Chewing gum and talking about talking

Earlier this week I looked at three cool archaeological discoveries -- cave art in Indonesia, and two finds in Egypt, one of a bone from someone killed in the battle recorded on the Rosetta stone, and the other about a researcher who found that the practice of tattooing has been around for a very long time.

But we're not done with mind-blowing archaeological stories, apparently, because there are two more that I just found out about, and which (if anything) are even cooler than the ones I wrote about Monday.

I learned of the first one from my friend, novelist and blogger Andrew Butters, whose blog Potato Chip Math is a must-read.  In this one, we find out that a team of geneticists have sequenced the DNA of a girl who lived in Denmark 5,700 years ago...

... from a wad of chewing gum.

Well, technically, it was birch sap, but same idea.  They were able to extract her DNA from the gum and sequence her entire genome, which allowed them not only to figure out what ethnic group she was from, but to make a good shot at her appearance.  She had dark skin and hair, they found, and blue eyes.  Here's an artist's reconstruction of what she might have looked like:

[Reconstruction by Tom Björklund]

The authors write:

Analysis of the human reads revealed that the individual whose genome we recovered was female and that she likely had dark skin, dark brown hair and blue eyes.  This combination of physical traits has been previously noted in other European hunter-gatherers, suggesting that this phenotype was widespread in Mesolithic Europe and that the adaptive spread of light skin pigmentation in European populations only occurred later in prehistory.  We also find that she had the alleles associated with lactase non-persistence, which fits with the notion that lactase persistence in adults only evolved fairly recently in Europe, after the introduction of dairy farming with the Neolithic revolution.

The period she lived in was when northern Europe was taken over by people known as the "Funnel Beaker Culture," so named because of their characteristic narrow-based, highly-ornamented pottery:

The 5,200 year old Skarpsalling vessel [Image is licensed under the Creative Commons Nationalmuseet, Skarpsallingkarret DO-9665 original, CC BY-SA 3.0]

"It is amazing to have gotten a complete ancient human genome from anything other than bone,'' said study lead author, evolutionary geneticist Hannes Schroeder, of the University of Copenhagen, in an interview with Science Alert.  "The DNA is so exceptionally well preserved that we were able to recover a complete ancient human genome from the sample… which is particularly significant since, so far, no human remains have been recovered from the site."

The second story goes back a great deal further in time than the little Neolithic Danish girl, though.  In fact, it kind of crosses the line from archaeology into paleontology, because in a paper in Science Advances we find out that the ability to speak might have been around in primates for twenty million years.

The study, led by Louis-Jean Boë of the University of Grenoble, analyzes the mechanics of human speech, in particular how the morphology of the mouth, trachea, and larynx allow for the production of meaningful sound.  It's been thought for years that the advent of speech occurred when our ancestors' larynxes (voice boxes) gradually moved downward, pulling the back of the tongue backward and downward as well and giving the tongue more mobility to shape sounds.  But what Boë's team found was that even if you accept that as the hallmark of speech, it goes a long way further back than we'd realized.

"First, even among primates, laryngeal descent is not uniquely human," Boë and his team write.  "Second, laryngeal descent is not required to produce contrasting patterns in vocalizations.  Third, living non-human primates produce vocalizations with contrasting patterns.  Thus, evidence now overwhelmingly refutes the long-standing laryngeal descent theory, which pushes back 'the dawn of speech' beyond ~200 ka ago to over ~20 Ma ago, a difference of two orders of magnitude."

So that means that at least from a mechanical standpoint, our distant ancestors had the capacity for speech.  Whether their brains were developed enough to say anything particularly interesting is still a matter of conjecture.  But evolution is all about minuscule gains.  Once the upper respiratory tract becomes capable of modulating sounds in a meaningful way, this puts selective pressure on the brain to refine its ability to understand and convey meaning with those sounds -- which puts pressure on the vocal apparatus to become better at producing subtle differences in sounds, and so on and so forth.  Which, as comedian Paula Poundstone notes, may not be entirely a good thing:

Be that as it may, it's a pretty cool discovery.  As I pointed out in Monday's post, it's incredible how much we can infer about our distant ancestors' appearance, culture, and abilities from evidence that would have been a closed book only ten years ago.  Our techniques for carrying out this research are only going to improve, so keep watching the journals -- my sense is that the amazing discoveries in this field have only just begun.

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This week's Skeptophilia book recommendation is pure fun, and a perfect holiday gift for anyone you know who (1) is a science buff, and (2) has a sense of humor.  What If?, by Randall Munroe (creator of the brilliant comic strip xkcd) gives scientifically-sound answers to some very interesting hypothetical questions.  What if everyone aimed a laser pointer simultaneously at the same spot on the Moon?  Could you make a jetpack using a bunch of downward-pointing machine guns?  What would happen if everyone on the Earth jumped simultaneously?

