Out of Africa

In a rather startling coincidence, just yesterday I wrote about how much the course of human evolution was constrained by our evolving in a place that had large predators, scarce resources, and seasonal drought, and almost simultaneously a paper was published in Nature Geoscience about exactly that.

A huge interdisciplinary team of geoscientists, sedimentologists, micro-paleontologists, geologists, geographers, geochemists, archaeologists, chronologists, evolutionary biologists, and climate modelers led by Verena Foerster of the University of Cologne set themselves a mammoth task -- to correlate shifts in climate in East Africa over the past 620,000 years with patterns of population growth, evolution, and dispersal amongst the hominin species that lived there. 

Starting with two 280-meter-long continuous sediment cores from the Chew Bahir Basin in southern Ethiopia, the team was able to analyze not only the sediment geology and chemistry, but such things as pollen and seed types, fossil content, and rate of deposition to infer what the climate was doing at the time.  What they found was that from 620,000 to 275,000 years ago, the climate was amazingly stable -- warm and humid -- but that interspersed through that time were short, abrupt, extreme drought phases.  These "arid pulses" led to sudden habitat fragmentation, as the climatic shifts didn't hit everywhere at once (nor with equal severity).  Some areas remained relatively wetter, while other areas not that far away were experiencing catastrophic drought.

When this happens -- a large swath of relatively uniform habitat becomes unstable and/or patchy -- it generally has two results; (1) animals become more mobile, migrating in search of resources that are now less reliable; (2) organisms less capable of moving undergo strong selective pressure to adapt to "the new normal."  Both of these affected our ancient relatives.  Some began to disperse more widely, presumably seeking out food and water, while others diversified in response to their new local climatic conditions, leading to rapid speciation.

Following this, the East African climate began to undergo more regular oscillations between congenial and hostile.  Wet phases, with abundant vegetation and deep freshwater lakes, alternated with dry phases during which the lakes evaporated almost completely, leaving only highly saline, alkaline ponds.  During this time, the Acheulean hand axe culture of the Lower Paleolithic (associated with our predecessor species Homo ergaster) was superseded by more sophisticated technologies and the emergence of modern Homo sapiens about sixty thousand years ago.

An Acheulean hand axe [Image licensed under the Creative Commons José-Manuel Benito Álvarez (España) —> Locutus Borg, Bifaz cordiforme, CC BY-SA 2.5]

Things only got dicier from there.  Between sixty and ten thousand years ago -- the highest layers of the sediment cores -- East Africa saw the most arid phase in the entire record.  This had two effects -- driving our ancestors out of Africa in search of better conditions, and triggering the extinction of virtually all our near relatives.  We won, apparently, by dint of our mobility and large brains, allowing us to cope with hostile and rapidly fluctuating conditions, eventually leading to our dispersing to every habitable land on Earth.

It's fascinating to me that we owe our own existence to fluctuations in the climate -- that the conditions in one part of the world molded us into the species we currently are.  Now that we have technology to avoid many of the caprices of the environment, we are also shielded from their evolutionary effects; you have to wonder how (or if) our distant descendants will be altered by climate shifts, more specifically those we ourselves are perpetrating.  It once again brings home the truth of the perspective that each species is not a separate entity, but is part of an intricate tapestry of life.  Pull on one thread, and the others will inevitably, and irrevocably change -- for good or ill.

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Water worlds

My older son has followed in his old man's footsteps, combining a fascination for astronomy, biology, chemistry, and physics with a wild imagination to generate a fantastic universe within which to spin fictional tales.  He is adding a skill I most definitely do not have -- art -- to create a brain-bending saga that I'm sure you will one day see sitting on people's bookshelves.

Just a couple of days ago, we were talking his creation, and were musing about the possibility of alien intelligence, and in particular, the fact that the kind of intelligence we humans evolved was very much driven by the kind of planet we live on.  The tools we create, which facilitated our dominance of the Earth, required availability of metal ores and the ability to make fire to smelt them.  Even our combative, competitive nature may well owe its origins to our having evolved in a place (east Africa) with plentiful large predators, scarce resources, and seasonal drought.

What kind of intelligence might develop on a planet with no dry land?  That intelligence can develop in aquatic life forms is undeniable; by most biologists' estimates whales and dolphins have about the same intelligence as the great apes, and at least some of the vocalizations they make might qualify as actual language.  (That question is currently not settled, but there have been some suggestive recent studies supporting that contention.)

