The most beautiful brain network

A couple of weeks ago, I wrote a piece here at Skeptophilia about some fascinating new research suggesting that there are links between our perceptions of artistic, musical, and mathematical beauty, and expressed some puzzlement about how those could possibly connect.  In one of those lovely near-synchronicities that happen sometimes, today I happened upon some new(er) research showing what the underlying connection might be -- in one single region of the brain.

In a paper published this week in the Proceedings of the National Academy of Sciences, a team made up of Edward A. Vessel and Ayse Ilkay Isik (of the Max Planck Institute), Amy M. Belfi (of the Missouri University of Science and Technology), Jonathan L. Stahl (of Ohio State University), and G. Gabrielle Starr (of Pomona College) showed that with different sorts of visual stimuli, our sense of aesthetic pleasure comes from activation of a part of the brain called the default-mode network.  The authors write:

Despite being highly subjective, aesthetic experiences are powerful moments of interaction with one’s surroundings, shaping behavior, mood, beliefs, and even a sense of self.  The default-mode network (DMN), which sits atop the cortical hierarchy and has been implicated in self-referential processing, is typically suppressed when a person engages with the external environment.  Yet not only is the DMN surprisingly engaged when one finds a visual artwork aesthetically moving, here we present evidence that the DMN also represents aesthetic appeal in a manner that generalizes across visual aesthetic domains, such as artworks, landscapes, or architecture.  This stands in contrast to ventral occipitotemporal cortex (VOT), which represents the content of what we see, but does not contain domain-general information about aesthetic appeal.

Using fMRI studies, the researchers compared the responses of the brains of volunteers to three types of visual stimuli; art, architecture, and photographs of natural landscapes.  The responses of the visual cortices of the test subjects showed great variation between these three different types -- evidently the brain's effort to categorize and interpret what it's seeing, so it's no great surprise that you'd respond differently while seeing the Mona Lisa than you would looking at Chartres Cathedral.

What was surprising, though, is that while viewing visual stimuli the test subjects found aesthetically pleasing, all of them had a high response in the default-mode network, which is usually associated with contemplation, imagination, self-reflection, and inward thought.  It's uncertain if the DMN actually encodes the basics of aesthetic response, but this certainly suggests a critical role.  "We don't know yet if DMN actually computes this representation," said Edward Vessel, lead author of the paper, in an interview in EurekAlert.  "But it clearly has access to abstract information about whether we find an experience aesthetically appealing or not."

This suggests to me a couple of interesting directions this research could go.  Obviously, it'd be intriguing to find out of the DMN is also active with other types of aesthetic appreciation (such as musical and mathematical aesthetics, the subject of the previous research).  What I'd find even more fascinating, though, is to see if there's a difference in the activity of the DMN depending upon how strongly the individual is aesthetically moved.  Those responses are so highly individual that finding a biological underpinning would be amazingly cool.  Why, for example, was my wife moved to tears while looking at paintings in a Van Gogh exhibition we attended a couple of years ago in New York City?  Why do I find Édouard Manet's 1882 masterpiece A Bar at the Folies-Bergère so emotionally evocative, while a lot of other art from the same period doesn't really grab me one way or the other?

[Image is in the Public Domain]

So this could be a window into finding out -- at least from a neurological standpoint -- how our brain modulates our aesthetic response.  The "why," of course, is more inscrutable -- demonstrating in an fMRI that I go into rapture hearing Stravinsky's Firebird isn't telling me anything I didn't already know, after all, and doesn't answer why I don't have the same response hearing Rachmaninoff's Piano Concerto #2.

But at least finding a neurological basis for such judgments would be a step forward.  The Vessel et al. research is a fascinating first step into understanding the sweetest of human behaviors -- our perception of beauty in the world around us.

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This week's Skeptophilia book recommendation made the cut more because I'd like to see what others think of it than because it bowled me over: Jacques Vallée's Passport to Magonia.

Vallée is an interesting fellow, and certainly comes with credentials; he has an M.S. in astrophysics from the University of Lille and a Ph.D. in computer science from Northwestern University.  He's at various times been an astronomer, a computer scientist, and a venture capitalist, and apparently was quite successful at all three.  But if you know his name, it's probably because of his connection to something else -- UFOs.

Vallée became interested in UFOs early, when he was 16 and saw one in his home town of Pontoise, France.  After earning his degree in astrophysics, he veered off into the study of the paranormal, especially allegations of alien visitation, associating himself with some pretty reputable folks (J. Allen Hynek, for example) and some seriously questionable ones (like the fraudulent Israeli spoon-bender, Uri Geller).

