdly interesting, particularly since I've had at least one cat in my household for a significant chunk of the past forty years.

So, maybe our personalities aren't as static as we'd like to think -- they can be influenced by a great many circumstances outside of our control.  Add parasite infestations to that list.  And if that whole idea upsets you too much, take comfort in the fact that Lafferty's research has spurred medical researchers to try to find a drug that can destroy the germ.  Nothing's been certified for human use so far, so don't cancel your appointment with your therapist just yet, but there are a couple that are looking promising.  What's uncertain is whether, if the pathogen were eradicated, it would reverse the changes in the brain -- if, for example, nervous, neurotic people would find themselves less anxiety-prone -- or if the alterations in the brain are more or less permanent.  But I, for one, would volunteer to give it a try, once (or if) the medication becomes available.

Until then, you should probably shouldn't worry.  What's a few brain parasites among friends, after all?  In fact, just forget I brought it up.  Relax, go and sit in your recliner, and pet your cat, Mr. Fluffkins, for a while.

You'll feel better.  Trust me.

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I've mentioned before how fascinated I am with the parts of history that still are largely mysterious -- the top of the list being the European Dark Ages, between the fall of Rome and the re-consolidation of central government under people like Charlemagne and Alfred the Great.  Not all that much was being written down in the interim, and much of the history we have comes from much later (such as History of the Kings of Britain, by Geoffrey of Monmouth, chronicling the events of the fourth through the eighth centuries C.E. -- but written in the twelfth century).

"Dark Ages," though, may be an unfair appellation, according to the new book Matthew Gabriele and David Perry called The Bright Ages: A New History of Medieval Europe.  Gabriele and Perry look at what is known of those years, and their contention is that it wasn't the savage, ignorant hotbed of backwards superstition many of us picture, but a rich and complex world, including the majesty of Byzantium, the beauty and scientific advancements of Moorish Spain, and the artistic genius of the master illuminators found in just about every Christian abbey in Europe.

It's an interesting perspective.  It certainly doesn't settle all the questions; we're still relying on a paucity of actual records, and the ones we have (Geoffrey's work being a case in point) sometimes being as full of legends, myths, and folk tales as they are of actual history.  But The Bright Ages goes a long way toward dispelling the sense that medieval Europe was seven hundred years of nothing but human misery.  It's a fascinating look at humanity's distant, and shadowed, past.

[Note: if you purchase this book using the image/link below, part of the proceeds goes to support Skeptophilia!]