By any other name...

Scientists have an undeserved reputation for being dry and humorless.

If you doubt the "undeserved" part, consider scientific names.  Because by convention scientific names usually have Greek or Latin roots, they sound pretty sophisticated and fancy -- until you translate them.  The adorable black-footed ferret of the American Rockies is Mustela nigripes, which translates to... "black-footed ferret."  The western diamondback rattlesnake, Crotalus atrox?  Greek for "scary noisemaker."  The name of the mammalian order containing shrews and moles, Eulipotyphla, is kind of insulting.  It means "really fat and blind."  But they only get sillier from there.  How about Eucritta melanolimnetes, a species of amphibian from the Carboniferous Period?  The name means "the real Creature from the Black Lagoon."

And the order of mammals that includes rabbits, Order Lagomorpha?  Translated from Greek, "Lagomorpha" literally means "it's shaped like a bunny."

The privilege of naming a newly-discovered species goes to the discoverer, and if they choose they can name it in honor of someone (it's considered bad form to name it after yourself).  Lots of biologists name species after their teachers or mentors, but the field is wide open.  Entomologists Kelly Miller and Quentin Wheeler named a species of slime-mold beetle after former Vice President Dick Cheney -- whether Agathidium cheneyi was an honor or an insult is open to interpretation.  Some paleontologists working in Madagascar liked to listen to music while they worked, and became convinced that whenever they played Dire Straits, they found lots of new fossils.  Thus, there's a species of Cretaceous dinosaur named Masiakasaurus knopfleri.  (Upon hearing about this, Mark Knopfler allegedly responded, "And people said I was a dinosaur before.")  A genus of carabid beetles, Agra, has a species named Agra schwartzeneggeri.  Terry Erwin, the entomologist responsible for that one, found a number of other Agra species, and thus we have Agra vation, Agra phobia, and Agra cadabra.

You can even name species after fictional characters.  Thus we have a fuzzy mite named Polemistus chewbacca, an Australian moth with marks that resemble a second head named Erechthias beeblebroxi, an Ordovician trilobite named Han solo, a sponge-like fungus from Malaysia named -- I shit you not -- Spongiforma squarepantsii, a cave-dwelling insect from Spain named Gollumjapyx smeagol, and -- my favorite -- a fish from the fjords of New Zealand named Fiordichthys slartibartfasti.

If you get why that last one is fall-out-of-your-chair hilarious, congratulations; you're as big a nerd as I am.

Some are just outright silly.  Consider the Australian wasp discovered by entomologist Arnold Menke in 1977.  He was so delighted at the find that he gave it the scientific name Aha ha.

And I would be remiss in not mentioning a genus of small mollusks named Bittium.  When a related genus of even smaller mollusks was discovered, they named it... you guessed it... Ittibittium.

The reason all this silliness comes up is a discovery that was the subject of a paper in PLOS-One.  Paleontologists working in Brazil found a fossil of a new species of tanystropheid, a group of Triassic dinosaurs with such bizarrely elongated necks that scientists are still trying to figure out how they walked without doing a face-plant.  (One possible answer is that they were aquatic, but that's not certain.)

Tanystropheus longobardicus, which is itself sort of a goofy name.  It means "long, bent thing with a long beard."  I have to wonder how many controlled substances the scientists had partaken of before they came up with that one.  [Image licensed under the Creative Commons Nobu Tamura email: nobu.tamura@yahoo.com http://spinops.blogspot.com/, Tanystropheus NT small, CC BY-SA 4.0]

Anyhow, the new species was christened Elessaurus gondwanoccidens.  The species name isn't so interesting -- it means "from western Gondwana," after one of the supercontinents around during the Triassic Period -- but the genus name is clever.  It plays on the usual -saurus (Greek for "lizard") ending of many genera of dinosaurs, but was actually named for Elessar, one of the many monikers of King Aragorn II from The Lord of the Rings.  Elessar, which means "elf-stone" in J. R. R. Tolkien's wonderful conlang Quenya, was the title Aragorn took after Sauron got his clocks cleaned by Frodo et al. and the former Strider became the King of Gondor.

So that's a look at the deadly serious, dry-as-dust subject of biological taxonomy.  And I haven't even gotten into the off-color ones, which is a whole subject in and of itself.  Suffice it to say that orchid is Greek for "testicle," and there's a mushroom with the scientific name Phallus impudicus ("shameless penis").  I'll leave you to research the rest of that topic on your own.

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Animalia paradoxa

Carl Linnaeus was born in Råshult, Sweden, on 23 May 1707.  His father Nils was the minister of the parish of Stenbrohult but was also an avid gardener, and the story goes that when Carl was young and got upset, Nils would bring him a flower and tell the little boy its name, and that always calmed him down.

The love of botany -- and of knowing the names of living things -- was to shape Carl Linnaeus's life.  Prior to his time, there was no systematic way of giving names to species; there were dozens of names in various languages for the same species, and sometimes several different names in the same language.  Additionally, the fact that this is before the recognition of the relatedness of all life meant that things were named simply by their superficial appearance, which may or may not indicate an underlying relationship.  We still have some leftovers from this haphazard practice, such as the various birds called buntings (from the Middle English buntynge, "small bird") that aren't necessarily related to each other.  (For example, the North American indigo bunting is in the cardinal family; the European pine bunting in the family Emberizidae.) 