But even though whales and dolphins are intelligent, they're non-technological.  It's entirely imaginable that there could be aquatic life forms that might exceed humans in memory storage, recall, complexity of communication, and flexible problem-solving, and yet they still might not have anything we would call hard technology.  Note that the water-world in the Star Wars universe -- Kamino, the origin of the eponymous clones of the Clone Wars -- still had to have a solid (if floating) surface, made of conventional materials like metals, glasses, and plastics, in order to have a technology similar enough to that in the rest of the canon for the story to be plausible.

It all comes down to how much the evolution of intelligent life is constrained -- hemmed in by drivers that would likely generate similar forms in all conceivable habitable worlds.  My conclusion is that there are constraints, but they're few in number -- things like having complex sensory organs, having those organs and the central processing unit (brain) located near the anterior end, having some kind of appendages for moving through whatever medium the planet is outfitted with, and having some mechanism for communicating between individuals.  That's about it.  Otherwise... all bets are off as to what we'll find when we first set foot on another planet.

[Image is in the Public Domain courtesy of NASA/JPL]

This significantly complicates the possibility of finding intelligent extraterrestrial life.  There could be a water-world populated by something like super-intelligent dolphins, and they would have no capacity for (nor, likely, any interest in) building radio transmitters and receivers.  So to us, such a planet would appear completely silent and devoid of life.  Our SETI (Search for Extraterrestrial Intelligence) efforts have been confined by necessity to looking for signals of the kind we ourselves send -- which might also restrict us to finding only the life that evolved on planets with conditions extremely similar to Earth.

The result is that we might well miss most of what's out there.  The reason this comes up -- besides my conversation a couple of days ago with Lucas -- is an article by University of Arizona astronomer Chris Impey that just appeared in The Conversation.  Impey tells us something that should encourage people like me, who would very much like it if extraterrestrial life exists out there somewhere; that a third of all exoplanets are "super Earths," planets with a mass between that of the Earth and Neptune.  Further, most of these orbit cool dwarf stars, which have a vastly longer life span than Main Sequence stars like the Sun, so there would be a great deal longer for life to evolve and become complex.  Impey says that the "most habitable of all possible worlds" would fall into the super Earth category -- roughly twice the mass of Earth, and twenty to thirty percent larger in volume.  (The reason is that a larger planet would have a thicker atmosphere with a greater heat-storage capacity, and thus be more resistant to the rapid changes in climate that have plagued the Earth since its formation.)

However, if that thicker atmosphere contained water vapor, you might well be looking at planets completely covered by a deep ocean -- a water-world, where any life would evolve along very different pathways that it has here.  In that case, the only way to see that it exists from our perspective here on Earth is by biosignatures, gases in the atmosphere that would be unlikely to exist unless there were life present to create them.  (An example is free oxygen in Earth's atmosphere; it's so reactive that without photosynthesizers like plants and phytoplankton producing it continuously, it would get locked up by chemical reactions and disappear from the atmosphere entirely.)

So despite what you might have seen on Star Trek, the most common intelligent alien life out there might not be bipedal humanoids with rubber facial prostheses.  We smart hairless apes might actually be vastly in the minority -- a possibility I find fascinating but a little mind-boggling.

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Look upwards

Since (surprise!) we've all once again survived the apocalypse, and Saturday September 24, 2022 turned out to be less of a "day to remember" than a "day I've already kind of forgotten," today I'm going to turn to one of my favorite topics, namely: space.

I've been continually wowed by the images coming in from the James Webb Space Telescope.  When it was first deployed, the astronomer and engineers responsible for it told us we were going to be blown away by the quality of the data it would send us, and if anything, that's been an understatement.  We've seen images of astonishing crystal clarity, not only photographs of galaxies further away than anything yet studied but detailed views of objects much closer to home.

It's one of the latter that prompted me to write today's post, because the latest posted image from the JWST is of the planet Neptune.  Just a couple of months ago I did an entire post on how generally weird Neptune is; a lot of our information on it is old, however, having come from the Voyager 2 flyby a little over thirty years ago.  Since then, we've had to study it from farther away, and a lot of what we've learned has raised more questions than answers.

So I was really eager to see what JWST would find out about the eighth planet.  And it's started out with a bang.  Check out this image, showing the planet with its rings and several of its fourteen moons:

[Image is in the Public Domain courtesy of NASA/JPL]

The rings are made of dark material -- this is actually the first time they've been directly observed since Voyager 2 (even the Hubble Space Telescope didn't have the optical resolution to see them).  The bright spots in the atmosphere are clouds of methane ice; the planet itself is not its usual deep cobalt blue because this image was taken in the near infrared range of the electromagnetic spectrum.

I find it deeply inspiring that despite the continuing turmoil down here on Earth, the scientists still have their eyes trained on deep space.  It also keeps us humble, you know?  Even as a child, when I'd look up at the sky through my little telescope, it always gave me a feeling of awe at how majestic, magnificent, and absolutely huge the universe was.

