June 29, 2024 • 58 mins
In this classic episode of Stuff to Blow Your Mind, Robert and Joe consider the form and evolution of the horse hoof, as well as related adaptations. (originally published 06/13/2023)
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Speaker 1 (00:06):
Hey, welcome to Stuff to Blow your Mind. It's Saturday.
It's time for a vault episode and this is going
to be Hoof's Part two, which originally published six thirteen,
twenty twenty three.
Speaker 2 (00:17):
Please enjoy Welcome to Stuff to Blow Your Mind, a
production of iHeartRadio.
Speaker 1 (00:31):
Hey, welcome to Stuff to Blow your Mind. My name
is Robert Lamb.
Speaker 3 (00:35):
And I'm Joe McCormick, and we're back with part two
of our series on the horse hoof. Now. In part one,
we discussed the anatomical form of the horse hoof, with
an emphasis on the alarming fact that the hoof is
essentially a highly specialized form of the tetrapod middle finger.
So when you see a horse galloping around, yes, it
(00:56):
is running around on all middle fingers and toes. We
talked about an ancient legend about the horse ridden by
Julius Caesar, which some artists have depicted as having dock
in hair and human feet instead of hoofs, at least
on the first two legs. Rob's idea, I think was
that this it's possible that these stories could be based
(01:19):
on observations of what are called polydactyl horses, horses born
with extra hooflets on the sides of the primary hoof,
which do in fact exist.
Speaker 1 (01:28):
Yeah, this seems to be the more sensible interpretation that
you see taken by folks. And I don't think anyone's
actually arguing that these horses had like human fore feet,
but it looks hilarious in the illustrations.
Speaker 3 (01:45):
It does. And we finally talked about the evolution of
the horse hoof, with the commonly accepted narrative being that
millions of years ago, the ancestors of modern horses lived
in more forested environments, maybe warmer, wetter environments. They were
much smaller, maybe about the size of dogs, and had
multiple toes per feet. Then, due to climate and habitat changes,
(02:08):
they became grassland dwellers, which drove them to evolve larger
body sizes and select for galloping speed, and these changes
coincided with the loss of peripheral toes until you end
up with the modern horse and its relatives in the
genus equis, so that would include the zebra and the
ass all having only one toe per foot, the columnar hoof.
(02:32):
Now today, we wanted to continue the series on the
horse hoof getting into a couple other things, about horsecof
evolution as well as the invention of the horseshoe. But
before we do that, I wanted to take a brief
detour into a metaphorical connection to the hoof, which concerns
medical diagnostics and more generally, the realm of statistical reasoning.
(02:55):
So there's a famous aphorism widely used in medical education,
often invoked by practicing physicians, and it goes like this,
when you hear hoof beats, look for horses, not zebras. Rob.
I think this thing may have come up on the
show in the past that I couldn't remember when, but
I'm sure you've heard this before, right.
Speaker 1 (03:16):
Yeah, yeah, And it basically is what it sounds like, right, it's,
you know, whatever the evidence seems to indicate, go for
the more likely and more statistically reasonable explanation for.
Speaker 3 (03:29):
The evidence, right. So I was looking up the history
of this quote in a chapter on medical aphorisms in
a book called White Coat Tails Medicine's Heroes, Heritage and
Misadventures by Robert B. Taylor published by Springer. So I'll
refer back to that chapter in a second. But yeah, Rob,
like you say, the point of this aphorism is that
when a patient presents with symptoms X, Y, and Z,
(03:52):
you should start by thinking about the most common conditions
within the population associated with that club of symptoms, rather
than jumping to assumptions about rare diseases. So, for example,
if a patient presents at a US clinic with flu
like symptoms, it's better to start by investigating the possibility
(04:13):
that they have the flu or common cold, or now
maybe COVID, rather than to start by investigating whether they
have contracted the hindra virus from a flying fox in Australia.
Taylor traces this saying back to an American medical researcher
named Theodore E. Woodward who lived nineteen fourteen to two
thousand and five, who taught at the University of Maryland
(04:36):
School of Medicine. And it seems actually the common form
of this aphorism might be a paraphrase, and the more
accurate original quote may have been don't look for zebras
on Green Street. That might be a little perplexing, but
it makes sense in the context because Green Street was
the location of the University of Maryland hospital in Baltimore,
(04:59):
and he was teaching at the University of Maryland to
students there, so of course you can see why it
would need to be rephrased to make more sense outside
of its original locality. But I also think the localization
to Baltimore geography highlights something important, which is that this
aphorism is only useful when you're talking about a known
population of patients in which the frequency of certain diseases
(05:23):
or conditions is fairly well understood. Because if you were
talking to a group of medical students, maybe in a
region of southern Africa where zebras are abundant, it might
make sense to use the aphorism inverted, I guess, depending
on how many horses there are around as well. But
in the same sense, you have to know what the
frequencies are in the population you're looking at before deploying this.
Speaker 1 (05:46):
Yeah, that's true.
Speaker 3 (05:47):
Now, I find this the reasoning behind the saying actually
kind of interesting, because if you interpret it in the
usual way, it's a piece of advice that can seem
rather obvious, like common explanations are more common than rare
way ones. But I think as a general rule, when
looking for explanations, we do have to be reminded to
start by considering what is most likely in terms of frequency,
(06:12):
because there are all kinds of mental biases that constantly
tempt us to start looking for highly unusual causes for
unexplained phenomena before we've exhausted all of the extremely commonplace
candidates for one thing. Unusual causes and explanations are usually
more exciting. They kind of stick in the mind because
(06:36):
of our level of interest in them, and they can
quite easily then come to mind when we start searching
around for an explanation. They're sort of at the top
of the toy box right now. In this section of
the book I was talking about, Taylor makes an interesting
point about the zebra aphorism, which I hadn't quite considered.
(06:56):
I was just thinking at the first order level of
more common explanations and less common explanations. But Taylor also
writes quote as a clinical corollary, experienced diagnosticians look first
for uncommon manifestations of common conditions rather than common manifestations
of uncommon diseases. Now that seemed really interesting to me.
(07:21):
I hadn't quite thought about it that way. And of
course it would depend on exactly how uncommon you mean
in each clause of that sentence, Like if you were
to represent them as actual percentage chances and stuff. The
math might break out in different ways. But if a
certain set of symptoms appears in I don't know, only
three percent of cases of an extremely common condition that
(07:42):
affects you know, millions of people every year, it is
probably still worth investigating that diagnosis the uncommon manifestation of
the extremely common condition before you look at the possibility
of a condition that matches the symptoms very closely. But
you know, you might only see all a couple of
cases in the world per year, it's extremely rare. You'd
(08:03):
still get way more hits of confirmation on the on
the uncommon version of the common condition.
Speaker 1 (08:11):
It reminds me of various discussions we've had about cryptozoology
and the interpretations and misinterpretations of dead animals and in
some cases dead human beings, where you're looking at some
rate of decay and yeah, are you looking at it
as the as an uncommon manifestation of a common condition,
and in other words, are you're looking at as kind
(08:32):
of like a novel pattern or appearance in decay of
just a normal, mundane animal, or are you going to
jump to the to that extreme level and think, well, no,
this is just how it looks and we've just never
seen this creature before.
Speaker 3 (08:48):
Yeah. Yeah. However, I want to come back on the
other end, because if you search for medical case reports
citing this aphorism, which I was doing a lot of times,
it will be specific to discuss cases where it was
a zebra on Green Street, the rare and unexpected diagnosis
that turned out to be correct. So just one example
(09:11):
I was looking at this was a case report published
in Clinical Practice in Cases in Emergency Medicine in twenty
nineteen by Loupez at All called Beware of the Zebra,
nine year Old with Fever. I believe this incident took
place in the US state of North Carolina. So it
was a nine year old girl whose family spoke only French,
(09:32):
and they presented at the hospital with the patient having
an abdominal pain, vomiting, intermittent fevers, fatigue, and headache, and
because there was a language barrier, everything had to be
done with the help of an interpreter, and it seems
that this led to some maybe some original misunderstandings about
the case history. So the doctors tried to diagnose based
(09:54):
on all the normal explanations that they would be likely
to see in their patient population, but none of the
common diagnoses really fit her case. Her condition continued to
get worse. It even became life threatening, and the breakthrough
seemed to come when the doctors began looking outside the
normal slate of conditions encountered in their practice in the
United States. Finally, they learned that the girl's family had
(10:18):
just in the weeks before, arrived from the Congo, where
malaria is common. The care providers eventually ordered a test
that would put them on the right track. They write
in their report, quote, this test was a peripheral blood smear,
specifically a thick and thin smear, which revealed Plasmodium falciparum,
and this is one of the protozoa responsible for causing malaria,
(10:41):
leading to a final diagnosis of cerebral malaria. And then
they write from here they contacted the twenty four hour
CDC hotline to immediately get the appropriate anti malarial medication.