Young Linnaeus was lucky enough not only to have supportive parents, but a variety of people who recognized his intellect and ability and nurtured him in his studies.  (Amongst them was the scientist and polymath Olof Celsius, whose nephew Anders gave us the Celsius temperature scale.)  He was primarily interested in botany, but quickly became frustrated with the fact that the same plant could have six different names in six different villages -- and worse still, it was impossible to communicate taxonomic information clearly to botanists in other countries, where the names would have come from their native language.

So he decided to do something about it.

Linnaeus came up with the idea of binomial nomenclature -- the "two-name naming system," more commonly called "scientific names."  Each species would be assigned a unique and unambiguous name made of the genus and species names, each derived from Latin or Greek (which were the common languages of science at the time).  The genus would include various related species.  His determinations of who was related to whom were based upon appearance -- this is long before genetics became the sine qua non of systematics -- and some of Linnaeus's classifications have been revised in the 250-odd years since he wrote his magnum opus, the Systema Naturae.  But even so, the system he created is the one we still use today.

And this is why scientists the world over will know, if you say Mustela nigripes, that you are talking about the black-footed ferret.  (The scientific name translates to... "black-footed ferret."  Just because they're fancy-sounding Latin and Greek words doesn't mean they're all that revelatory.)

So Linnaeus took the first steps toward ordering the natural world.  But what is less well-known is that he included a few animals in his book that are more than a little suspect -- and labeled them as such, illustrating an admirable dedication to honoring hard evidence as the touchstone for scientific understanding.

In a section called "Animalia paradoxa," Linnaeus listed some "species" that had been reported by others, but for which there was no clear evidence.  From the tone of his writing, it's obvious he was doubtful they existed at all, and was only including them to point out that any reports of them were based upon hearsay.  These included the following genera, along with his description of them:

• Hydra: "body of a snake, with two feet, seven necks and the same number of heads, lacking wings, preserved in Hamburg, similar to the description of the Hydra of the Apocalypse of St.John chapters 12 and 13.  And it is provided by very many as a true species of animal, but falsely.  Nature for itself and always the similar, never naturally makes multiple heads on one body.  Fraud and artifice, as we ourselves saw [on it] teeth of a weasel, different from teeth of an Amphibian [or reptile], easily detected."
• Monoceros: "Monoceros of the older [generations], body of a horse, feet of a 'wild animal,' horn straight, long, spirally twisted.  It is a figment of painters.  The Monodon of Artedi [= narwhal] has the same manner of horn, but the other parts of its body are very different."
• Satyrus: "Has a tail, hairy, bearded, with a manlike body, gesticulating much, very fallacious, is a species of monkey, if ever one has been seen."
• Borometz: "The Borometz or Scythian Lamb is reckoned with plants, and is similar to a lamb; whose stalk coming out of the ground enters an umbilicus; and the same is said to be provided with blood from by chance devouring wild animals.  But it is put together artificially from roots of American ferns. But naturally it is an allegorical description of an embryo of a sheep, as has all attributed data."
• Manticora: "Has the face of a decrepit old man, body of a lion, tail starred with sharp points."

A manticore, from Johannes Jonston's Historiae Naturalis (1650) [Image is in the Public Domain]

I've always admired Linnaeus -- like him, I've been fascinated with the names of things since I was little, and started out with plants -- but knowing about his commitment to avoid getting drawn into the superstition and credulity of his time makes me even more fond of him.  He was unafraid to call out the Animalia paradoxa as probable hoaxes, and that determination to follow the rules of scientific skepticism still guides taxonomists to this day.

Of course, sometimes there are some bizarre "forms most beautiful and most wonderful" in the natural world, to borrow a phrase from Darwin.  When the first taxidermied pelts and skeletons of the duck-billed platypus were sent from Australia back to England, many English scientists thought they were a prank -- that someone had stitched together the remains of various animals in an attempt to play a joke.  And once convinced that they were real, the first scientific name given to the platypus was...

... Ornithorhynchus ("bird-billed") paradoxa.

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The nibblers

I'm always on the lookout for fascinating, provocative topics for Skeptophilia, but even so, it's seldom that I read a scientific paper with my jaw hanging open.  But that was the reaction I had to a paper from a couple of months ago in Nature that I just stumbled across yesterday.

First, a bit of background.

Based on the same kind of genetic evidence I described in yesterday's post, biologists have divided all living things into three domains: Eukarya, Bacteria, and Archaea.  Eukarya contains eukaryotes -- organisms with true nuclei and complex systems of organelles -- and are broken down into four kingdoms: protists, plants, fungi, and animals.  Bacteria contains, well, bacteria; all the familiar groups of single-celled organisms that lack nuclei and most of the other membrane-bound organelles.  Archaea are superficially bacteria-like; they're mostly known from environments most other living things would consider hostile, like extremely salty water, anaerobic mud, and acidic hot springs.  In fact, they used to be called archaebacteria (and lumped together with Bacteria into "Kingdom Monera") until it was discovered in 1977 by Carl Woese that Archaea are more genetically similar to eukaryotes like ourselves than they are to ordinary bacteria, and forced a complete revision of how taxonomy is done.

