Skeptophilia (skep-to-fil-i-a) (n.) - the love of logical thought, skepticism, and thinking critically. Being an exploration of the applications of skeptical thinking to the world at large, with periodic excursions into linguistics, music, politics, cryptozoology, and why people keep seeing the face of Jesus on grilled cheese sandwiches.

Wednesday, January 5, 2022

Floral invaders

I used to ask a question to my biology classes, during the unit on ecology: what are the only two commonly-eaten fruits that are native to North America?

Some of the most frequent wrong answers -- and where those plants are actually native:

  • Apples ("American as apple pie," right?)  Nope, native to Europe, brought over in the early seventeenth century by the French settlers of eastern Canada and now naturalized across the continent.
  • Peaches, apricots, and pears -- native to central Asia.
  • Plums -- native to China (although there are a few wild North American plum varieties, they're not the ones you ever see in the grocery store).
  • Kiwi fruit -- native to east Asia.
  • Cherries, strawberries, blackberries, and raspberries -- native to Europe.
  • Citrus fruits -- native to southern Asia and Australia.
  • Pineapples -- native to South America.
  • Bananas -- native to southeast Asia, Papua-New Guinea, and Australia.

Some students -- knowing their botany -- thought I was being tricky and had in mind plants whose product are fruits in the botanical sense, but not to be found in the fruit section of the grocery store, like cucumbers (south Asia) and tomatoes (Central and South America), but no.

The only two commonly-consumed fruits that are native to North America are blueberries and cranberries.  (Squash is also an example, if you count introductions that preceded European colonization; they were widely used by Indigenous Americans, but even they originally came from Mexico and Central America.)

It might be especially hard to believe this apropos especially of blackberries and raspberries, which have gone wild and in many places (like my back yard) form nearly impenetrable thorny thickets of vines.  We have the birds to thank for this; birds consume the berries and then carry the seeds far and wide, a dispersal strategy that is effective enough that both species are now found in every state in the continental United States and every province of Canada.

[Image is in the Public Domain]

Well, so what?  Why does this matter?  The problem is the degree to which non-native (or exotic) species have infiltrated ecosystems -- and changed them.  I could just as well used garden flowers as my example group, but most high school students know fruits way better than flowers.  And I'm ignoring what might be the single most common group of exotic plants in the United States, so ubiquitous that we hardly even think about them; the various common species of lawn grasses.

There are two commonly-cited problems with non-natives. Certainly the best known is that when exotic organisms take hold, they can outcompete and replace native species.  The most successful exotics are the ones that are ecological generalists, able to utilize a wide variety of resources and habitats, and those have especially taken hold in the disturbed ecosystems of cities; consider where you are most likely to find dandelions, burdock, pigeons, house sparrows, and rats, for example.  A second is the accidental introduction of pests that end up destroying native organisms -- three we're constantly fighting here in the northeastern United States are Japanese beetles, the spotted lanternfly, and the emerald ash borer.  (Once again, there's another example in this category you may not have thought about -- feral cats, which take a tremendous toll on native birds.  But I'm guessing the cat lovers in my readership won't appreciate my labeling cats as "exotic pests...")

A third, and less-explored, aspect of the transport of species into new regions is homogenization.  Enough new introductions, and previously diverse and unique ecosystems start looking very much alike.  This was the subject of a paper last week in Nature Communications by a team led by Qiang Yang of the University of Konstanz (Germany), detailing a way to quantify this loss of uniqueness.  

The authors write:

Regional species assemblages have been shaped by colonization, speciation and extinction over millions of years.  Humans have altered biogeography by introducing species to new ranges.  However, an analysis of how strongly naturalized plant species (i.e. alien plants that have established self-sustaining populations) affect the taxonomic and phylogenetic uniqueness of regional floras globally is still missing.  Here, we present such an analysis with data from native and naturalized alien floras in 658 regions around the world.  We find strong taxonomic and phylogenetic floristic homogenization overall, and that the natural decline in floristic similarity with increasing geographic distance is weakened by naturalized species.  Floristic homogenization increases with climatic similarity, which emphasizes the importance of climate matching in plant naturalization.  Moreover, floristic homogenization is greater between regions with current or past administrative relationships, indicating that being part of the same country as well as historical colonial ties facilitate floristic exchange, most likely due to more intensive trade and transport between such regions.  Our findings show that naturalization of alien plants threatens taxonomic and phylogenetic uniqueness of regional floras globally.  Unless more effective biosecurity measures are implemented, it is likely that with ongoing globalization, even the most distant regions will lose their floristic uniqueness.

The problem is, halting this trend is going to be tough.  In a lot of ways, that ship has already sailed.  We can act on local scales -- like my wife's and my effort to convert a section of our property into a native wildflower meadow -- but there has already been too much pot-stirring to have a chance of separating the mixture back to its original configuration of ingredients.  It may be that the best we can do is to mitigate the damage to the extent we can; replacing lawn, choosing to plant natives, removing unwanted exotics when you find them -- and keeping your cats indoors. 

And, of course, remember the somewhat encouraging truth that even introduced species can eventually come into equilibrium with the natives.  European Starlings, introduced into North America in the late nineteenth century, had multiplied into such enormous numbers that in many regions they were the most common bird around, but in the last fifty years have declined to more reasonable (and stable) numbers.  (The only scary thing about this is that we don't have a clear idea of why they've declined -- by some estimates, to fifty percent of the total population in 1970 -- and scarier still, there's been a commensurate decline in native species during the same time frame.)

But the harsh fact is that we've already made irreparable changes to the world's ecosystems, and that's not going to stop any time soon.  The important thing now is to learn from past mistakes -- and do what we can to protect what's still left of our beautiful and unique biodiversity.

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

One of my favorite writers is the inimitable Mary Roach, who has blended her insatiable curiosity, her knowledge of science, and her wonderfully irreverent sense of humor into books like Stiff (about death), Bonk (about sex), Spook (about beliefs in the afterlife), and Packing for Mars (about what we'd need to prepare for if we made a long space journey and/or tried to colonize another planet).  Her most recent book, Fuzz: When Nature Breaks the Law, is another brilliant look at a feature of humanity's place in the natural world -- this time, what happens when humans and other species come into conflict.

Roach looks at how we deal with garbage-raiding bears, moose wandering the roads, voracious gulls and rats, and the potentially dangerous troops of monkeys that regularly run into humans in many places in the tropics -- and how, even with our superior brains, we often find ourselves on the losing end of the battle.

Mary Roach's style makes for wonderfully fun reading, and this is no exception.  If you're interested in our role in the natural world, love to find out more about animals, or just want a good laugh -- put Fuzz on your to-read list.  You won't be disappointed.

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


Tuesday, January 4, 2022

Virtue signaling

Well, I once again broke the Cardinal Rule of the Internet, namely: don't argue online with strangers.

This time, the source of the argument was the one and only television show I really obsess over, which is Doctor Who.  On Saturday, we watched the eagerly-awaited New Year's special, "Eve of the Daleks," and (IMHO) it was fantastic, easily one of the best in the last three seasons.

It was not only a nifty story with some really funny moments (especially from the character of Sarah, played with deft wit by the Irish comedienne Aisling Bea as the weary, snarky owner of the self-storage facility where the entire episode takes place), but it featured a revelation that got the fan base buzzing.  About 2/3 of the way through, we find out that the Doctor's companion Yaz (played by Mandip Gill) has fallen in love with the Doctor (currently in a female incarnation, played by Jodie Whittaker).  The scene is sweet and subtle, and Mandip Gill does a beautiful job expressing the painful difficulty many LGBTQ people have in admitting who they are (as Yaz says, even to herself).