Munroe's answers make for fascinating, and often hilarious, reading.  His scientific acumen, which shines through in xkcd, is on full display here, as is his sharp-edged and absurd sense of humor.  It's great reading for anyone who has sat up at night wondering... "what if?"

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

Searching for a lost hope

As a biologist, I know that extinction is the way of the world.  Well above 99% of the species that have ever existed on Earth have gone extinct, and in fact (given the sparseness of the fossil record) chances are most of those we don't know about and will never know about.  Extinction is simply a fact of existence.

The soft-hearted side of me, though, finds it terribly sad.

As a dedicated birder, it's heartbreaking that I will never see a Great Auk, a Carolina Parakeet, a Passenger Pigeon, or a Dodo, all of which were driven to extinction in the past three hundred years by humans.  Even the pretty little Labrador Duck, which was already in decline before humans began overhunting them and destroying their habitat -- and so was probably doomed anyhow -- looks at me with its glass-bead eyes from the museum shelves with what I can only interpret as reproach.

"Extinction is forever" has gotten to be a cliché, but there's no denying its truth.  I'm not the only one who finds it tragic, which explains the ends people will go to in order to prove particular species live on.  My wife used to work for the Cornell University Laboratory of Ornithology as a sound archivist, and she was involved (in a tangential way, she'd tell you, but enough to merit a free t-shirt) with the efforts to relocate the Ivory-billed Woodpecker, widely thought to have been extinct since the mid-1940s.  The only evidence of its continued existence was a blurry ten-second bit of video that even the wishful thinkers couldn't swear was conclusive, but it was enough to mount an expedition to the swamps of Arkansas to look for it.  And several expert birders -- who are far too knowledgeable to mistake it for the related, but much smaller (and differently-patterned) Pileated Woodpecker -- swear they got good looks at what was known as "the Lord God bird" because that's what people would shout when what looked like a black, white, and red pterodactyl flew overhead.

So hope still exists, at least for some of the species currently considered extinct.  One of the most controversial -- the thylacine, also known as the Tasmanian tiger or Tasmanian wolf -- is currently the subject of a one-man relocation effort that hit the news just this week.

Australian Neil Waters is so invested in re-finding the thylacine that he purchased a huge tract of land in northern Tasmania, and plans on devoting the next two years to the search.  Waters claims to have seen thylacines himself twice before, and points out that there's not a lot you could mistake for them:

[Image is in the Public Domain]

Known for their amazing "scissor" gape, the thylacine -- which, despite its two common names, is neither a wolf nor a tiger, but a marsupial like the kangaroo and the koala -- were persecuted for an alleged affinity for eating sheep, and the last known individual died in a zoo in Hobart in 1936.  Since then there has been no hard evidence of its continued existence, although if you compare the sightings reports, the thylacine beats the Ivory-billed Woodpecker hands down.  The number of alleged sightings of thylacines number in the hundreds, with dozens more coming in every year.

[Image is in the Public Domain]

"[T]he hundreds of people who have reported sightings cannot all be wrong," Waters said.  "This is a long-term project and I am prepared to give it a couple of years – or until my finances run out.  My dream is to prove the thylacine is alive and well and have a management plan put in place to ensure their continued survival."

Another argument in favor of optimism is that it's not like seeing them was an everyday occurrence even when there was still a sizable number of them -- they were known for being shy and nocturnal.  So if there's a small population still out there, Waters reasons, it's no wonder they're seldom seen.

He adds that he's not interested in hand-waving, my-brother's-best-friend-saw-it-for-sure kind of arguments, but wants hard evidence that the experts will find unassailable.  "I have nothing to gain from faking anything," he said.  "I don't want to prove a fallacy."

The "nothing to gain" part isn't really all that accurate -- after all, he's already been featured in news media worldwide, and there are probably reality-TV shows that would love to do an episode or two on his hunt.  Not meaning to cast aspersions against him, because he certainly sounds sincere, and I really want to think that the second part -- that he doesn't want to fake evidence for a falsehood -- is the truth.

So for now I'm 100% in Waters's camp, and wish him the best of luck.  He certainly seems to be going about it the right way.  If they're still out there, there's hard evidence somewhere, and he's determined enough to have a real shot at finding it.

But part of it is wishful thinking on my part, because I really want the thylacine to still be alive.  They're cool, weird, and unique as the largest recent carnivorous marsupial.  Plus, finding it alive would mean one fewer irreversible assaults on the natural world to lay at humanity's feet -- and heaven knows, we have enough of those.

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This week's Skeptophilia book recommendation is pure fun, and a perfect holiday gift for anyone you know who (1) is a science buff, and (2) has a sense of humor.  What If?, by Randall Munroe (creator of the brilliant comic strip xkcd) gives scientifically-sound answers to some very interesting hypothetical questions.  What if everyone aimed a laser pointer simultaneously at the same spot on the Moon?  Could you make a jetpack using a bunch of downward-pointing machine guns?  What would happen if everyone on the Earth jumped simultaneously?