So things have stood since 1977: three domains (Bacteria, Archaea, and Eukarya), and within Eukarya four kingdoms (Protista, Plantae, Fungi, and Animalia).

But now a team led by Denis Tikhonenkov, of the Russian Academy of Scientists, has published a paper called "Microbial Predators Form a New Supergroup of Eukaryotes" that looks like it's going to force another overhaul of the tree of life.

Rather than trying to summarize, I'm going to quote directly from the Tikhonenkov et al. paper so you get the full impact:

Molecular phylogenetics of microbial eukaryotes has reshaped the tree of life by establishing broad taxonomic divisions, termed supergroups, that supersede the traditional kingdoms of animals, fungi and plants, and encompass a much greater breadth of eukaryotic diversity.  The vast majority of newly discovered species fall into a small number of known supergroups.  Recently, however, a handful of species with no clear relationship to other supergroups have been described, raising questions about the nature and degree of undiscovered diversity, and exposing the limitations of strictly molecular-based exploration.  Here we report ten previously undescribed strains of microbial predators isolated through culture that collectively form a diverse new supergroup of eukaryotes, termed Provora.  The Provora supergroup is genetically, morphologically and behaviourally distinct from other eukaryotes, and comprises two divergent clades of predators—Nebulidia and Nibbleridia—that are superficially similar to each other, but differ fundamentally in ultrastructure, behaviour and gene content.  These predators are globally distributed in marine and freshwater environments, but are numerically rare and have consequently been overlooked by molecular-diversity surveys. In the age of high-throughput analyses, investigation of eukaryotic diversity through culture remains indispensable for the discovery of rare but ecologically and evolutionarily important eukaryotes.

The members of Provora are distinguished not only genetically but by their behavior; to my eye they look a bit like a basketball with tentacles, using weird little tooth-like structures to nibble their way forward as they creep along.  (Thus "nibblerid," which is their actual name, despite the fact that it sounds like a comical monster species from Doctor Who.)  The first one discovered (in 2017), the euphoniously-named Ancoracysta twista, is a predator on tropical coral, and was found in (of all places) a home aquarium.  Since then, they've been found all over the place, although they're not common anywhere; the only place they've never been seen is on land.  But just about every aquatic environment, fresh or marine, has provorans of some kind.

An electron micrograph of a provoran [Image from Tikhonenkov et al.]

The provorans appear to be closely related to no other eukaryote, and Tikhonenkov et al. are proposing that they warrant placement in their own supergroup (usually known as a "kingdom").  But it raises questions of how many more outlier supergroups there are.  A 2022 analysis by Sijia Liu et al. estimated the number of microbial species on Earth at somewhere around three million, of which only twenty percent have been classified.  It's easy to overlook them, given that they're microscopic -- but that means there could be dozens of other branches of the tree of life out there about which we know nothing. 

It's amazing how much more sophisticated our understanding of evolutionary descent has become.  When I was a kid (back in medieval times), we learned in science class that there were three divisions; animals, plants, and microbes.  (I even had a Golden Guide called Non-Flowering Plants -- which included mushrooms.)  Then it was found that fungi and animals were more closely related than fungi and plants, and that microbes with nuclei and organelles (like amoebas) were vastly different from those without (like bacteria).  There it stood till Woese came along in 1977 and told us that the bacteria weren't a single group, either.

And now we've got another new branch to add to the tree.  The nibblers.  Further illustrating that we don't have to look into outer space to find new and astonishing things to study; there is a ton we don't know about what's right here on Earth.

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A flower in amber

Today's post comes to us purely from the "Okay, This Is Cool" department.

I've been fascinated with plant taxonomy since long before I knew the word.  I couldn't have been more than about seven years old when a friend of the family gave me a lovely old book by the early twentieth-century botanical illustrator F. Schuyler Mathews called Field Book to American Trees and Shrubs.  Not only did I use it to try to identify every tree in my neighborhood, I found out something about how plants are classified -- not by leaf shape (which at the time seemed to me the most logical characteristic to use) but by flower structure.  That's when I learned that beeches, oaks, and chestnuts are in the same family; so are rhododendrons, heather, blueberries, and cranberries; so are birches, alders, and hazelnuts; so, most surprisingly to me, are willows and poplars.

It was also my first introduction to how difficult the classification of organisms actually is, something I learned a great deal more about when I took evolutionary biology in college.  The standout from Mathews's book in that respect is the genus Crataegus, hawthorns, of which he lists (and illustrates with beautiful woodcuts) over a hundred species, many of which looked (and still look) exactly alike to my untrained eye.  Taxonomists argue vehemently over how particular species are to be placed and who is related to whom, although the advent of genetic analysis and cladistics has now provided a more rigorous standard method for classification.