Vallée didn't really get the proof he was looking for (of course, because if he had we'd probably all know about it), but his decades of research compiles literally hundreds -- perhaps thousands -- of alleged sightings and abductions.  And that's what Passport to Magonia is about.  To Vallée's credit, he doesn't try to explain them -- he doesn't have a favorite hypothesis he's trying to convince you of -- he simply says that there are two things that are significant: (1) the number of claims from otherwise reliable and sane folks is too high for there not to be something to it; and (2) the similarity between the claims, going all the way back to medieval claims of abductions by spirits and "elementals," is great enough to be significant.

I'm not saying I necessarily agree with him, but his book is lucid and fascinating, and the case studies he cites make for pretty interesting reading.  I'd be curious to see what other Skeptophiles think of his work.

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

Impulsive art

It's no surprise to the people who know me that I'm an enthusiast of body art.

Well, if it was a surprise, it isn't any more, because last month I had a tattoo completed that's a full sleeve, so a little hard to hide except when I'm wearing long sleeves.  Which, being that this is upstate New York, is something on the order of ten months of the year, so maybe people didn't find out till this summer.

In any case, the design has two parts -- a twining series of vines in honor of my gardener mother, and a snake in honor of my outdoorsman, animal-loving father.

Me being worked on by my artist, the incomparable James Spiers of Model Citizen Tattoos

This comes up because of a study done recently at Wilfred Laurier University (Waterloo, Ontario) by a pair of social psychologists, Anne Wilson and Bradley Ruffle, to find out if there was any personality component to the choice of getting tattoos.  They sorted a thousand volunteers into three groups -- no ink at all, ink that can be easily hidden, and visible ink.  They then gave the volunteers personality assessments geared toward finding out how they scored on measures of short-sightedness and impulsivity.

What they found is that the visible-tattoo group considered the future the least, and were the most impulsive, and the non-tattooed people were the most future-oriented and least impulsive (with the non-visible tattooed people, of course, in the middle on both metrics).  This is, on first glance, not surprising; we've all seen cases of ink that was clearly an ill-thought-out spur of the moment decision (the guy who has "No Ragrets" scrawled on his upper chest being the classic example).  I'm kind of at the other end of the spectrum -- not only am I pretty cautious by nature, I also thought about the decision for all three of my tattoos for over a year, then once I made the decision to go for it, spent equally long planning the design.  As a result, I've never regretted (or ragretted, as the case may be) any of my ink for a moment.

My first tattoo (which I got about fifteen years ago)

So it's unsurprising that counterbalancing outliers like myself would be the fraction of people who either make impulsive jumps into getting inked, or else don't think through the consequences (such as trying to find employment with companies that have a no-visible-ink policy).

My second one, from about eight years ago -- a Celtic dragon in honor of my Scottish grandma.  [Nota bene: my leg usually isn't this hairless.  This photo was taken the day I got the tattoo done.]

The researchers determined short-sightedness by using a delayed-gratification scenario -- you can get a small payment now, or wait three weeks and get a larger payment.  In the Wilson and Ruffle study, the immediate payment was a dollar, and the delayed payment increased from a dollar to two-fifty (the idea was to see how much of an incentive it would take for people to wait).  The trend was that the non-tattooed people were willing to wait to get a larger payout much more readily than the tattooed people were.

What strikes me is that I'm not at all averse to waiting for a larger reward; I'm about as far from an instant-gratification type as you can get.  But the difference in my life between a dollar and two-fifty is so small that it doesn't seem to matter much, so I can't imagine that small a change influencing my decision any.  Now, if you went from ten to twenty-five dollars, that'd be a hell of a lot more of an incentive, even though it's the same percentage increase.  An extra fifteen bucks would make a difference to me.

So I wonder what would happen if you sliced the data a different way -- group the people according to wealth.  My guess is the poorer people would jump at a quicker (and smaller) reward, and the wealthier people would be more willing to wait -- regardless of their body art.

That's only a guess, of course, and even if I'm right the trend that Wilson and Ruffle found is pretty interesting.  I've had people comment on my tattoos from the standpoint that I don't "seem like the type who would get tattooed."  I don't know about that -- I've always loved body art (artistically done, and in moderation, it can be absolutely beautiful).  I guess being a shy introvert does make it kind of weird that I'd do something that makes me more noticeable.