Munroe's answers make for fascinating, and often hilarious, reading.  His scientific acumen, which shines through in xkcd, is on full display here, as is his sharp-edged and absurd sense of humor.  It's great reading for anyone who has sat up at night wondering... "what if?"

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

A lens into the past

I have the unfortunate tendency to get fascinated by things that are impossible to research.

I was asked not too long ago about when and where -- if time travel into the past were possible -- I'd like to visit.  My immediate answer was Britain during the "Dark Ages," the period between the withdrawal of Roman forces in the 5th century C.E. and the Anglo-Saxon conquest in the 7th century.

My friend asked why I picked that time and place.  What was so interesting about it?

"I don't know if there's anything interesting about it," I responded.  "It's because no one really knows what happened during that time span.  There are almost no written records -- just about everything we know is from writings done three or four hundred years later.  It's the lack of information that fascinates me."

Fortunately, it's not always necessary to have written records to find out about a place's history.  That's why we have archaeology.  We can obtain a remarkably clear picture about a long-gone society simply from the debris it leaves behind.

There were three wonderful examples of this just in the last two weeks.

In the first, researchers in the Nile Delta found a skeleton and other artifacts in a place called Tell Timai (known as Thmouis in Ptolemaic times).  The skeleton was dated to about 180 B.C.E.  It showed numerous signs of trauma -- both healed and unhealed injuries to the bone, and evidence that its owner hadn't been buried so much as thrown on the ground and covered with a thin layer of dirt and sand.

Why the timing of this is interesting is that the man's death was during the same period as a revolt against Pharaoh Ptolemy V by native Egyptian rebels (the Ptolemies themselves were Greeks, and were widely regarded by their native subjects as usurpers).  Ptolemy successfully squashed the rebellion, an event that is recorded on one of the most famous written documents of all -- the Rosetta Stone.

The skeleton of the unfortunate Tell Timai man not only shows injuries typically suffered on the battlefield, but was surrounded by evidence of battle -- arrowheads and scorched "ballista balls" (a baseball-sized projectile fired from Greek and Roman catapults).  Also present were coins dating to no earlier than 205 B.C.E.  This is precisely the timing of the Thmouis Revolt -- the Rosetta Stone says it went on in a sporadic fashion starting around 206 B.C.E. and ending with the decisive battle twenty years later.

So it appears that the Tell Timai skeleton is a war casualty from a battle recorded on one of the world's most celebrated written records.


Archaeological findings can go back a hell of a lot longer ago than 2,200 years, however.  Another discovery that was reported last week is from Indonesia, and gives us a lens into a time when (as far as we know) writing had yet to be invented.  A cave painting on the island of Sulawesi, dated to 43,900 years ago, is a hunting scene -- by itself not that uncommon -- but the hunters depicted are what archaeologists call therianthropes, which are mythical human/animal hybrids.

A detail of the Sulawesi cave painting

What's exciting about this is that it shows the artist wasn't just depicting realism, (s)he was telling a story.  We've apparently been storytellers for a very long time, something that (as a novelist) makes me very happy.

"The human-animal figures in the Sulawesi hunting scene are quite small relative to the pig and anoa [a small native species of buffalo] images," said Nicholas Conard, archaeologist at the University of Tübingen.  "That may be because ancient artists depicted these therianthropes as flying.  In the stories and personal accounts of people from modern foraging groups, movements through spirit worlds are often via flight rather than walking or running."

So just like we do today, our very distant ancestors enjoyed telling fanciful stories about strange creatures -- and some of those stories made their way into art.


People who know me are aware of another of my strange obsessions, and that's with body art.  I have three tattoos, one of which is a full sleeve that extends onto my chest -- it's not like I exactly keep it secret, or anything.  So after finding the previous article, about our history as storytellers, it made me happy to jump to the next, which shows that we've also been decorating our own bodies for a long, long time.

Archaeologist Anne Austin, of the University of Missouri, was working with three thousand year old mummies from Deir el-Medina in Egypt, and upon analyzing x-rays found clear evidence of tattoos.  One woman, presumed to be a religious leader or practitioner of magic, had no fewer than thirty tattoos, including an intricate pattern of crosses on both of her arms.  Another had symmetrically-placed images of the Eye of Horus, and a third a seated baboon -- symbolizing knowledge and wisdom -- on the side of her neck.

"Only tattooed females have been identified at Deir el-Medina," Austin said.  "Discoveries there challenge an old idea that tattoos on women connoted fertility or sexuality in ancient Egypt.  Deir el-Medina tattoos appear to be more closely associated with women’s roles as healers or priestesses."