What I didn't know, even after my umpteenth perusal of the Field Book, was that the strange and magical-sounding scientific names of plant families Mathews mentions are barely scratching the surface.  You go elsewhere in the world, all bets are off; you'll run into plants that are in families with no members at all in the United States.  An odd historical filigree is that one of the reasons the British colonizers felt so at home in northeastern North America was that the plants were familiar; oaks, ashes, beeches, birches, willows, maples, pines, and spruces are found in both places (although the exact species vary).  Go to southeast Asia, South America, or pretty much anywhere in Africa, though, and even someone well-versed in the plants of North America and western Europe might well not recognize a single species.  I found that to be the case in Malaysia -- a (very) little bit of reading about the flora of the places I visited gave me at least a name or two, but I'd say 95% of what I saw I couldn't even have ventured a guess about.

One of the many peculiar plants I saw in the rain forests of Malaysia -- I still don't know what it is, but it sure has a cool-looking leaf.

The reason this comes up is an article sent to me by a friend and loyal reader of Skeptophilia about a fossil from Myanmar that was the subject of a recent paper in The Journal of the Botanical Institute of Texas.  Encased in amber, the flower is almost perfectly preserved -- despite being just this side of one hundred million years old, a point at which the dinosaurs would still be in charge of everything for another thirty-four million years.

If it sounds like figuring out the taxonomy of modern plants is a challenge, it gets way worse when you start looking at plant fossils.  Not only do we not have living plants to analyze genetically, often what we're having to judge by is what's left of a leaf or two.  Fortunately, in this case what the researchers have is a preserved flower -- remember that flowering plants are classified by flower structure -- and that was enough to convince them that they were not only looking at a previously unrecorded species, but a previously unrecorded genus -- and possibly a whole new family.

The flower of the newly-named Micropetasos burmensis [Image by George Poinar of Oregon State University)

Most fascinating of all, the researchers aren't even sure how Micropetasos fits into known plant systematics.  The paper says about all we can say so far is that it seems to belong to the clade Pentapetalae -- which doesn't narrow it down much, as that same clade contains such distantly-related plants as roses, asters, cacti, cucumbers, and cabbage.

Long-time readers might recognize the name of the lead author of the paper -- George Poinar.  This isn't the first time he's pulled off this kind of botanical coup.  About a year and a half ago, I wrote about another of Poinar's discoveries in Burmese amber, a little flower called Valviloculus pleristaminis, which also was of uncertain placement amongst known plant families.  Amazing that in bits of fossilized tree sap we can find remnants that allow us to piece together the flora of the Cretaceous Period.

Of course, what it always brings up is the elegiac thought that however many fossils we find, the vast majority of species that have existed on Earth left no traces whatsoever that have survived to today.  If we were to take a time machine back a hundred million years, Micropetasos and Valviloculus we might perhaps recognize from Poinar's work; but there would be thousands more that are completely unfamiliar.  The lion's share of prehistory is unknown -- and unknowable.

But at least we have one more little piece, a tiny flower in amber.  When it was growing, there were triceratopses and T. rexes stomping around, and our closest ancestors were small, rodent-like critters that still had tens of millions of years of evolution before they'd even become primates.  That we can have any sort of lens into that distant, ancient world is astonishing.

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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!]

The evolution of Little Red Riding Hood

Every once in a while, I'll run across a piece of scientific research that is so creative and clever that it just warms my heart, and I felt this way yesterday when I stumbled onto a link to the article in PLoS ONE called "The Phylogeny of Little Red Riding Hood," by Jamshid Tehrani of the University of Bristol.

The reason I was delighted by Tehrani's paper is that it combines two subjects I love -- evolutionary biology and mythology and folklore.  The gist of what Tehrani did is to use a technique most commonly used to assemble species into "star diagrams" -- cladistic bootstrap analysis -- to analyze worldwide versions of the "Little Red Riding Hood" story to see to what degree a version in (for example) Senegal was related to one in Germany.

Cladistic bootstrap analysis generates something called a "star diagram" -- not, generally, a pedigree or family tree, because we don't know the exact identity of the common ancestor to all of the members of the tree, all we can tell is how closely related current individuals are.  Think, for example, of what it would look like if you assembled the living members of your family group this way -- you'd see clusters of close relatives linked together (you, your siblings, and your first cousins, for example) -- and further away would be other clusters, made up of more distant relatives grouped with their near family members.

So Tehrani did this with the "Little Red Riding Hood" story, by looking at the similarities and differences, from subtle to major, between the way the tale is told in different locations.  Apparently there are versions of it all over the world -- not only the Grimm Brothers Fairy Tales variety (the one I know the best), but from Africa, the Middle East, India, China, Korea, and Japan.  Oral transmission of stories is much like biological evolution; there are mutations (people change the story by misremembering it, dropping some pieces, embellishment, and so on) and there is selection (the best versions, told by the best storytellers, are more likely to be passed on).  And thus, the whole thing unfolds like an evolutionary lineage.

In Tehrani's analysis, he found three big branches -- the African branch (where the story is usually called "The Wolf and the Kids"), the East Asian branch ("Tiger Grandmother"), and the European/Middle Eastern Branch ("Little Red Riding Hood," "Catterinella," and "The Story of Grandmother").  (For the main differences in the different branches, which are fascinating but too long to be quoted here in full, check out the link to Tehrani's paper.)