They put the girl on a quinine drip and admitted
her to the pediatric intensive care unit. And then they say,
quote remarkably, within four weeks, she made a full recovery
(11:03):
and returned home with her family. So thankfully, the patient
was all right in the end, but she potentially could
have died if doctors hadn't made the locally unusual but
correct diagnosis and given her the right treatment. And so
the authors say in their conclusion quote, many of us
are taught the common aphorism in medical school. When you
hear hoof beats, think horses, not zebras. When approaching a
(11:27):
nine year old with fever, we hear the hoof beat
symptoms and tend to think of the typical diagnoses that
are commonly seen in our pediatric population. Yet if we
are not thinking about the zebras, we will miss this
common presentation of a disease that is uncommon north of
the equator, which could lead to high morbidity and possibly
even mortality for patients. So it's very good that they
(11:48):
were able to discover this intervene and probably save the
girl's life. But it highlights how there's a difficult balance,
Like if you go looking for zebras before you look
for horses on Green Street, you will waste a lot
of time and resources and potentially cause frequent misdiagnoses that
could harm people. But if you never consider the possibility
(12:10):
of zebra's on Green Street. There will be rare but
very real cases where you could save somebody's life but
you don't.
Speaker 1 (12:18):
Yeah, that's a great point. Yeah, certainly looking at the
like the professional end of the scenario, because on the
other end, like say the user end and the media end,
I mean, zebra on Green Street. That's a great headline.
You're gonna that's the headline that's gonna stick in your mind,
and then when you're going to see the doctor, you're
gonna be like, hey, doc, is it possible that a
(12:39):
rare amiba is eating my flesh? Or something to that effect,
because that's what you saw in the headline, that's what
you saw on the the documentary series that that that
sensationalized a rare case, right.
Speaker 3 (12:53):
I Mean. The the difficult thing is like, because of
the way we emotionally react to stories like this, I
feel like it kind of tends to have the effect
of making us think, well, maybe then I should start
looking for diagnoses of unusual diseases in patient populations. So
it just highlights like diagnosis in the specific case of medicine,
(13:14):
and searching for explanations for unknown phenomena generally is really difficult.
It involves a balance between prioritizing likely explanations, which are
by very definition almost always going to be correct, but
also being open minded enough to catch the unusual ones
(13:35):
when they arise. And obviously, I think a big part
of the art of medicine is gaining good intuition and
establishing sound processes to prioritize explanations in a reasonable way
based on what we know about frequency, but then also
to be able to catch the cases that are unusual
(13:56):
and intervene appropriately to help people. All right, you want
to talk a little bit about the evolution of the
horse hoof?
Speaker 1 (14:12):
Yeah, yeah, we should probably talk a little bit more
about how they came to run about in their middle fingers.
Speaker 3 (14:17):
We talked in the last episode about a pretty commonly
accepted story of how that evolutionary process occurred, but there
was still some uncertainty about exactly why the one toe
making contact with the ground is favored over keeping the
larger number of toes that the ancestors of horses used
to have, And to some degree I think that question
(14:39):
is still not fully settled. There are still some questions
about why exactly the one toe was favored. We do
know that the ancestors of horses and zebras and asses
had multiple toes per foot. But what is gained by
going quad bird? You know, the middle fingers across all
four feet, So the evolution of is called monodactyly, having
(15:01):
one toe monodactyly. It has long been assumed that that
was useful for allowing a large animal like a modern horse,
to achieve greater running speed. But I came across an
interesting alternative idea explored in a paper called the Evolution
of equid monodactyly, a review including a new hypothesis published
(15:22):
in Frontiers and Ecology and Evolution by Christine M. Janis
and Raymond Bernor, and basically here the authors asked what
if the evolution of the modern equine hoof was a
product of selection for endurance rather than speed, meaning that
the primary advantage conferred was in the evolution of an
(15:45):
efficient and energy efficient spring foot that would support long
distance trots at medium speed to locate better food resources. So,
under their hypothesis, the law of extra toes may have
been a coincidental byproduct of the selection for the more
(16:06):
efficient spring foot, which helps the horse conserve energy while foraging,
rather than an adaptation for top speed. Running, which again
is assumed to be primarily for the purpose of escaping
the jaws of predators. Now I cite this not to
say that I think their hypothesis is definitely correct. I
(16:26):
have no expertise to decide between which explanation of the
horsfof evolution better fits the evidence, but this possibility made
me think back again to the Zebras on Green Street
saying about how sometimes certain explanations seem more likely to
us not because they're actually more common, but because they're
more mentally salient. It reminds me I've talked before about
(16:50):
this idea that I have the sort of sex and
violence principle in evolutionary reasoning, where what I think I've
observed is that when people without or sometimes even with
biological training, are trying to think of possible evolutionary explanations
for a trait in an organism, we are a little
too quick to resort to explanations involving either predation or mating,
(17:15):
and we often overlook extremely common mechanisms in nature, like
temperature regulation and energy efficiency, which play a huge role
in the success of a life form. But I think
maybe they're not as interesting to our brains as sex
or violence, so we're less likely to think of them.
They do not bleed, so they do not lead in
(17:37):
the mind.
Speaker 1 (17:38):
Yeah, it kind of reminds me of past discussions we've
talked about concerning the stegosaurus, for example, you know, and
memory serves you know that there have been various interpretations
over the years, for there are those curious plates on
their back, as well as very interpretations of just how
they are positioned. But yeah, you can with something like that,
you can. You're inevitably you're going to find those explanations
(18:01):
that have to do with mating, or protection from predators,
or protection when they're in conflict with others of their kind.
But yeah, I guess sometimes these ideas that they're used
for temperature regulation or something like that may feel less exciting.
May it may feel more mundane. Though I guess you
(18:21):
could also argue that maybe the more exotic or mysterious
the feature is, like say those backridges on the stegosaurus,
maybe that cancels it out to some degree.
Speaker 3 (18:33):
I don't know, but.
Speaker 1 (18:34):
It's hard to imagine a like a seven year old
or an eight year old playing with the toy stegosaurus
and be like, look, mom and dad, this guy's warming
up in the sun watching. That's not what bathtub dinosaurs do.
They bite each other.
Speaker 3 (18:48):
But again I want to make clear I'm not saying
I think that the trotting foraging spring hook explanation is
necessarily better than the high speed running explanation for the horse.
I don't know, but I think it's important to remember
to consider those types of explanations as well. Now, another
question that has come up in several things I was
(19:09):
reading is about should we really say that the horse
only has one toe? I mean, it really does basically
have only one toe that makes contact with the ground,
But in what sense did it really quote lose the
other toes. One example of this counter narrative I was
reading is in an article in The New York Times
(19:30):
by Veronique Greenwood published February eighth, twenty twenty, called a
horse has five toes and then it doesn't. And this
article tells the story of a researcher named Catherine Kavanaugh,
a biologist at the University of Massachusetts Dartmouth, who was
looking at preserved horse embryos in the lab when she
discovered something very interesting, which is that during the earliest
(19:54):
stages of gestation, the area of the embryo that will
eventually develop to become the foot become the hoof in
that area. The embryonic horses have five toes, so this
period during development only lasts for a couple of days
before the extra toes begin to sort of fuse and vanish.
(20:15):
But to read from the article briefly quote, the discovery
implies something profound about how anatomical development works. As an
embryo puts itself together, growing from a tiny wad of
cells into multiple specialized tissues, fed by blood vessels and
linked by the winding threads of nerves, it is following
a template. That template is subject to evolution, just like
(20:38):
other things about the animal. But some moments in the
process or some routes that development takes may not easily
be altered, And so the researcher here, Catherine Kavanaugh, is
quoted saying something about the early steps in toe development
is stabilized. We don't know why, but that's what we
think is going on. So I found it's also interesting
(21:00):
because it's an example of how stages in development can
become evolutionarily fixed even when they differ from the final form.
So like for some reason, as the horse is growing
as an embryo, it needs to develop five fingers before
or five toes before it can lose four of the
(21:22):
toes per hoof, so you know, eventually it will have
functionally one toe making contact with the ground, but the
development process has to go through this other stage first.
Speaker 1 (21:34):
For some reason, it reminds me of something we discussed
in our whale episodes about the blowhole of the whale
being seen to, of course, through the fossil record, travel
up the snout up to the top of the head,
but we can also observe this movement in the womb
as the fetal whale is developing.
Speaker 3 (21:52):
Yeah. Another interesting thing about the horse hoof is that
there are some people who have pointed out how vestiges
of the missing toes can still sort of be found
as little sort of ridges on the sides of the hoof. Yeah.
Speaker 1 (22:07):
I ran across this a lot in some of the
veterinary sources I was looking at.
Speaker 3 (22:12):
But don't let this take away from your mental enjoyment
of thinking about the horses running around on its middle fingers,
which it functionally is it is, I.
Speaker 1 (22:20):
Mean to me, it makes it even more weird. It's
kind of like if you were to It's kind of
like if you're looking at Kermit the Frog and someone
were to tell you, Like there's a difference in saying, hey,
there's somebody's hand in there, and and someone saying, actually,
all the bones of a human hand are present in
Kermit the frog, but they have been repurposed and formed
into the skeletal structure of this bipedal frog creature. Like
(22:43):
that's even crazier, And I feel like that's more in
line with what we know about the horses.
Speaker 3 (22:49):
Splendid analogy, Bravo. All right, are we ready to talk
about the horse shoe?
Speaker 1 (22:55):
Yeah, this is something that originally I didn't think we
were going to cover, or if we were to cover,
we might come back, but I felt like it's kind
of so closely linked to our understanding of the horse
and the human use of the horse. And at the
same time, in discussing this, we are going to be
kind of blowing through the domestication of the horse rather quickly.