It's amazing what we can learn about human history without written records (or, in the case of the Tell Timai skeleton, how we can supplement what written records we have).  Everything the archaeologists uncover makes the picture clearer.  As my dear friend, the novelist Cly Boehs (author of the brilliant Back Then and The Most Intangible Thing) puts it, "We are made of the stories we tell."

And sometimes those stories resonate down through the ages, giving us a glimpse of societies that have been gone for thousands of years.

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This week's Skeptophilia book recommendation is pure fun, and a perfect holiday gift for anyone you know who (1) is a science buff, and (2) has a sense of humor.  What If?, by Randall Munroe (creator of the brilliant comic strip xkcd) gives scientifically-sound answers to some very interesting hypothetical questions.  What if everyone aimed a laser pointer simultaneously at the same spot on the Moon?  Could you make a jetpack using a bunch of downward-pointing machine guns?  What would happen if everyone on the Earth jumped simultaneously?

Munroe's answers make for fascinating, and often hilarious, reading.  His scientific acumen, which shines through in xkcd, is on full display here, as is his sharp-edged and absurd sense of humor.  It's great reading for anyone who has sat up at night wondering... "what if?"

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

The interstellar lighthouse

It's funny the questions you don't think to ask.  You find out something, accept it without any objections, and only later -- sometimes much later -- you stop and go, "Wait a moment."

That happened to me just yesterday, about a topic most of us don't ponder much, and that's the peculiar astronomical object called a neutron star.  It was on my mind not by random chance -- even I don't just sit around and say, "Hmm, how about those neutron stars, anyway?" -- but because of some interesting new research (about which I'll tell you in a bit).

I first learned about these odd beasts when I took a class called Introduction to Astronomy at the University of Louisiana.  The professor, Dr. Whitmire, explained them basically as follows.

Stars are stable when there's a balance between two forces -- the outward pressure from the heat generated in the core, and the inward pull because of the gravity exerted by the star's mass.  During most of a star's life, those two are in equilibrium, but when the core exhausts its fuel, the first force diminishes and the star begins to collapse.  With small stars like the Sun, the collapse continues until the mutual repulsion of the atoms' electrons becomes a sufficient force to halt it from shrinking further.  This generates a white dwarf. 

In a star between 10 and 29 times the mass of the Sun, however, the mutual electric repulsion isn't strong enough to stop the collapse.  The matter of the star continues to fall inward until it's only about ten kilometers across -- a star shrunk to the diameter of a small city.  This causes some pretty strange conditions.  The matter in the star becomes unimaginably dense; a teaspoon of it would have about the same mass as a mountain.  The pressure forces the electrons into the nuclei of the atoms, crushing out all the space, so that what you have is a giant electrically-neutral ball -- effectively, an enormous atomic nucleus made of an unimaginably huge number of neutrons.

The first neutron star ever discovered, at the center of the Crab Nebula [Image is in the Public Domain, courtesy of NASA/JPL]

The immense gravitational pull means that the surface of a neutron star is the smoothest surface known; any irregularities would be flattened out of existence.  (It's worth mentioning that even the Earth is way smoother than most people realize.  The distance between the top of Mount Everest and the bottom of the Marianas Trench is less, as compared to its size, than the topographic relief in a typical scratch on a billiard ball.)

So far, so good.  But it was the next thing Dr. Whitmire told us that should have made me pull up short, and didn't until now -- forty years later.  He said that as a neutron star forms, the inward collapse makes its rotational speed increase, just like a spinning figure skater as she pulls in her arms.  Because of the Conservation of Angular Momentum, this bumps up the rotation of a neutron star to something on the order of making a complete rotation thirty times per second.  A point on the surface of a typical neutron star is moving at a linear speed of about one-third of the speed of light.

Further, because neutron stars have a phenomenally large magnetic field, this creates two magnetic "funnels" on opposite sides of the star that spew out jets of electromagnetic radiation.  And if these jets aren't aligned with the star's spin axis, they whirl around like the beams of a lighthouse.  A neutron star that does this, and appears to flash on and off like a strobe light, is called a pulsar.

This was the point when the red flags should have started waving, especially since I majored in physics and had taken a class called "Electromagnetism."  One of the first things we learned is that Scottish physicist James Clerk Maxwell discovered that magnetic fields are generated when charged particles move.  So how can a neutron star -- composed of electrically-neutral particles -- have any magnetic field at all, much less one so huge?  (The magnetic field of a typical neutron star is on the order of ten million Tesla; by comparison, one of the largest magnetic fields ever generated in the laboratory is a paltry sixteen Tesla, but was still enough to levitate a frog.)

The answer is a matter of conjecture.  One possibility is that even though a neutron star is neutral overall, there is some separation of charges within the star's interior, so the whirling of the star still creates a magnetic field.  Another possibility is that since neutrons themselves are composed of three quarks, and those quarks are charged, neutrons still have a magnetic moment, and the alignment of these magnetic moments coupled with the star's rotation is sufficient to give it an overall enormous magnetic field.  (If you want to read more about the answer to this curious question, the site Medium did a nice overview of it a while back.)

