Life on ice

I'm currently reading planetary scientist Sarah Stewart Johnson's wonderful book The Sirens of Mars, about the search for signs of life on Mars (and other planets in the Solar System).  What strikes me whenever I read anything on this topic is that everything we've learned supports the contention that life is common in the universe.  (Not necessarily intelligent life; as I've dealt with before, that's another discussion entirely.)  As I learned from another great book I read a while back, Michael Ray Taylor's Dark Life: Martian Nanobacteria, Rock-Eating Cave Bugs, and Other Extreme Organisms of Inner Earth and Outer Space, every place we've looked on Earth -- however seemingly inhospitable -- we've found living things.  Fissures in rocks miles underneath the Earth's surface; deep-sea hydrothermal vents under crushing pressures and sky-high temperatures; brine ponds containing water many times the salinity of seawater; alkaline and acidic hot springs; chilly, pitch-dark caves with toxic air; anaerobic, sulfur-filled mud.  Teeming with life, all of them.

Not only that, but the building blocks of life are kind of everywhere.  When Stanley Miller and Harold Urey did their mind-blowing experiment back in 1953, it was unclear whether they had just happened on the right formula; they'd included their best guesses as to the constituents of the early Earth's atmosphere, and used artificial lightning as an energy source, and in short order they had organic compounds in enormous quantities.  It turned out, though, that the results had been not so much of a happy accident as an inevitability.  As long as you have (1) a reducing atmosphere (i.e. no free oxygen), (2) inorganic sources of carbon, hydrogen, oxygen, nitrogen, phosphorus, and sulfur, and (3) some kind of an energy source, you end up synthesizing all twenty amino acids found in living things (plus some we don't use), DNA and RNA nucleotides, simple sugars, fatty acids, glycerol, and a host of other organic compounds.

In other words, every monomer you need to build an organism.  All from off-the-shelf inorganic chemicals and some kind of power source.

What became clear after Miller and Urey published their results is that the early Earth's seas -- and by extension, the seas of any planet with a reducing atmosphere and sufficient liquid water -- might be expected to be brimming with the building blocks of life.  This so-called "primordial soup" on Earth gave rise to primitive life in a relative flash, and there's no reason to expect the same wouldn't happen elsewhere.

What came as something of a shock, though, is that you don't even need warm, Earthlike conditions to generate biochemistry.  Not long ago, astrophysicists started finding the characteristic signatures of organic compounds in interstellar nebulae.  And just last week researchers at the University of Copenhagen announced that they'd discovered organic compounds in a cloud of gas, dust, and ice called Chameleon 1 -- one of the coldest, darkest places ever to be studied, located about six hundred light years away.

The Tarantula Nebula [Image courtesy of NASA, ESA, CSA, STScI, and the Webb ERO Production Team]

Detected by their spectroscopic fingerprints -- the characteristic frequencies of light they absorb from the ambient starlight -- these chemicals were located during a new study using the James Webb Space Telescope.  "With the application of observations, e.g. from ALMA [the Atacama Large Millimeter Array, which was also used in the study], it is possible for us to directly observe the dust grains themselves, and it is also possible to see the same molecules as in the gas observed in the ice," said Lars Kristensen, who co-authored the study.

"Using the combined data set gives us a unique insight into the complex interactions between gas, ice and dust in areas where stars and planets form," added Jes Jørgensen, who also co-authored.  "This way we can map the location of the molecules in the area both before and after they have been frozen out onto the dust grains and we can follow their path from the cold molecular cloud to the emerging planetary systems around young stars."

What this shows is that a great many of the compounds in the primordial soup may have formed before the coalescence of the Earth, and might already have been present when the seas formed.  "This study confirms that interstellar grains of dust are catalysts for the forming of complex molecules in the very diffuse gas in these clouds, something we see in the lab as well," said Sergio Ioppolo, another co-author.

Further evidence that biochemistry -- and almost certainly life -- is plentiful in the universe.

I wonder what life is like on other worlds.  Surely whatever it is, it's evolved into a host of forms completely different from what we have here, ones that have adapted to whatever the local conditions are.  Different sets of environmental challenges would generate new and innovative evolutionary solutions, as would a different set of one-off occurrences (such as the Chicxulub Meteorite collision that ended the supremacy of the dinosaurs and put us mammals on the pathway to pretty much running the place).  Now, take that diversity, those "endless forms most beautiful and most wonderful," as Darwin so trenchantly put it -- and multiply that by a million times.