Oh, well.  People are complex, which keeps social psychologists like Wilson and Ruffle in business.  Like Whitman said, "Do I contradict myself?  Very well, then, I contradict myself.  (I am large; I contain multitudes.)"

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This week's Skeptophilia book recommendation made the cut more because I'd like to see what others think of it than because it bowled me over: Jacques Vallée's Passport to Magonia.

Vallée is an interesting fellow, and certainly comes with credentials; he has an M.S. in astrophysics from the University of Lille and a Ph.D. in computer science from Northwestern University.  He's at various times been an astronomer, a computer scientist, and a venture capitalist, and apparently was quite successful at all three.  But if you know his name, it's probably because of his connection to something else -- UFOs.

Vallée became interested in UFOs early, when he was 16 and saw one in his home town of Pontoise, France.  After earning his degree in astrophysics, he veered off into the study of the paranormal, especially allegations of alien visitation, associating himself with some pretty reputable folks (J. Allen Hynek, for example) and some seriously questionable ones (like the fraudulent Israeli spoon-bender, Uri Geller).

Vallée didn't really get the proof he was looking for (of course, because if he had we'd probably all know about it), but his decades of research compiles literally hundreds -- perhaps thousands -- of alleged sightings and abductions.  And that's what Passport to Magonia is about.  To Vallée's credit, he doesn't try to explain them -- he doesn't have a favorite hypothesis he's trying to convince you of -- he simply says that there are two things that are significant: (1) the number of claims from otherwise reliable and sane folks is too high for there not to be something to it; and (2) the similarity between the claims, going all the way back to medieval claims of abductions by spirits and "elementals," is great enough to be significant.

I'm not saying I necessarily agree with him, but his book is lucid and fascinating, and the case studies he cites make for pretty interesting reading.  I'd be curious to see what other Skeptophiles think of his work.

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

The best of the worst

It's mid-September, so you know what that means:

It's time for this year's Ig Nobel Prizes.

The Ig Nobel Prizes celebrate the loopy side of science in a ceremony that has been taking place at Harvard University annually for the last 29 years.  The idea is to recognize research (and researchers) whose work is probably never going to receive an actual Nobel -- but deserves to be in the spotlight purely for the absurdity and humor value.

The winners each year get invited to a ceremony wherein they're wined and dined and given their cash prize (a $10 trillion bill from Zimbabwe, which is worth a few cents).  They then have to give an acceptance speech, which if it goes over sixty seconds is interrupted by an eight-year-old girl yelling, "Please stop, I'm bored" over and over until they give up.

As is usual with the Ig Nobel Ceremony, good times were had by all and sundry.  The audience is encouraged to participate by folding up their programs into paper airplanes and throwing them at the presenters, and needless to say they rose to the occasion.

So, without further ado, here are the 2019 winners:

• Research finding that eating pizza is correlated with lower risk of dying of various diseases -- but only if the pizza is made and consumed in Italy.
• A study showing that not only dogs can learn using "clicker training;" it also works for training orthopedic surgeons.
• The finding that the degree of asymmetry in how low testicles hang on postmen (both clothed and naked) in France depends on the temperature.
• A study to figure out how much drool is produced by an average five-year-old child.
• An invention of a diaper-changing machine (now patented) by an American engineer.
• A comparative study of paper money in various countries to find out which is the dirtiest.  (The winner was the Romanian leu.)
• Research into finding which areas of the body are the most pleasurable to scratch.  (The back and the ankle, apparently.)
• A study finding that holding a pen in your mouth to stretch your facial muscles in a "pseudo-smile" makes you happy -- then a further study finding that the opposite is true.
• Research into why (and how) wombats make cube-shaped poop.

If you're so inclined, the link provided has further links to each of the academic papers that won prizes.

As is usual for the Ig Nobels, the studies that won raise more questions than they answer.  For example:

• The asymmetrical-ball-hanging study immediately made me wonder, "why French postmen?"  Would we expect that there would be a different pattern amongst, say, Argentinian stockbrokers?  (Maybe because they're in the Southern Hemisphere?  You know, the testicular Coriolis effect, or something?)  Or were French postmen just the group they found that was the easiest to convince to drop trou in the name of science?
• Who in their right mind would volunteer their child to test a diaper-changing machine?  That's the kind of thing I can imagine going very wrong.  Strangely hilarious, but very wrong.
• If forcing a smile with a pen first worked and then didn't, why did they bother writing a paper about it?
• The pizza experiment just sounds like the scientists taking advantage of an opportunity to use grant money to hang around in Italy going to restaurants.  Which places it squarely in the "why didn't I think of that first?" category.
• Would you want to go under the knife with a surgeon who'd been trained using a clicker?  ("Good incision!"  *click click*  *trainer pulls the surgeon's mask aside and sticks a treat in his mouth*)

I suppose having further questions is a good thing in science, because after all that's how progress is made.  One thing leads to another is kind of the status quo.