So it turns out that neutron stars aren't the simple things they appeared to be at first.  Not that this is much of a surprise -- seems like every time we answer one question in science, it generates three new ones.  What brought this up in the first place was yet another anomalous observation about neutron stars, described in a series of papers this past week in Astrophysical Journal Letters.  The conventional wisdom was that a neutron star's magnetic field would be oriented along an axis (which, as noted above, may not coincide perfectly with the star's spin axis).  This means that it would behave a bit like an ordinary magnet, with a north pole and a south pole on geometrically opposite sides.

That's what astronomers thought, until they found a pulsar with the euphonious name J0030+0451, 1,100 light years away in the constellation of Pisces.  Using the x-ray jets from the pulsar -- which should be aligned with its magnetic field -- they mapped the field itself, and found something extremely strange.

Instead of two jets, aligned with the poles of the magnetic field, J0030+0451 has three -- and they're all in the southern hemisphere.  One is (unsurprisingly) at the southern magnetic pole,  but the other two are elongated crescents at about sixty degrees south latitude.

To say this is surprising is an understatement, and the astronomers are still struggling to explain it.

"From its perch on the space station, NICER [the Neutron star Interior Composition Explorer] is revolutionizing our understanding of pulsars," said Paul Hertz, astrophysics division director at NASA Headquarters in Washington.  "Pulsars were discovered more than fifty years ago as beacons of stars that have collapsed into dense cores, behaving unlike anything we see on Earth."

It appears that we still have a way to go to fully explain how they work.  But that's how it is with the entire universe, you know?  No matter where we look, we're confronted by mysteries.  Fortunately, we have a tool that has proven over and over to be the best way of finding answers -- the collection of protocols we call the scientific method.  I  have no doubt that the astrophysicists will eventually explain the odd magnetic properties of pulsars.  But the way things go, all that'll do is open up more fascinating questions -- which is why if you're interested in science, you'll never run out of things to learn.

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This week's Skeptophilia book recommendation is pure fun, and a perfect holiday gift for anyone you know who (1) is a science buff, and (2) has a sense of humor.  What If?, by Randall Munroe (creator of the brilliant comic strip xkcd) gives scientifically-sound answers to some very interesting hypothetical questions.  What if everyone aimed a laser pointer simultaneously at the same spot on the Moon?  Could you make a jetpack using a bunch of downward-pointing machine guns?  What would happen if everyone on the Earth jumped simultaneously?

Munroe's answers make for fascinating, and often hilarious, reading.  His scientific acumen, which shines through in xkcd, is on full display here, as is his sharp-edged and absurd sense of humor.  It's great reading for anyone who has sat up at night wondering... "what if?"

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

The origin of Antarctican

Here's a bit of writing that should be familiar to most of you.

Fæder ure þu þe eart on heofonum; Si þin nama gehalgod to becume þin rice gewurþe ðin willa on eorðan swa swa on heofonum.  Urne gedæghwamlican hlaf syle us todæg, and forgyf us ure gyltas swa swa we forgyfað urum gyltendum; and ne gelæd þu us on costnunge ac alys us of yfele soþlice.

Recognize it?

It's the Lord's Prayer in English as it was spoken only a thousand years ago.  My guess is a lot of you had no idea what it was (although I have a number of regular readers who, like me, are aficionados of obscure languages; y'all don't count).  There are a few words that haven't changed in that time -- in this passage, only "us" and "and" -- but most have changed dramatically.  There are even a couple of letters that don't exist in Modern English, strikingly ð (pronounced like the first consonant in there) and þ (the first consonant in thin), both of which are written as "th" in Modern English.

Languages change, and they change at different rates.  Old Norse and Modern Icelandic are really more like different dialects of the same language than they are like different languages, even though just as much time has passed between Old Norse and Modern Icelandic as between Old English and Modern English.  There are sometimes sudden jumps -- the Norman Conquest in the 11th century and the Great Vowel Shift in the 15th are the two best-known examples from English, although the Viking Invasions of the 9th and 10th centuries had a significant effect, too, not only on vocabulary and pronunciation, but on place names.  (The subject of my master's thesis was how the Vikings affected Old English and Old Gaelic, which should win an award for research with no practical applications whatsoever.)

[Image licensed under the Creative Commons M. Adiputra, Globe of language, CC BY-SA 3.0]

These huge leaps are uncommon, however, and most language change progresses slowly and gradually.  The parallels to biological evolution are obvious, and the argument over whether language change is smooth or goes by fits-and-starts is just as silly as the corresponding argument over evolutionary gradualism vs. punctuated equilibrium.  It's not that one is the correct model and the other is not; both are correct, just in different circumstances.