That is what is very likely to be out there in the cosmos.

If I can be forgiven for ending a post with a quote by Carl Sagan two days in a row, the line he put in the mouth of his iconic character Ellie Arroway (from the book and the movie Contact) seems apposite: "If we're the only ones in the universe, it seems like an awful waste of space."

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A tadpole in the cosmic sea

If you've taken some college-level physics, you can readily attest to the fact that analyzing the motion of objects in perfectly regular, symmetrical orbits is hard enough.  The various bodies orbiting the Sun are, by and large, in elliptical orbits as per Kepler's Laws; there are only tiny deviations from the predicted paths for a couple of them, notably Mercury (whose orbit precesses -- the long axis of the ellipse gradually shifts position -- its proximity to the Sun causes it to experience larger effects from General Relativity than other planets in the Solar System) and Uranus (which experiences small alterations in its orbit due to the gravitational pull of Neptune; in fact, that's how Neptune was discovered).

If you look farther out into space, however, you find that there are some really oddly-shaped conglomerations of matter out there, and it's been difficult for astrophysicists to account for their configurations and patterns of motion.  One example is the peculiar Tadpole Nebula, located 27,000 light years away, in the constellation of Sagittarius:

Artist's depiction of the Tadpole Nebula [Image courtesy of Keio University]

The strange shape of the Tadpole is odd enough, but an analysis of the light emitted from it, and the motion of the gas and dust within it, suggests something stupendous; the Tadpole has been stretched out because it's orbiting a black hole -- with a mass a hundred thousand times that of the Sun.

The Tadpole Nebula is near the center of the Milky Way; from our perspective, the galactic center also lies in Sagittarius.  (In fact, when you're looking toward the constellation of Sagittarius in late summer, consider the fact that if it weren't for the dust clouds in the way, you'd be able to see the glorious spectacle of the Milky Way's nucleus -- other than the Sun, it'd be far and away the brightest thing in the sky.)  And the Milky Way itself has at its center a stupendously large black hole, this one estimated to be four million times the mass of the Sun.  But the Tadpole shows that there are other enormous gravitational attractors out there, capable of taking a huge cloud of gas and stretching it out into a celestial question mark.

My wife and I just finished rewatching the old series Cosmos last week, and I was struck over and over at how delighted Carl Sagan would have been to see the developments and discoveries that have been made since his tragic death of bone marrow cancer in 1996 at the age of 62.  His wonder at the beauty of the universe shines through in every word.  I more than once remarked while watching the series, "He's not only a scientist, he's a poet."  How much more would he be awestruck by what we know today -- the sparkling clarity of the images coming in from the James Webb Space Telescope, the information we're learning about the planets and moons in our own Solar System, the thousands of exoplanets that have been discovered.

I'll conclude with a quote from Sagan, which seems a fitting way to end: "Who would not feel awed?  There is a wide, yawning black infinity.  In every direction, the extension is endless; the sensation of depth is overwhelming.  And the darkness is immortal.  Where light exists, it is pure, blazing, fierce; but light exists almost nowhere, and the blackness itself is also pure and blazing and fierce...  The nitrogen in our DNA, the calcium in our teeth, the iron in our blood, the carbon in our apple pies were made in the interiors of collapsing stars.  We are a way for the universe to know itself."

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Anxiety and stigma

I am mentally ill.

I say it that openly, and that bluntly, for a reason: mental illness still has a significant and entirely undeserved stigma in our society, a stigma shared by virtually no other group of illnesses.  I've never heard of someone ashamed to say they have bronchitis, high blood pressure, arthritis, heart disease, or cancer.  While no one would question the gravity of any of those or the impact on the patients and their families, none of those carry the same sense of shame -- the underlying feeling that somehow, it requires an apology, that it's the sufferer's fault for "not trying hard enough."

"Suck it up and deal."  "Just focus on the good things."  "Let go of the negatives."  All, perhaps, well meant, and all entirely useless.  Whatever the underlying cause of the anxiety and depression I've battled my entire life -- whether they're from a neurochemical imbalance, a genetic predisposition (there is good evidence that depression, at least, runs in both sides of my family), trauma from the emotional abuse I endured as a child, or all three -- what I experience is just as real as any symptoms coming from a purely physical illness.

