Species, types, and the "No True Scotsman" fallacy

One of the most frustrating of logical fallacies is the No True Scotsman fallacy.

It gets its name from an almost certainly apocryphal story, in which a serial rapist and killer is being pursued by the police in Glasgow, and a Scottish MP encourages the police to search amongst the immigrant population of the city.  "No Scotsman would do such a thing," the MP said.

When the criminal was caught, and turned out to be 100% Scottish, the MP was challenged about his remark.

"Well," he said, drawing himself up, "no true Scotsman would have done such a thing!"

The crux of this fallacy is that if you make a statement that turns out, in view of evidence, to be false, all you do is shift your ground -- redefine the terms so as to make your original point unassailable.

Very few other fallacies have such a capacity for making me want to smack my forehead into a wall as this one.  Someone who commits this fallacy can't be pinned down, can't be backed into a corner, can't receive his comeuppance from the most reasoned argument, the most solidly incontrovertible evidence.  The dancing skills of a master of the No True Scotsman fallacy are Dancing With The Stars quality.

All of this comes up because of an online discussion that I read, and (yes) participated in, a couple of days ago, on the topic of the demonstrability of evolution.  Someone, ostensibly a supporter of evolution but seemingly not terribly well-read on the subject, was using such evidence as the fossil record as a support for the idea.  A creationist responded, "The fossil record, and fossil dating, are inaccurate.  You evolutionists always think that bringing us a bunch of bones and shells proves your point, but it doesn't, because no one can really prove how old they were, and none of them show one species turning into another.  You can't show a single example, from the present, of one species becoming another, and yet you want us to believe in your discredited theory."

Of course, I couldn't let a comment like that just sit there, so I responded, "Well, actually, yes, I can.  I know about a dozen examples of speciation (one species becoming another) occurring within a human lifetime."

Challenged to produce examples, I gave a few, including the ones that I described in an earlier post (Grass, gulls, mosquitoes, and mice, February 9, 2012), and then sat back on my haunches with a satisfied snort, thinking, "Ha.  That sure showed him."

Well.  I should have known better.  His response, which I quote verbatim: "All you did was show that one grass can become another grass, or a mosquito can become another mosquito.  If you could show me a mosquito that turned into a bird, or something, I might believe you."

Now, hang on a moment, here.  You asked me for one thing -- to show one species turning into a different species, in the period of a few decades.  I did so, adhering to the canonical definition of the word species.  And now you're saying that wasn't what you wanted after all -- you want me to show one phylum turning into a different one, in one generation?

I sat there, sputtering and swearing, and not sure how to answer.  So I said something to the effect that he'd pulled a No True Scotsman on me, and had changed the terms of the question once he saw I could answer it, and he'd damned well better play fair.  He humphed back at me that we evolutionists couldn't really support our points, and we both left the discussion as I suspect most people leave discussions on the internet -- unconvinced and frustrated.  So I was pondering the whole thing, and after taking my blood pressure medications I had a sudden realization of where the confusion was coming from.  It was from the idea of a type of organism.

Most people who aren't educated in the biological sciences (and I'm not including just formal education, here; there are many people who have never taken a single biology class and know plenty about the subject) really don't understand the concept of species.  They think in types.  A bird is one type of thing; a bug is a different one.  If you pressed them, they might admit that there were a few types of birds that seemed inherently different.  You have your big birds (ostriches), your medium-sized birds (robins), and your little birds (hummingbirds).  I've had students that have thought this way, and when they hear I'm a birdwatcher, they seem incredulous that this could be a lifelong avocation.  Wouldn't I run out of new birds to see pretty quickly?  When I tell them that there are over 10,000 unique species of birds, they seem not so much awed as uncomprehending.

The phylogenetic tree of birds (Class Aves) [credit: Dr. Gavin Thomas, University of Sheffield, UK]

I suspect that the source of this misapprehension is the same as the source of the general misapprehension regarding the antiquity of the Earth and the origins of life: the Bible.  In Leviticus 11, where they go through the whole unclean-foods thing that eventually would be codified as the Kosher Law, they split up the natural world in only the broadest-brush terms; you have your animals that have hooves and chew the cud, various combinations of ones that don't, creatures that have fins and scales and ones that don't, insects that jump and ones that don't, and a few different classes of birds (which, to my eternal amusement, includes bats).  And that's pretty much it.  Plants were sorted out into ones that had edible parts (wheat, figs, olives), ones that had useful wood (boxwood, cedar, acacia), and ones that had neither of the above (thorn bushes).  And these distinctions worked perfectly well for a Bronze-Age society.  It kept you from eating stuff that was bad for you, told you what you could build stuff from, and so on.  But as a scientific concept, the idea of "types of living things" kind of sucks.  And yet it still seems to live on in people's minds, lo unto this very day.