While it was a wonderful scene, to many Who fans it was hardly a surprise; there have been clues throughout the last two seasons that Yaz was falling for the Doctor.  Having it confirmed, however, was nice, and for queer fans of Who (myself very much included) it was a welcome sign of acceptance and representation of LGBTQ identity.

But then the backlash started.

I'm sure you can imagine it, so I'll only give you a handful of examples:

  • Of course Chibs [showrunner Chris Chibnall] had to take the opportunity to ram his woke agenda down our throats.  I don't know why we can't just have a good story for a change.
  • Oh, god, here we go with the fucking virtue signaling.  The characters have to tell us what we should think, feel, and approve of.
  • If Yaz and the Doctor kiss, I'm done.

My responses were pretty much what you'd expect, and their responses to my responses also pretty much what you'd expect.  Nothing much accomplished, but I've been stewing about it ever since, so I thought I'd write about it here.

What gets me is it's gotten to be that any time some bigot sees something in a movie, television show, or book that pushes the cultural envelope, it's labeled as "virtue signaling" or "wokeness," and forthwith dismissed as a manipulative attempt by the writer to force an agenda.  They seem to see no difference between LGBTQ people and minorities appearing in a work of fiction, and a deliberate attempt to push an opinion -- as if merely being visible is an affront to their sensibilities.

I've run into this repeatedly myself, as an author.  I have been asked more than once why the characters of Dr. Will Daigle (in Whistling in the Dark and Fear No Colors) and Judy Kahn (in Signal to Noise) were written as LGBTQ.  I used to answer this question by going into how I create characters, but I finally ran out of patience -- now my tendency is to snap back, "Because queer people exist," and then watch the person squirm (which, at least, most of them have enough self-awareness to do).  Not once have I ever been asked why (for example) I made the character of Seth Augustine (in The Snowe Agency Mysteries) 100% straight.

Straight, apparently, is the default, and anything else is due to the author trying to make a point about how virtuous and woke (s)he is.

This is reminiscent of the furor that surrounded the choice of actress Jodie Turner-Smith (who is Black) to play the lead role in Channel 5's miniseries Anne Boleyn.  It wasn't historically accurate, people said; the real Boleyn was (of course) a White Englishwoman.  Conservative commentator Candace Owens, who never can resist an opportunity to throw gasoline on a fire, said that she had no problem with a Black Anne Boleyn "so long as the radical left promises to keep their mouth shut if in the future Henry Caville [sic] is selected to play Barack Obama and Rachel McAdams can play Michelle."

Which isn't just tone-deaf, it's a false equivalence ignoring the fact that for decades -- in fact, since the beginnings of cinematic history -- filmmakers have been doing exactly that.  Take, for example, the evil Chinese mastermind Fu Manchu, who has been played in movies and television by a long list of actors -- Christopher Lee, Boris Karloff, Warner Oland, Harry Agar Lyons, Henry Brandon, and John Carradine, to name a few.  Notice anything about this list?

Not one of them is Chinese.  In fact, Fu Manchu has never been played by a Chinese actor.

John Wayne played Genghis Khan in The Conqueror.  Yul Brynner played King Mongkut of Thailand in The King and I.  Laurence Olivier played Othello in the 1965 movie adaptation of the play.  It's not a thing of the distant past, however.  In 2007 Angelina Jolie played (real-life) Afro-Cuban journalist Mariane Pearl in A Mighty Heart.  Johnny Depp played Tonto in the 2013 movie The Lone Ranger -- although the character of Tonto isn't exactly a realistic portrayal of Native Americans anyhow, so maybe that one shouldn't count.  Worse, in 2016 White actor Joseph Fiennes played Michael Jackson in the movie Elizabeth, Michael, and Marlon.  Going back to Doctor Who, there's the 1977 episode "The Talons of Weng Chiang," which is not a bad story at its core but is rendered unwatchably cringe-y by White actor John Bennett's attempt to portray the Chinese bad guy Li H'sen Chang, and a script that bought into every one of the ugly "sinister Asian devils" stereotypes in existence.

What about the recent turning of the tables?  Could it be that some of the inclusion and representation, and some of the casting choices, were made as a deliberate attempt to prove a point?  I guess, but then you'd have to demonstrate to me how you knew what the intentions of the writers are.  If you don't know the writers made those decisions based upon a desire to appear "woke," then it's hard to see how you'd distinguish that from simply representing the diversity of people out there.  Or, in the case of Turner-Smith's portrayal of Anne Boleyn, that she was the best actress for the role.

But back to Yaz, the Thirteenth Doctor, and "Eve of the Daleks."  I've yet to hear anyone come up with a cogent reason why Yaz shouldn't be a lesbian.  And as far as Chris Chibnall's alleged attempt to force a "woke agenda" on us, allow me to point out that Doctor Who has been at the forefront of representation pretty much since the beginning of the modern era in 2005, with people of color playing major roles (to name only two of many examples, Freema Agyeman as companion Dr. Martha Jones, and Pearl Mackie as companion Bill Potts -- who was also queer).  The character of Captain Jack Harkness (played by John Barrowman) gave new meaning to "pansexual" by flirting with anyone and everyone, ultimately falling hard -- and tragically -- for a Welshman named Ianto Jones.  My favorite example, though, is the relationship -- not only queer but inter-species -- between the inimitable Silurian Vastra (Neve McIntosh) and her badass partner Jenny Flint (Catrin Stewart).

So if you don't like representation, stop watching the fucking show.  Because it's here to stay -- as it should be.

And I, for one, will cheer loudly if Yaz kisses the Doctor.  High time that happened.

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

One of my favorite writers is the inimitable Mary Roach, who has blended her insatiable curiosity, her knowledge of science, and her wonderfully irreverent sense of humor into books like Stiff (about death), Bonk (about sex), Spook (about beliefs in the afterlife), and Packing for Mars (about what we'd need to prepare for if we made a long space journey and/or tried to colonize another planet).  Her most recent book, Fuzz: When Nature Breaks the Law, is another brilliant look at a feature of humanity's place in the natural world -- this time, what happens when humans and other species come into conflict.

Roach looks at how we deal with garbage-raiding bears, moose wandering the roads, voracious gulls and rats, and the potentially dangerous troops of monkeys that regularly run into humans in many places in the tropics -- and how, even with our superior brains, we often find ourselves on the losing end of the battle.

Mary Roach's style makes for wonderfully fun reading, and this is no exception.  If you're interested in our role in the natural world, love to find out more about animals, or just want a good laugh -- put Fuzz on your to-read list.  You won't be disappointed.

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


Monday, January 3, 2022

The origin of venom

We're all aware of animals with venomous bites -- most of the familiar ones being either snakes or spiders.  It's an interesting topic, but before we begin, let's get our definitions straight, as summed up in this online conversation that has since gone viral (deservedly):


There are a lot of animals that are venomous which are neither snakes nor spiders, however.  There are mollusks like the blue-ringed octopus and the deadly cone snails of the south Pacific, many jellyfish (including the phenomenally venomous box jellies, most common in the waters off the east coast of Australia), scorpions, a few lizards (like the gila monster), and even mammals like the bizarre solenodons, which look like scaled-down versions of the Rodents Of Unusual Size from The Princess Bride.

[Image licensed under the Creative Commons Seb az86556, Hispaniolan Solenodon crop, CC BY-SA 3.0]

In fact, it's the mammalian venomous animals, including not only solenodons but various shrews and the oddball primate called the slow loris, that bring the topic up today.  A paper appeared last week in BMC Biology, about some research out of the University of Okinawa supporting the startling conclusion that the noxious proteins in the saliva of venomous mammals are structurally related to the proteins that serve the same function in hemotoxic snakes like rattlesnakes, vipers, and adders.