It reminds me of the words of Apollo 11 astronaut Michael Collins, about his experience of seeing the Earth from space: "The thing that really surprised me was that it [Earth] projected an air of fragility.  And why, I don’t know.  I don’t know to this day.  I had a feeling it’s tiny, it’s shiny, it’s beautiful, it’s home, and it’s fragile."

It's a perspective we all should have.

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An apocalypse to remember

Hi!  Hope you're having a lovely day so far.  Enjoy what you can of it, because we're all gonna die today.

At least that's the contention of the Usual Suspects on the interwebz.  The whole thing started ten days ago, when a German politician named Friedrich Metz was giving a speech, and said, "Dear colleagues…September 24, 2022 will be remembered by all of us as a day which we will say, 'I remember exactly where I was…'"

Then (depending on who you believe) either the mic cut out or else he just refused to elaborate further.  Of course, this immediately caused multiple orgasms amongst the conspiracy theory types, who took Metz's statement and crafted it into what was basically a Mad Libs for wingnuts, of the form "[Choose one from column A] stopped Metz from talking because they don't want people finding out that [Choose one from column B] is going to happen."

Choices for A:

• The Bilderberg Group
• The Illuminati
• The Jews
• Scientists
• The Far Right
• The Far Left
• Gray aliens from Zeta Reticuli
• The Reptilians

Choices for B:

• a gigantic solar flare that will wipe out the electrical grid
• a massive engineered cyclone headed for the US Gulf Coast
• the complete collapse of the world economy
• a collision from a huge meteorite
• a deliberately-planned worldwide blackout
• an electromagnetic pulse that will turn anyone who has 5G into a mind-controlled zombie
• a supervolcano eruption
• the sudden takeover of major world governments by either the Far Left or the Far Right (depending on which one you went for before)
• an open alien invasion

As always, they're basing their conclusions (if I can even dignify them with that word) on evidence so slim that to call it wafer-thin would be an insult to wafer-makers.  One guy said one semi-alarmist thing, and all of a sudden, it's the end of the world.

Apocalypse by Albert Goodwin (1903) [Image is in the Public Domain]

It also conveniently ignores the fact that these wacko catastrophists have an exactly zero batting average.  There have been so many predictions of apocalyptic events that Wikipedia even has a page keeping track of them, headed by the wonderful phrase, "This is a dynamic list and may never be able to satisfy particular standards for completeness."

So the apocalyptoids keep saying, "No, really!  It's really gonna happen this time, we promise!", and nothing continues to happen except the world kind of limping along the way it always has.  But who knows?  Maybe this time we'll finally, at long last, have a winner.  September 24, 2022, will be the day we'll all remember, except for those of us who died in the supervolcano eruption or megacyclone or whatnot.

At this point, I'm frankly rooting for the apocalypse.  I live in a part of the world so quiet that watching the farmer across the road running his hay baler is considered high entertainment.  I'd rather not be vaporized by a meteor strike, but honestly, some of the others sound at least like welcome reprieves from boredom.  Alien invasion?  Solar flares?  Hell, bring 'em on.  I'm ready.

Illuminati, do your worst.  And that goes double for you gray aliens from Zeta Reticuli.

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The orphan

Whenever the topic here at Skeptophilia takes a paleontological turn, I always seem to focus on bizarre creatures very far removed from the iconic T. rexes and stegosauruses that typically grace the covers of children's books on prehistoric life.

I'm not sure why the charismatic dinosaurs hold less of a fascination for me than weird critters like spiky Hallucigenia (which means "causes hallucinations" in Greek, and is such an anomaly that the earliest fossil reconstructions were upside down), Opabinia (with its five eyes and vacuum-hose mouth), and Anomalocaris (Greek for "abnormal shrimp" -- abnormal indeed, with mouthparts like a pair of serrated scissors).

So given my penchant for appreciating the odd, I suppose it's no shock that my attention was immediately grabbed by a new piece of research about a creature nicknamed "the Alien Goldfish."  More surprising, though, is that I'd never even heard of this thing.

Named Typhloesus ("blind eater"), this peculiar animal was discovered in Carboniferous-age rocks in Bear Gulch, Montana, in 1973.  Early studies were confounded by the discovery within one of the fossils of hard, toothlike structures that turned out not to be from the animal itself but from its last meal, a conodont fish.  Once that was cleared up, it rapidly became obvious that Typhloesus was an "orphan" -- a species which, like its weird contemporary Tullimonstrum, wasn't closely related to anything we know of.