I've gone to hell and back trying to find a medication that helps; none of the standard meds made much of a difference, and several gave me horrible side effects.  Right now the depression is reasonably well in check from the combination of the compassion and support of my family and friends and a set of coping mechanisms (exercise being top of the list).  The anxiety is tougher because it can come on without any warning, and is often triggered by activities that "should be positive" -- getting together with friends, engaging in creative pursuits, even leaving the house.

Edvard Munch, Anxiety (1894) [Image is in the Public Domain]

The reason this comes up is a pair of studies I ran into last week that resonated so strongly with my experience that I found myself saying, "Why didn't the researchers just ask me?  I coulda told them that."  The first, that appeared in the International Journal of Psychophysiology, investigated fear responses -- specifically, how quickly startle reactions ceased once a person realized something surprising wasn't actually a threat.  What they did was show test subjects photographs of two women, then suddenly substituted one with a photograph of a woman showing fear and accompanied it by the sound of a woman screaming at 95 decibels, delivered through headphones.  (I'm so sound-sensitive that just reading about this made me anxious.)  What was fascinating is that (of course) all the test subjects startled, but the ones without anxiety disorders very quickly learned that it wasn't a threat -- on repeated exposures to the same stimulus, they stopped reacting.  The people with anxiety disorders didn't.  Every time the photo changed and the scream came, they reacted, even when they knew it was coming.

This is all too familiar to me.  I once lamented to a therapist, "Exposure therapy doesn't work on me."  I have dreadful social anxiety; I take a long time to open up to people, and when I'm in a large group I tend to shut down completely.  I've been at parties where all night long, I've said exactly two sentences: "Hi, how are you this evening?" and "Good night, thanks for inviting me."  It doesn't seem to matter how many social gatherings I go to where nothing bad happens; I still get overwrought the next time, and spend the lead-up to the event hoping like hell there'll be a dog there to socialize with.

The second study, that appeared in the journal Behavioural and Cognitive Psychotherapy, looked at the ways that people with social anxiety cope, and found that those same "safety behaviors" -- such as rehearsing ahead of time what they'll say, avoiding eye contact, shying away physically if they feel like they're in the way, and not talking unless spoken to -- cause others to perceive them as less likable, more standoffish, aloof, and superior, and less authentic.

Which, of course, is the most vicious of vicious cycles.  I know I do all of those things, not to mention finding an excuse to leave early.  I also have a tendency to get tongue-tied when people do speak to me directly, which probably is why in short order they decide that they'd be better off finding someone else to chat with.

Both studies had me saying, "Yeah, exactly."  Even so, I'm glad these sorts of papers are appearing in well-respected journals.  All of it is a step not only toward finding out what underlies mental illness, but toward reducing the stigma.  Sufferers from disorders like depression and social anxiety aren't simply weird, and we're certainly not doing it for attention (something I was accused of pretty much continuously when I was a kid).  We're just struggling, in the same way that someone with a physical illness might struggle.

I have some hope that the stigma is diminishing.  I've been heartened by the support Senator John Fetterman of Pennsylvania has received following his revelation that he was entering the hospital for treatment for clinical depression.  We still have a long way to go -- there are still people who look at Fetterman's actions as evidence of weakness or instability -- but far more are responding with empathy, with an understanding that we sufferers from mental illness are every bit as deserving of compassionate care as someone dealing with any other kind of illness.

And while understanding that won't cure us, it certainly goes a long way to making us feel like we're not so alone.

(IMPORTANT NOTE: if you, or someone you know, are considering self-harm, please call the Suicide Hotline number now.  The number is 988, and there are people there who can help you and provide the emotional support you need.)

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PreachGPT

AI systems like ChatGPT have a lot of people worried, but I just bumped into a story about a group who wouldn't have occurred to me -- pastors.

Apparently, there's been a sudden spike of interest in (and concern over) the use of ChatGPT for sermon-writing.  As you might imagine, the uneasiness creative people feel about AI producing prose, poetry, art, and music is amplified a hundredfold when the issue starts to encroach on religion.