On first glance, this may not seem that odd, but consider what it means.  Saying the venom proteins have the same function is not the same as saying they have the same structure.  If the proteins have the same structure, it means that the genes that produced them do as well.  And if that's the case, chances are, those genes share a common ancestor -- and then descended (albeit with modifications) through the ensuing three hundred million years since the lineages that led to today's venomous snakes and mammals split.

Venoms in these animals are complex mixtures of chemicals, but both rattlesnakes and solenodons (for example) have venom containing a class of complex proteins called kallikrein serine proteases.  These are protein-degrading enzymes that in many animals have a function in regulating blood pressure -- accounting for the localized tissue breakdown and drop in blood pressure you see in the victim of a rattlesnake bite.

What's curious -- and what touched off this particular piece of research -- is that all mammals, ourselves included, have small amounts of kallikrein serine proteases in the saliva.  In us (and, in fact, in most mammals), they seem to serve no purpose -- they appear to be vestigial remnants from our ancestry.  But in the lineages that led to both venomous snakes and venomous mammals, they increased in concentration until they could be used, injected into a bite, to subdue and digest prey.

"In [last week's] paper, we hypothesized that in the ancestor of snakes and mammals, there was a common group of genes that had a toxic potential," said Agneesh Barua, who was the co-lead-author along with Ivan Koladurov.  "Snakes and mammals then took different evolutionary paths, with snake lineages evolving diverse and increasingly toxic concoctions, while in mammals, venom did evolve, but to a much lesser degree.  But what we wanted to know is whether the toxins within mammal and snake venom evolved from a common ancestral gene...  There are so many different serine proteases that have a high degree of similarity, that until now, it was too difficult to isolate the right genes needed to determine the evolutionary history.  [Our results are] really strong evidence for our hypothesis that venom evolved from a common group of genes in an ancestor that had a toxic potential.  But the most surprising thing was that non-toxic salivary kallikreins, like those found in humans and mice, also evolved from the same ancestral gene."

Yet another nail in the coffin of creationism, if you needed one.

What I find coolest about this is that it's a reminder of the unity of our biodiversity here on Earth -- that the tapestry of life was produced from threads with a common source, a couple of billion years ago.  And, best of all, that in looking at today's organisms, we can still see remnants of that common origin, even in pairs of species that look nothing alike.

I'll end with the prescient quote attributed to Chief Seattle, that seems more apt today given our knowledge from science than it did when he wrote it in 1854: 
This we know: the Earth does not belong to man, man belongs to the Earth.  All things are connected like the blood that unites us all.  Humankind has not woven the web of life.  We are but one strand within it.  Whatever we do to the web, we do to ourselves.  All things are bound together; all things connect.
*********************************

One of my favorite writers is the inimitable Mary Roach, who has blended her insatiable curiosity, her knowledge of science, and her wonderfully irreverent sense of humor into books like Stiff (about death), Bonk (about sex), Spook (about beliefs in the afterlife), and Packing for Mars (about what we'd need to prepare for if we made a long space journey and/or tried to colonize another planet).  Her most recent book, Fuzz: When Nature Breaks the Law, is another brilliant look at a feature of humanity's place in the natural world -- this time, what happens when humans and other species come into conflict.

Roach looks at how we deal with garbage-raiding bears, moose wandering the roads, voracious gulls and rats, and the potentially dangerous troops of monkeys that regularly run into humans in many places in the tropics -- and how, even with our superior brains, we often find ourselves on the losing end of the battle.

Mary Roach's style makes for wonderfully fun reading, and this is no exception.  If you're interested in our role in the natural world, love to find out more about animals, or just want a good laugh -- put Fuzz on your to-read list.  You won't be disappointed.

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


Saturday, January 1, 2022

The perimeter of ignorance

In the past week, I watched two things that were interesting in juxtaposition.

One of them came my way because for my holiday gift my wife got me a subscription to Master Class, which has hundreds of online video classes on everything from political science to cooking.  I signed up for and watched a series of lectures by the eminent astrophysicist Neil deGrasse Tyson, director of New York City's Hayden Planetarium, on the scientific endeavor and how to think effectively about science and how to talk about it to others.

In his class, Dr. Tyson says the following:
The frontier of discovery is a messy place.  You don't know what the next step is, sometimes you don't even know what question to ask.  As the area of our knowledge grows, so too does the perimeter of our ignorance.  It's thrilling and scary at the same time...  The scientific method is whatever it takes to not fool yourself into thinking something is true that is not, or into thinking something is not true that is.  That pathway, it's not straight; it's curved, it has off-ramps to nowhere, and you don't know which of the paths in front of you are going to lead to the right place...  The cool thing about it is that nature is the ultimate judge, jury, and executioner.  You can argue all you want, but if nature disagrees with you, you're wrong.  If you care about critical thinking and science literacy, the degree to which you believe something is true should be proportional to the evidence that supports it.  If after all the experiments are done, there is convergence in a result, you have successfully winnowed out the effects of bias on that result.  No one is without bias -- just be ready to get your stuff checked.  And be ready to abandon your cherished thoughts and ideas in the face of conflicting evidence.
The other is the trailer to a video called Gods Among Us that was sent to me by a friend who is evidently trying to cause my brain to explode.  Here are a sampling of quotes (you can watch the trailer yourself if you dare, and want to know more about the context and sources, but I can promise you these were not cherry-picked to make the video sound ridiculous -- they all sound like this):
  • There are quite a few extraterrestrials walking around, humanoid ones, so we've got them walking amongst us.  You may just think they look like nice people, or they may feel a bit different to you, but they're there and you see them every day. 
  • How is it that these higher-dimensional energies can be brought down, can be downloaded, into our ordinary four-dimensional space-time experience?
  • There are thousands, possibility millions, out there leading these double lives.  They will lead us into telepathic abilities, they will lead us into being able to heal ourselves, even to being able to change our bodies.
  • The DNA in us can exist as a toroid.  It can be used as a tool to bring higher-dimensional energy into our physical bodies, convert it into electromagnetic fields that can then be used to convert the physiological and biochemical processes in us.
  • I was contacted by a being who said he was from the constellation of Orion.
  • You want to know what your DNA is?  It's 34% human, 28% tall white Zeta, and 38% Annunaki.  
The people interviewed seemed to fall into three categories: (1) researchers, all of whom seem somehow to have earned Ph.D.s; (2) people who claim to have been contacted by aliens; (3) people who claim to be human/alien hybrids themselves.  The whole thing was accompanied by music that sounds like it was rejected from Music From the Hearts of Space on the basis of being too ethereal.

Okay, I'm scoffing, but there's a serious point to be made here.  A number of claims in Gods Among Us are empirically testable.  I'm not referring to the eyewitness testimony of things like alien contact; as Dr. Tyson also points out, eyewitness testimony may be the highest standard of evidence in the court of law, but it's the lowest form of evidence in science.  "I saw it with my own eyes" is simply not enough in science.  We have far too many ways of getting it wrong to trust one person's word for something.

But there are many other kinds of statement in this video that could be tested.  DNA can become a toroid that funnels energy from outside of us into our bodies and changes our biochemistry?  Fine, demonstrate it in the lab.  There are beings who can communicate with you telepathically?  Set up a situation where they tell you something you couldn't have otherwise known, and have it verified by an independent researcher.  Over half of our DNA is extraterrestrial?  Sequence it and show me that it doesn't overlap, gene for gene, with 99% of the DNA from our nearest primate relatives (and in the 70-80% range with all other mammal species).

Oh, and you can't "be from a constellation."  A constellation is a random assemblage of stars sitting at wildly varying distances from the Earth that only appear to be near each other from our perspective.  Saying you're "from a constellation" makes about as much sense as someone asking you how to find your house, and your answering them, "You'll find it on the horizon."