Put all together, Tehrani came up with the following cladogram:

WK = "The Wolf and the Kids," TG = "Tiger Grandmother," "Catt" = "Catterinella," GM = "The Story of Grandmother," and RH = "Little Red Riding Hood;" the others are less common variations that Tehrani was able to place on his star diagram.

The whole thing just makes me very, very happy, and leaves me smiling with my big, sharp, wolflike teeth.

Pure research has been criticized by some as being pointless, and this is a stance that I absolutely abhor.  There is a completely practical reason to support, fund, and otherwise encourage pure research -- and that is, we have no idea yet what application some technique or discovery might have in the future.  A great deal of highly useful, human-centered science has been uncovered by scientists playing around in their labs with no other immediate goal than to study some small bit of the universe.  Further, the mere application of raw creativity to a problem -- using the tools of cladistics, say, to analyze a folk tale -- can act as an impetus to other minds, elsewhere, encouraging them to approach the problems we face in novel ways.

But I think it's more than that.  The fundamental truth here is that human mind needs to be exercised.  The "what good is it?" attitude is not only anti-science, it is anti-intellectual.  It devalues inquiry, curiosity, and creativity.  It asks the question "how does this benefit humanity?" in such a way as to imply that the sheer joy of comprehending deeply the world around us is not a benefit in and of itself.

It may be that Tehrani's jewel of a paper will have no lasting impact on humanity as a whole.  I'm perfectly okay with that, and I suspect Tehrani would be, as well.  We need to make our brains buckle down to the "important stuff," yes; but we also need to let them out to play sometimes, a lesson that the men and women currently overseeing our educational system need to learn.  In a quote that seems unusually apt, considering the subject of Tehrani's research, Albert Einstein said: "I am enough of an artist to draw freely upon my imagination.  Imagination is more important than knowledge.  Knowledge is limited.  Imagination encircles the world." 

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I was an undergraduate when the original Cosmos, with Carl Sagan, was launched, and being a physics major and an astronomy buff, I was absolutely transfixed.  Me and my co-nerd buddies looked forward to the new episode each week and eagerly discussed it the following day between classes.  And one of the most famous lines from the show -- ask any Sagan devotee -- is, "If you want to make an apple pie from scratch, first you must invent the universe."

Sagan used this quip as a launching point into discussing the makeup of the universe on the atomic level, and where those atoms had come from -- some primordial, all the way to the Big Bang (hydrogen and helium), and the rest formed in the interiors of stars.  (Giving rise to two of his other famous quotes: "We are made of star-stuff," and "We are a way for the universe to know itself.")

Since Sagan's tragic death in 1996 at the age of 62 from a rare blood cancer, astrophysics has continued to extend what we know about where everything comes from.  And now, experimental physicist Harry Cliff has put together that knowledge in a package accessible to the non-scientist, and titled it How to Make an Apple Pie from Scratch: In Search of the Recipe for our Universe, From the Origin of Atoms to the Big Bang.  It's a brilliant exposition of our latest understanding of the stuff that makes up apple pies, you, me, the planet, and the stars.  If you want to know where the atoms that form the universe originated, or just want to have your mind blown, this is the book for you.

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

Dire straits

During my junior year as an undergraduate, I had to take a humanities elective as part of my degree requirements and settled upon a class in archaeology, a subject which had always been an interest of mine.  The course description sounded pretty cool, and I thought it would be a fun challenge to take on.

However, I had not reckoned with the fact that the professor, one Dr. Servello, seemed to have a screw loose.  I found this out early on when one day he caught a glimpse of some genealogical charts in my binder (part of a family tree project I was doing as an anniversary gift for my parents), and added that to the fact that I wore a St. Christopher medal, and concluded from this that I was a member of a cult.

He kept me after class that day to ask me what my cult believed.  When I protested that in fact, I did not belong to a cult, he became genuinely concerned and said, "No, no, you don't need to be afraid to tell me!  I'm fascinated by alternative belief systems!"

But the most striking thing about Dr. Servello was that he never admitted to being wrong.  About anything.  He had a nearly Trumpian ability to continue arguing his point even after having hard evidence that he'd misspoken thrown into his face.  One time he argued for a half-hour over the correct pronunciation of a Chinese archaeological site -- with a student from China.  In very short order we learned not to bother contradicting him about any of the wacky things he said, because it never accomplished anything but wasting inordinate amounts of class time.

But as in any group, in the class there was That Guy.  He felt duty-bound to challenge Dr. Servello every time he made shit up, which was usually several times per class.  But the one that stands out in my memory was the epic argument that ensued when Dr. Servello was telling us about dire wolves.

"It's one of the largest predatory mammals ever," he said, with great conviction.  "They were fourteen feet tall at the shoulder."

Simultaneously all of the two-dozen-odd students in the class gave Dr. Servello the human equivalent of the Canine Head Tilt of Confusion.  Even so, most of us just added it to our growing list of bizarre Servello-isms, and were prepared to let it go.

But not That Guy.

"That's impossible," he said flatly.

"No, no, they were huge!" Dr. Servello insisted.  "Biggest predatory mammal ever!"

"That's impossible," That Guy said through clenched teeth.  "A wolf that big could look into a second-story window."