So, anyway, that was my brief excursion into that least useful of endeavors, the Online Argument.  It gave me a nice example of the No True Scotsman fallacy to write about here.  And it really didn't affect my blood pressure all that much, but it did make me roll my eyes.  Which seems to happen frequently when I get into conversations with creationists.

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Pink, pink, gold

When I was in Ecuador in 2019, I was blown away by its natural beauty.  The cloud forests of the mid-altitude Andes are, far and away, the most beautiful place I've ever been, and I've been lucky enough to see a lot of beautiful places.  Combine that with the lovely climate and the friendliness of the people, and it puts the highlands of Ecuador on the very short list of places I'd happily move to permanently.

What brought me there were the birds.  It's a tiny country, but is home to 1,656 species of birds -- about one-sixth of the ten-thousand-odd species found worldwide.  Most strikingly, it has 132 different species of hummingbirds.  Where I live, in upstate New York, we have only one -- the Ruby-throated Hummingbird (Archilochus colubris) -- but there, they have an incredible diversity within that one group.  Because each species is dependent on particular flowers for their food source, some of them have extremely restricted ranges, often narrow bands of terrain at exactly the right climate and altitude to support the growth of that specific plant.  You go a few hundred meters up or downhill, and you've moved out of the range where that species lives -- and into the range of an entirely different one.

The most striking thing about the hummingbirds is their iridescence.  My favorite one, and in the top five coolest birds I've ever seen, is the Violet-tailed Sylph (Aglaiocercus coelestis):

[Image licensed under the Creative Commons Andy Morffew from Itchen Abbas, Hampshire, UK, Violet-tailed Sylph (33882323008), CC BY 2.0]

What's most fascinating about birds like this one is that the feathers' stunning colors aren't only due to pigments.  A pigment is a chemical that appears colored to our eyes because its molecular structure allows it to absorb some frequencies of light and reflect others; the chlorophyll in plants, for example, looks green because it preferentially absorbs light in the red and blue-violet regions of the spectrum, and reflects the green light back to our eyes.  Hummingbirds have some true pigments, but a lot of their most striking colors are produced by interference -- on close analysis, you find that the fibers of the feathers are actually transparent, but when light strikes them they act a bit like a prism, breaking up white light into its constituent colors.  Because of the spacing of the fibers, some of those wavelengths interfere destructively (the wavelengths cancel each other out) and some interfere constructively (they superpose and are reinforced).  The spacing of the fibers determines what color the feathers appear to be.  This is why if you look at the electric blue/purple tail of the Violet-tailed Sylph from the side, it looks jet black -- your eyes are at the wrong angle to see the refracted and reflected light.  Look at it face-on, and suddenly the iridescent colors shine out.

So the overall color of the bird comes from an interplay between whatever true pigments it has in its feathers, and the kind of interference you get from the spacing of the transparent fibers.  This is why when you recombine these features through hybridization, you can get interesting and unexpected results -- as some scientists from Chicago's Field Museum found out recently.

Working in Peru's Cordillera Azul National Park, on the eastern slopes of the Andes, ornithologist John Bates discovered what he'd thought was a new species in the genus Heliodoxa, one with a glittering gold throat.  He was in for a shock, though, when the team found out through genetic analysis that it was a hybrid of two different Heliodoxa species -- H. branickii and H. gularis -- both of which have bright pink throats.

"It's a little like cooking: if you mix salt and water, you kind of know what you're gonna get, but mixing two complex recipes together might give more unpredictable results," said Chad Eliason, who co-authored the study.  "This hybrid is a mix of two complex recipes for a feather from its two parent species...  There's more than one way to make magenta with iridescence.  The parent species each have their own way of making magenta, which is, I think, why you can have this nonlinear or surprising outcome when you mix together those two recipes for producing a feather color."

The gold-throated bird apparently isn't a one-off, as more in-depth study found that it didn't have an even split of genes from H. branickii and H. gularis.  It seems like one of its ancestors was a true half-and-half hybrid, but that hybrid bird then "back-crossed" to H. branickii at least once, leaving it with more H. branickii genes.  All of which once again calls into question our standard model of species being little cubbyholes with impermeable walls.  The textbook definition of species -- "a morphologically-distinct population which can interbreed and produce fertile offspring" -- is unquestionably the most flimsy definition in all of biology, and admits of hundreds of exceptions (either morphologically-identical individuals which cannot interbreed, or morphologically-distinct ones that hybridize easily, like the Heliodoxa hummingbirds just discovered in Peru).

In any case, the discovery of this hybrid is fascinating.  You have to wonder how many more of them there are out there.  The fact that its discovery ties together the physics of light, genetics, and evolution is kind of amazing.  Just further emphasizes that if you're interested in science, you will never, ever be bored.