One example of how a constellation would look from an altered perspective; the Big Dipper as seen after a ninety-degree rotation around the entire group

However, the most insidious problem with the people who make claims like these is their belief that mainstream science rejects their conclusions out of hand not because there's insufficient evidence, but because the claims contradict scientific orthodoxy.  They seem to think that scientists are sitting in this never-changing edifice they've built, and they'll fight you tooth and nail if you try to change one thing about it.  Contrast this to Dr. Tyson's statement about the scientific frontier; in science, you are always on the boundary between what is known and what is unknown.  Scientific orthodoxy changes every time we get a new body of evidence, which is all the time.  In fact, that's how scientific careers are made.  If there really was evidence of all the stuff Gods Among Us claims, the scientists would be trampling each other to death to be the first to publish it in a peer-reviewed journal.

Consider, as only one of many illustrative examples, how the theory of plate tectonics arose.  The belief -- the "scientific orthodoxy," if you will -- was that the Earth was static.  The continents stayed put.  Even if there were periodic events like earthquakes and volcanoes to shake things up, everything was more or less in the same place as it always had been.

Why, in fact, would you think the opposite?  A static Earth seemed common sense.  How could continents move in solid rock?

But in the 50s and 60s, the evidence from a variety of sources -- where exactly volcanoes and earthquakes took place, the position and age of hotspot island chains like Hawaii, the contours of Africa and South America, the fossil record, and (most importantly) the evidence from magnetometer readings near the Mid-Atlantic Ridge -- had piled up to the extent that there was no choice but to overturn our understanding of how geology worked.  In other words, faced with hard, verifiable, repeatable scientific research, the "scientific orthodoxy" had to change drastically.  And far from being suppressed by the scientific establishment, this put rocket fuel into the careers of the first geologists who wrote a paper about it -- Frederick Vine and Drummond Matthews -- and today, they're in every introduction-to-geology textbook written.

So if there was demonstrable evidence that over 50% of our DNA came from a non-terrestrial source?  That's Nobel-Prize-material, right there.

Could the people in Gods Among Us be right?  I suppose so.  But thus far they have not met the minimum threshold of evidence that it would take to convince anyone who wasn't already convinced.  I'll end with a quote from another physicist, Richard Feynman, which seems particularly apposite here: "The first principle of science is that you must not fool yourself.  And you are the easiest person to fool."

 **********************************

Neil deGrasse Tyson has become deservedly famous for his efforts to bring the latest findings of astronomers and astrophysicists to laypeople.  Not only has he given hundreds of public talks on everything from the Big Bang to UFOs, a couple of years ago he launched (and hosted) an updated reboot of Carl Sagan's wildly successful 1980 series Cosmos.

He has also communicated his vision through his writing, and this week's Skeptophilia book-of-the-week is his 2019 Letters From an Astrophysicist.  A public figure like Tyson gets inundated with correspondence, and Tyson's drive to teach and inspire has impelled him to answer many of them personally (however arduous it may seem to those of us who struggle to keep up with a dozen emails!).  In Letters, he has selected 101 of his most intriguing pieces of correspondence, along with his answers to each -- in the process creating a book that is a testimony to his intelligence, his sense of humor, his passion as a scientist, and his commitment to inquiry.

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



Friday, December 31, 2021

Waves

For this week's Fiction Friday, a short story that was inspired by something that my son and a friend saw while walking along the Delaware River while they were students at Salem College in Carney's Point, New Jersey.  The description of what they saw is pretty much as it happened and was related to me.

The explanation of it, however, is pure fiction.

I hope.

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

Waves

October gloom hung low over the Delaware River, wisps of mist rising from the murky, oil-slicked water to vanish into the uniform gray of the clouds.  Nick Dominique and Brady Elkano tramped silently through the knee-high grass, boots making squelching noises in the muddy ground that sloped at an imperceptible angle down toward the river’s shore.

“Whose stupid fucking idea was it to come down here today?”  Brady pulled his scuffed khaki jacket around him and shivered.

“Yours,” Nick said.

“Well, I’m freezing my ass off.”

“It’s not that bad.”  Nick was tall and lanky, his bony limbs never quite covered by shirts and pants that always seemed too wide in the waist and too short in the arms and legs.  He ran fingers through unkempt curly brown hair.  “Better than playing computer games in the apartment all afternoon.”

“At least the apartment has heat.”  Brady was compact and sturdy and dark, and turned a wry eye on his friend.  “There’s nothing down here but trash anyway.”

“I dunno.  There’s the stuff from the military depot.  Jake Warshawski said he found some kind of old air pump.  It was half-buried in the mud, but he took it out and cleaned it up and he said it needed a few parts but looked like he could get it working.”

“What do you want with an air pump?”

Nick laughed.  “Dude.  You know what I mean.  There’s not gonna be another air pump.  I just mean, you never know what we might find.”

Brady shivered again.  “You should drop out of college and be a junk collector.”

By this time, they were at the river’s edge.  On the other side they could see the skyline of Wilmington, Delaware, vague and fogged and surreal, its perpetual noise and bustle and traffic deadened by distance and still air.  The water flowed smoothly, silently, only a few eddies showing turbulence as it flowed over unseen obstructions.  Nick picked up a rock from the mud and sent it skittering across the surface, leaving a trail of circular waves before disappearing with a plunk.

“I think my boots are leaking,” Brady said.  Nick ignored him, and picked up a stick to poke around in the ragged, brown stalks of dying grass.

“What are you looking for?” Brady said, after watching him for five minutes.

“I’ll know when I find it.”

Brady swore under his breath. “My boots are leaking.”

“Take ‘em off.”

“You are ridiculous.”  But both boys wandered along the shore, kicking at washed up garbage and branches, every once in a while leaning over to fish something interesting out of the saturated soil.  Nick found a gear wheel missing two teeth, rinsed the grime off of it in the river, and shook it dry.

“What’re you gonna do with that?”

“I don’t know yet.”

Upstream they came on a long concrete jetty, sticking out into the river like a finger.  On the upstream side the mud was thicker, and there were pieces of net, a chunk of a Styrofoam cooler, and an old wooden sign that had the words “Keep Out” painted on it in stenciled black letters.  Brady stepped up onto the jetty and walked the thirty or so feet until it began to look crumbled and unsafe, and stood there, looking out over the river.  Nick stayed nearer to shore, poking around in the mud, still looking for interesting finds that the current might have washed his way.

That was when he noticed something shiny.

It was a mere pinpoint, like a speck of glitter on the surface of the black, smelly ooze.  He was still holding a stick he’d found earlier, and he pushed at it, and it didn’t move.  He could feel that the speck was just the top bit of something large and solid, so he lay down on his belly on the rough cement surface of the jetty and reached his long fingers down into the frigid mud.

Whatever it was had a smooth surface, and it was stuck more firmly than he expected.  He pulled on it, and felt it give a little.  Then with a thick slurping sound, it came loose, and sat, dripping sulfur-smelling goo, in the palms of both hands.

He swiveled around and dunked it in the comparatively cleaner water on the other side of the jetty.  Now the whole thing showed itself to be a gleaming metal ring, about two inches wide and perhaps five across.  It was heavy, gold in color, and had an inscription around it that said:

AQUA * VITAE * EST *VITA * SAPIENTIAE * AQUA * MORTIS * EST * MORS * SAPIENTIAE

He stared at it, frowning.  Nick had taken a couple of years of Latin in high school, and he recognized the word for “water,” but the rest of it didn’t make much sense.  He thought vita meant “road,” but something about that didn’t sound right.

Honestly, at the time he was taking Latin, he’d been far more interested in hiking and climbing trees and learning to shoot a bow and arrow than in memorizing conjugations and declensions.