There followed a good forty-five minute-long argument, ending with That Guy grabbing his binder and storming out of class.

I related the story to some friends later.  These friends always waited with bated breath for me to come out of archaeology class, to see what lunatic pronouncements Dr. Servello had made that day.  This one, however, was impressive even by comparison to his previous efforts.

"That," one of my friends said reverently, "is one big bow-wow."

The topic comes up because while dire wolves are not fourteen feet high at the shoulder (which, for the record, would make them taller than a full-grown male African elephant) they are a fascinating species.  They were pretty impressive animals -- adults averaged a meter high at the shoulder and a little over two meters from tip to tail -- but their skeletal morphology led taxonomists to believe they were simply larger cousins of the North American gray wolf, descended from a parental species that had crossed the Bering Land Bridge into Eurasia.  But that idea is being challenged by some new analysis of DNA from dire wolves who were trapped in the La Brea Tar Seeps forty-some-odd thousand years ago, and a comparison with gray wolf DNA supports a conclusion that the last common ancestry of the two species was around 5.7 million years ago, before the ancestors of today's gray wolves had crossed into North America.

Dire wolf skeleton in the Sternberg Museum, Hays, Kansas [Image licensed under the Creative Commons James St. John, Canis dirus Sternberg Museum, CC BY 2.0]

The research, which was the subject of a paper in Nature this week, suggests that the morphological similarities between gray wolves and dire wolves are due to convergent evolution -- the evolution of superficially similar traits in distantly-related species that are under the same selective pressures.  And of course, these two were starting out closer in structure anyhow; no one is doubting that dire wolves are canids.  But the DNA difference is striking enough that the researchers are proposing to take the dire wolf out of the genus Canis and place it in its own new genus -- Aenocyon, meaning "terrible wolf."

"These results totally shake up the idea that dire wolves were just bigger cousins of gray wolves," said paleontologist Grant Zazula, who was not involved in the new study, in an interview with Scientific American.  "The study of ancient DNA and proteins from fossil bones is rapidly rewriting the ice age and more recent history of North America’s mammals."

It is not, for the record, rewriting how big they were.  As terrible as Aenocyon was, it wouldn't have towered over an elephant.  However, it is thought to have had the greatest bite force of any canid ever, and as it seems to have been a pack hunter, could take down some of the megaherbivores of its time -- giant ground sloths, North American camels and horses, bison... and even mastodons.

But like most of the Ice Age megafauna, the changing climate at the end of the Pleistocene put the dire wolf in dire straits.  They're thought to have persisted in areas of the northern Rockies as little as 9,500 years ago, but when the big prey animals began to disappear, selection favored their smaller (now thought to be distant) cousins, gray wolves.

Which is kind of a shame.  They were impressive beasts, even if they weren't the big bow-wows Dr. Servello claimed they were.  And it's nice to clarify at least a little more of their genetics and history, turning a lens on a species we thought we understood.

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As a biologist, I've usually thought of myself as immune to being grossed out.  But I have to admit I was a little shocked to find out that the human microbiome -- the collection of bacteria and fungi that live in and on us -- outnumber actual human cells by a factor of ten.

You read that right: if you counted up all the cells in and on the surface of your body, for every one human cell with human DNA, there'd be ten cells of microorganisms, coming from over a thousand different species.

And that's in healthy humans.  This idea that "bacteria = bad" is profoundly wrong; not only do a lot of bacteria perform useful functions, producing products like yogurt, cheese, and the familiar flavor and aroma of chocolate, they directly contribute to good health.  Anyone who has been on an antibiotic long-term knows that wiping out the beneficial bacteria in your gut can lead to some pretty unpleasant side effects; most current treatments for bacterial infections kill the good guys along with the bad, leading to an imbalance in your microbiome that can persist for months afterward.

In The Human Superorganism: How the Microbiome is Revolutionizing the Pursuit of a Healthy Life, microbiologist Rodney Dietert shows how a lot of debilitating diseases, from asthma to allergies to irritable bowel syndrome to the inflammation that is at the root of heart disease, might be attributable to disturbances in the body's microbiome.  His contention is that restoring the normal microbiome should be the first line of treatment for these diseases, not the medications that often throw the microbiome further out of whack.

His book is fascinating and controversial, but his reasoning (and the experimental research he draws upon) is stellar.  If you're interested in health-related topics, you should read The Human Superorganism.  You'll never look at your own body the same way again.

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

Elephant shrews, babblers, and stilt mice

Because I'm tired of doomscrolling on Twitter and getting more and more discouraged about what's going on in the United States right now, today we're going to focus on: cool zoological discoveries.

In the last few weeks, there have been three papers that look at some amazing research on various animal species.  Let's start with the one in the Zoological Journal of the Linnean Society that described two new species of the rodent group with the amusing name "stilt mice" -- African mice with extra-long feet they stand upright on (a little like kangaroos).  If this isn't weird enough, they are also aquatic.

It's been a difficult group to study.  One of the stilt mice was known from a single specimen collected in Ethiopia 93 years ago, and had not been seen since.  This new study didn't find any more of that species -- scientists surmise that it was already on the brink of extinction when the specimen was collected -- but found what are probably its closest cousins.