On the other hand, I have a hard time seeing what more you could do with cubical wombat poop.

So that's this year's Ig Nobels.  Remember this next time you hear people say that scientists are humorless, pedantic geeks.  Anyone who can get a grant to investigate back scratches is okay in my book, because back scratches are fucking awesome.

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This week's Skeptophilia book recommendation made the cut more because I'd like to see what others think of it than because it bowled me over: Jacques Vallée's Passport to Magonia.

Vallée is an interesting fellow, and certainly comes with credentials; he has an M.S. in astrophysics from the University of Lille and a Ph.D. in computer science from Northwestern University.  He's at various times been an astronomer, a computer scientist, and a venture capitalist, and apparently was quite successful at all three.  But if you know his name, it's probably because of his connection to something else -- UFOs.

Vallée became interested in UFOs early, when he was 16 and saw one in his home town of Pontoise, France.  After earning his degree in astrophysics, he veered off into the study of the paranormal, especially allegations of alien visitation, associating himself with some pretty reputable folks (J. Allen Hynek, for example) and some seriously questionable ones (like the fraudulent Israeli spoon-bender, Uri Geller).

Vallée didn't really get the proof he was looking for (of course, because if he had we'd probably all know about it), but his decades of research compiles literally hundreds -- perhaps thousands -- of alleged sightings and abductions.  And that's what Passport to Magonia is about.  To Vallée's credit, he doesn't try to explain them -- he doesn't have a favorite hypothesis he's trying to convince you of -- he simply says that there are two things that are significant: (1) the number of claims from otherwise reliable and sane folks is too high for there not to be something to it; and (2) the similarity between the claims, going all the way back to medieval claims of abductions by spirits and "elementals," is great enough to be significant.

I'm not saying I necessarily agree with him, but his book is lucid and fascinating, and the case studies he cites make for pretty interesting reading.  I'd be curious to see what other Skeptophiles think of his work.

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

The illusion of truth

Because we apparently need one more cognitive bias to challenge our confidence in what we hear on the news on a daily basis, today I'm going to tell you about the illusory truth effect.

The idea here is that if you hear a falsehood repeated often enough, in your mind, it becomes a fact.  This is the "big lie" approach that Hitler recommends in Mein Kampf:

All this was inspired by the principle—which is quite true within itself—that in the big lie there is always a certain force of credibility; because the broad masses of a nation are always more easily corrupted in the deeper strata of their emotional nature than consciously or voluntarily; and thus in the primitive simplicity of their minds they more readily fall victims to the big lie than the small lie, since they themselves often tell small lies in little matters but would be ashamed to resort to large-scale falsehoods. 

It would never come into their heads to fabricate colossal untruths, and they would not believe that others could have the impudence to distort the truth so infamously.  Even though the facts which prove this to be so may be brought clearly to their minds, they will still doubt and waver and will continue to think that there may be some other explanation.  For the grossly impudent lie always leaves traces behind it, even after it has been nailed down, a fact which is known to all expert liars in this world and to all who conspire together in the art of lying.

But the most referenced quote framing this idea comes from Nazi Propaganda Minister Joseph Goebbels: "If you tell a lie big enough and keep repeating it, people will eventually come to believe it."

Which is more than a little ironic, because there's no evidence Goebbels ever said (or wrote) that -- although he certainly did embody the spirit of it.

The topic comes up because of a study that appeared in Cognition this week, called, "An Initial Accuracy Focus Prevents Illusory Truth," by psychologists Nadia M. Brashier (of Harvard University) and Emmaline Drew Eliseev and Elizabeth J. Marsh (of Duke University).  And what they found was simultaneously dismaying and heartening; that it is very easy to get people to fall for illusory truth through repetition, and they can be inoculated against it by having them read the source material with a critical eye the first time, striking out erroneous information.  Doing that, apparently, inoculates them against falling for the lie later, even after repeated exposure.