[Image is in the Public Domain]

He stood up, gripping the ring tightly, as if he were afraid it would escape from his hand.  “Hey!  Brady!  You gotta see what I found.”

His friend turned, his expression unreadable in the gloom.  Nick walked down the jetty, his long stride closing the distance quickly.

“What is it?” Brady said as Nick approached.  His voice sounded ready to be unimpressed.  “Something else for your trash collection?”

“No.  This is really cool.”  He held out the ring.

Brady’s dark eyebrows rose.  “Wow.”
 
“Told you.”

Brady took it, and peered at the writing that encircled the outside.  “What does that mean?”

“Beats the hell out of me.”

“Well, it’s interesting.  You think it could be some kind of Indian artifact or something?”

“Could be,” Nick said, but he sounded doubtful.  “Did the Indians around here cast stuff in gold?”

“You think that’s gold?”

“It’s heavy enough to be.  But it's got a Latin inscription.  I don't think the Indians would have written in Latin.”

Brady frowned, and handed it back.  “I wonder if we should, like, contact a museum or something.”

“Maybe.”  Nick held it up in the thin, gray light.  “I wonder what it was for?  It’s too big to be a bracelet.”

Brady shrugged, and looked out over the river again. Nick continued to stare at the metal ring, which is why he didn’t see what was happening until he heard Brady’s voice saying, “Nick, what the fuck is that?”

Nick peered past his friend, and at first thought he was looking at some sort of optical illusion, a trick of the odd, attenuated light or the rank mist that hung low over the water.  But it was unmistakable.  The river water had bubbled up, like there was some sort of disturbance underneath it, as if a giant head was about to surface.  Waves rolled off of it, making soft slushy noises and proceeding outward in all directions.  The boys stood still, watching.  Already the first and smallest ones were rocking against the tip of the jetty, splitting and turning down the sides until they dissipated against the mud.

“We should get out of here,” Brady said.

For once, Nick didn’t argue.  Brady shoved past him, taking off at a jog down the cement wall, Nick following him at a fast walk.  They reached shore in a few seconds, and Nick turned over his shoulder to look out over the river.  The disturbance was still there, like a dark, wet hill, churning waves now slopping against the shore.  But nothing else was visible of whatever it was that was causing it.

Brady kept at his jog all the way across the grassy meadow, and up toward the road where Nick’s truck, an aging Toyota pickup, was parked.  When they scrambled up the embankment, both boys turned back toward the river, but the low scrubby trees along the road obscured their view.

It wasn’t until they were both in the truck, the engine coughing into life, that Nick spoke.  “That was creepy.”

“No shit.”

“What do you think it was?”

“I have no idea.”

“Maybe a big fish or something.”  He pulled the truck out onto the road, and accelerated back toward town.

Brady gave Nick a scowl.  “A fish?  How big a fish would it have to be?”

“I dunno.  You got a better suggestion?”

“No.”

“Okay, then.”

They made the rest of the drive in silence.  Even Nick was happy to step back into the warmth of the house where he and Brady rented rooms, both leaving their mud-caked shoes on the front porch.

“I’m hitting the shower.”  Nick pulled off his jacket and threw it on the couch in the living room.

“Let me know when you’re done,” Brady said, plopping down in a rocking chair and turning on the television with a remote.  “I’m next.”

Nick trotted up the stairs, his sock-clad feet making little noise on the wooden steps, and went into the bathroom.  He shucked his damp, dirt-splotched clothes and turned on the shower, giving it a minute for the antiquated water heater to pump some warm water up to the second floor, then he stepped in.

The heat felt delicious on his skin, but he noticed something else almost immediately.  At first, he thought he was overhearing Brady downstairs listening to the television, but he quickly realized it couldn’t be that—there was no way it would be audible from this far away, not with the door closed and the water running.

But he heard a voice.  Thin, low, but clearly audible.

Where did you put it?  I can’t see it.  I can’t.  Where is it?  Where did you put it?

Over and over, a monotonous drone, repeating the same words over and over.  The voice had a strange, rolling accent, but he couldn’t place what sort.  It sounded antiquated and stilted and vaguely British, the sort of accent you might expect from a second-string actor in a Shakespearean play.

Nick stood there, the water cascading over his skin, his shower forgotten for a moment.  He frowned, listening, trying to figure out where the voice was coming from, but it seemed not to be localizable.  He turned the water off, hoping to hear it more clearly.

As soon as he did, the voice stopped.

Nick stood there in the shower, naked and dripping wet, his face a study in confusion.  After a moment, he turned the faucet on again.

The voice started again, as soon as the hot water hit his skin.

He hurried through the rest of his shower, then dried off and cinched the towel around his waist. He picked up his filthy clothes and walked back to his room, pitching them into the hamper.  There was a loud clunk as the pocket of his trousers hit the side of the hamper, and he reached in and pulled them out again, extracting the gleaming metal ring.

He stared at it for a moment, then set it on his dresser, and got out dry clothes and began to dress.

Where did you put it?  I can’t see it.

When he was fully dressed, he picked up the ring again, looked at the inscription, and then sat down at his computer.

Twenty minutes of messing about with Google Translate later, he had scrawled on a piece of scrap paper the words “Water Life Is Life Wisdom Water Death Is Death Wisdom.”  Vita evidently meant “life,” not “road.”  But he was no closer to figuring out what the mysterious words meant.

He went to the window, where gray light was filtering in through the grimy glass pane, and turned the ring over in his hand.  Bits of river mud still clung to the surface, now drying to a gray-brown, fouling the inside of the ring where there were other, fainter engravings.  Nick went back into the bathroom.  From the upstairs landing, he could hear Brady’s television show still playing.  Either his roommate had forgotten about showering, or (more likely) had fallen asleep in front of the television.  Nick pulled a couple of pieces of paper towel from a roll hanging on the wall, turned on the tap, and put the ring under the stream.

And immediately the voice was back, but with a more sinister tone. There it is.  Who are you?  What are you doing with it?  Give it back.

Nick jerked his hand out of the water as if he’d been stung.  There was water dripping from the ring into the sink, and in rhythm with the water drops, he heard clipped bits of words. it… give… where… you?... NOW.

He retreated into his room, drying the ring on the edge of his shirt, listening for the voice and hearing nothing but silence.

Nick looked at the inside of the ring.  There were shallow grooves running the circumference of the ring, but they were difficult to see.  The metal was polished smooth, whether through artifice or through long use was impossible to tell, and it had all but eradicated the markings.  He squinted at them, and thought he could make out the rippling contour of a long body.  At first, he thought it was a snake, but after some turning of the ring this way and that, he could make out the impressions of jointed legs ending in claws.  A dragon, perhaps.

Still holding the ring, he trotted downstairs to the living room.  His roommate, as expected, was lying sprawled in the recliner, eyes closed and mouth hanging open, a game show of some kind playing unheeded on the television.

“Hey, Brady,” Nick said.

Brady opened one eye, blinked, and said, in a slurred voice, “You done with the shower?”

“Yeah.  But that’s not why I woke you up.  Take a look at this.”  He handed the ring to his friend, who peered at it, then looked up and shrugged.

“Yeah?”

“I think this ring is…”  He had started to say cursed but stopped in time; it sounded ridiculous, even to him.  “...weird,” he finished.

“Weird how?”  Brady gave him a wry eye.  “Some kind of artifact, maybe.”

“Look, dude, just get up, I need to show you something.”

Brady gave a groan and stood up.  Nick led him into the kitchen, then put his hand out for the metal ring.  Nick turned the faucet with a squeak, and the water began to flow over the ring.  Immediately the monotonous droning voice began again, in the middle of a sentence, as if it had been speaking, unheard, the whole time.

yours.  Give it back.  Now.  It must come back to me.  I will find you.  You must not keep it.