The big jumps, of course, are easier to detect.  The effects of the Norman Invasions of England were profound, as words were adopted from French and then bent to conform to English phonological rules.  It's why we have so many pairs of words for food, one for its living farmyard state and the other for when it's on the table.  Cow/beef; sheep/mutton; pig/pork; chicken/poultry; calf/veal.  In each case, the first is from Old English (because the lower socioeconomic class Anglo-Saxons were the ones on the farm raising the animals) and the other from French (because their Norman overlords only saw the animal after being cooked).

But the similarity between language evolution and biological evolution runs a lot deeper than its pace.  Like evolutionary change in populations, language "speciation" not only needs small changes (corresponding to genetic mutations), selection (some forms succeeding and others disappearing), and some form of isolation.  Isolated populations take off on their own paths, often very different from the parent population, and because of the small number of individuals often do so more quickly than a large group would -- a sort of linguistic genetic drift.  (A good example is the Cornish language, which branched off from Welsh as a dialect in Roman times; by the 13th century, when the earliest extant examples of Cornish were written down, the two had evolved into two no longer mutually intelligible languages.)

This topic comes up because of some recent amazingly cool research by Jonathan Harrington, Michele Gubian, Mary Stevens, and Florian Schiel of the University of Munich, in which linguists have -- perhaps for the first time -- seen the beginnings of a dialect forming as it happens.  In "Phonetic Change in an Antarctic Winter," published last month in the Journal of the Acoustical Society of America, we find out about a study of the people who were isolated at the field station of the British Antarctic Survey during the long, frigid Antarctic winter, and about whom the researchers found something astonishing.

They started with a variety of accents, coming as they did from different English-speaking regions, but over the six months they were isolated, their accents began to converge into a distinct way of speaking unlike any of the "parent" accents.  Vowel sounds, especially, merged.  As an example, some of the speakers started out pronouncing the vowel sound in the word food as a front vowel (this is more common in British English), whereas others used a back vowel (more common in American English).  After only six months, the two sounds had converged, and everyone pronounced the sound as a middle vowel about halfway between the two extremes.

The authors write:

An acoustic analysis was made of the speech characteristics of individuals recorded before and during a prolonged stay in Antarctica.  A computational model was used to predict the expected changes due to close contact and isolation, which were then compared with the actual recorded productions.  The individuals were found to develop the first stages of a common accent in Antarctica whose phonetic characteristics were in some respects predicted by the computational model.  These findings suggest that the phonetic attributes of a spoken accent in its initial stages emerge through interactions between individuals causing speech production to be incrementally updated.

Of course, since the field station isn't permanently occupied by the same people, it's pretty likely that when the eleven test subjects went back to their homes (eight from various regions of England, one from the United States, and the other two -- who were not native speakers -- to Iceland and Germany) their accent reverted to the pronunciations typical for their milieu.

But it does give us a lens into how dialects form in other less contrived situations, and you can easily see how -- given enough time -- you might end up with modes of speaking so different that they would no longer be mutually intelligible.

Even, perhaps, to the point that "Fæder ure þu þe eart on heofonum" becomes "Our Father, who art in heaven."

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This week's Skeptophilia book of the week is brand new; Brian Clegg's wonderful Dark Matter and Dark Energy: The Hidden 95% of the Universe.  In this book, Clegg outlines "the biggest puzzle science has ever faced" -- the evidence for the substances that provide the majority of the gravitational force holding the nearby universe together, while simultaneously making the universe as a whole fly apart -- and which has (thus far) completely resisted all attempts to ascertain its nature.

Clegg also gives us some of the cutting-edge explanations physicists are now proposing, and the experiments that are being done to test them.  The science is sure to change quickly -- every week we seem to hear about new data providing information on the dark 95% of what's around us -- but if you want the most recently-crafted lens on the subject, this is it.

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

A fight over dates

One of the most frustrating things about science, from the point of view of non-scientists, is that sometimes we have to say "we simply don't know the answer to that yet."

Of course, I'm sure it's frustrating enough to the scientists as well, but at least they should be used to it.  Science is always pushing at the boundaries of what we know, and using evidence and logic to find explanations.  It's inevitable that sometimes even a significant amount of evidence is insufficient to reach a conclusion.  At that point, the only honest thing to say is "we don't know, and may never know."

This drives a lot of people nuts.  The attitude is that because science has proven to be pretty damn good at finding answers, that it should have a 100% hit rate.  Meteorologists can't always accurately predict the track or intensity of storms?  Ha, I'd like to have a job where I could be wrong half the time and still get paid!  The promising new cancer drug turns out not to work in vivo?  Don't listen to the medical professionals, they'll say something is good for you today and then say the opposite tomorrow.  This fault is at risk of an imminent earthquake?  Okay, then tell me when, down to the hour and minute, so I can plan ahead.

Otherwise, what good are you scientists, anyhow?