[Image licensed under the Creative Commons RyanMinkoff, Academic dishonesty, CC BY-SA 4.0]

What's especially frightening about the dismaying part of this study is that being taken in by repeated falsehoods even works for purely factual, easily checkable information.  One of the statements they used was "The fastest land mammal is the leopard," which most people recognize as false (the fastest land mammal is the cheetah).  The surmise is that if you keep seeing the same incorrect statement, you begin to doubt your own understanding or your own memory.

I know this happens to me.  There are few topics I'm so completely confident about that I could hear someone make a contradicting statement and think, "No, that's definitely wrong."  I'm much more likely to think, "Wait... am I remembering incorrectly?"  Part of the problem is that I'm a raging generalist; I know a little bit about a great many things, so if an expert comes along and says I've got it wrong, I'm putting my money on the expert.  (I've also been called a "dilettante" or a "dabbler" or "a light year across and an inch deep," but on the whole I like "generalist" better.)

The problem is, it's easy to mistake someone who simply speaks with a lot of confidence as being an expert.  Take, for example, Donald Trump.  (Please.  No, really, please.  Take him.)  He's lied so many times there's a whole Wikipedia page devoted to "Veracity of Statements by Donald Trump."  As only one example of the illusory truth effect, take his many-times-repeated statement that he would have won the popular vote if it hadn't been for millions of votes cast fraudulently for Hillary Clinton, and also that his electoral college win was "the biggest landslide in history" (it wasn't even close; of the 58 presidential elections the United States has had, Donald Trump's electoral college win comes in at #46).

The problem is, Trump makes these statements with so much confidence, and with such frequency, that it's brought up the question of whether he actually believes them to be true.  Even if he's lying, the technique is remarkably effective -- a sort of Gish gallop of falsehood (the latter term named after creationist Duane Gish, who was known for swamping his debate opponents with rapid-fire arguments of dubious veracity, wearing them down simply by the overall volume).  A lot of his supporters believe that he won by a landslide, that Clinton only did as well as she did because of rampant fraud, and a host of other demonstrably false beliefs (such as the size of Trump's inauguration crowd, attendance at his rallies, how well the economy is doing, and that the air and water in the United States are the highest quality in the world).

So to put the research by Brashier et al. to work, somehow people would have to be willing and able to fact check these statements as they're happening, the first time they hear them -- not very likely, especially given the role of confirmation bias in affecting how much people believe these statements at the outset (someone who supports Trump already would be more likely to believe him, for example when he's stated that the number of illegal immigrants is the highest it's ever been, when in fact it peaked in 2007 and has been falling steadily ever since).

In any case, it's hard to see how all this helps us.  The traction of "alternative facts" has simply become too great, as has the vested interest of partisan and sensationalized media.  Not for nothing do Brashier et al. call our current situation "the post-truth world."

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This week's Skeptophilia book recommendation is pure fun: science historian James Burke's Circles: Fifty Round Trips Through History, Technology, Science, and Culture.  Burke made a name for himself with his brilliant show Connections, where he showed how one thing leads to another in discoveries, and sometimes two seemingly unconnected events can have a causal link (my favorite one is his episode about how the invention of the loom led to the invention of the computer).

In Circles, he takes us through fifty examples of connections that run in a loop -- jumping from one person or event to the next in his signature whimsical fashion, and somehow ending up in the end right back where he started.  His writing (and his films) always have an air of magic to me.  They're like watching a master conjuror create an illusion, and seeing what he's done with only the vaguest sense of how he pulled it off.

So if you're an aficionado of curiosities of the history of science, get Circles.  You won't be disappointed.

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

Life in the shadows

In Michael Ray Taylor's brilliant1999 book Dark Life, the author looks at some of the strangest forms of life on Earth -- extremophiles, organisms (mainly bacteria) that thrive in places where nothing else does.  Surrounding hydrothermal vents under crushing pressures and temperatures over 100 C, buried underground below the deepest mines, frozen in Antarctic ice, floating in boiling, acidic hot springs.  Taylor himself is a veteran spelunker and got interested in the topic after running into the aptly-named snottites -- biofilms found in caves that hang downward from the ceiling and are the consistency of, well, snot.

The brilliant colors of Grand Prismatic Spring in Yellowstone National Park are due, in part, to extremophilic bacteria [Image is in the Public Domain]

Taylor's contention -- that such bizarre creatures are so numerous that they outnumber all other life forms on Earth put together -- just got a boost last week from a piece of research published in the Journal of Geomicrobiology.  Written by a team from the University of Toronto -- Garnet S. Lollar, Oliver Warr, Jon Telling, Magdalena R. Osburn, and Barbara Sherwood Lollar -- it describes the discovery, 7,900 meters underground, of a thriving ecosystem of microbes in a mine 350 kilometers north of Toronto.