The article is well worth a thorough read, and I won't steal the writer's thunder except to mention a handful of quotes from pastors to give you the all-too-predictable flavor of their responses to AI-generated sermons:

• It lacks a soul -- I don't know how else to say it.  (Hershael York, Southern Baptist)

• ChatGPT might be really great at sounding intelligent, but the question is, can it be empathetic?  And that, not yet at least, it can’t. (Joshua Franklin, Orthodox Jewish)

• While the facts are correct, there’s something deeper missing.  AI cannot understand community and inclusivity and how important these things are in creating church.  (Rachael Keefe, United Church of Christ)

• When we listen to the Word preached, we are hearing not just a word about God but a word from God.  Such life-altering news needs to be delivered by a human, in person.  A chatbot can research.  A chatbot can write.  Perhaps a chatbot can even orate.  But a chatbot can’t preach. (Russell Moore, Southern Baptist)

To make my own stance clear right from the get-go, I'm what the philosophers call a de facto atheist -- I'm not a hundred percent sure there's no higher power (mostly because I'm not a hundred percent sure of anything), but the complete lack of hard evidence tilts me in the direction of disbelief.  As far as spiritual concerns, like the existence of a soul (or at least "something more" than our physical being), I'm an agnostic.  There is a great deal of weird shit out there that might be explainable by virtue of some sort of non-materialistic model -- but it might just as well have to do with a combination of our own flawed cognitive processes and incomplete understanding of science.  (If you have five minutes, watch this video by physicist Sabine Hossenfelder about why quantum wackiness doesn't support the existence of souls.  I'm not as convinced as she is, but wherever you're starting, belief-wise, it'll get you thinking.)

Apropos of AI, this lands me squarely in Alan Turing's camp.  How on earth am I supposed to judge if a particular AI system "really is intelligent" other than its output -- given that I don't have any access to the inner workings of another human's brain, and barely have access to my own?  The only way to judge intelligence is by what you see externally.  So is ChatGPT intelligent?  In my opinion, the question is honestly not so much difficult as it is meaningless.  It implies that intelligence is some kind of either-or, a threshold that you cross irrevocably, whereas it really seems to be more like a gradually-shifting gray area.  Coming up with a final answer regarding ChatGPT (or any other AI) is drawing an arbitrary line in the sand and then arguing over which side of that line something falls.

[Image licensed under the Creative Commons mikemacmarketing, Artificial Intelligence & AI & Machine Learning - 30212411048, CC BY 2.0]

Interestingly, one person on the r/atheism subreddit asked ChatGPT if it wanted to buy his soul.  Here's how it responded:

I'm sorry, but as an AI language model, I don't have the ability to buy or own anything, including souls.  Moreover, the concept of selling one's soul is often used in literature or mythology, but in reality, it's not a valid transaction that can be made.  Your soul is a metaphysical concept that is not subject to exchange or monetary value.  It's important to focus on living a meaningful and fulfilling life rather than trying to sell or trade something that's intangible and invaluable.

I'm not sure whether to laugh or shudder.

In any case, you can understand why the pastors are concerned, given that they don't share my agnosticism over souls and spirits and whatnot, and the prevailing attitude is that there is a qualitative difference between human intelligence and any potential artificial intelligence, no matter how clever it gets.  They're backed into a corner; presented with a sermon written by ChatGPT, they have no choice but to claim that it "lacks a soul" -- because, after all, they think the computer it came from lacks one, too.

Me, I wonder how accurate that view would turn out to be.  It'd be interesting to run a Turing-test-style experiment on some pastors -- give them a bunch of sermons, half of them written by qualified pastors and half written by ChatGPT, and see if they really could detect the lack of soul in the ones from AI.  I suspect that, like all too many other AI applications, we're getting to the point that it'd be a damned difficult determination.  And if they couldn't figure it out, what then?  I'm reminded of the quote from Spock in the James Blish novel Spock Must Die: "A difference that makes no difference is no difference."

Given the rate at which this is all moving forward, we're embarking upon an interesting time.  Although I'm not religious, I empathize with the pastors' dismay; I have a strong sense that the fiction I write has some ineffable something that an AI could never emulate.  But how much of that certainty is simply fear?  I'm not sure my "oh, no, an AI won't ever be able to write a novel like I can" is any different from Reverend Moore's statement that "a chatbot can't preach."  We all get territorial about different things, perhaps, and fight like hell to keep those boundaries secure.  Maybe at heart, the fervor of the religious and the passion of the creatives are really manifestations of the same thing.

I wonder what ChatGPT would have to say about that.

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Canine mathematics

I remember a while back reading an interesting paper that concluded that dogs have a concept of fairness and morality.

There have been a number of studies confirming this, most strikingly an investigation involving border collies.  Pairs of dogs were trained to do a task, then rewarded with doggie biscuits.  The thing was, Dog #1 was rewarded for correctly doing the task with one biscuit, and Dog #2 with two biscuits for doing the same task.