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Birds of a feather

The word species has got to be the mushiest term in all of science.

It's one of those situations where you think you know what something means until you start pushing on it.  When humans started to put a serious effort into categorizing other life forms -- Aristotle is usually credited with being the first to do this in a systematic way -- it seemed obvious enough.  Members of a species are similar morphologically.  Put more simply, you can tell a cat from a dog because they look different.

The problem is, this starts to cause problems just about immediately.  What about organisms that look very different, but we still consider to be the same species?  Dogs, in fact, are a good example.  Imagine you're an alien scientist arriving on Earth, and you're looking at a St. Bernard and a chihuahua.  If a human said, "These are the same species," my guess is you'd do whatever passes for laughter on your home world, then get back in your spaceship and fly away after writing "No intelligent life" on the map of the Solar System.

Dogs, of course, aren't the only ones; there are lots of examples in nature of different-looking organisms that are considered conspecific.  So in the 1800s, the definition was revised to, "a group of organisms that are capable of mating and producing offspring."  This worked until people started to think about mules, which are the offspring of a horse and a donkey (usually considered separate species).  Then, it was pointed out that although alive and well, (most) mules are infertile, so a word was added to take care of that problem: "a group of organisms that are capable of mating and producing fertile offspring."

It only got worse from here.  An awkward difficulty with the above definition is, what about asexual species?  They kind of don't fit in no matter how you look at it.  Oh, well, maybe they get their own version of the definition.  But what about ring species?  This is a group of populations, often arranged in a ring around a geographical barrier (thus the name) where all of them can interbreed except for the ones at the "ends" of the ring  It's been observed multiple times, including a group of salamanders in California, the Greenish Warbler of central Asia, and a ring of gull species -- the latter of which goes all the way around the world.

So do these represent one species, or many?  Within the ring, some of them are interfertile, and others aren't.  And splitting the ring doesn't help; then you're separating populations that are interfertile.  In fact, like asexual species, ring species seem to be unclassifiable with the canonical definition.

It all comes, my evolutionary biology professor said to us, from the desperation humans have to pigeonhole everything.  "The only reason we came up with the concept of a species in the first place," he said, "is because humans have no near relatives."

Of course, none of this sits well with the creationists, because a central tenet of their beliefs is that each kind of life form was created by God as-is and nothing's changed since.  Which is all well and good until you ask, "What do you mean by 'kind of life form'?"  They respond that God created "discrete forms with genetic boundaries to interbreeding," which they call baramins (a neologism coined from the Hebrew words for "created" and "kind").  So the ring species of gulls isn't a problem because gulls are a "kind."  In fact, you can define "kind" in this context as "a classification of life forms that conveniently makes all of the internal contradictions go away.  Now stop asking questions."  

In any case, there really is no good, consistent definition of species that covers all the exceptions.  Even now that we have genetic analysis -- which is currently the touchstone for classification -- it only further reinforces the fact that evolution generates a continuum of forms, and you're asking for trouble if you try to subdivide them.  Only in cases like ourselves, where there are no living near relatives, does it seem clear-cut.

Take the study out of the University of Colorado that appeared in Nature Communications this week.  It's about a trio of species of birds, so being a rather fanatical birder, it immediately caught my eye.  The species involved (and I use that term guardedly, for reasons that will become obvious) are the Common Redpoll, (Acanthis flammea) the Hoary Redpoll (Acanthis hornemanni), and the Lesser Redpoll (Acanthis cabaret), all types of finch with a characteristic red splotch on the forehead.  

Common Redpoll (Acanthis flammea) [Image licensed under the Creative Commons Cephas, Carduelis flammea CT6, CC BY-SA 3.0]

The Lesser Redpoll is only found in Europe, but the other two occur in North America.  They have pretty obvious color differences; the Lesser Redpoll is brownish, the Hoary Redpoll is almost white, and the Common Redpoll is somewhere in the middle, with reddish flanks.  The size differs, as well, with the Lesser at the small end and the Hoary at the large end.

Lesser Redpoll (Acanthis cabaret) [Image licensed under the Creative Commons Carduelis_cabaret.jpg: Lawrie Phipps derivative work: MPF (talk), Carduelis cabaret1, CC BY 2.0]

However, the differences aren't huge.  We get Common Redpolls at our bird feeders in winter fairly regularly, but Hoary Redpolls are a rare sighting in our area.  Every winter I scan the flocks of redpolls looking for whiter individuals, but I still have never seen one.  However, I may be able to cross that one off the list of "species I haven't seen" -- because the current study has shown that despite the differences in appearance, all three are a single species.