The life forms are odd in a number of respects.  The first is that they're anaerobic -- they don't need oxygen to survive.  The second is that they metabolize sulfur, primarily in the form of iron sulfate, better known as pyrite or fool's gold.  It's a food chain completely unhooked from light -- for nearly every other organism on Earth, the energy they contain and utilize can ultimately be traced back to sunlight.  Here, if you follow the energy backwards, you arrive at the geothermal heat from the mantle of the Earth producing reduced (high energy) compounds that can support a food web, similar to what you see in deep-sea hydrothermal vents.

"It's a fascinating system where the organisms are literally eating fool's gold to survive," team member Barbara Sherwood Lollar said in an interview with NBC News. "What we are finding is so exciting — like ‘being a kid again’ level exciting."  The ecosystem is in the Laurentian Shield, one of the oldest and most geologically-stable places on Earth, so it's likely that this thriving community deep underground has been there for a billion years or more.  "The number of systems we've looked at so far really is limited, but they probably had a single origin at some point in life’s four-billion-year history."  As far as their discovery, she added, "We see only what we look for.  If we don't look for something, we miss it."

And it's a lot to miss.  The current research springboards off a 2018 report sponsored by the Deep Carbon Observatory conducted by a team led by Cara Magnabosco, a geobiologist at the Swiss technical university ETH Zurich, which estimated that some 5 x 10^29 cells live in the deep Earth.

For those you who don't like scientific notation, that's five hundred thousand trillion trillion organisms.  Put succinctly, it's a really freakin' huge number.

Considering the (to us) inhospitable conditions a lot of these organisms live under, it raises hopes of finding life in other, perhaps unexpected, places in the universe.  Astronomers talk about the "Goldilocks zone," the region around a star that has temperatures where water is a liquid, and that to host life a planet would have to have a similar mass to Earth and be orbiting a star relatively similar to the Sun.  The University of Toronto research suggests that may be placing unnecessary and inaccurate strictures on where life can exist, and that we may have to rethink our definition of what we mean by "hospitable conditions."

"We're finding we really don't understand the limits to life," Sherwood Lollar said.

Which also raises the question of whether we'd recognize alien life if we saw it.  Star Trek may have been prescient; they expanded the boundaries of what we think of as life by featuring aliens that were gaseous, crystalline, thrived at searing temperatures, could tolerate the chill dark vacuum of space, or were composed of pure energy.  While some of these -- at least at first glance -- seem pretty far-fetched, what the current research suggests is that we shouldn't be too hasty to say, "Okay, that's out of the question."

"We've literally only scratched the surface of the deep biosphere," said Robert Hazen, mineralogist at the Carnegie Institution’s Geophysical Laboratory in Washington, and co-founder of Deep Carbon Observatory.  "Might there be entire domains that are not dependent on the DNA, RNA and protein basis of life as we know it?  Perhaps we just haven’t found them yet."

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This week's Skeptophilia book recommendation is pure fun: science historian James Burke's Circles: Fifty Round Trips Through History, Technology, Science, and Culture.  Burke made a name for himself with his brilliant show Connections, where he showed how one thing leads to another in discoveries, and sometimes two seemingly unconnected events can have a causal link (my favorite one is his episode about how the invention of the loom led to the invention of the computer).

In Circles, he takes us through fifty examples of connections that run in a loop -- jumping from one person or event to the next in his signature whimsical fashion, and somehow ending up in the end right back where he started.  His writing (and his films) always have an air of magic to me.  They're like watching a master conjuror create an illusion, and seeing what he's done with only the vaguest sense of how he pulled it off.

So if you're an aficionado of curiosities of the history of science, get Circles.  You won't be disappointed.

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

A new view of the Indus Valley

It's always fun when I stumble across some research that ties together three of my fascinations -- linguistics, genetics, and unsolved mysteries.

The research in question was published this week in Science, and gives us a new lens into the mysterious Indus Valley (or Harappan) Civilization.  This civilization, which started some time around 3,300 B.C.E. and lasted for a good two thousand years, flourished in what is now the western part of India and eastern part of Pakistan, producing massive cities, temples, a distinctive form of pottery, work in tin, bronze, lead, and copper, and a mysterious script that no one has been able to decipher (in fact, some linguists don't even believe it's a written language -- possibly just a set of non-linguistic symbols).