(23:18):
Like this is a topic that has received a lot
of attention over the years in varying fields. I mean,
there's genetic research, there's archaeology, there's you know, various cultural inquiries.
It's kind of all over the place, and there are
a lot of unanswered questions about, you know, especially when
you get into you know, the exact who's and wins
(23:39):
and whares, say, horse domestication and even the development or
the horseshoe. But I feel like covering the horseshoe also
helps us understand the hoof a little bit more so,
briefly talking about the modern horse, the modern horse has
a long and pivotal history as a human steed. Many
animals have, of course as mounts for human riders, and
(24:03):
many have served as a pack and draft animals. I
know that, at least on the artifact and perhaps elsewhere
in some core episodes, we've touched on the importance of
the camel and the donkey. But the horse, the horse
is just a whole different matter, both in terms of
the impact that it's had, like I think, the larger
impact that it's had globally, and also just how it
(24:24):
has captured the imagination. Not to diminish the camel or
the donkey, because in particular regions, the camel and the
donkey have been far more important. Whole books have been
written about the camel and the donkey, and I've read
parts of them. If you want to hear a little
bit more about that, go back to the Monster Fact
episode I did on Donkeys of Dune, which touched on
(24:44):
this a little bit. Now, as we've discussed, the modern
horse evolved over the course of fifty to sixty million
years from a diminutive ancestor, and then it would have
reached identifiable form somewhere around four to four point five
years ago, then migrating across the Bearing Strait via some
sort of a primitive land bridge into Eurasia about eleven
(25:07):
thousand years ago, then becoming stinct in North America after that,
and it would not come back around the globe to
North America until it was reintroduced via European conquest in
the fifteenth century seehe Now. Of the wild horse's three ancestors,
two went extinct and a third the Takei or Mongolian
(25:28):
wild horse or Preswalski's horse. These are all the different
names for the same creature. Essentially, this survived only in
captivity and then was subsequently has been subsequently reintroduced into
the wild, though with some important caveats worth discussing. Should
we come back around to talk about the reintroduction of
a species. There are lots of sort of ups and
(25:50):
downs with that particular story, as there are with some
other species reintroduction tales. Now much has been written about
the role of the horse in the history of human conflict,
and there is indeed just so much much that we
could and I guess should one day discuss about that.
You know, the use of say, chariot technology, even the
saddle like, they're just so many different angles to take
(26:13):
now is pointed out by equine warfare expert and Highland,
and this is in Brian and Fagin's The Seventy Great
Inventions of the Ancient World. DNA evidence suggests that the
domestication of the horse took place independently in several different
places and times. And according to them, and this was
this book came out in two thousand and four, so
(26:34):
I'm going to touch on a more recent source on
all this in just a second. They were talking about
the earliest domestication having possibly taken place on the Eurasian
Step somewhere around four thousand BCE, though they did highlight
that the proof was inconclusive. I've also seen other sources
just put it that The geographic origin of horse domestication
(26:54):
is simply an unknown, and there of course a handful
of likely areas and times, based on different findings, spread
across Eurasia, from as far west as Iberia to as
far east as Siberia. Now more recently. The more recent
source I was looking at on this though, was a
twenty twenty one analysis of ancient horse DNA, and this
(27:15):
seemed to narrow it down to the Eurasian step the
Volga Dawn region, so that would seem to possibly be
the strong contender for where the who. That's a little
bit more complex, is pointed out by Amber Dance in
a solid twenty twenty two article for Smithsonian Magazine titled
When Did Humans Domesticate the Horse? The region was home
(27:35):
to diverse peoples who may have engaged in horse domestication
in the earliest time period. The win in all of
this sounds like it was maybe four two hundred years ago,
pushing us back to the twenty one hundred s BCE.
Based on all of this, though, Dance also points out
that quote clear evidence of horse domestication doesn't appear in
(27:55):
the archaeological record until about five hundred years ago. That
would push things back obviously now, as Highland and Fagan
pointed out, stud records from twenty three hundred BC and
what is now Iraq include data on donkeys, mules, and
some horses. There are Sumerian proverbs that refer to horse
riding during this time period. But yeah, like I say,
(28:18):
this is a topic we could go on about at
some length, but suffice to say that the evidence points
to this general time period, but it has still long
been a topic of dispute.
Speaker 3 (28:38):
Now.
Speaker 1 (28:39):
One thing that I liked in Dance's article is that
they point out that horses were coexisting alongside human beings
long before we were able to ride them or really
do anything with them. They were around during the time
of Stone Age human beings. They no doubt inspired Stone
Age human beings and human populations. Our ancestors depicted them
(29:01):
in their cave art, but it would have been a
long time before they could figure out how to master
these beasts and truly harness the power.
Speaker 3 (29:09):
Of the horse. Yeah. I don't know if this is
still the dominant view, but I recall reading years ago
that many researchers thought that humans probably hunted horses for
food before they domesticated them.
Speaker 1 (29:22):
Yeah, that's that's what I saw indicated. And these sources
I was looking at as well, you know, I mean,
you see them from afar. They look cool, they looked
really neat. Look at that those flowing manes. I mean,
it's kind of interesting to think that some of the
some of the impressions we have watching a horse running
about with its kind, you know, across the field. You know,
(29:43):
maybe we're feeling some of the same things our ancient
ancestors would have felt, you know, these sort of deep
down impressions, but with the added level of we probably
don't think about maybe running them down with our spears
and cooking them up later and making things out of them.
Of course, this would have been This was how we
interacted with pretty much everything in the natural world during
(30:07):
that time period. And of course if we were going
to hunt a horse, we would have to depend on
human ingenuity, human strategy, human tool use, and eventually when
humans figure out figured out how to truly harness the horse,
they also had to employ various tools. So if anyone
out there, if you're like me, most of your experience
(30:29):
with horses is probably in video games where you break
a wild horse or train a wild horse by doing
something like I don't know, whistling at it, or you know,
you jump up on its back. I was asking my son,
how do you get a horse? And Zelden He's like, oh,
you just jump on its back and I don't know,
you do something else and then you're good to go.
Speaker 3 (30:47):
Yeah, Breath of the Wild is kind of a bucking
Bronco thing. You jump on the horse and if you
can hold on long enough while it's trying to kick
you off, then it becomes your friend. There you go.
Speaker 1 (30:56):
Yeah, then that's fine for video game, but a lot
more complex. If you read any like serious westerns about
breaking horses and so forth, you get into a little
Cornett McCarthy, you're gonna you know, it's it's it's a
longer process, a lot more more kicking, maybe a few
more busted ribs in the process.
Speaker 3 (31:18):
And so.
Speaker 1 (31:20):
One thing that Hyland and Fagan point out is that
as humans were mastering horses, they inevitably turned to bovine
control mechanisms, so cows were domesticated much earlier. Humans had
had much earlier figured out some of the ways that
they could use tools and things they they built to
control these large and powerful creatures, and they were able
(31:42):
to adapt some of those for the domestication of the horse,
and they evolved from there to include things like metal
bits and harnesses, ultimately things like armor horse armor for battle,
chariot technology, and of course things like the saddle and
stirrup loops. But all of this discussion thus far has
been in service of the horse hoof and of course
(32:03):
the horseshoe. As we mentioned already in the previous episode
on the horse hoof, the hoof, while certainly an amazing adaptation,
is not indestructible, and the domestication of the horse took
this creature out of its sort of normal environment in
activities and placed it in those that suited us best,
especially in the use of things like agriculture, travel, ultimately warfare,
(32:28):
and at some point, and much like horse domestication itself,
likely various points in various times in ancient history, humans
who made use of the horse realize that hoofs require
special care, and that this care could in fact be
preventative care, so the hoof, like the human foot, could
be protected and reinforced.
Speaker 3 (32:50):
This is one of those things like drinking animal milk,
that's the questions like who's the first person who tried
to do this, You really got to wonder.
Speaker 1 (32:59):
Yeah, and again this kind of gets into sort of
the everyday nature of the horse and horse related technology.
It just seems so common. You know, it's the stuff
of westerns and fantasy shows, fantasy shows in which the
horse is not the most fantastic element. You know, we're
focusing on the dragon, but meanwhile, here's this animal running
(33:21):
around on its on its single toes, and we have
augmented this creature with various contraptions and straps and bits.
And also we have we have nailed these these shoes.
We call them a shoe, but you know, it's like
it's like an iron loop onto the bottom of their
their hoof walls in order to make them more capable
(33:43):
of keeping up with what we need them to do.
Technologically enhanced. Is the horse cyborgs? Yeah, yeah, yeah, and
in some respects now, there have been many different approaches
to this over the ages, because again, like the Bay Sick,
none of it is the realization that, oh man, we're
rough on these horses. We should we're having to clean
(34:07):
up and take care of them after we use them
too hard. Let's try and protect that hoof a little bit,
and there have been various ways to sort of address
this again in different times.
Speaker 3 (34:17):
In different places.
Speaker 1 (34:18):
Some early examples from parts of Asia have been based
in apparently in medicinal organic wrappings to treat injuries. So
you're working your horse too hard, the horse is suffering
various injuries or ailments of the hoof, so you start
wrapping it up in things to protect it and to
(34:38):
heal it. And then it seems to be a case
of treatment becoming preventative, where it's realized, oh, you know,
let's just keep something wrapped around the hoof or at
least when we're using the horse, or at least in
certain environmental circumstances, and that can help make the hoof
last longer.