Hoary Redpoll (Acanthis hornemanni) [Image licensed under the Creative Commons Ron Knight from Seaford, East Sussex, United Kingdom, Arctic Redpoll (Acanthis hornemanni) (13667519855), CC BY 2.0]

The color and size differences, the researchers found, are due to a "supergene complex" -- a single cluster of genes that work together to produce a specific phenotype.  What's striking is that despite the differences in that gene complex between the three different groups of redpolls, they are otherwise about as genetically identical as it's possible to get.  And... they're all potentially interfertile.

"Often times we assume that a lot of traits can act independently, meaning that different traits can be inherited separately from one another, but this particular result shows that sometimes these traits are actually tightly linked together," said Erik Funk, lead author on the paper, in an interview in Science Daily.  "At least for these birds, they're inheriting a whole group of traits together as one."

Birders tend to hate it when confronted with "lumpers," as they call researchers who merge species together, therefore reducing the number of potential birds to chase after.  They much prefer "splitters," who take previously single species and subdivide them, like another "winter finch," the Red Crossbill (Loxia curvirostra), which according to some taxonomists isn't a single species but several -- possibly as many as seven.  In any case, my point here is that this kind of thing happens all the time.  Like I said at the beginning, we think we have a clear idea of what's meant by a species until we start examining it.

But to me, this only increases my fascination with the natural world.  It's a beautiful, subtle, and complex interlocking web of organisms, and maybe the most surprising thing of all is that we do think it should be simple and easily classifiable.  As usual, our scheme for understanding the world turns out to be woefully inadequate -- and once again, science has come to the rescue by turning a lens on a small and unassuming bird as a way of pointing out how much more we have to learn.

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As I've mentioned before, I love a good mystery, which is why I'm drawn to periods of history where the records are skimpy and our certainty about what actually happened is tentative at best.  Of course, the most obvious example of this is our prehistory; prior to the spread of written language, something like five thousand years ago, most of what we have to go by is fossils and the remnants of human settlements.

Still, we can make some fascinating inferences about our distant ancestors.  In Lost Civilizations of the Stone Age, by Richard Rudgely, we find out about some of the more controversial ones -- that there are still traces in modern languages of the original language spoken by the earliest humans (Rudgely calls it "proto-Nostratic"), that the advent of farming and domestication of livestock actually had the effect of shortening our average healthy life span, and that the Stone Age civilizations were far more advanced than our image of "Cave Men" suggests, and had a sophisticated ability to make art, understand science, and treat illness.

None of this relies on any wild imaginings of the sort that are the specialty of Erich von Däniken, Zecharia Sitchin, and Giorgio Tsoukalos; and Rudgely is up front with what is speculative at this point, and what is still flat-out unknown.  His writing is based in archaeological hard evidence, and his conclusions about Paleolithic society are downright fascinating.

If you're curious about what it was like in our distant past, check out Lost Civilizations of the Stone Age!

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

An alpine gem in China

In order to produce new species -- so goes the evolutionary model -- you need two things: isolation (splitting off the population that will eventually become the new species from the parent population) and selection (environmental conditions that favor different traits in the splinter population than the ones favoring the parent population).  Given those two, and sufficient time, sooner or later you'll have two (or more) separate species.

The classic example of this, of course, is the group of birds called "Darwin's finches," that evolved from a parent population of tanagers from mainland South America (their closest relative is the Dull-colored Grassquit of Colombia, Ecuador, and Peru) something on the order of two million years ago.  Once arrived in the islands, they thereafter fragmented to fill the available niches in a process that has been nicknamed adaptive radiation.

So split off a population and give it some new conditions to contend with, and you'll end up with new species.  Which is what happened to a whole ecosystem's worth of species thirty million years ago -- leading to one of the most biodiverse spots on Earth.

New research into the genetics of the dozens of unique species in the Hengduan Mountains and Qinghai Plateau of western China has given us a fascinating lens into this process.  In "Ancient Orogenic and Monsoon-Driven Assembly of the World’s Richest Temperate Alpine Flora," by Wen-Na Ding, Robert Spicer, and Yao-Wu Xing of the Chinese Academy of Sciences and Richard Ree of Chicago's Field Museum, we read about a biotic province created by mountain building that not only raised the elevation (and thus lowered the average temperature), but altered wind currents to create monsoons -- and isolated the populations trapped there from their relatives on the other side of the mountain range.

"The theory is, if you increase the ruggedness of a landscape, you're more likely to have populations restricted in their movement because it's harder to cross a deeper valley than a shallow valley," said study co-author Richard Ree, in an interview with Science Daily.  "So any time you start increasing the patchiness and barriers between populations, you expect evolution to accelerate...  The combined effect of mountain-building and monsoons was like pouring jet fuel onto this flame of species origination.  The monsoon wasn't simply giving more water for plants to grow, it had this huge role in creating a more rugged topography.  It caused erosion, resulting in deeper valleys and more incised mountain ranges."