Typhloesus pursuing a conodont

The recent study, though, found that a close examination of Typhloesus fossils showed the animal had a radula -- a rasping, toothlike organ found in mollusks, especially gastropods (snails).  So if the research team's conclusions are correct, Typhloesus was a free-swimming, shell-less gastropod -- perhaps a little like modern nudibranchs.

Not everyone is convinced, though.  There are other animals who have evolved radula-like structures, and the placement of this orphan species in Phylum Mollusca is still tentative at best.  Mark Purnell, of the Centre for Palaeobiology at the University of Leicester, who was not involved in the current research, said, "It is still a very strange animal.  [The researchers] have found some tantalizing new information, but it is far from being a slam-dunk case in terms of definitely knowing what this weird thing is."

It's fascinating to contemplate how different the world was back then -- during the Carboniferous Period there were nearly worldwide rainforests of "trees" more closely related to today's ferns and club mosses, which drove the oxygen concentration of the atmosphere so high (35%, by some estimates, as compared to the current 21%) that animals like arthropods got huge.  There were predatory dragonflies with seventy-centimeter wingspans, and millipedes two and a half meters long and a half a meter wide, weighing an estimated fifty kilograms.

And in the oceans, there were some creatures so strange they've yet to be placed into the animal family tree with any real certainty.  It certainly brings home the truth of the final words of Charles Darwin's The Origin of Species, that evolution continually produces "endless forms most beautiful and most wonderful."

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Look me in the eye

It's fascinating how much information can transfer between two humans solely through eye contact.

I say that as a person who has a serious issue with doing this at all.  I have no idea where my avoidant behavior comes from, although I do recall hearing "Look at me when I'm talking to you!" a lot as a kid when I was in trouble.  But I find making sustained eye contact dreadfully uncomfortable.  I recall vividly being in a men's workshop a while back where one of the exercises was standing, a foot or so apart, face-to-face with another man, and simply holding each other's gazes for three minutes.  Those three minutes seemed to drag on forever, and it required phenomenal willpower on my part not to look away.

[Image is in the Public Domain]

Perhaps part of it is my intense dislike of being the focus of attention, another outcome of my rather unfortunate childhood.  Interestingly, this tendency never bothered me much while I was teaching; to me, a teacher isn't (or shouldn't be) saying "Hey, look at me!", (s)he is saying about the topic being studied, "Hey, let's look at this other thing together, isn't this cool?"

I've wondered, though, if my tendency to look away when people glance at me has influenced my ability to form relationships.  I can see how this might make me seem aloof or unfriendly.  It's certainly contributed to a regrettable inability on my part to be able to tell when someone is flirting with me.  My friends, knowing my general cluelessness, have been known to say, "Um... you do realize (s)he was flirting with you, right?"  The answer almost always is "no."  The sad truth is that I wouldn't know if someone was flirting with me unless they were holding up a sign that said, "HEY.  STUPID.  I AM CURRENTLY FLIRTING WITH YOU."

And given the fact that I would probably be looking away the whole time, even that might not help.

The reason all this squirm-inducing stuff comes up is because of a study out of the University of Würzburg published this week in the Journal of Experimental Psychology, entitled, "Don't Look At Me Like That: Integration of Gaze Direction and Facial Expression," in which we find out that for most people, whether or not we have a desire to meet someone's eyes depends strongly on what their facial expression is.

The researchers, led by Christina Breil, used photos of individuals who were either looking toward or away from the viewer, and had one of four emotional expressions: joy, anger, disgust, and fear.  The team measured how quickly volunteers looked into the eyes of the person in the photograph, and how long that (virtual) eye contact was maintained.  What they found was that we tend to look more quickly into the eyes of people expressing joy or anger (and hold the gaze longer), and be reluctant to look at those expressing disgust or fear.  In fact, the disgust and fear photos attracted more attention when the person in the photo was looking away from the viewer.

The anger results interested me the most, because I get really uncomfortable (even more uncomfortable than normal, which is saying something) around angry people.  I'm a champion conflict-avoider, which probably won't come as any real shock.  Breil et al. explain that this is thought to occur because anger, while generally considered unpleasant, is still an "approach-oriented" emotion; note that we even call angry confrontations "getting in your face."  Disgust and fear, on the other hand, are "avoidance-oriented;" they make us want to retreat from whatever it was that elicited the response.

I wonder how someone with a generally avoidant orientation, like myself, would have done with this experiment.  I certainly don't have nearly the problem looking at a photograph that I do looking into the eyes of a real person.  But if I hadn't known what the gist of the experiment was beforehand (which the volunteers, of course, didn't), it'd have been interesting to see how I'd have reacted.