It all comes from a fundamental misapprehension of the scientific process -- that it should provide certainty.  It'd be nice, but the real world usually doesn't cooperate, and sometimes even with their best efforts, the scientists have to admit befuddlement.

I ran into an especially good example of that a couple of days ago because of a dear friend, a history scholar and loyal reader of Skeptophilia, who asked me if I'd ever heard of Hueyatlaco and the Steen-McIntyre report.  She sent me a link from the rather loopy site s8int called "Details of the Steen-McIntyre Hueyatlaco Coverup" that (despite their seeming bent toward Ancient Astronauts explanations of things) gives the basics of the story -- and it's a pretty peculiar one, even when you don't credit any of the woo-woo trappings.

Now, keep in mind that until two days ago I'd never heard of this, so I still consider my own knowledge shallow and tentative, and I ask forgiveness for any mistakes or misapprehensions I have (and request a quick note if there's something in this post I can correct).  But this is what I've gathered.

Hueyatlaco is an archaeological dig site in the state of Puebla in central Mexico.  In the 1960s, an archaeologist named Cynthia Irwin-Williams was working at the site and uncovered stone tools and the bones of pre-glacial North American mammals (such as the woolly rhinoceros) that showed signs of having been butchered for meat.  Williams thought that such an early site deserved close attention, and she sent samples to the USGS for radioisotope dating.

The results were more than a little perplexing.  The date returned by the USGS was on the order of 250,000 years ago.  This predates modern Homo sapiens by a good fifty thousand years, so -- if the date was accurate -- the tools and the animal bones were associated not with modern humans, but with our predecessors, possibly the Neanderthals or Denisovans.  Also perplexing was that this would push back the earliest hominid occupation of North America not just by a little, but by a factor of sixteen!

It's understandable why the scientists found that hard to swallow.  The idea that humans (or their near relatives) had been in the Americas for 230-odd-thousand years longer than we thought they had, and had left no traces whatsoever during that time except at this one site, was difficult to believe.  So the natural conclusion was reached that the dating of the site was somehow askew.

Then repeated attempts kept giving the same age.

Hueyatlaco [Image licensed under the Creative Commons https://www.flickr.com/photos/xhumpty/, Valsequillo dam, CC BY-SA 2.0]

Most archaeologists stuck to their guns, and said the most parsimonious explanation was still that somehow the dating protocol was being applied incorrectly.  The samples were contaminated with older rocks, perhaps, which would give a systematic overestimate for the site's age.  Then, to muddy the waters further, there were allegations of a conspiracy to cover up the anomalous data.  The official report from the USGS simply dropped one of the zeroes, reporting the site's age as 25,000, not 250,000 years.  One of the archaeologists who'd been working on the site, Virginia Steen-McIntyre, was pressured to do her dissertation not on the perplexing Hueyatlaco data, but on more conventional research into volcanic ash strata.  Steen-McIntyre decided, however, that she wouldn't be silenced, and came out with a report of her own, taking apart the critics a point at a time -- and included a claim that she was harassed for being unwilling to stay silent.

Other scientists have tried (and failed) to resolve the odd data.  Biostratigrapher Sam Vanlandingham published two papers, in 2001 and 2004, first reconfirming the dating of the strata to not tens, but hundreds of thousands of years ago, and then (most startling of all) confirming this using microfossils of diatoms from contemporaneous sediments at the site -- and demonstrating that those diatom species had been extinct for at least eighty thousand years.

The upshot of it all is that we still don't have an answer.  Most archaeologists still doubt the existence of hominids in the Americas prior to the arrival of the ancestors of the Native Americans on the order of (at the most) twenty thousand years ago, and assert that there is not a single grain of evidence that the Neanderthals and Denisovans (or any other hominds, for that matter) ever made it to the Western Hemisphere.  But that leaves us with a puzzle -- multiple studies, cross-checked and confirmed, keep agreeing with the older date as found by Irwin-Williams, Steen-McIntyre, and others.

So if you've been waiting for an answer... well, that's it, folks.  We don't know.  It's one of the most curious archaeological puzzles I've ever run across, and at this point, the words I hear about it most often from reliable sources are "contentious" and "uncertain" and "controversial."  A lot of experts have a lot of opinions about it, but no one has been able to do either of two things -- explain how the dates could be correct when there's no evidence of hominids in the Americas at any time during the next two hundred thousand years, or explain how the dates could be incorrect when they've been independently corroborated multiple times.

As frustrating as it is, that's where we have to leave it if we're going to be scrupulously honest about things.  As good skeptics, we have to be willing to leave the question in abeyance, indefinitely if need be, for want of conclusive evidence to settle it.  In science, the answer "We don't know yet" is always the fallback when the data is insufficient to merit a conclusion -- however that offends our deep desire to be a hundred percent sure about everything in the universe.