Within a few rounds, Dog #1 refused to cooperate.  "I'm not working for one biscuit when he gets two," seemed to be the logic.  So -- amazing as it seems -- at least some dogs understand fair play, and will forego getting a treat at all if another dog is getting more.

It also implies an understanding of quantity.  Now, "two is more than one" isn't exactly differential calculus, but it does suggest that dogs have at least a rudimentary numeracy.  The evolutionary advantage of a sense of quantity is obvious; if you can do a quick estimate of the number of predators chasing you, or the size of the herd of antelope you're chasing, you have a better sense of your own safety (and such decisions as when to flee, when to attack, when to hide, and so on).

Guinness, either pondering Fermat's Last Theorem or else trying to figure out how to open the kitchen door so he can swipe the cheese on the counter

But how complex dogs' numerical ability is has proven to be rather difficult to study.  Which is why I found a paper I stumbled across in Biology Letters so fascinating.

Entitled, "Canine Sense of Quantity: Evidence for Numerical Ratio-Dependent Activation in Parietotemporal Cortex," by Lauren S. Aulet, Veronica C. Chiu, Ashley Prichard, Mark Spivak, Stella F. Lourenco, and Gregory S. Berns, of Emory University, this study showed that when dogs are confronted with stimuli differing only in quantity, they process that information in the same place in their brains that we use when doing numerical approximation.

The authors write:

The approximate number system (ANS), which supports the rapid estimation of quantity, emerges early in human development and is widespread across species.  Neural evidence from both human and non-human primates suggests the parietal cortex as a primary locus of numerical estimation, but it is unclear whether the numerical competencies observed across non-primate species are subserved by similar neural mechanisms.  Moreover, because studies with non-human animals typically involve extensive training, little is known about the spontaneous numerical capacities of non-human animals.  To address these questions, we examined the neural underpinnings of number perception using awake canine functional magnetic resonance imaging.  Dogs passively viewed dot arrays that varied in ratio and, critically, received no task-relevant training or exposure prior to testing.  We found evidence of ratio-dependent activation, which is a key feature of the ANS, in canine parietotemporal cortex in the majority of dogs tested.  This finding is suggestive of a neural mechanism for quantity perception that has been conserved across mammalian evolution.

The coolest thing about this study is that they controlled for stimulus area, which was the first thing I thought of when I read about the experimental protocol.  What I mean by this is that if you keep the size of the objects the same, a greater number of them has a greater overall area, so it might be that the dogs were estimating the area taken up by the dots and not the number.  But the researchers cleverly designed the arrays so that although the number of dots varied from screen to screen, the total area they covered was the same.

And, amazing as it sounds, dogs not only had the ability to estimate the quantity of dots quickly and pick the screen with the greatest number, they were apparently doing this with the same part of their brains we use for analogous tasks.

"We went right to the source, observing the dogs' brains, to get a direct understanding of what their neurons were doing when the dogs viewed varying quantities of dots," said study lead author Lauren Aulet, in a press release in Science Daily.  "That allowed us to bypass the weaknesses of previous behavioral studies of dogs and some other species...  Part of the reason that we are able to do calculus and algebra is because we have this fundamental ability for numerosity that we share with other animals.  I'm interested in learning how we evolved that higher math ability and how these skills develop over time in individuals, starting with basic numerosity in infancy."

I wonder, though, how this would work with our dogs. As I've mentioned before, Cleo (our Shiba Inu) has the IQ of a lima bean, and even has a hard time mastering concepts like the fact that regardless how many times she lunges at her own tail, it's going to remain firmly attached to her butt.  Guinness is smarter (not that the bar was set that high), but I don't know how aware of quantity he is.  He's more of an opportunist who will take advantage of any situation that presents itself, be it a single CheezDoodle someone dropped on the floor or (as happened a while back) a half-pound of expensive French brie that was left unguarded for five minutes on the coffee table.

I doubt he worried about quantity in either case, frankly.

But the Aulet et al. study is fascinating, and clues us in that the origins of numeracy in our brains goes back a long, long way.  The most recent common ancestor between humans and dogs is on the order of eighty million years ago -- predating the extinction of the dinosaurs by fourteen million years -- so that numerical brain area must be at least that old, and is probably shared by most mammalian species.  It's a little humbling to think that a lot of the abilities we humans pride ourselves on are shared, at least on a basic level, with our near relatives.