Speaker 3 (34:56):
That's interesting.
Speaker 1 (34:58):
Then there's this whole area of early hoof boots. Now
these are not to be confused with the hoof boots.
Humans make and wear themselves so that their own feet
can look like hooves. If you're not familiar with these,
treat yourself, go do an image search. A lot of
them are cloven hoofs for like sador costumes, but other
(35:18):
times they are horse hooves for horse related dress.
Speaker 3 (35:23):
When you i didn't realize at first. You meant like
that these were for costumes or recreational I was like,
what is the functional reason to make your foot into
a hoof?
Speaker 1 (35:32):
To be a satyr or to be a horsey? And
you find that, you know, some of them are very
goth looking, some of them more and more on the
furry end of the spectrum. But yeah, I saw some
of these recently at a at a Renaissance festival that
I went to with my family. There's a sadar guy
over there walking around on hoof boots.
Speaker 3 (35:50):
Man, you think being in high heels for a long
time is rough? It turn your foot into a hoof.
Speaker 1 (35:55):
I know it. It looks, it looks unpleasant, I mean,
but I guess it's like really awesome high heels, right,
I mean, nobody's wearing those for comfort. You're wearing them
to look cool. And the same goes for those those
weird goat boots you might be wearing to the renfest.
All right, So what we're talking about here not those
sorts of hoof boots. These are basically different approaches where
(36:18):
you would take like essentially like a leather sheath for
the hoof, sometimes augmented with metal studs on the bottom,
essentially making you know, you think about basically the same
sort of adaptations you would make to a human boot.
You know, well, it's like wrap that, let's wrap that
foot up in leather. Or it's a little slippery, let's
put some studs on the bottom of that so it
(36:39):
doesn't slip around. And it's also worth noting that modern
hoof boots exist as horseshoe alternatives. You see a lot
of this, particularly in the realm of natural horsemanship, sort
of like modern backing away from some of the the
aspects of horsemanship that might be considered a little bit
(37:02):
too rough or unnecessarily rough, especially for what we might
be asking of our horses in the modern age, and
so you might see a hoof boot, which in many
of these cases they look like like little like sports
shoes for a horse. They can slip those on, and
I'm to understand that also sometimes they're used in addition
to a normal horseshoe. Equestrians out there listening to the episode,
(37:23):
if you have some thoughts on hoofboots right in, we
would love to see them. Same goes for people who
just like dressing like satyrs. We also want to see
your hoof boots. Nobody needs to feel left out. But
then there's also the hippo sandal, and this is exactly
what it sounds like. It is a sandal of sorts
for horse hooves. These were especially common in the northwestern
(37:46):
Roman Empire and it was I think largely a temporary solution.
So the idea is, this is not something that was
nailed on. It was something that was strapped on, and
if you look at examples, it looks like basically like
a strap on horse hoof. You can see that like
these were generally made out of iron. They would cover
the bottom of the hoof wall and then you would
(38:08):
strap it on, but it wasn't going to be on
their long term. Once you got wherever you were riding to,
or I don't know, after battle or whatever the scenario is,
then it's time to take these hippo sandals off. And
then eventually we get to the proper iron horseshoe, which
everyone knows what this looks like because it exists in
(38:28):
the public mind outside of mere equestrian interests, and even
outside of its use on the horse, it has become
an artifact of some significance across multiple cultures. It is
this U shaped twist of iron that is actually nailed
into place in the horse's hoof walls. The origin of
(38:49):
this particular invention or artifact is also difficult to well
nail down, if I guess you could say, with different
possibilities emerging, I've read that the Gulls are thought to
have possibly innovated this. Others have said the Celts may
have done it, or being among the first to do it,
and there's some evidence stemming from ancient grave sites. But
(39:12):
one thing to keep in mind here is that initially
you might think, oh, well, they're made out of iron,
at least they're going to keep longer. But then we
have to realize iron would have been precious, and therefore
iron would often be reused or even re forged, thus
robbing us of evidence in many cases of these particular artifacts.
(39:33):
But it's possible that the use of iron horseshoes go
back to perhaps four hundred BCE. But like a lot
of this, the use of iron horseshoes is rather broadly
difficult to define and nail down because their use often
bumps up against and coexists with other forms of protecting
the hoof. So you might have a period of time
(39:56):
and a part of the world where some people are
using a horseshoe, using the hippo sandal or some other innovation,
or or indeed where there'll be a whole culture that's
not using anything and they're depending on stage just switching
out horses and find you know, realizing that they can't
and shouldn't just run the horse to death. But they
(40:18):
may realize, well, we just need to switch them out more,
and this is going to be our approach to making
the most out of a given hoof and making the
hoofs and therefore the horse itself lasts longer for us.
(40:38):
Now the horse shoe itself has a life all its
own at this point outside of merely nailing it in
place in the bottom of a horse's foot. As we've
touched on a bit already, the horseshoe has long been
seen as a good luck icon in many different cultures,
in many different times, and it's only kind of interesting
(41:00):
chase down like why this is? Like why did people
start admiring the horseshoe and nailing it up and attracting
some level of significance to it?
Speaker 3 (41:10):
Very good question. I often find myself wondering about things
like this, like how did a certain item or image
come to have good magic or bad magic associated with it?
Speaker 1 (41:22):
Yeah, yeah, So one of the first places I turned
to for an answer on this is the book Magical
House Protection by Brian Hoggard, a former guest on the show.
I think it was on last October while you were
on a parnal leave. But the book deals with various
things that people have hidden away in their walls and
(41:42):
under their floorboards throughout Europe, in the US predominantly, but
also just throughout the world as a way of protecting
the house from bad luck, evil spirits, and what have you.
And Hoggard wrote that, yeah, you find horseshoes being associated
with good luck throughout the British Isles, Europe, the United
States quote, and it would seem the rest of the world.
(42:04):
He writes that the horseshoe is sometimes displayed pointing upward quote,
so that the luck doesn't run out, which I thought
was fun. You know this idea that it's like, well,
don't have it facing down, because then all the luck's
going to run out of the ends of the horseshoe.
But meanwhile, in other areas, other traditions. It is common
to display the horseshoe with the points down.
Speaker 3 (42:24):
I think of it with the points down, I think
because I think of it hanging up just by a
nail through the middle.
Speaker 1 (42:30):
Yeah, that's the easiest to do, right. If you hang
it the other way, you's a little more complicated or well,
I guess it depends. I mean, you g The thing
about the horseshoe, I guess too, is it is made
to be nailed in place, and therefore it can be
nailed in its intended place, the bottom of a horse's hoof,
or it can be nailed in place on a barn
wall or above your door or what have you. Anyway,
(42:53):
Hoggard highlights two main reasons for the horseshoes perceived power. One,
and it's certainly a big one, is the closer relation
between humans and their horses. You know, these are animals
that were highly important to the people who owned them
and or used them. They were animals that we ultimately
cared about, and we also had various, you know, supernatural
(43:16):
traditions concerning them. And if not your actual mundane horses,
you have these ideas of mythic horses and so forth.
And this is something that also influenced the use of
horse skulls and things like that in other traditions. The
other key fact that he highlights is that these are
made of iron, and iron was thought to provide protection
against quote witchcraft and the fairy folk. Yes, and as
(43:40):
Hoggard chronicles in that book, iron horseshoes and iron nails
were often used in these household productive magics, hidden in
walls and so forth. I also looked at this was
an older paper, but I thought it highlighted some interesting concepts.
This is an eighteen ninety six paper by Robert M.
Lawrence published in the Journal of American Folklore titled The
Folklore the Horseshoe, and Lawrence points out that the horseshoe,
(44:03):
though shaped the way it's shaped for practical reasons, obviously
it would have essentially stood in or resembled pre existing
and potent symbols in different traditions and in different cultures,
and he highlights some of the key ones here. So
picture the horseshoe, just a standard horseshoe, and then think
about these. The first one he mentions is the idea
(44:25):
of an arch, just a protective arch, something that would
be even in an age before horseshoes positioned above a
doorway or on a threshold. I believe he highlights the
I want to say a Scottish tradition of having an
arch shaped from from just the branch of a tree
would sometimes be used like this.
Speaker 3 (44:46):
Well, this may be saying the same thing as saying
that it sort of resembles an arch, but it also
sort of resembles a doorway, which is like an arch
and good luck symbols of various kinds are often put
on or around a doorway.
Speaker 1 (44:57):
Yeah, yeah, I think that's a pretty solid one. The
next one he brings up is that a horseshoe is
also reminiscent of a serpent, and therefore it could tie
into various traditions and involve the use of some sort
of a serpent symbol. Be that a serpent, that's you know,
I guess it depends what your snack is doing. It
may be it may be straight, it may be coiled up,
(45:18):
it may be eating its own tail. I mean, there's
so many different ways the snake has been utilized in
different iconography over the ages, but this one seems sensible.
The idea of like the horseshoe as a serpent. Another
big one the horseshoe is the crescent moon. Now the
next one is one that he writes that he thinks
the evidence is mediocre for this, and he's kind of
(45:39):
begrudgingly mentioned that. He's like, I'm gonna mention it, but
I don't like it. And that's that the horseshoe could
also stand in for various ophallic imagery. So the horseshoe
as thallus.