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

This week's Skeptophilia book of the week is brand new; Brian Clegg's wonderful Dark Matter and Dark Energy: The Hidden 95% of the Universe.  In this book, Clegg outlines "the biggest puzzle science has ever faced" -- the evidence for the substances that provide the majority of the gravitational force holding the nearby universe together, while simultaneously making the universe as a whole fly apart -- and which has (thus far) completely resisted all attempts to ascertain its nature.

Clegg also gives us some of the cutting-edge explanations physicists are now proposing, and the experiments that are being done to test them.  The science is sure to change quickly -- every week we seem to hear about new data providing information on the dark 95% of what's around us -- but if you want the most recently-crafted lens on the subject, this is it.

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

The family tree

One of the things I find endlessly fascinating about evolution is that we can use information we have in the present to infer what happened in the (very) distant past.

And I'm not even talking about fossils, here, as interesting as they are.  As Richard Dawkins points out, even if the entire fossil record ceased to exist, the evidence for evolution would still be overwhelming.  What I'm thinking about is the use of DNA to determine relationships between current species, and from that theorize about when their most recent common ancestor lived, and even what it might have looked like.

This comes up because of a recent paper in Nature that analyzed the genomes of over a thousand different species of plants and algae to construct the most detailed and accurate cladogram (which you can think of as a family tree) of the entire kingdom that has ever been created.  There are an estimated 500,000 species of plants currently in existence, so while this is still using a partial data set, it's pretty damned impressive.

"Some species began to emerge and evolve several hundreds of millions of years ago," said plant physiologist Professor Marcel Quint from the Institute of Agricultural and Nutritional Sciences at Martin Luther University Halle-Wittenberg, in an interview with Science Daily.  "However, today we have the tools to look back and see what happened at that time...   Some of these gene families have duplicated over the course of millions of years.  This process might have been a catalyst for the evolution of plants.  Having significantly more genetic material might unleash new capacities and completely new characteristics."

The results, as you might expect, provided a few surprises.  "We used to think that the greatest genetic expansion had occurred during the transition to flowering plants," said Martin Porsch, also from MLU-Halle-Wittenberg.  "After all, this group contains the majority of existing plant species today.  However, the new data reveal that the genetic foundations for this expansion in biodiversity had been laid much earlier.  The transition from aquatic to terrestrial plants was the starting point for all further genetic developments.  This development was the greatest challenge for plants, and so they needed more genetic innovations than ever before."

"We found an enormous increase in genetic diversity at the time of this transition, after that it reached a plateau," added Ivo Grosse, bioinformatician at MLU-Halle-Wittenberg, who co-authored the paper.  "From this time on, almost all of the genetic material was available to drive evolutionary progress and generate the biodiversity we see today."

So without further ado, here's their cladogram:

It confirmed something that I found fascinating when I first heard about it, back in the early 2000s -- that the division of flowering plants into "monocots" and "dicots" -- familiar to every high school biology student -- needed to be revisited, because "dicot" isn't a monophyletic clade -- all descended from a single ancestor that includes no other descendants.  It was found that the peculiar New Zealand species Amborella was technically a dicot (networked leaf veins, flower parts in fours or fives, two seed leaves) but was far more distantly related to other dicots than monocots (such as grasses, lilies, palms, and so on) were.

Amborella trichopoda [Image licensed under the Creative Commons Scott Zona from USA (original upload author), Amborella trichopoda (3065968016) fragment, CC BY 2.0]

When it was later found that the same was true of water lilies, it clued the geneticists in that there was something seriously amiss with our understanding of the family tree of plants.

So the new cladogram supports the older research, putting Amborella, water lilies, lotuses, and star anise as outgroups within the entire phylum of flowering plants; a self-contained clade with all the monocots next; and the rest of the dicots scattered along the remainder of the tree.

I know I'm a science nerd, and a little over-enthusiastic about genetics sometimes, but I think this research is amazingly cool.  The idea that we could look at a plant's DNA, here in 2019, and infer its relationship with other species from which it branched off hundreds of millions of years ago, is boggling.  It makes me wonder what other surprises are out there in the DNA of the nine-million-odd species of life on Earth -- and also realize that when it comes to understanding the other denizens with which we share the planet, we've only barely begun.

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

This week's Skeptophilia book of the week is brand new; Brian Clegg's wonderful Dark Matter and Dark Energy: The Hidden 95% of the Universe.  In this book, Clegg outlines "the biggest puzzle science has ever faced" -- the evidence for the substances that provide the majority of the gravitational force holding the nearby universe together, while simultaneously making the universe as a whole fly apart -- and which has (thus far) completely resisted all attempts to ascertain its nature.

Clegg also gives us some of the cutting-edge explanations physicists are now proposing, and the experiments that are being done to test them.  The science is sure to change quickly -- every week we seem to hear about new data providing information on the dark 95% of what's around us -- but if you want the most recently-crafted lens on the subject, this is it.

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