But now y'all'll have to excuse me, because Cleo is barking like hell at something.  Maybe it's the evil UPS guy, whom she and Guinness both hate.  Maybe a squirrel farted somewhere in this time zone.  Maybe she's frustrated by the fact that she still can't quite catch her own tail.  

Or maybe she's stuck on one of her linear algebra homework problems.  You can see how that's a possibility.

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After the Pax Romana

My fellow author and twin-brudda-from-anudda-mudda Andrew Butters is one of several people who are always the lookout for cool developments in science and history to throw my way, and this time he's found one that is right square in my wheelhouse.

I've always had a near-obsession with the western European "Dark Ages" -- between the collapse of Roman rule at the end of the fourth century C. E. and the consolidation of Frankish rule under Charlemagne in the middle of the eighth.  Part of the reason for my fascination is that so little is known for certain about it.  When people are fighting like hell just to stay alive, not too many of them are going to prioritize writing books about the experience, or (honestly) even bothering to learn how to read and write.  Add to that the fact that during the turmoil, a great many of the books that had been written beforehand were destroyed, and it all adds up to a great big question mark.

The people who lived on the fringes of the once-great Roman Empire -- the Celts in the west, the Germanic tribes and Scandinavians in the north, the Slavs in the east -- took advantage of the chaos to reestablish some degree of autonomy, although they left little in the way of written records either, so what we know of their customs, politics, and beliefs is only from what's left of their buildings, monuments, and other durable artifacts.

But that doesn't mean there isn't more out there to find.  The link Andrew sent me, from the site LiveScience, describes a site from the province of Galicia in northern Spain, an area that even today owes much of its culture and music to its Celtic heritage.  Castro Valente, originally thought to be from the Iron Age and therefore pre-Roman, has turned out to be from that awkward blank spot in history I'm so fascinated with -- the fifth century C.E., shortly after the Romans wrote finis on the Pax Romana and hightailed it back to Italy to defend the home country against the Visigoths and Vandals.

Using lidar (light detection and ranging -- a relatively new technique using lasers to map out underground archaeological sites), researchers from University College London and the University of Santiago de Compostela found that the site is the remains of a fortress that had been built on the remains of an Iron Age settlement, but the main structure is of early fifth century construction.  It's huge, covering an area of twenty-five acres, comprised of thirty towers and a defensive wall a little over a kilometer long.

Part of the wall at Castro Valente

The people of the region had never been "pacified" (using that term from the Roman perspective) for long.  The northwestern part of the Iberian peninsula was inhabited by three Celtic groups, the Callaeci in the far northwest, the Lusitani in what is now northern Portugal, and the Astures a little to the east (you might surmise, correctly, that the last-mentioned gave their name to Asturia, the modern name for the north-central province of Spain).  All three were perpetual thorns in the side to the would-be rulers of the region.  The northwestern part of the Iberian Peninsula was only under nominal Roman control even at the height of the Empire, and when a long spate of unfortunately-timed inept rulers kept the central government of Rome in continuous upheaval, followed by repeated invasions from the east by Germanic and Slavic armies, the subjugated people in the west thought that'd be a fine time for them to assert their own independence.  (In fact, right around the same time that Castro Valente was being built, Rome itself was sacked by the Visigoths under Alaric -- a blow from which the Roman Empire never really recovered.)

The hilltop fort could only do so much, though.  Most of that region eventually fell to the Suebi, a Germanic people originally from the Elbe River valley.  The Kingdom of the Suebi lasted for 170 years, at which point they, too, were conquered by the Visigoths, which lasted until 720 C.E. when the Muslim Umayyad Caliphate pretty much overran the entire Iberian Peninsula.

When you think of the history of Spain, chances are you don't think of the Celts and the Germans -- but they had a major role in shaping the language and culture of the region.  This influence is strongest in the northern and western parts of the region; in fact, in modern Galicia there's a significant link still to the Celtic nations.  They even share a musical tradition -- I own a set of Galician bagpipes (a beautiful instrument called a gaita).  Check out this incredible performance by Susana Seivane -- whose father designed my pipes!

It's fascinating to see ancient history still present around us -- not only in the artifacts and archaeological sites, but in the culture we enjoy in the modern world.  These traditions have their roots in the distant past -- in this case, stretching back to a tumultuous period when it looked like the entire established order was collapsing permanently.  That it didn't is a tribute to human resilience and perseverance through a time where day-to-day life was fraught with danger, something we can read in the remnants of stone walls and foundations still standing in the now-peaceful Spanish woodlands.