Speaker 3 (45:51):
Huh, I need to have the case made for that.
It's not evident to me. Yeah.
Speaker 1 (45:58):
I looked around for more horses on this to see
if there was anybody advocating for this, and I didn't
find anything. Maybe it's out there and I just couldn't
find it. I did see some images of some Roman
phallic icons and charms that maybe kind of remind like
I could maybe see it, like there's more than one
way to create a phallic symbol, and some of them
(46:20):
are I guess, more horseshoe like than others. But still
I think maybe Lawrence is right and saying that maybe
there's not as much sense behind this. This one I
thought was interesting. The prong shape of the horseshoe as
a deterrent to evil spirits or as a kind of trap.
So the idea that the horseshoe is either the thing
(46:40):
that's gonna kind of like catch the limb of an
evil spirit, you know, you know, like, oh, you put
your limb, your arm in there, and now you can't
get it out, or kind of like the prongs of
some sort of a poking fork.
Speaker 3 (46:54):
Okay, Yeah, that the horseshoe does have a shape that
seems to contain yeah.
Speaker 1 (46:59):
In this this lined up with a lot of what
Hoggard wrote about concerning witch bottles, which bottles would often
have a bunch of nails in them, and the idea
that like, here's this evil spirit coming into your house
and then it smells some of your hair that's in
this bottle that's buried.
Speaker 3 (47:14):
Under the floorboards.
Speaker 1 (47:15):
Oh, it went into that bottle after that hair smell,
and now it's found a whole bunch of nails. Good
luck getting out of their spirit.
Speaker 3 (47:22):
Iron nails maybe.
Speaker 1 (47:24):
Yeah, yeah, yeah, I believe they would have been in
most of these cases. Now, Lawrence also points to the
sacred nature of the horse and the virtues of iron,
as Hoggart did. He points to examples from various cultures
and traditions, including the ancient Romans, Arabic traditions, Chinese and
Scottish traditions. So again, it's one of these things when
you start, it's just it's spread all over. Some other
(47:46):
ideas that he mentions include the horseshoe is a thing
that captures traps or transmits bad luck. The position is
sometimes important here, and like it could be a situation
where it's like, Okay, here's the horseshoe. You got all
your bad luck in that. Now leave it on the
ground and see if someone picks it up and catches
(48:07):
all that bad luck you just put into it. Then
there's an idea of numerology coming into it, particularly concerning
the number of nails in a horseshoe versus the number
of nail holes. He writes, quote in Northumberland, the holes
free of nails are counted as these indicate, presumably in years,
how soon the finder of the shoe may expect to
(48:29):
be married. And I guess in this case they're like,
you know, you're out in the field, you find a horseshoe.
It's like, oh, I found a horseshoe. Let's find out
how long I'm going to be single? Which and again,
you know, we're not familiar with this tradition and we
can kind of snicker at it. But I guess there
are a lot of things like this. I mean, it's
kind of on a very very like slender level. It's
almost like you know, not stepping on a crack, right,
(48:50):
you know, like we know that's not there's not accurate,
but we can't help but think about it when we
do it. And so I can imagine there could be
this tradition whereas, oh I found a horseshoe exciting for me,
Maybe I'm going to take this home and put it
up over my doorway for good luck. But also what
if it's right? What if I am three years from
finding my wife that sort of thing.
Speaker 3 (49:10):
Well, also, I mean things like this are done for fun,
even if people don't necessarily believe it's literally predictive. I mean,
you know, she loves me, She loves me, not on
flower pedals and stuff.
Speaker 1 (49:22):
Yeah, catching the flowers at a wedding and so forth.
The other thing you mentioned is that you could consider
the horseshoe in its resemblance to a halo. M Okay, yeah,
so I don't remember that coming up at all in
our episodes about the Halo. We did a series on
the Halo, and there was a lot of fun. But
I guess again, we might just think of it like,
(49:42):
what are some major icons and symbols within any given
culture that could then here comes this artifact, this, here
comes this horseshoe. What does that horseshoe remind us of? Now,
outside of all these superstitions and so forth and older traditions,
the emblem of a horseshoe, I think really potent. One
(50:03):
example of this that came to mind is the various
cartoon interpretations of this, as well as how it's presented.
Sometimes in science textbooks. The horseshoe magnet has become a
kind of fixed symbol for magnetism, despite the fact that
horseshoe magnets are technically obsolete, since like the nineteen fifties,
you don't need a horseshoe shaped magnet. All the magnets
(50:25):
on your fridge are likely not horseshoe shaped.
Speaker 3 (50:27):
I was thinking about the horseshoe magnet, and especially when
you were talking about the various magical powers associated with them,
because of the way horseshoe magnets are represented in cartoons,
as like emitting beams of magic power or with like
zigzagging lightning of magnetic I don't know what, you know,
the like zappiness coming out of them.
Speaker 1 (50:49):
Yeah, yeah, I mean, it might be a scenario where
you've stopped to think and maybe you're like, hey, do
I know how magnets work? And then instantly you're struck
with that cartoon image or that or that little icon
your science textbook growing up, where oh, yeah, there is
horseshoe lightning bolts. Now I got it, Now I can
move on.
Speaker 3 (51:06):
Now.
Speaker 1 (51:07):
Another concept that some people may be thinking of, there's
also this horseshoe theory of politics, which I'm to understand.
I didn't know a lot about it previously, but it's
my understanding. It's also it's not something that's really that
much of a thing within actual political science, but you
sometimes see it in a lot of popular discourse about
(51:27):
people's political leanings and their ideologies. This idea that instead
of it being like a sliding linear scale between on
one on one end, like leftist extremism and on the
other end right wing extremism, and then in the middle,
you know, just just you know middle of the road,
you know, neutrality and so forth. Then instead of it
(51:49):
being shaped like that, we should really curve it, and
then it's more of a horseshoe, and that by virtue
of this horseshoe shape, it's illustrated that the extremes of
either side are actually closer than you might think. And
this is generally it's employed to talk about like either
like an overarching theme, like perhaps that in the extremes
there's more of a draw towards like a strong leader
(52:12):
type or totalitarianism or something, or that you might find
particular sentiments, say like an anti vaccine sentiment in both
the far left and the far right, despite these groups
having little else in common in terms of their ideology.
Speaker 3 (52:26):
Yeah, I've heard people using this analogy in different ways.
I mean, in I think in one sense it is
often used to mean that people think that at the
far extremes of the political spectrum people actually come to
share some political ideas. And then I think the other
idea is that is that at the furthest extremes of
(52:47):
the political spectrum, people have more i don't know, sort
of personality based or epistemic things in common apart from
political positions. And I'm not sure which version of the
of the model people are really talking about when they
invoke it often.
Speaker 1 (53:04):
Yeah, and I do. It kind of comes comes back
to our discussion earlier though about like how do we,
you know, interpreting data and thinking about like the underlying
truth of a given situation or a mystery. Like obviously,
the way people think about the world. They're different ideologies
and their political viewpoints. I mean, there's a lot of
complexity going on here, and that complexity can be overwhelming.
(53:25):
I mean, as we try to make sense of the
world's around us, the larger world and perhaps even the
closer world of our friend circles and our families and
so forth, and it might be tempting to say, but hey,
look at this horseshoe, Look at this. I think this
explains it all. You know, it provides maybe a simple
model that may I mean, maybe it provides some insight,
(53:47):
but also a level of insight that at least you
can sort of nod your head at and think like, Okay,
well this kind of lines up with some of the
things I'm observing.
Speaker 3 (53:55):
Well, yeah, I think another twist, for example, is whether
or not it is useful to think about political beliefs
as a spectrum at all, meaning that they extend along
a single dimension, or whether it's more useful to decompose
political beliefs into a number of different types of I
(54:18):
don't know, preferences and personality traits. And then in a say,
a representative democracy with two major parties we represent, we
discover that political behavior manifests in varying degrees of like
or dislike for those main two parties. But you know,
that doesn't fully explain people's the depths of people's beliefs
(54:42):
and preferences.
Speaker 1 (54:44):
Yeah, though in isolation it can at least seem to
make some sense. I had a case of this over
the weekend. I was in a city that has a
lot of crystal stores, so I wasn't necessarily out to
venture into a crystal store, but by virtue of where
I was, I just was going to wind up in
one eventually, and I was looking looking around at them.
Crystals are beautiful, you know, I think they can. They're
(55:07):
nice to look at, and maybe they're a nice focus
sometimes to take you out of the past in the
future and put you into the present. But they have
all these little notes on them about what they're good
for and what focus in the crystal will allegedly do
for you. And on one table I found one that
it was promised would help me connect with quote Christ consciousness,
and on the other it would help me communicate with extraterrestrials.
(55:30):
And so generally speaking, I don't know. I would expect
that people looking to connect with either would have rather
different world views, you know, the person with the Christ
crystal and the person with the extraterrestrial crystal, Like maybe
they want different things out of life. But also they
may have both wandered into this crystal store, which makes
me think that think of the you know, the ends
(55:52):
of the of the horseshoe, you know, arching towards each other.
Speaker 3 (55:56):
Every crystal store I go in, I ask for their
Nixon consciousness crystal, What will help me communicate with Nixon?