A Harappan seal with an example of the Indus Valley script [Image licensed under the Creative Commons PHGCOM IndusValleySeals.JPG, Indus seal impression, CC BY-SA 3.0]

Considering the extent of the artifacts and archaeological sites the civilization left behind, it's amazing how little we know for sure about them.  Their affiliations to other groups who were around at the same time (especially in the Middle East), what language they spoke, what religion they practiced -- all are inferences based on relatively scanty evidence.

This latest research adds a significant piece to what we know for sure about the mysterious Harappans.  The researchers who conducted it, a team made up of scientists from Washington University, Harvard Medical School, and the University of Vienna, looked at DNA extracted from 523 skeletons in the region dating all the way back to twelve thousand years ago.  The scientists were trying to shed light on two questions.  First, where did the Indus Valley Civilization's agricultural knowhow come from -- was it a local invention/innovation, or was it brought into a previous hunter-gatherer society by an influx of migrants?  And second, what is the origin of the languages spoken in the region then and now?

The answer to the first question seems to be that Harappans' agriculture was an innovation of their own.  The researchers found traces of DNA from contemporaneous farming cultures no nearer than Iran, and no evidence that they got any further than that.  So it seems like the Indus Valley transition from hunters to farmers was something they figured out for themselves.

What the research uncovered vis-à-vis the second question was that there was a DNA signature from European hunter-gatherers, but not as big as expected.  The usual linguistic model is that when there's a major language shift, it's usually caused by a large influx of migrants (consider the shifts from Native languages to English in Australia and the Americas).  Here, there was not nearly the amount of European and Middle Eastern DNA to explain the shift to an Indo-European language; the Eurasians who showed up there, the Yamnaya people, were apparently present in fairly small numbers.  What's fascinating, though, is that Yamnaya DNA is disproportionally present in modern-day Indians of the highest social classes -- since social class has traditionally been hereditary in Indian culture, the surmise is that the Indo-European speaking Yamnaya were in charge, and their language ended up superseding (or at least strongly influencing) the language(s) spoken at the time.

It's kind of analogous to the influence Norman French had on Old English in the years after the Norman Invasion in 1066 C. E.  Most of our terms that have to do with governance come from Latin via French, while a lot of the basic vocabulary (pronouns, prepositions, and so on) are from the original Germanic language.  Even more interesting is that the Norman Invasion left pairs of parallel words associated with food -- the one used for the animal as it's found on the farm is from the Old English peasants who raised them, and the one for the meat as it's seen on the table from Norman French aristocracy who only came in contact with the animal after it was cooked.  (Thus cow/beef, sheep/mutton, pig/pork, chicken/poultry, and so on.)  As the Indo-European influx into India happened five centuries earlier, you have to wonder if those kinds of word pairs existed for while there, too, eventually being swamped by the higher-prestige Indo-European verbiage.

So this research gives us one more piece of the puzzle regarding a group of people about whom we've known relatively little, despite their being ancestral to the vast majority of the population on the Indian Subcontinent.  And, of course, this is nowhere near the last word on the subject.  We'll continue to uncover more, and refine our understanding of the Harappans -- a civilization that has been gone for almost three thousand years.

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This week's Skeptophilia book recommendation is pure fun: science historian James Burke's Circles: Fifty Round Trips Through History, Technology, Science, and Culture.  Burke made a name for himself with his brilliant show Connections, where he showed how one thing leads to another in discoveries, and sometimes two seemingly unconnected events can have a causal link (my favorite one is his episode about how the invention of the loom led to the invention of the computer).

In Circles, he takes us through fifty examples of connections that run in a loop -- jumping from one person or event to the next in his signature whimsical fashion, and somehow ending up in the end right back where he started.  His writing (and his films) always have an air of magic to me.  They're like watching a master conjuror create an illusion, and seeing what he's done with only the vaguest sense of how he pulled it off.

So if you're an aficionado of curiosities of the history of science, get Circles.  You won't be disappointed.

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

Walk of life

Even considering my background in evolutionary biology, there are a lot of things about the natural world that I take for granted.

For example, bilateral symmetry.  It's so common amongst animals that it's easy to think it's universal, when there's no real reason it should be.  (I recall vividly being startled when I first ran across H. P. Lovecraft's "Great Old Ones" -- who had five-way symmetry.)  What's likely is that a very long time ago, one of our successful ancestors was bilateral, and passed that characteristic down to its descendants -- which include the majority of Kingdom Animalia.