Brady jumped, and said, under his breath, “Holy shit.”

Nick shut the tap off, and once again, the voice broke up into fragments.

I will find you.  You must not… ring…  Give… I… find… keep…

And then it stopped.

"You heard it, too."  It was not a question.

Brady looked at his friend with wide eyes.  "Yes."

"This has to do with the thing we saw in the river."

"All we saw was a bunch of waves."

"Yeah, but something was causing them.  There was something under there."

Brady didn't have an answer to that.

"What should we do?" Nick asked.

"I dunno.  Give it back?"

"Throw it into the river?"

"That's what I'm thinking."  Brady's voice shook.

"What if it's valuable?  And besides, suppose there is some kind of, um, thing, there in the river.  How could it get it back?  There's no way it could know where we are."

"You didn't notice how the voice broke up when the water stopped?"

"Yes."

"And there were pieces of it whenever a drip hit the sink."

"Okay," Nick said.  "I see where you're going.  Whenever the water makes a connection, it can talk to us.  But that doesn't mean it knows where we are."

"All water connects.  The water goes down the sink, into the sewer, then to some kind of treatment plant, then out to the river.  It's linked all the way.  If it can talk to us, it can find out where we are."

"When I was in the shower, I heard the voice, but all it did was ask questions about the ring.  When I put the ring itself under water, it said, 'There it is.'"

"There you go," Brady said.  "There's no reason to think that it doesn't know where we are."

"Not if the ring is away from the water."

"You need to throw it back, dude."

"I dunno."  Nick could hear the doubt in his own voice, and wondered if he was just making excuses to keep it.  "If it's worth something, we should try to find a museum to buy it from us.  I'd split the money with you."  He smiled, even though it looked a little shaky.  "Even though I'm the one that found it."

"Okay, I guess.  But I don't think it's a good idea.  This is freaky."

There was no arguing with that.  But Nick looked at the gold ring, with its strange, archaic words, and his heart beat a little faster.  Not yet.  It could wait until he'd thought more about this.

***

Sleep was restless that night.  There were no dreams, or at least none of note, but Nick tossed and turned, troubled by a vague anxiety that things weren't right.  Several times he found himself lying in bed, listening, hearing nothing, but all of his senses on alert.  Finally at around four o'clock he drifted off into a doze, but he got up at six feeling unrefreshed, hoping that a shower and coffee would wake him up.

He walked into the bathroom, and had turned on the tap before he remembered about his experience from the previous day.

He turned the water off, and got dressed.  He could skip a day's shower.

Nick put coffee on, being careful about getting his hands under the stream from the tap, and was standing listening to the comforting gurgle from the percolator when it registered that the ring was gone.

He'd left it on the counter, he was certain of that, after his demonstration to Brady that the voice in the water was real.  But the counter was empty, except for the dirty dishes from last night's dinner.  Frowning, he went up the stairs, his bare feet making little noise on the steps, and knocked on Brady's bedroom door.

No answer.

"Hey, Brady, wake up."

Still no answer.

"Dude, did you take the ring?  I hope you didn't get any smart ideas about throwing it back on your own. 'cuz I'll be pissed if you did."

Silence.

Nick opened the door.
 
What struck him first was the damp chill in the air.  The window stood wide open, and a cold breeze was blowing in.

The next thing he saw was that Brady wasn't there.

Nick walked in, feeling an icy sensation that the winter air was insufficient to cause.  Brady's bedsheets were rumpled, as if he'd slept in it, but the blanket and bed surface were soaking wet.  From the mattress came the heavy smell of river water.  There was also a wet spot between the window and the bed, cool and slick under his feet.

"Brady?"  His voice came out in a breathless whisper.

No answer, not that he expected one.

Nick ripped apart Brady's room, becoming more and more frantic, pitching aside sodden textbooks and piles of clothing, pulling boxes out of his closet, opening drawers in his desk.  He finally found the ring in Brady's sock drawer.

It couldn't see the ring, because it wasn't underwater.  But it found Brady.  It found him, and took him away.

Nick went to the bathroom, walking like a somnambulist, turned the tap on, and dunked the ring under the stream.  Instantly the voice started again, thin and whispery and evil.

There it is.  I knew he had it hidden.  Give it back.  It is not yours.  Give it back.

"What did you do with Brady?"  Nick said, his breath coming in tight, painful whistles.

He is here with me.  You will be soon.  You will stay with me forever.

"Where are you?"

You know.  And I know where you are.  Give it back.  It is not yours.

A catch formed in his throat, an angry sob that wanted to exit, but Nick kept it behind clenched teeth.  "You killed him."

He will be here with me forever.  So will you, very soon.

"I'll give you your fucking ring back.  Why do you want it so much?  So much that you would kill?"

Because it is mine.  It has been mine since I came here.

"How long have you been here?"

Longer than I can remember.  Years uncounted, I have been here. I will be here when you are gone.  Unless I bring you here to be with me.  Then we will stay here together forever.

Nick turned off the water, and the voice was cut off.

Still holding the dripping gold ring in his hand, he went to the closet and grabbed his jacket, pulling it on as he walked outside and toward his truck.  He grabbed something else as he walked, from where it leaned against the wall of the garden shed, and tossed it into the bed of the truck before he got in.

He kept himself from thinking as he drove toward the Delaware River and the jetty where he'd found the ring the previous day.  If he let himself think, he'd fall apart.  There was time for falling apart later.  Now, he had a task to accomplish.

As he scrambled down the embankment into the wet field that bordered the river, he saw drag marks.  Something large had passed this way, very recently.  The dead grass was crushed and slimy with mud in a great swath between the river and the highway.  As he walked toward the jetty, his boots squelching in the ooze, he saw once again the bubble of water about twenty yards out, rising from the flat surface of the river.  There was something under there, something that sensed his approach and was coming to meet him.

Something that perhaps resembled the serpentine design on the inside of the ring. But he didn't let himself think about that, either.

He walked out onto the jetty, reached the end, stood there, leaning out toward the oil-slicked water.

"You want your goddamn ring back?" Nick shouted.  "Here you go."

He set the ring down on the stone, and hefted the sledgehammer he'd brought from the garden shed.  There was a sloshing noise, and the disturbance began to move, accelerating toward shore.

Nick raised the steel head of the sledgehammer high, brought it down on the glittering surface of the ring.  It took three strikes, during which time the raised blob of water began to boil and churn.  White waves of turbulence streamed away from it, like the bow wave of a boat.  But on the third hit, the ring split in two, twisting and blackening, and there was a smell of sulfur that quickly dissipated on the winter breeze.

The raised hemisphere of water collapsed.  A few small waves lapped the shore, and then the river flowed on smoothly, its surface flat and glassy and gray under the cloud cover.

***

A woman walking her dog found Brady Elkano's body washed up on a gravel spit downstream two days later.  An autopsy determined that he had drowned, although there were some unexplained gouges in the skin of his left leg.  Suicide was suspected, but given Brady's personality, it didn't seem plausible.  Nick argued against that explanation with particular vehemence, although he didn't have any better explanation for why his friend had apparently hiked down to the river in the middle of the night to go swimming wearing nothing but a pair of boxers.

Brady's parents came a week later to take his belongings, his father sternly silent, his mother weeping quietly as they boxed his clothes and books and personal items.

By that time, his bed had dried out, although a year later, when Nick Dominique graduated from college and moved to Colorado, the air in Brady's room still carried the faint stink of river mud.

 **********************************

Neil deGrasse Tyson has become deservedly famous for his efforts to bring the latest findings of astronomers and astrophysicists to laypeople.  Not only has he given hundreds of public talks on everything from the Big Bang to UFOs, a couple of years ago he launched (and hosted) an updated reboot of Carl Sagan's wildly successful 1980 series Cosmos.