He's out there somewhere.
Speaker 1 (56:06):
Oh man, there's got to be a crystal. There's got
to be one that will do it. Unrelated to Nixon, though,
in discussing this, I am also thinking I don't think
Lawrence mentioned horns or antlers, but this would seem at
least just you know, off the top of my head,
this would seem to be like a potent symbol to
jump to and we're interpreting, like how people connected with
this horseshoe with this, you know, for all intensive purposes,
(56:30):
this new artifact that lines up with various symbols of
potents like the horns and antlers have long been and
still are things of symbolic power.
Speaker 3 (56:43):
In a quite literal sense in their biological context, but
then in a metaphorical sense to humans.
Speaker 1 (56:48):
Yeah, yeah, all right, Well, on that note, we're going
to go ahead and close this episode out, but we'd
love to hear from everyone out there if you have
thoughts about the horse, whof the horseshoe, interpretations of the horseshoe,
the use of hoof boots, be they equine hoof boots
or human hoof boots. Everything is fair game.
Speaker 3 (57:06):
Right in.
Speaker 1 (57:07):
We'd love to hear from you. In the meantime, you
can find all of our core episodes, so Stuff to
Blow your Mind on Tuesdays and Thursdays and the Stuff
to Blow your Mind podcast feed. On Mondays, we do
listener mail, Wednesdays we do a short form Monster Factor Artifact,
and on Fridays we do Weird House Cinema. That's our
time to set aside most serious concerns and just talk
about a weird film.
Speaker 3 (57:24):
Huge thanks to our excellent audio producer JJ Posway. If
you would like to get in touch with us with
feedback on this episode or any other, to suggest a
topic for the future, or just to say hello, you
can email us at contact stuff to Blow your Mind
dot com.
Speaker 2 (57:46):
Stuff to Blow Your Mind is production of iHeartRadio. For
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Apple Podcasts, or wherever you listen to your favorite shows.
Hey, welcome to Stuff to Blow your Mind. It's Saturday.
It's time for a vault episode and this is going
to be Hoof's Part two, which originally published six thirteen,
twenty twenty three.
Speaker 2 (00:17):
Please enjoy Welcome to Stuff to Blow Your Mind, a
production of iHeartRadio.
Speaker 1 (00:31):
Hey, welcome to Stuff to Blow your Mind. My name
is Robert Lamb.
Speaker 3 (00:35):
And I'm Joe McCormick, and we're back with part two
of our series on the horse hoof. Now. In part one,
we discussed the anatomical form of the horse hoof, with
an emphasis on the alarming fact that the hoof is
essentially a highly specialized form of the tetrapod middle finger.
So when you see a horse galloping around, yes, it
(00:56):
is running around on all middle fingers and toes. We
talked about an ancient legend about the horse ridden by
Julius Caesar, which some artists have depicted as having dock
in hair and human feet instead of hoofs, at least
on the first two legs. Rob's idea, I think was
that this it's possible that these stories could be based
(01:19):
on observations of what are called polydactyl horses, horses born
with extra hooflets on the sides of the primary hoof,
which do in fact exist.
Speaker 1 (01:28):
Yeah, this seems to be the more sensible interpretation that
you see taken by folks. And I don't think anyone's
actually arguing that these horses had like human fore feet,
but it looks hilarious in the illustrations.
Speaker 3 (01:45):
It does. And we finally talked about the evolution of
the horse hoof, with the commonly accepted narrative being that
millions of years ago, the ancestors of modern horses lived
in more forested environments, maybe warmer, wetter environments. They were
much smaller, maybe about the size of dogs, and had
multiple toes per feet. Then, due to climate and habitat changes,
(02:08):
they became grassland dwellers, which drove them to evolve larger
body sizes and select for galloping speed, and these changes
coincided with the loss of peripheral toes until you end
up with the modern horse and its relatives in the
genus equis, so that would include the zebra and the
ass all having only one toe per foot, the columnar hoof.
(02:32):
Now today, we wanted to continue the series on the
horse hoof getting into a couple other things, about horsecof
evolution as well as the invention of the horseshoe. But
before we do that, I wanted to take a brief
detour into a metaphorical connection to the hoof, which concerns
medical diagnostics and more generally, the realm of statistical reasoning.
(02:55):
So there's a famous aphorism widely used in medical education,
often invoked by practicing physicians, and it goes like this,
when you hear hoof beats, look for horses, not zebras. Rob.
I think this thing may have come up on the
show in the past that I couldn't remember when, but
I'm sure you've heard this before, right.
Speaker 1 (03:16):
Yeah, yeah, And it basically is what it sounds like, right, it's,
you know, whatever the evidence seems to indicate, go for
the more likely and more statistically reasonable explanation for.
Speaker 3 (03:29):
The evidence, right. So I was looking up the history
of this quote in a chapter on medical aphorisms in
a book called White Coat Tails Medicine's Heroes, Heritage and
Misadventures by Robert B. Taylor published by Springer. So I'll
refer back to that chapter in a second. But yeah, Rob,
like you say, the point of this aphorism is that
when a patient presents with symptoms X, Y, and Z,
(03:52):
you should start by thinking about the most common conditions
within the population associated with that club of symptoms, rather
than jumping to assumptions about rare diseases. So, for example,
if a patient presents at a US clinic with flu
like symptoms, it's better to start by investigating the possibility
(04:13):
that they have the flu or common cold, or now
maybe COVID, rather than to start by investigating whether they
have contracted the hindra virus from a flying fox in Australia.
Taylor traces this saying back to an American medical researcher
named Theodore E. Woodward who lived nineteen fourteen to two
thousand and five, who taught at the University of Maryland
(04:36):
School of Medicine. And it seems actually the common form
of this aphorism might be a paraphrase, and the more
accurate original quote may have been don't look for zebras
on Green Street. That might be a little perplexing, but
it makes sense in the context because Green Street was
the location of the University of Maryland hospital in Baltimore,
(04:59):
and he was teaching at the University of Maryland to
students there, so of course you can see why it
would need to be rephrased to make more sense outside
of its original locality. But I also think the localization
to Baltimore geography highlights something important, which is that this
aphorism is only useful when you're talking about a known
population of patients in which the frequency of certain diseases
(05:23):
or conditions is fairly well understood. Because if you were
talking to a group of medical students, maybe in a
region of southern Africa where zebras are abundant, it might
make sense to use the aphorism inverted, I guess, depending
on how many horses there are around as well. But
in the same sense, you have to know what the
frequencies are in the population you're looking at before deploying this.
Speaker 1 (05:46):
Yeah, that's true.
Speaker 3 (05:47):
Now, I find this the reasoning behind the saying actually
kind of interesting, because if you interpret it in the
usual way, it's a piece of advice that can seem
rather obvious, like common explanations are more common than rare
way ones. But I think as a general rule, when
looking for explanations, we do have to be reminded to
start by considering what is most likely in terms of frequency,
(06:12):
because there are all kinds of mental biases that constantly
tempt us to start looking for highly unusual causes for
unexplained phenomena before we've exhausted all of the extremely commonplace
candidates for one thing. Unusual causes and explanations are usually
more exciting. They kind of stick in the mind because
(06:36):
of our level of interest in them, and they can
quite easily then come to mind when we start searching
around for an explanation. They're sort of at the top
of the toy box right now. In this section of
the book I was talking about, Taylor makes an interesting
point about the zebra aphorism, which I hadn't quite considered.
(06:56):
I was just thinking at the first order level of
more common explanations and less common explanations. But Taylor also
writes quote as a clinical corollary, experienced diagnosticians look first
for uncommon manifestations of common conditions rather than common manifestations
of uncommon diseases. Now that seemed really interesting to me.
(07:21):
I hadn't quite thought about it that way. And of
course it would depend on exactly how uncommon you mean
in each clause of that sentence, Like if you were
to represent them as actual percentage chances and stuff. The
math might break out in different ways. But if a
certain set of symptoms appears in I don't know, only
three percent of cases of an extremely common condition that
(07:42):
affects you know, millions of people every year, it is
probably still worth investigating that diagnosis the uncommon manifestation of
the extremely common condition before you look at the possibility
of a condition that matches the symptoms very closely. But
you know, you might only see all a couple of
cases in the world per year, it's extremely rare. You'd
(08:03):
still get way more hits of confirmation on the on
the uncommon version of the common condition.
Speaker 1 (08:11):
It reminds me of various discussions we've had about cryptozoology
and the interpretations and misinterpretations of dead animals and in
some cases dead human beings, where you're looking at some
rate of decay and yeah, are you looking at it
as the as an uncommon manifestation of a common condition,
and in other words, are you're looking at as kind
(08:32):
of like a novel pattern or appearance in decay of
just a normal, mundane animal, or are you going to
jump to the to that extreme level and think, well, no,
this is just how it looks and we've just never
seen this creature before.