This all started back in the Oligocene Epoch, thirty million years ago, and the area has been pretty well isolated ever since.  The result is plants like the Himalayan lantern (Agapetes lacei):

.... which you wouldn't guess is a relative of rhododendrons and azaleas; the alpine monkshood (Aconitum gymnandrum):

... the gorgeous little Paraquilegia microphyllum:

... and literally hundreds of others, species found there and nowhere else on Earth.

The remoteness and general inaccessibility of the area has limited the human impact (fortunately), but scientists are rightly concerned with the effects that climate change will have on these subalpine valleys and plateaus.  Even if we're not directly damaging the ecosystem, our actions elsewhere imperil it, just as our out-of-control fossil fuel use has led to the thawing of the Arctic and the threat of ice sheet collapse in Antarctica -- the latter of which recent research has suggested could add three meters to the average sea level over a very short period, with catastrophic consequences.

But for now, let's just focus on this pristine gem of an ecosystem, and marvel at the processes that created it.  Once again, we see the truth of Darwin's words, with which he ended The Origin of Species: "There is grandeur in this view of life, with its several powers, having been originally breathed into a few forms or into one; and that, whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being, evolved."

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This week's Skeptophilia book recommendation is a fun and amusing discussion of a very ominous topic; how the universe will end.

In The End of Everything (Astrophysically Speaking) astrophysicist Katie Mack takes us through all the known possibilities -- a "Big Crunch" (the Big Bang in reverse), the cheerfully-named "Heat Death" (the material of the universe spread out at uniform density and a uniform temperature of only a few degrees above absolute zero), the terrifying -- but fortunately extremely unlikely -- Vacuum Decay (where the universe tears itself apart from the inside out), and others even wilder.

The cool thing is that all of it is scientifically sound.  Mack is a brilliant theoretical astrophysicist, and her explanations take cutting-edge research and bring it to a level a layperson can understand.  And along the way, her humor shines through, bringing a touch of lightness and upbeat positivity to a subject that will take the reader to the edges of the known universe and the end of time.

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

Species, types, and the "No True Scotsman" fallacy

One of the most frustrating of logical fallacies is the No True Scotsman fallacy.

It gets its name from an almost certainly apocryphal story, in which a serial rapist and killer is being pursued by the police in Glasgow, and a Scottish MP encourages the police to search amongst the immigrant population of the city.  "No Scotsman would do such a thing," the MP said.

When the criminal was caught, and turned out to be 100% Scottish, the MP was challenged about his remark.

"Well," he said, drawing himself up, "no true Scotsman would have done such a thing!"

The crux of this fallacy is that if you make a statement that turns out, in view of evidence, to be false, all you do is shift your ground -- redefine the terms so as to make your original point unassailable.

Very few other fallacies have such a capacity for making me want to smack my forehead into a wall as this one.  Someone who commits this fallacy can't be pinned down, can't be backed into a corner, can't receive his comeuppance from the most reasoned argument, the most solidly incontrovertible evidence.  The dancing skills of a master of the No True Scotsman fallacy are Dancing With The Stars quality.

All of this comes up because of an online discussion that I read, and (yes) participated in, a couple of days ago, on the topic of the demonstrability of evolution.  Someone, ostensibly a supporter of evolution but seemingly not terribly well-read on the subject, was using such evidence as the fossil record as a support for the idea.  A creationist responded, "The fossil record, and fossil dating, are inaccurate.  You evolutionists always think that bringing us a bunch of bones and shells proves your point, but it doesn't, because no one can really prove how old they were, and none of them show one species turning into another.  You can't show a single example, from the present, of one species becoming another, and yet you want us to believe in your discredited theory."

Of course, I couldn't let a comment like that just sit there, so I responded, "Well, actually, yes, I can. I know about a dozen examples of speciation (one species becoming another) occurring within a human lifetime."

Challenged to produce examples, I gave a few, including the ones that I described in an earlier post (Grass, gulls, mosquitoes, and mice, February 9, 2012), and then sat back on my haunches with a satisfied snort, thinking, "Ha. That sure showed him."

Well. I should have known better.  His response, which I quote verbatim: "All you did was show that one grass can become another grass, or a mosquito can become another mosquito.  If you could show me a mosquito that turned into a bird, or something, I might believe you."

Now, hang on a moment, here.  You asked me for one thing -- to show one species turning into a different species, in the period of a few decades.  I did so, adhering to the canonical definition of the word species.  And now you're saying that wasn't what you wanted after all -- you want me to show one phylum turning into a different one, in one generation?

I sat there, sputtering and swearing, and not sure how to answer.  So I said something to the effect that he'd pulled a No True Scotsman on me, and had changed the terms of the question once he saw I could answer it, and he'd damned well better play fair.  He humphed back at me that we evolutionists couldn't really support our points, and we both left the discussion as I suspect most people leave discussions on the internet -- unconvinced and frustrated.  So I was pondering the whole thing, and after taking my blood pressure medications I had a sudden realization of where the confusion was coming from.  It was from the idea of a type of organism.