So if we ever find alien life, there's no reason to suspect that it will share some of these probably-arbitrary characteristics with terrestrial life.  Still, there are a few features that are significant enough advantages that it's likely to be found in other living things, wherever and however they evolved.  One of these is cephalization -- having the important organs, including the central nervous system and sensory receptors, near the anterior end.  Having your eyes and nose near your mouth makes a great deal of sense from the standpoint of finding food, and it's pretty likely to be a feature that shows up again and again.  (Consider flight -- such a great adaptation that it's evolved independently at least seven times in Earth's history, in birds, insects, bats, colugos, flying squirrels, sugar gliders, and pterodactyls.)

Locomotion itself is one of those abilities that is so useful that it's likely to show up wherever life occurs, but it's one of those things that's so universal we tend not to think about it, or even be aware there are exceptions.  (In fact, when I got students in my introductory biology classes to brainstorm for characteristics they thought were true for all living things, "able to move" was the most common wrong answer.)

This comes up because of a paper that was published in Nature last week, my awareness of which I once again owe to my sharp-eyed friend Andrew Butters of the brilliant blog Potato Chip Math.  In it we learn about a fossil that seems to be the earliest direct evidence we have of locomotion in an animal.  The fossil, which has been dated to around 540 million years ago, is the trail of a critter named Yilingia spiciformis ("spiky creature from Yiling"), about which the authors, Zhe Chen, Chuanming Zhou, and Xunlai Yuan (of the Chinese Academy of Sciences), and Shuhai Xiao (of Virginia Technological College of Sciences) have the following to say:

The origin of motility in bilaterian animals represents an evolutionary innovation that transformed the Earth system.  This innovation probably occurred in the late Ediacaran period—as evidenced by an abundance of trace fossils (ichnofossils) dating to this time, which include trails, trackways and burrows.  However, with few exceptions, the producers of most of the late Ediacaran ichnofossils are unknown, which has resulted in a disconnection between the body- and trace-fossil records.  Here we describe the fossil of a bilaterian of the terminal Ediacaran period (dating to 551–539 million years ago), which we name Yilingia spiciformis (gen. et sp. nov).  This body fossil is preserved along with the trail that the animal produced during a death march. Yilingia is an elongate and segmented bilaterian with repetitive and trilobate body units, each of which consists of a central lobe and two posteriorly pointing lateral lobes, indicating body and segment polarity.  Yilingia is possibly related to panarthropods or annelids, and sheds light on the origin of segmentation in bilaterians.  As one of the few Ediacaran animals demonstrated to have produced long and continuous trails, Yilingia provides insights into the identity of the animals that were responsible for Ediacaran trace fossils.

So what this represents is not just the dawn of motility, but the dawn of bilateral symmetry, and Yilingia may have been one of the earliest animals that had both.  It might not be our direct ancestor, but certainly was a close cousin to whatever was, and many of the features we now see in virtually all animals were locked in around that time.

It's awe-inspiring to look at this simple little fossil, the tracks of a critter that marched its way on the seafloor half a billion years ago, at a time when there was not a single thing living on the land, when the continents were bare rock, sand, dust, and dirt as far as the eye could see.  And even more amazing to realize that this innovation -- the ability to move -- was passed down through all that time, refined in a thousand different ways, and is the direct ancestor to our ability to walk, run, crawl, and jump.

So far from feeling demeaned by our connections to our primitive ancestry, as the creationists would frame it, I feel exalted by it -- we are linked in an unbroken chain of relationships to every living thing on Earth, and everything we can do, every structure in our bodies down to the molecular level, is directly due to inheritance that stretches back to the very first life in the primordial seas.

And if that's not a mind-blowing thought, I don't know what is.

********************************************

This week's Skeptophilia book recommendation is pure fun: science historian James Burke's Circles: Fifty Round Trips Through History, Technology, Science, and Culture.  Burke made a name for himself with his brilliant show Connections, where he showed how one thing leads to another in discoveries, and sometimes two seemingly unconnected events can have a causal link (my favorite one is his episode about how the invention of the loom led to the invention of the computer).

In Circles, he takes us through fifty examples of connections that run in a loop -- jumping from one person or event to the next in his signature whimsical fashion, and somehow ending up in the end right back where he started.  His writing (and his films) always have an air of magic to me.  They're like watching a master conjuror create an illusion, and seeing what he's done with only the vaguest sense of how he pulled it off.

So if you're an aficionado of curiosities of the history of science, get Circles.  You won't be disappointed.

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