"It's underappreciated how little is known about the biodiversity of small mammals, especially in tropical parts of the world," said Tom Giarla, professor of biology at Siena College in New York and lead author of the study.  "We're not discovering a whole lot of new lions, tigers, and bears, but there's an incredible potential for discovery of new species of small mammals because they're tough to find.  And they're sort of underappreciated animals -- they're really cool when you start to learn about their ecology.  These are semi-aquatic mice, so they're not just your average, everyday rodents."

[Image courtesy of Velizar Simeonovski, Field Museum]

Study co-author Julian Kerbis Peterhans, researcher at the Field Museum, agrees.  "These mice are long-footed, kind of like a kangaroo.  They sit up on their haunches, and they wade through shallow streams with their whiskers on the water's surface detecting movements, like sonar.  They have unusually large brains in order to process this sensory information from their whiskers when they hunt. They're cute, too.  When I caught my first one some thirty years ago, it was the most beautiful African mouse I'd ever seen, it had water repellent fur that's very thick and lush and warm and cozy.  They're incredibly soft, and they have this remarkable snow-white belly."

The second paper appeared in the journal Biotropica, and is a study of a bird called the Sulawesi babbler (Pellorneum celebense) that lives on a number of islands in eastern Indonesia.  What the researchers found was that the babblers were undergoing rapid evolution on the smaller islands in its range -- the birds on smaller islands had a greater amount of sexual dimorphism (physical difference between the sexes) than birds on larger islands.  In particular, the size difference was measurably greater on the small islands of Kabaena, Muna, and Buton.

[Image licensed under the Creative Commons A.S.Kono, Pelanduk sulawesi 1, CC BY-SA 3.0]

What the zoologists think is going on is that on smaller islands, with limited resources, having high sexual dimorphism helps to decrease competition if the resources are partitioned.  Partitioning is seen in a lot of groups of related species -- the wood warblers of my home state of New York are a good example, where you might have six or seven species of small, forest-dwelling, insect-eating birds in the same quarter of an acre of woods.  The way they've "solved" the problem of high competition -- and I put "solved" in quotation marks, because of course the birds didn't figure it out -- is that they each occupy different bits of the habitat.  Blackburnian warblers are usually high up in the treetops, yellow-rumped warblers in the low understory, black-throated-blue warblers in the middle parts of trees, and so on.

It's a remarkably efficient way of decreasing interspecific competition.

But this is one of only a handful of cases I know of where the resources are partitioned between different sexes of the same species.  (The others I'm aware of are some tropical hummingbirds, where the bill shapes of males and females are adapted to fit different species of flowers, and the extinct huia, a bird from New Zealand for whom the male and female bill shape were so different you might well think they're different species.)

The third paper is about the rediscovery of an animal that hasn't been seen for fifty years -- a species of elephant shrew from Somalia.  Elephant shrews are neither shrews nor (obviously) elephants.  They have a superficial similarity to shrews, but genetic analysis has shown that they are actually more closely related to elephants than they are to shrews.  (Another indicator that appearance has little relevance to genetic closeness.)  They're in their own order, Macroscelidia.

[Image licensed under the Creative Commons Galen B. Rathbun, Petrosaltator rozeti-Zootaxa, CC BY 3.0]

In any case, the Somali sengi (Elephantulus revoilii) was known from thirty-nine different specimens in museums, but hadn't been seen in the wild in fifty years -- until now.  A colony of them was discovered in the country of Djibouti, the exact location of which is being kept secret.

The rediscovery, and the genetic information scientists are gleaning from these animals, looks like it's going to force a re-analysis of the taxonomy of the group, with the Somali sengi ended up in its own, new genus (Galegeeska).  The research is ongoing, and we'll undoubtedly be finding out more about these strange little animals of the east African desert.

So that's our news from the zoological world for today.  All in all, a much happier topic than a lot of others I could have chosen.  Better to focus, at least for a while, on the wonderful and multifarious critters out there in the world -- many of which we have just begun to understand.

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One of my favorite TED talks is by the neurophysiologist David Eagleman, who combines two things that don't always show up together; intelligence and scientific insight, and the ability to explain complex ideas in a way that a layperson can understand and appreciate.

His first book, Incognito, was a wonderful introduction to the workings of the human brain, and in my opinion is one of the best books out there on the subject.  So I was thrilled to see he had a new book out -- and this one is the Skeptophilia book recommendation of the week.

In Livewired: The Inside Story of the Ever-Changing Brain, Eagleman looks at the brain in a new way; not as a static bunch of parts that work together to power your mind and your body, but as a dynamic network that is constantly shifting to maximize its efficiency.  What you probably learned in high school biology -- that your brain never regenerates lost neurons -- is misleading.  It may be true that you don't grow any new neural cells, but you're always adding new connections and new pathways.

Understanding how this happens is the key to figuring out how we learn.

In his usual fascinating fashion, Eagleman lays out the frontiers of neuroscience, giving you a glimpse of what's going on inside your skull as you read his book -- which is not only amusingly self-referential, but is kind of mind-blowing.  I can't recommend his book highly enough.