Most people who aren't educated in the biological sciences (and I'm not including just formal education, here; there are many people who have never taken a single biology class and know plenty about the subject) really don't understand the concept of species.  They think in types.  A bird is one type of thing; a bug is a different one.  If you pressed them, they might admit that there were a few types of birds that seemed inherently different; you have your big birds (ostriches), your medium-sized birds (robins), and your little birds (hummingbirds).  I've had students that have thought this way, and when they hear I'm a birdwatcher, they seem incredulous that this could be a lifelong avocation.  Wouldn't I run out of new birds to see pretty quickly?  When I tell them that there are over 10,000 unique species of birds, they seem not so much awed as uncomprehending.

The phylogenetic tree of birds (Class Aves) [credit: Dr. Gavin Thomas, University of Sheffield, UK]

I suspect that the source of this misapprehension is the same as the source of the general misapprehension regarding the antiquity of the Earth and the origins of life: the bible.  In Leviticus 11, where they go through the whole unclean-foods thing that eventually would be codified as the Kosher Law, they split up the natural world in only the broadest-brush terms; you have your animals that have hooves and chew the cud, various combinations of ones that don't, creatures that have fins and scales and ones that don't, insects that jump and ones that don't, and a few different classes of birds (which, to my eternal amusement, included bats).  And that's pretty much it.  Plants were sorted out into ones that had edible parts (wheat, figs, olives), ones that had useful wood (boxwood, cedar, acacia), and ones that had neither of the above (thorn bushes).  And these distinctions worked perfectly well for a Bronze-Age society; it kept you from eating stuff that was bad for you, told you what you could build stuff from, and so on.  But as a scientific concept, the idea of "types of living things" is pretty ridiculous.  And yet it still seems to live on in people's minds, lo unto this very day.

So, anyway, that was my brief excursion into that least useful of endeavors, the Online Argument.  It gave me a nice example of the No True Scotsman fallacy to tell my Critical Thinking classes about.  And it really didn't affect my blood pressure all that much, but it did make me roll my eyes.  Which seems to happen frequently when I get into conversations with creationists.

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If you are one of those people who thinks that science books are dry and boring, I'll give you a recommendation that will put that misconception to rest within the first few pages: Sam Kean's The Disappearing Spoon: And Other True Tales of Madness, Love, and the History of the World from the Periodic Table of Elements.

Kean undertook to explain, from a human perspective, that most iconic of all images from the realm of chemistry -- the Periodic Table, the organized chart of elements from the simplest (hydrogen, atomic number 1) to largest and most complex (oganesson, atomic number 118).  Kean's sparkling prose shows us the personalities behind the science, including the notoriously cranky Dmitri Mendeleev; tragic, brilliant Henry Moseley, a victim of World War I; and shy, self-effacing Glenn T. Seaborg, one of only two individuals to have an element named after them while they were still alive.

It's a fun read, even if you're not a science geek -- maybe especially if you're not a science geek.  Because it allows you to peer behind the curtain, and see that the scientists are just like the rest of us, with rivalries, jealousies, odd and misplaced loyalty, and all the rest of the faults the human race is subject to.

[If you purchase the book from Amazon using the image/link below, part of the proceeds goes to supporting Skeptophilia!]

Scientific names, Indigo Children, and Alpha Thinkers

Most people are, by nature, categorizers.  We like to put labels on things, sort the world into neat little boxes.  For many of us, this drive is integral to our understanding of the world.

An example from my own field is the concept of species.  The definition seems simple enough: a group of morphologically similar individuals that are capable of interbreeding and producing fertile offspring.  It seems, on the surface, that given this definition, it should be trivial to determine whether two individuals are, or are not, members of the same species.

The problem is, the world is messy, and doesn't often acquiesce to our desire to paste labels on various bits of it.  The word species is actually one of the hardest to pin down definitions in biology.  Ring species, fertile hybrids, morphologically distinct populations that can interbreed, morphologically identical populations that cannot, and so on, all point up that we're trying to draw firm distinctions in a realm where those distinctions probably don't exist.  As my long-ago vertebrate zoology professor once said, "The only reason that humans came up with the concept of 'species' is that Homo sapiens has no near relatives."

It's funny how serious taxonomists get about this, however.  There are fierce arguments over whether species should be "lumped" or "split" (particularly contentious amongst birdwatchers, who often bump up their lists with no hard work if what was once a single species gets divided into two or more).  There are endless arguments even about what names species should be given, and every month taxonomic oversight groups publish lists of name changes, to the chagrin of biologists who then have to go back and alter their records.