Speaker 3 (08:48):
Yeah. Yeah. However, I want to come back on the
other end, because if you search for medical case reports
citing this aphorism, which I was doing a lot of times,
it will be specific to discuss cases where it was
a zebra on Green Street, the rare and unexpected diagnosis
that turned out to be correct. So just one example
(09:11):
I was looking at this was a case report published
in Clinical Practice in Cases in Emergency Medicine in twenty
nineteen by Loupez at All called Beware of the Zebra,
nine year Old with Fever. I believe this incident took
place in the US state of North Carolina. So it
was a nine year old girl whose family spoke only French,
(09:32):
and they presented at the hospital with the patient having
an abdominal pain, vomiting, intermittent fevers, fatigue, and headache, and
because there was a language barrier, everything had to be
done with the help of an interpreter, and it seems
that this led to some maybe some original misunderstandings about
the case history. So the doctors tried to diagnose based
(09:54):
on all the normal explanations that they would be likely
to see in their patient population, but none of the
common diagnoses really fit her case. Her condition continued to
get worse. It even became life threatening, and the breakthrough
seemed to come when the doctors began looking outside the
normal slate of conditions encountered in their practice in the
United States. Finally, they learned that the girl's family had
(10:18):
just in the weeks before, arrived from the Congo, where
malaria is common. The care providers eventually ordered a test
that would put them on the right track. They write
in their report, quote, this test was a peripheral blood smear,
specifically a thick and thin smear, which revealed Plasmodium falciparum,
and this is one of the protozoa responsible for causing malaria,
(10:41):
leading to a final diagnosis of cerebral malaria. And then
they write from here they contacted the twenty four hour
CDC hotline to immediately get the appropriate anti malarial medication.
They put the girl on a quinine drip and admitted
her to the pediatric intensive care unit. And then they say,
quote remarkably, within four weeks, she made a full recovery
(11:03):
and returned home with her family. So thankfully, the patient
was all right in the end, but she potentially could
have died if doctors hadn't made the locally unusual but
correct diagnosis and given her the right treatment. And so
the authors say in their conclusion quote, many of us
are taught the common aphorism in medical school. When you
hear hoof beats, think horses, not zebras. When approaching a
(11:27):
nine year old with fever, we hear the hoof beat
symptoms and tend to think of the typical diagnoses that
are commonly seen in our pediatric population. Yet if we
are not thinking about the zebras, we will miss this
common presentation of a disease that is uncommon north of
the equator, which could lead to high morbidity and possibly
even mortality for patients. So it's very good that they
(11:48):
were able to discover this intervene and probably save the
girl's life. But it highlights how there's a difficult balance,
Like if you go looking for zebras before you look
for horses on Green Street, you will waste a lot
of time and resources and potentially cause frequent misdiagnoses that
could harm people. But if you never consider the possibility
(12:10):
of zebra's on Green Street. There will be rare but
very real cases where you could save somebody's life but
you don't.
Speaker 1 (12:18):
Yeah, that's a great point. Yeah, certainly looking at the
like the professional end of the scenario, because on the
other end, like say the user end and the media end,
I mean, zebra on Green Street. That's a great headline.
You're gonna that's the headline that's gonna stick in your mind,
and then when you're going to see the doctor, you're
gonna be like, hey, doc, is it possible that a
(12:39):
rare amiba is eating my flesh? Or something to that effect,
because that's what you saw in the headline, that's what
you saw on the the documentary series that that that
sensationalized a rare case, right.
Speaker 3 (12:53):
I Mean. The the difficult thing is like, because of
the way we emotionally react to stories like this, I
feel like it kind of tends to have the effect
of making us think, well, maybe then I should start
looking for diagnoses of unusual diseases in patient populations. So
it just highlights like diagnosis in the specific case of medicine,
(13:14):
and searching for explanations for unknown phenomena generally is really difficult.
It involves a balance between prioritizing likely explanations, which are
by very definition almost always going to be correct, but
also being open minded enough to catch the unusual ones
(13:35):
when they arise. And obviously, I think a big part
of the art of medicine is gaining good intuition and
establishing sound processes to prioritize explanations in a reasonable way
based on what we know about frequency, but then also
to be able to catch the cases that are unusual
(13:56):
and intervene appropriately to help people. All right, you want
to talk a little bit about the evolution of the
horse hoof?
Speaker 1 (14:12):
Yeah, yeah, we should probably talk a little bit more
about how they came to run about in their middle fingers.
Speaker 3 (14:17):
We talked in the last episode about a pretty commonly
accepted story of how that evolutionary process occurred, but there
was still some uncertainty about exactly why the one toe
making contact with the ground is favored over keeping the
larger number of toes that the ancestors of horses used
to have, And to some degree I think that question
(14:39):
is still not fully settled. There are still some questions
about why exactly the one toe was favored. We do
know that the ancestors of horses and zebras and asses
had multiple toes per foot. But what is gained by
going quad bird? You know, the middle fingers across all
four feet, So the evolution of is called monodactyly, having
(15:01):
one toe monodactyly. It has long been assumed that that
was useful for allowing a large animal like a modern horse,
to achieve greater running speed. But I came across an
interesting alternative idea explored in a paper called the Evolution
of equid monodactyly, a review including a new hypothesis published
(15:22):
in Frontiers and Ecology and Evolution by Christine M. Janis
and Raymond Bernor, and basically here the authors asked what
if the evolution of the modern equine hoof was a
product of selection for endurance rather than speed, meaning that
the primary advantage conferred was in the evolution of an
(15:45):
efficient and energy efficient spring foot that would support long
distance trots at medium speed to locate better food resources. So,
under their hypothesis, the law of extra toes may have
been a coincidental byproduct of the selection for the more
(16:06):
efficient spring foot, which helps the horse conserve energy while foraging,
rather than an adaptation for top speed. Running, which again
is assumed to be primarily for the purpose of escaping
the jaws of predators. Now I cite this not to
say that I think their hypothesis is definitely correct. I
(16:26):
have no expertise to decide between which explanation of the
horsfof evolution better fits the evidence, but this possibility made
me think back again to the Zebras on Green Street
saying about how sometimes certain explanations seem more likely to
us not because they're actually more common, but because they're
more mentally salient. It reminds me I've talked before about
(16:50):
this idea that I have the sort of sex and
violence principle in evolutionary reasoning, where what I think I've
observed is that when people without or sometimes even with
biological training, are trying to think of possible evolutionary explanations
for a trait in an organism, we are a little
too quick to resort to explanations involving either predation or mating,
(17:15):
and we often overlook extremely common mechanisms in nature, like
temperature regulation and energy efficiency, which play a huge role
in the success of a life form. But I think
maybe they're not as interesting to our brains as sex
or violence, so we're less likely to think of them.
They do not bleed, so they do not lead in
(17:37):
the mind.
Speaker 1 (17:38):
Yeah, it kind of reminds me of past discussions we've
talked about concerning the stegosaurus, for example, you know, and
memory serves you know that there have been various interpretations
over the years, for there are those curious plates on
their back, as well as very interpretations of just how
they are positioned. But yeah, you can with something like that,
you can. You're inevitably you're going to find those explanations
(18:01):
that have to do with mating, or protection from predators,
or protection when they're in conflict with others of their kind.
But yeah, I guess sometimes these ideas that they're used
for temperature regulation or something like that may feel less exciting.
May it may feel more mundane. Though I guess you
(18:21):
could also argue that maybe the more exotic or mysterious
the feature is, like say those backridges on the stegosaurus,
maybe that cancels it out to some degree.
Speaker 3 (18:33):
I don't know, but.
Speaker 1 (18:34):
It's hard to imagine a like a seven year old
or an eight year old playing with the toy stegosaurus
and be like, look, mom and dad, this guy's warming
up in the sun watching. That's not what bathtub dinosaurs do.
They bite each other.
Speaker 3 (18:48):
But again I want to make clear I'm not saying
I think that the trotting foraging spring hook explanation is
necessarily better than the high speed running explanation for the horse.
I don't know, but I think it's important to remember
to consider those types of explanations as well. Now, another
question that has come up in several things I was
(19:09):
reading is about should we really say that the horse
only has one toe? I mean, it really does basically
have only one toe that makes contact with the ground,
But in what sense did it really quote lose the
other toes. One example of this counter narrative I was
reading is in an article in The New York Times
(19:30):
by Veronique Greenwood published February eighth, twenty twenty, called a
horse has five toes and then it doesn't. And this
article tells the story of a researcher named Catherine Kavanaugh,
a biologist at the University of Massachusetts Dartmouth, who was
looking at preserved horse embryos in the lab when she
discovered something very interesting, which is that during the earliest
(19:54):
stages of gestation, the area of the embryo that will
eventually develop to become the foot become the hoof in
that area. The embryonic horses have five toes, so this
period during development only lasts for a couple of days
before the extra toes begin to sort of fuse and vanish.
(20:15):
But to read from the article briefly quote, the discovery
implies something profound about how anatomical development works. As an
embryo puts itself together, growing from a tiny wad of
cells into multiple specialized tissues, fed by blood vessels and
linked by the winding threads of nerves, it is following
a template. That template is subject to evolution, just like
(20:38):
other things about the animal. But some moments in the
process or some routes that development takes may not easily
be altered, And so the researcher here, Catherine Kavanaugh, is
quoted saying something about the early steps in toe development
is stabilized. We don't know why, but that's what we
think is going on. So I found it's also interesting
(21:00):
because it's an example of how stages in development can
become evolutionarily fixed even when they differ from the final form.
So like for some reason, as the horse is growing
as an embryo, it needs to develop five fingers before
or five toes before it can lose four of the
(21:22):
toes per hoof, so you know, eventually it will have
functionally one toe making contact with the ground, but the
development process has to go through this other stage first.