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Life finds a way

I've written here before about the Permian-Triassic Extinction, sometimes nicknamed "the Great Dying."  It occurred 251.9 million years ago, and like the Cretaceous Extinction 186 million years later -- the one that knocked out the non-avian dinosaurs -- it happened suddenly, destroying ecosystems worldwide that had been thriving prior to the event.

The cause of this cataclysm is still a matter of some debate.  Hypotheses include:

• The formation of the Siberian Traps, an unimaginably huge lava flow covering most of eastern Siberia. (Its volume is estimated at four million cubic kilometers.)  The eruption would have burned everything in its wake, ripping through the vast Carboniferous coal and limestone beds, pumping tons of carbon dioxide into the atmosphere.  It would also have released huge amounts of sulfur dioxide -- not only a poison, but one of the most powerful greenhouse gases.  The result; massive global warming, oceanic acidifiction, and a catastrophic change in ecosystems worldwide.
• The lockup of Pangaea.  The collision of smaller continents to form a supercontinent has a number of effects -- the eradication of coastline along the colliding margin, ecological changes from shifting ocean currents, and collapse of mid-ocean ridges (resulting in a huge drop in sea level) among them.
• A "methane burp."  This sounds innocuous, but really, really isn't.  There's a tremendous amount of methane locked up in the form of clathrates -- a network of water ice with methane trapped inside.  These "frozen methane hydrates" coat the entire deep ocean floor.  The stuff is stable under cold temperatures and high pressures, but if something disturbs them, they begin to come apart, releasing bubbles of methane gas.  The bubbles expand as they rise, displacing more and more water, and when they hit the surface it causes a tsunami, not to mention releasing tons of methane into the atmosphere, which is not only toxic, it's also a greenhouse gas.
• Bombardment by swarms of comets and/or meteorites.  The problem with confirming this hypothesis is that any geological evidence of meteorite collisions would be long since eroded away.  If the object(s) that impacted the Earth were metallic meteorites, it's possible that you could use the same technique Luis Alvarez pioneered to explain the Cretaceous Extinction, which wiped out most of the dinosaurs -- enrichment of a layer of sediment by dust that's high in metallic elements not found in large quantities elsewhere.  But if it was a comet (mostly ice) or a rocky meteorite, we might not see much in the way of evidence of the event.

Current expert opinion is that the first one is strongly implicated as the prime cause, but the others may have played a role as well.

In any case, the end result was the extinction of an estimated 95% of marine life and 85% of terrestrial life.  Several groups that had been dominant for millions of years -- trilobites, eurypterids, blastoids, and the orthid and productid brachiopods, for example -- were wiped out completely.

It's hard to fathom what this would be like (although we'd damn well better try; there are estimates of the current, largely anthropogenic, extinction rate that place it in the same range as the Permian-Triassic).  Overall, it seems like ninety percent of the world's species died.  At the same rates today, we'd be left with a grand total of two hundred species of birds in all of North America -- and only forty different kinds of mammals.  

The reason this rather dismal topic comes up is some new research that actually provides a glimmer of hope; a find by paleontologists in China suggesting that after this cataclysm, life rebounded amazingly fast -- resulting in thriving and diverse ecosystems in as little as a million years.

Artists' reconstruction of the Guiyang biota [Image courtesy of artists Dinghua Yang and Haijun Song]

The most amazing thing about this is that at that point, the situation was still, in a word, lousy.  The average sea surface temperature at the equator is estimated at around 35 C (95 F).  The pH was still way down -- how far down isn't known, but certainly enough to inhibit calcium carbonate production by mollusks and corals.  The carbon dioxide levels were still sky-high.  But astonishingly, the organisms that made it through the bottleneck managed to adapt even to these hostile conditions.  Even in the (very) early Triassic Period, life found a way to adapt.

I hesitate to draw too much cheer from all this, however.  The fact that the species who survived the Great Dying eventually did okay is little consolation to the tens of thousands of species that went extinct.  Even if what we're now doing -- rampant fossil fuel use, pollution, and deforestation -- won't wipe out every last living thing on Earth, the results could still be beyond catastrophic.  And while it's "geologically rapid," "recovery in a million or so years" won't help our children and grandchildren.

It's time we extend "learn from the past rather than ignoring it" to prehistoric events, not just historical ones.

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