He has also communicated his vision through his writing, and this week's Skeptophilia book-of-the-week is his 2019 Letters From an Astrophysicist.  A public figure like Tyson gets inundated with correspondence, and Tyson's drive to teach and inspire has impelled him to answer many of them personally (however arduous it may seem to those of us who struggle to keep up with a dozen emails!).  In Letters, he has selected 101 of his most intriguing pieces of correspondence, along with his answers to each -- in the process creating a book that is a testimony to his intelligence, his sense of humor, his passion as a scientist, and his commitment to inquiry.

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



Thursday, December 30, 2021

Creepy crawlies

Whenever we have a wet summer -- not an uncommon occurrence in our rainy climate -- we have a plague of little pests trying to get into our house.

They're called millipedes, slinky guys maybe a couple of centimeters long, with lots of legs (not a thousand, though).  They're completely harmless; they don't bite like their cousins the centipedes do, and if you poke at them, they coil up into a ball.  So I guess they're really more of a nuisance than an actual problem.  They don't even damage anything, the way mice can.  Mostly what they seem to do is get in through every crack and crevice (there are lots of these in a big old house like ours), look around for a while, then curl up and die.

[Image licensed under the Creative Commons Totodu74, Anadenobolus monilicornis 03, CC BY-SA 3.0]

So I don't like them, and I wish they stayed outside, but in the grand scheme of things they're no big deal.  Imagine, though, if they were bigger.

A lot bigger.

Just last week, paleontologists announced the discovery on a beach in Northumberland, England, of a millipede fossil from the Carboniferous Period.  It's been dated to the middle of the period, about 326 million years ago.  It looks a bit like the millipedes I see trundling across my basement floor in summer.

Only this one was 2.6 meters long (approximately the length of a Mini Cooper), a half a meter across, and weighed something on the order of fifty kilograms.

It's been named Arthropleura, and holds the record as the largest-known arthropod in Earth's history.  Nothing is known for sure about its behavior; if it's like the rest of millipedes, it was a scavenger on leaf detritus, but there's no way to know for certain.  Given its size, it could well have been a lot more dangerous than the ones we have around now.  To paraphrase the old joke about five-hundred-pound gorillas:

Q:  What does a fifty-kilogram millipede eat?

A:  Anything it wants.

Those of you who are (like me) biology nerds may be frowning in puzzlement at this point.  How on earth could an arthropod get so big?  Their size is limited by the inefficiency of their respiratory system (not to mention the weight of their exoskeletons).  Most arthropods (millipedes included) breathe through pairs of holes called spiracles along the sides of the body.  These holes open into a network of channels called tracheae, which bring oxygen directly to the tissues.  Contrast that with our system; we have a central oxygen-collecting device (lungs), and the hemoglobin in our blood acts as a carrier to bring that oxygen to the tissues.  It's a lot more efficient, which is why the largest mammals are a great deal bigger than the largest arthropods.  (So, no worries that the bad sci-fi movies from the 50s and 60s, with giant cockroaches attacking Detroit, could actually happen.  A ten-meter-long cockroach not only wouldn't be able to oxygenate its own tissues fast enough to survive, it couldn't support its own weight.  It wouldn't eat Detroit, it would just lie there and quietly suffocate.)

So how could there be such ridiculously enormous millipedes?

The answer is as fascinating as the beast itself is.  As the temperature warmed and rainfall increased after the previous period (the Devonian), it facilitated the growth of huge swaths of rain forest across the globe.  In fact, it's the plant material from these rain forests that produced the coal seams that give the Carboniferous its name.  But the photosynthesis of all these plants drove the oxygen levels up -- by some estimates, to around 35% (contrast that to the atmosphere's current 21% oxygen).  This higher oxygen level facilitated the growth of animals who are limited by their ability to uptake it -- i.e., arthropods.  (At the same time, there was a dragonfly species called Meganeura with a seventy-centimeter wingspan.  And unlike millipedes, these things were carnivores, just as modern dragonflies are.)

Eventually, though, the system was unsustainable, and a lot of the rain forests began to die off in the Late Carboniferous, leading to a drier, cooler climate.  However, remember the coal seams -- by that time a huge percentage of the carbon dioxide that had fed the photosynthesis of those rain forests was now locked underground.  The fuse was lit for a catastrophe.

Fast forward to the end of the next period, the Permian, 255 million years ago.  What seems to have happened is a series of colossal volcanic eruptions that created the Siberian Traps, a basalt deposit covering most of what is now Siberia.  The lava ripped through the coal seams, blasting all that stored carbon into the atmosphere as carbon dioxide.  The temperature in the late Permian had been cool and dry, and the spike of carbon dioxide created a commensurate spike in the temperature -- as well as a huge drop in oxygen, used up by the burning coal.  The oxygen concentration seems to have bottomed out at around twelve percent, just over half of what it is now.  The extra carbon dioxide dissolved into ocean water, dropping the pH, and the increasing acidity dissolved away the shells of animals who build them out of calcium carbonate -- e.g. corals and mollusks.

Wide swaths of ocean became anoxic, acidic dead zones.  The anaerobic organisms began to eat through all the dead organic matter, churning out more carbon dioxide and another nasty waste product, sulfur dioxide (which gives the horrible smell to rotten eggs, and is also an acidifier).  The result: an extinction that wiped out an estimated ninety percent of life on Earth.  In short order, a thriving planet had been turned into a hot, dead, foul-smelling wasteland, and it would take millions of years to recover even a fraction of the previous biodiversity.

Of course, at highest risk would be the big guys like our friends Arthropleura and Meganeura, and the Earth hasn't seen giant arthropods like this since then.  Today, the largest arthropod known is the Japanese spider crab (Macrocheira), topping out at around twenty kilograms -- but crabs and other crustaceans have gills and an oxygen carrier called hemocyanin, so they can boost the efficiency of their respiratory system somewhat over their terrestrial cousins.  The largest insect today is the African Goliath beetle (Goliathus), at about a tenth of a kilogram.  And in today's atmosphere, it's at a pretty significant disadvantage.  They may look big and scary, but in reality, they're slow-moving, harmless creatures.  Kind of a beer can with six legs, is how I think of them.

So that's today's look at creepy-crawlies of the past.  In my opinion it's just as well the big ones became extinct.  The last thing I need is having to shoo a fifty-kilogram millipede out of my basement.

 **********************************

Neil deGrasse Tyson has become deservedly famous for his efforts to bring the latest findings of astronomers and astrophysicists to laypeople.  Not only has he given hundreds of public talks on everything from the Big Bang to UFOs, a couple of years ago he launched (and hosted) an updated reboot of Carl Sagan's wildly successful 1980 series Cosmos.

He has also communicated his vision through his writing, and this week's Skeptophilia book-of-the-week is his 2019 Letters From an Astrophysicist.  A public figure like Tyson gets inundated with correspondence, and Tyson's drive to teach and inspire has impelled him to answer many of them personally (however arduous it may seem to those of us who struggle to keep up with a dozen emails!).  In Letters, he has selected 101 of his most intriguing pieces of correspondence, along with his answers to each -- in the process creating a book that is a testimony to his intelligence, his sense of humor, his passion as a scientist, and his commitment to inquiry.

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



Wednesday, December 29, 2021

The battle of the sexes

Today I'm going to tell you about the latest weird and fascinating research in genetics, but first, a brief refresher from high school biology to set the context.

You may recall that back in the 1800s, an Austrian monk named Gregor Mendel made the first serious stab at trying to figure out how inheritance works.  Prior to this, about all they knew was "like begets like," which sometimes works and sometimes leads you to think that there's such thing as "royal blood," despite evidence to the contrary such as the fact that a lot of those royals were nuttier than squirrel shit.