The same urge to divide a messy reality into neat compartments pervades a lot of other fields, too, and the results are sometimes more pernicious than the biologist's need to decide whether some plant or another is a new species.  In psychology, for example, it has driven the use of diagnostic labels on groups of behaviors that might not actually be conditions in the clinical sense.  ADD and ADHD, for example, are diagnoses that even the experts can't agree upon -- whether or not they are actual medical conditions, how (or if) cases should be medicated, and inconsistencies in how they are diagnosed have all led to significant controversy.  (There's a nice overview of the arguments here.)

Then, there's the urge to relabel in order to give a previously stigmatized group a more positive spin.  The adoption of the word "gay" to mean "homosexual" in the 20th century was, in part, to find a positive word to identify people who have throughout history been the targets of the worst sorts of epithets.  In the 1990s, a group of atheists tried the same kind of rebranding, and settled on calling themselves "The Brights" -- a move that to many people, including myself, seemed so self-congratulatory as to be cringeworthy.

More recently, there have been two rather interesting examples of this same sort of thing.  One is the idea of "Indigo Children," which is an increasingly popular label given to kids who are "empathetic, sensitive, intelligent, and don't fit in well."  I can understand the difficulties that parents of sensitive children face -- one of my own sons certainly could be described by those words, and he had a hell of a time making it through the teasing and bullying that seem to be an entrenched part of middle school culture.  But labeling these kids, even with a positive term, doesn't help the situation, and might even make it worse if the label makes the child feel even more different and isolated.  Add to that a pseudoscientific twist that you often see on "Indigo Child" websites -- that "Indigo Children" frequently have paranormal abilities -- and you have a fairly ugly combination of a non-evidence-based false diagnosis with a heaping helping of New-Agey condescension.  (For a particularly egregious example of this, go here -- and note that the article begins with a statement that the easiest way to identify "Indigo Children" is that they have "indigo-colored auras.")

Just yesterday, I found another good example of this -- the idea of the "Alpha Thinker."  Eric Schulke, who wrote the article I linked and who works for the "Movement for Indefinite Life Extension," tells us that Alpha Thinkers "... are creatives, innovators, pioneers. They acutely and agilely navigate an abundance of diverse, fallacy aware thinking. The alpha thinker can’t bring themselves to live at the last outpost and not venture further. They cannot resist poking their finger through the realm of subatomic particles. They can’t stay on this side of the atmosphere. They look into biology and the elements. They want to know why we are here, why the universe and all of existence is here, how far it goes, what is out there, what the hell is going on. Alpha thinkers are the universe’s way of creating the devises [sic] needed to help bring out all of the potential in its elements."

Well, that's just fine and dandy, but how do you know if someone is an "Alpha Thinker?"  It turns out that you more or less have to wait for them to do something smart:  "It is not a college degree that signifies the alpha thinker. As the alpha thinker knows, its [sic] an abundance of fallacy-aware thinking that signifies it...  Alpha thinkers control the elements. They are cosmic titans, the leaders of humankind, the explorers of the universe setting sail with fierce urgency."

Spinoza, Newton, and Thomas Paine, we are told, were "Alpha Thinkers," which strikes me as kind of an odd trio to choose, but I guess there's no denying these three men were bright guys.  Then, we are given two curious pieces of information: (1) whether or not you are an "Alpha Thinker" can be determined by an electroencephalogram; and (2) from "historical times" until now the ratio of "Alpha Thinkers" to ordinary folks has increased from 1 in 99 to 1 in 6.

So, I'm thinking: how can you know that's true, given that the EEG machine was only invented in 1924, and most people in the world will never have an EEG done during their lifetimes?  It seems to me that the label "Alpha Thinker" is just a new way to say "smart person," and Schulke is pulling made-up statistics out of his ass in order to support his point that there's something inherently different about them.  Further evidence of this comes at the end of the article, where Schulke gives the whole thing a New Age twist by saying that "Alpha Thinkers" are here to guide us into the next stage, the "Transhuman Revolution."

Oh, and of course, throughout the article Schulke makes it clear that he's an "Alpha Thinker."  As if there were any doubt of that.

So, there you are.  Today's musings about human nature.  I suspect that all of the above really, in the long haul, does minimal damage, with the possible exception of the misdiagnosis of individuals who are actually mentally ill and who don't receive treatment because they are labeled "Indigo Children" or "Alpha Thinkers," or whatever.  But it is a curious tendency, isn't it?  I think I'll wrap this up here, because I need to go update the database of my birdwatching sightings and see if any of the scientific names have changed.

Species, types, and the No True Scotsman fallacy

One of the most frustrating of logical fallacies is the No True Scotsman fallacy.  It gets its name from an almost certainly apocryphal story, in which a serial rapist and killer is being pursued by the police in Glasgow, and a Scottish MP encourages the police to search amongst the immigrant population of the city.  "No Scotsman would do such a thing," the MP said.