The eyes, they say, are the window to the soul.  Certainly we express a great deal of feeling with them.  And how we respond to those expressions seems to be pretty nearly universal -- illustrating that once again, for social animals, effective communication is a strong driver for evolution.

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Memory offload

In James Burke's brilliant series The Day the Universe Changed, there's a line that never fails to shock me when I think about it, but which goes by so quickly you might miss it if you're not paying attention.  (This is typical of Burke -- I've heard his deservedly famous series Connections as being like "watching a pinball game on fast-forward.")

The line comes up at the beginning of the last episode, "Worlds Without End," in which he's giving a quick summary of humankind's progression through technology.  He says, "In the fifteenth century, the invention of the printing press took our memories away."

Recording our knowledge in some kind of semi-permanent fashion is at odds with our need to keep anything important in memory.  I'm riffing on that concept in my current work-in-progress, The Scattering Winds, which is about a post-apocalyptic world in which some parts of society in what is now the United States have gone back to being non-literate.  All of the knowledge of the culture is entrusted to the mind of one person -- the Keeper of the Word -- whose sacred task it is to remember all lore, language, music, and history.

Then... because of a refugee from another place -- the apprentice to the Keeper learns about written language, and acquires the rudiments of reading, then goes in search of any books that might have survived the disasters and plagues that ended the world as we know it.  He realizes that this (re)discovery will end the vocation he's studied his whole life for, but the lure of lost knowledge is too powerful to resist even so.

He knows that in a very real sense, the rediscovery of written language will take his memory away.

The internet, of course, has only deepened the scope of the problem.  A few years ago, I had a student who had what seemed to me a weird approach to figuring things out.  When presented with a question he didn't know the answer to, his immediate response was to pull out his school-issued iPad and Google it.  Often, he didn't even give his brain a chance to wrestle with the question; if the answer wasn't immediately obvious, out came the electronics.

"What have you learned by doing that?" I recall asking him, trying to keep the frustration out of my voice.

"I got the right answer," he said.

"But the answer isn't the point!"  Okay, at that point my frustration was pretty clear.

I think the issue I had with this student comes from two sources.  One is the education system's unfortunate emphasis on Getting The Right Answer -- that if you have The Right Answer on your paper, it doesn't matter how you got it, or whether you really understand how to get there.  But the other is our increasing reliance on what amounts to external memory.  When we don't know something, the ease and accessibility of answers online makes us default to that, rather than taking the time to search our own memories for the answer.

The loss of our own facility for recall because of the external storage of information was the subject of a study in the journal Memory.  Called "Cognitive Offloading: How the Internet is Increasingly Taking Over Human Memory," the study, by cognitive psychologists Benjamin Storm, Sean Stone, and Aaron Benjamin, looked at how people approach the recall of information, and found that once someone has started relying on the internet, it becomes the go-to source, superseding one's own memory:

The results revealed that participants who previously used the Internet to gain information were significantly more likely to revert to Google for subsequent questions than those who relied on memory.  Participants also spent less time consulting their own memory before reaching for the Internet; they were not only more likely to do it again, they were likely to do it much more quickly.  Remarkably, 30% of participants who previously consulted the Internet failed to even attempt to answer a single simple question from memory.

This certainly mirrors my experience with my students.  Not all of them were as hooked to their electronics as the young man in my earlier anecdote, but it is more and more common for students to bypass thinking altogether and jump straight to Google.

"Memory is changing," lead author Storm said.  "Our research shows that as we use the Internet to support and extend our memory we become more reliant on it.  Whereas before we might have tried to recall something on our own, now we don't bother.  As more information becomes available via smartphones and other devices, we become progressively more reliant on it in our daily lives."

What concerns me is something that the researchers say was outside the scope of their research; what effect this might have on our own cognitive processes.  It's one thing if the internet becomes our default, but that our memories are still there, unaltered, should the Almighty Google not be available.  It's entirely another if our continual reliance on external "offloaded" memory ultimately weakens our own ability to process, store, and recall.  It's not as far-fetched as it sounds; there have been studies that suggest that mental activity can stave off or slow down dementia, so the "if you don't use it, you lose it" aphorism may work just as much for our brains as it does for our muscles.

In any case, maybe it'd be a good idea for all of us to put away the electronics.  No one questions the benefits of weightlifting if you're trying to gain strength; maybe we should push ourselves into the mental weightlifting of processing and recalling without leaning on the crutch of the internet.  And as Kallian discovers in The Scattering Winds, the bounty of information that comes from the external storage of information -- be it online or in print -- comes at a significant cost to our own reverence for knowledge and depth of understanding.

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