Anyhow, Mendel studied some traits in pea plants that seemed to obey a few statistical rules.  He made the understandable error of concluding that all traits inherit according to those rules, which turned out to be wrong; actually "Mendelian" traits, that obey all four of Mendel's Laws, are in the minority.  But for a first-order approximation, it wasn't bad. 

One trait in humans that is Mendelian is the Rh blood group gene.  Some people have a gene that makes the Rh protein; in others, the gene is defective, and makes nothing.  You only need one copy of the Rh-producing gene to have the Rh protein in your blood ("Rh-positive"), so the Rh-producing gene is said to be dominant; you only lack the protein ("Rh negative") if both of your copies of the gene are defective, so the non-functional gene is said to be recessive.

Since everyone has two copies of every gene -- one came from your mother, the other from your father -- this makes the inheritance pattern for Rh pretty simple.  (The "everyone has two copies" rule is broken by sex-linked genes, but this doesn't affect today's topic and is a subject for another day.)  Let's say, for example, that parent 1 is Rh-negative (so both copies are defective), and parent 2 is Rh-positive but has one defective and one normal copy.  Their kids inherit a defective copy from parent 1 (that's all (s)he's got), and the one that inherits from parent 2 has a 50/50 probability of being the normal or the defective one.  So the kids each have a 50% chance of being negative or positive.

The important part here is that I didn't stipulate which parent was which; in fact, it doesn't matter.  It works exactly the same way if the mom is parent 1 as it does if the dad is parent 1.

Okay, here's the second bit of background.  There's a group of terrible genetic defects called deletions, in which one of the patient's chromosomes broke somewhere along the process, and is missing a big chunk of genetic information.  You're supposed to have 23 matched pairs, one of each pair from dad and one from mom (again, ignoring the sex chromosomes).  In a deletion, when you match them up (a process called karyotyping) you find that one of the pairs isn't matched, because one member of the pair has a piece missing.

A karyotype for an individual with a deletion on the long arm of chromosome 4 (indicated by the arrow)

Each chromosome contains genes that guide development, and a person with a deletion only has a single copy of the genes in the deleted segment rather than the usual two.  The result is that (s)he only produces half the normal amount of the product made by that gene, and fetal development goes seriously awry.  Most deletions are so bad that they result in death of the embryo and miscarriage; the ones who survive to birth usually have drastic physical and mental abnormalities.

Once again, in the description of deletion, there's no indication which parent the broken chromosome came from.  In the above karyotype, you can't tell if the abnormal copy of chromosome 4 came from the mom or from the dad.  Shouldn't matter, right?  Mendel showed that the trait expresses the same way regardless which parent contributed what to the offspring.

With me so far?  Because here's where it gets a little weird.

The first inkling we had that there was more to the story came from a pair of genetic disorders that seemed, on first glance, to have absolutely nothing in common.  Angelman syndrome results in severe physical and developmental problems, including jerky or spastic movement of the limbs, little capacity for speech, cognitive impairment, and difficulty gaining and keeping on weight.  They often have no interest in food, so their diet has to be carefully managed.  Prader-Willi syndrome causes abnormal skull and brain growth, weak muscles, small hands and feet, and -- most strikingly -- an insatiable fixation on eating.  A friend of mine who worked in a home for the developmentally disabled once told me about a teenager who lived there who suffered from Prader-Willi syndrome, and he was so unable to control his hunger that he'd raid people's desks for food, and if that didn't work, he'd eat inedible things like chalk.

So nothing alike, are they?  Imagine researchers' puzzlement when they found out that both disorders were caused by the same deletion -- the loss of a chunk of the long arm of chromosome 15.

How could the same genetic damage result in such differing outcomes?  You're probably already guessing, given what I said earlier, that it has to do with which parent the damaged chromosome came from, and if so, you're right.  If the deletion was on the maternal copy of the chromosome, the child gets Prader-Willi syndrome; if it's the paternal copy, (s)he gets Angelman syndrome.

This was the first example ever discovered of the phenomenon of genomic imprinting -- where the gene expresses differently depending which parent it comes from.  But there's an even more curious part of the Prader-Willi/Angelman situation, and it has to do with hunger.

Let's say you're a male proto-hominid on the African savanna, and your significant other has just told you that you're gonna be a proud proto-hominid father.  The fetus is surviving inside the mom by obtaining nutrients through the placenta, so in essence, the baby is existing as a parasite on the mom (which continues even after birth, because of breastfeeding).  The dad's interest is (in the pure evolutionary sense) having the baby feed as much as possible, even at the expense of the mother; after all, the baby is his genes' way of surviving, and if the mom weakens, he can always find another mate.  The mom, on the other hand, certainly wants the baby to survive (half the baby's genes come from her, after all), but for her to survive is actually more important.  It's the opposite of the dad's situation; if the baby dies, she can have another baby, but if she dies, she's done for.

So the dad's imprint on the genes is to have the baby feed insatiably; the mom's imprint is to limit the baby's feeding to a level that isn't deleterious to her.  The system all works fine as long as the baby inherits copies of the imprinted genes from both parents; the competing interests of the mother and father balance each other out.  

But in a chromosome 15 deletion, that balance doesn't happen.  A baby with Angelman syndrome only has the maternal copy of a gene called UBE3A, and during egg formation, this gene is imprinted, with the result that it pushes the baby toward the mother's end of the spectrum, feeding-wise.  Thus the lack of interest in food you seen in kids with Angelman syndrome.  In Prader-Willi syndrome, the baby only has the paternal copy -- so the father's interest wins, and the kid wants to eat continuously.

All of this is lead-up to the research that came out last week in the journal Developmental Cell, in which a team of geneticists at Cambridge University found out that the missing chunk of chromosome 15 doesn't just cause opposite behavioral disorders depending on which parent it comes from; it actually changes the number of blood vessels that develop in the placenta long before the baby is born.  A gene called IGF2 (also in the target region of chromosome 15) controls the rate of blood vessel growth, and once again, it's in the dad's interest to have as many blood vessels as possible (favoring the baby at the expense of the mother) and in the mom's interest to inhibit blood vessel growth (favoring the mother at the expense of the baby).  And once again, if both copies are present and work correctly, the competing interests balance out, and the placenta develops normally -- resulting in an at-term overall length of blood vessels of 320 kilometers if you stretched them out end to end.  The genomic imprinting shows up, though, if one of the copies of the genes is defective or missing, because then the parent that contributed the working copy "wins."

So that's another odd twist on inheritance and development, for your morning entertainment.  It all brings to mind the comment made by my genetics professor, Dr. Lemmon, when I was an undergraduate.  "It's not strange when something goes wrong with our developmental genetics," she told us.  "There are a million ways things could go wrong.  What's phenomenal is how often everything goes right."

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Neil deGrasse Tyson has become deservedly famous for his efforts to bring the latest findings of astronomers and astrophysicists to laypeople.  Not only has he given hundreds of public talks on everything from the Big Bang to UFOs, a couple of years ago he launched (and hosted) an updated reboot of Carl Sagan's wildly successful 1980 series Cosmos.

He has also communicated his vision through his writing, and this week's Skeptophilia book-of-the-week is his 2019 Letters From an Astrophysicist.  A public figure like Tyson gets inundated with correspondence, and Tyson's drive to teach and inspire has impelled him to answer many of them personally (however arduous it may seem to those of us who struggle to keep up with a dozen emails!).  In Letters, he has selected 101 of his most intriguing pieces of correspondence, along with his answers to each -- in the process creating a book that is a testimony to his intelligence, his sense of humor, his passion as a scientist, and his commitment to inquiry.

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