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

Fishy business

My evolutionary biology professor told our class, many years ago, "The only reason we came up with the word species is because humans have no near relatives."

It's a comment that has stuck with me.  We perceive species as being these little cubbyholes with impenetrable sides, and once you've filed something there, it stays put.  Of course a polar bear and a grizzly bear are different species.  How could they be otherwise?

But when you start pushing at the definition a little, you find that it gives way almost immediately.  Ask some non-scientist how they know polar bears and grizzly bears are different species, and you'll likely get an answer like, "Because they look completely different."  And, to be fair, that's more or less how the father of taxonomy, Carl Linnaeus, did it.

Problems creep in almost immediately, though.  The "of course different species" polar and grizzly bears look far more alike than do, say, a chihuahua and a St. Bernard.  (Imagine trying to convince an alien biologist that those two are members of the same species.)  So very quickly, scientists were forced into refining the definition so as to capture the separateness of two different species in such a way that the term could be applied consistently.

What they ultimately landed on was the canonical definition used in just about every biology textbook in the world: "Members of the same species are capable of potentially interbreeding and producing viable and fertile offspring."  (The "fertile" part had to be added because of the famous example of a horse and a donkey being able to produce a viable hybrid -- but that hybrid, the mule, is almost always infertile.)

The problem was, even that wasn't enough to clarify things. Polar bears and grizzly bears, for example, can and do hybridize in the wild, and the offspring (the rather unfortunately-named "pizzly bear") are almost always fertile.  This isn't an aberration.  These kinds of situations are common in the wild.  In fact, in my part of the world, there are two birds that look dramatically different -- the blue-winged warbler and the golden-winged warbler -- but they will happily crossbreed.  When the hybrids were first observed by scientists, they were different enough from both parents that it was thought they were a third separate species, which was called Brewster's warbler.  It was only after long observation that biologists figured out what was going on -- especially given that "Brewster's warblers" are potentially interfertile with either parental species.

In fact, the more you press the definition, the more it falls apart, the more exceptions you find.  Today's taxonomists are usually wary about labeling something a "species" -- or when they do, they're aware that it's potentially an artificial distinction that has no particular technical relevance.  They are much more comfortable talking about genetic overlap and most recent common ancestry, which at least are measurable.

The reason all this comes up is because of a startling discovery brought to my attention by a friend and long-time loyal reader of Skeptophilia.  Researchers in Hungary have produced a hybrid between an American paddlefish and a Russian sturgeon -- two species no one could confuse with each other -- and they appear to be fertile, and normal in every other way.

The more you look at these "sturddlefish," the more shocking they get.  Sturgeon and paddlefish are not only separate species, they're in separate families -- two layers of classification above species.  "I’m still confused," said Prosanta Chakrabarty, ichthyologist at Louisiana State University.  "My jaw is still on the floor.  It’s like if they had a cow and a giraffe make a baby."

He quickly amended that statement -- giraffes and cows have a recent common ancestor only a few million years ago, whereas paddlefish and sturgeons have been separate lineages for 184 million years.  To get anything comparable, Chakrabarty said, you'd have to have something like a human coming out of a platypus egg.

The scientists believe that the reason this happened is because of the relatively slow rate of evolution of both lineages (especially the sturgeons).  Sturgeons now look pretty similar to sturgeons two hundred million years ago, while almost all of the mammalian biodiversity you see around you -- divergence between, say, a raccoon and a squirrel -- happened since the Cretaceous Extinction, 66 million years ago.  But even so, it's pretty remarkable.  To my eye, paddlefish and sturgeon look way more different than lots of pairs of species that can't interbreed, so once again, we're confronted with the fact that the concept of species isn't what we thought it was -- if it has any biological relevance at all.

Atlantic Sturgeon (Acipenser oxyrhynchus)

American Paddlefish (Polyodon spathula)  [Both this and the above image are in the Public Domain]

This brings us back to the unsettling (but exciting) fact that whenever we think we have everything figured out, nature reaches out and astonishes us.  It's why I'll never tire of biology -- to paraphrase Socrates, the more we know, the more we realize how little we know.

But one thing I know for sure is that the biologists really need to come up with better names than "sturddlefish" and "pizzly bear."

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This week's Skeptophilia book recommendation of the week is by the brilliant Dutch animal behaviorist Frans de Waal, whose work with capuchin monkeys and chimps has elucidated not only their behavior, but the origins of a lot of our own.  (For a taste of his work, watch the brilliant TED talk he did called "Moral Behavior in Animals.")

In his book Mama's Last Hug: Animal Emotions and What They Tell Us About Ourselves, de Waal looks at this topic in more detail, telling riveting stories about the emotions animals experience, and showing that their inner world is more like ours than we usually realize.  Our feelings of love, hate, jealousy, empathy, disgust, fear, and joy are not unique to humans, but have their roots in our distant ancestry -- and are shared by many, if not most, mammalian species.

If you're interested in animal behavior, Mama's Last Hug is a must-read.  In it, you'll find out that non-human animals have a rich emotional life, and one that resembles our own to a startling degree.  In looking at other animals, we are holding up a mirror to ourselves.

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