When the criminal was caught, and turned out to be 100% Scottish, the MP was challenged about his remark.

"Well," he said, drawing himself up, "no true Scotsman would have done such a thing!"

The crux of this fallacy is that if you make a statement that turns out, in view of evidence, to be false, all you do is shift your ground -- redefine the terms so as to make your original point unassailable.

Very few other fallacies have such a capacity for making me want to smack my forehead into a wall as this one.  Someone who commits this fallacy can't be pinned down, can't be backed into a corner, can't receive his comeuppance from the most reasoned argument, the most solidly incontrovertible evidence.  The dancing skills of a master of the No True Scotsman fallacy are Dancing With The Stars quality.

All of this comes up because of an online discussion that I read, and (yes) participated in, a couple of days ago, on the topic of the demonstrability of evolution.  Someone, ostensibly a supporter of evolution but seemingly not terribly well-read on the subject, was using such evidence as the fossil record as a support for the idea.  A creationist responded, "The fossil record, and fossil dating, are inaccurate.  You evolutionists always think that bringing us a bunch of bones and shells proves your point, but it doesn't, because no one can really prove how old they were, and none of them show one species turning into another.  You can't show a single example, from the present, of one species becoming another, and yet you want us to believe in your discredited theory."

Well, of course, I couldn't let a comment like that just sit there, so I responded, "Well, actually, yes, I can.  I know about a dozen examples of speciation (one species becoming another) occurring within a human lifetime."

Challenged to produce examples, I gave a few, including the ones that I described in an earlier post (Grass, gulls, mosquitoes, and mice, February 9, 2012), and then sat back on my haunches with a satisfied snort, thinking "Ha.  That sure showed him."

Well.  I should have known better.  His response, which I quote verbatim:  "All you did was show that one grass can become another grass, or a mosquito can become another mosquito.  If you could show me a mosquito that turned into a bird, or something, I might believe you."

Now, wait just a second, here.  You asked me for one thing -- to show one species turning into a different species, in the period of a few decades.  I did so, adhering to the canonical definition of the word species.  And now you're saying that wasn't what you wanted after all -- you want me to show one phylum turning into a different one, in one generation?

So I sat there, sputtering and swearing, and not sure how to answer.  So I said something to the effect that he'd pulled a No True Scotsman on me, and had changed the terms of the question once he saw I could answer it, and he'd damned well better play fair.  He humphed back at me that we evolutionists couldn't really support our points, and we both left the discussion as I suspect most people leave discussions on the internet -- unconvinced and frustrated.  So I was pondering the whole thing, and after taking my blood pressure medications I had a sudden realization of where the confusion was coming from.  It was from the idea of a type of organism.

Most people who aren't educated in the biological sciences (and I'm not including just formal education, here; there are many people who have never taken a single biology class and know plenty about the subject) really don't understand the concept of species.  They think in types.  A bird is one type of thing; a bug is a different one.  If you pressed them, they might admit that there were a few types of birds that seemed inherently different; you have your big birds (ostriches), your medium-sized birds (robins), and your little birds (hummingbirds).  I've had students that have thought this way, and when they hear I'm a birdwatcher, they seem incredulous that this could be a lifelong avocation.  Wouldn't I run out of new birds to see pretty quickly?  When I tell them that there are over 10,000 unique species of birds, they seem not so much awed as uncomprehending.

I suspect that the source of this misapprehension is the same as the source of the general misapprehension regarding the antiquity of the Earth and the origins of life: the bible.  In Leviticus 11, where they go through the whole unclean-foods thing that eventually would be codified as the Kosher Law, they split up the natural world in only the broadest-brush terms; you have your animals that have hooves and chew the cud, various combinations of ones that don't, creatures that have fins and scales and ones that don't, insects that jump and ones that don't, and a few different classes of birds (which, to my eternal amusement, included bats).  And that's pretty much it.  Plants were sorted out into ones that had edible parts (wheat, figs, olives), ones that had useful wood (boxwood, cedar, acacia), and ones that had neither of the above (thorn bushes).  And these distinctions worked perfectly well for a Bronze-Age society; it kept you from eating stuff that was bad for you, told you what you could build stuff from, and so on.  But as a scientific concept, the idea of "types of living things" is pretty ridiculous.  And yet it still seems to live on in people's minds, lo unto this very day.

So, anyway, that was my brief excursion into that least useful of endeavors, the Online Argument.  It gave me a nice example of the No True Scotsman fallacy to tell my Critical Thinking classes about, when we hit that topic in a few weeks.  And it really didn't affect my blood pressure all that much, but it did make me roll my eyes.  Which seems to happen frequently when I get into conversations with creationists.