Speaker 1 (21:34):
For some reason, it reminds me of something we discussed
in our whale episodes about the blowhole of the whale
being seen to, of course, through the fossil record, travel
up the snout up to the top of the head,
but we can also observe this movement in the womb
as the fetal whale is developing.
Speaker 3 (21:52):
Yeah. Another interesting thing about the horse hoof is that
there are some people who have pointed out how vestiges
of the missing toes can still sort of be found
as little sort of ridges on the sides of the hoof. Yeah.
Speaker 1 (22:07):
I ran across this a lot in some of the
veterinary sources I was looking at.
Speaker 3 (22:12):
But don't let this take away from your mental enjoyment
of thinking about the horses running around on its middle fingers,
which it functionally is it is, I.
Speaker 1 (22:20):
Mean to me, it makes it even more weird. It's
kind of like if you were to It's kind of
like if you're looking at Kermit the Frog and someone
were to tell you, Like there's a difference in saying, hey,
there's somebody's hand in there, and and someone saying, actually,
all the bones of a human hand are present in
Kermit the frog, but they have been repurposed and formed
into the skeletal structure of this bipedal frog creature. Like
(22:43):
that's even crazier, And I feel like that's more in
line with what we know about the horses.
Speaker 3 (22:49):
Splendid analogy, Bravo. All right, are we ready to talk
about the horse shoe?
Speaker 1 (22:55):
Yeah, this is something that originally I didn't think we
were going to cover, or if we were to cover,
we might come back, but I felt like it's kind
of so closely linked to our understanding of the horse
and the human use of the horse. And at the
same time, in discussing this, we are going to be
kind of blowing through the domestication of the horse rather quickly.
(23:18):
Like this is a topic that has received a lot
of attention over the years in varying fields. I mean,
there's genetic research, there's archaeology, there's you know, various cultural inquiries.
It's kind of all over the place, and there are
a lot of unanswered questions about, you know, especially when
you get into you know, the exact who's and wins
(23:39):
and whares, say, horse domestication and even the development or
the horseshoe. But I feel like covering the horseshoe also
helps us understand the hoof a little bit more so,
briefly talking about the modern horse, the modern horse has
a long and pivotal history as a human steed. Many
animals have, of course as mounts for human riders, and
(24:03):
many have served as a pack and draft animals. I
know that, at least on the artifact and perhaps elsewhere
in some core episodes, we've touched on the importance of
the camel and the donkey. But the horse, the horse
is just a whole different matter, both in terms of
the impact that it's had, like I think, the larger
impact that it's had globally, and also just how it
(24:24):
has captured the imagination. Not to diminish the camel or
the donkey, because in particular regions, the camel and the
donkey have been far more important. Whole books have been
written about the camel and the donkey, and I've read
parts of them. If you want to hear a little
bit more about that, go back to the Monster Fact
episode I did on Donkeys of Dune, which touched on
(24:44):
this a little bit. Now, as we've discussed, the modern
horse evolved over the course of fifty to sixty million
years from a diminutive ancestor, and then it would have
reached identifiable form somewhere around four to four point five
years ago, then migrating across the Bearing Strait via some
sort of a primitive land bridge into Eurasia about eleven
(25:07):
thousand years ago, then becoming stinct in North America after that,
and it would not come back around the globe to
North America until it was reintroduced via European conquest in
the fifteenth century seehe Now. Of the wild horse's three ancestors,
two went extinct and a third the Takei or Mongolian
(25:28):
wild horse or Preswalski's horse. These are all the different
names for the same creature. Essentially, this survived only in
captivity and then was subsequently has been subsequently reintroduced into
the wild, though with some important caveats worth discussing. Should
we come back around to talk about the reintroduction of
a species. There are lots of sort of ups and
(25:50):
downs with that particular story, as there are with some
other species reintroduction tales. Now much has been written about
the role of the horse in the history of human conflict,
and there is indeed just so much much that we
could and I guess should one day discuss about that.
You know, the use of say, chariot technology, even the
saddle like, they're just so many different angles to take
(26:13):
now is pointed out by equine warfare expert and Highland,
and this is in Brian and Fagin's The Seventy Great
Inventions of the Ancient World. DNA evidence suggests that the
domestication of the horse took place independently in several different
places and times. And according to them, and this was
this book came out in two thousand and four, so
(26:34):
I'm going to touch on a more recent source on
all this in just a second. They were talking about
the earliest domestication having possibly taken place on the Eurasian
Step somewhere around four thousand BCE, though they did highlight
that the proof was inconclusive. I've also seen other sources
just put it that The geographic origin of horse domestication
(26:54):
is simply an unknown, and there of course a handful
of likely areas and times, based on different findings, spread
across Eurasia, from as far west as Iberia to as
far east as Siberia. Now more recently. The more recent
source I was looking at on this though, was a
twenty twenty one analysis of ancient horse DNA, and this
(27:15):
seemed to narrow it down to the Eurasian step the
Volga Dawn region, so that would seem to possibly be
the strong contender for where the who. That's a little
bit more complex, is pointed out by Amber Dance in
a solid twenty twenty two article for Smithsonian Magazine titled
When Did Humans Domesticate the Horse? The region was home
(27:35):
to diverse peoples who may have engaged in horse domestication
in the earliest time period. The win in all of
this sounds like it was maybe four two hundred years ago,
pushing us back to the twenty one hundred s BCE.
Based on all of this, though, Dance also points out
that quote clear evidence of horse domestication doesn't appear in
(27:55):
the archaeological record until about five hundred years ago. That
would push things back obviously now, as Highland and Fagan
pointed out, stud records from twenty three hundred BC and
what is now Iraq include data on donkeys, mules, and
some horses. There are Sumerian proverbs that refer to horse
riding during this time period. But yeah, like I say,
(28:18):
this is a topic we could go on about at
some length, but suffice to say that the evidence points
to this general time period, but it has still long
been a topic of dispute.
Speaker 3 (28:38):
Now.
Speaker 1 (28:39):
One thing that I liked in Dance's article is that
they point out that horses were coexisting alongside human beings
long before we were able to ride them or really
do anything with them. They were around during the time
of Stone Age human beings. They no doubt inspired Stone
Age human beings and human populations. Our ancestors depicted them
(29:01):
in their cave art, but it would have been a
long time before they could figure out how to master
these beasts and truly harness the power.
Speaker 3 (29:09):
Of the horse. Yeah. I don't know if this is
still the dominant view, but I recall reading years ago
that many researchers thought that humans probably hunted horses for
food before they domesticated them.
Speaker 1 (29:22):
Yeah, that's that's what I saw indicated. And these sources
I was looking at as well, you know, I mean,
you see them from afar. They look cool, they looked
really neat. Look at that those flowing manes. I mean,
it's kind of interesting to think that some of the
some of the impressions we have watching a horse running
about with its kind, you know, across the field. You know,
(29:43):
maybe we're feeling some of the same things our ancient
ancestors would have felt, you know, these sort of deep
down impressions, but with the added level of we probably
don't think about maybe running them down with our spears
and cooking them up later and making things out of them.
Of course, this would have been This was how we
interacted with pretty much everything in the natural world during
(30:07):
that time period. And of course if we were going
to hunt a horse, we would have to depend on
human ingenuity, human strategy, human tool use, and eventually when
humans figure out figured out how to truly harness the horse,
they also had to employ various tools. So if anyone
out there, if you're like me, most of your experience
(30:29):
with horses is probably in video games where you break
a wild horse or train a wild horse by doing
something like I don't know, whistling at it, or you know,
you jump up on its back. I was asking my son,
how do you get a horse? And Zelden He's like, oh,
you just jump on its back and I don't know,
you do something else and then you're good to go.
Speaker 3 (30:47):
Yeah, Breath of the Wild is kind of a bucking
Bronco thing. You jump on the horse and if you
can hold on long enough while it's trying to kick
you off, then it becomes your friend. There you go.
Speaker 1 (30:56):
Yeah, then that's fine for video game, but a lot
more complex. If you read any like serious westerns about
breaking horses and so forth, you get into a little
Cornett McCarthy, you're gonna you know, it's it's it's a
longer process, a lot more more kicking, maybe a few
more busted ribs in the process.
Speaker 3 (31:18):
And so.
Speaker 1 (31:20):
One thing that Hyland and Fagan point out is that
as humans were mastering horses, they inevitably turned to bovine
control mechanisms, so cows were domesticated much earlier. Humans had
had much earlier figured out some of the ways that
they could use tools and things they they built to
control these large and powerful creatures, and they were able
(31:42):
to adapt some of those for the domestication of the horse,
and they evolved from there to include things like metal
bits and harnesses, ultimately things like armor horse armor for battle,
chariot technology, and of course things like the saddle and
stirrup loops. But all of this discussion thus far has
been in service of the horse hoof and of course
(32:03):
the horseshoe. As we mentioned already in the previous episode
on the horse hoof, the hoof, while certainly an amazing adaptation,
is not indestructible, and the domestication of the horse took
this creature out of its sort of normal environment in
activities and placed it in those that suited us best,
especially in the use of things like agriculture, travel, ultimately warfare,
(32:28):
and at some point, and much like horse domestication itself,
likely various points in various times in ancient history, humans
who made use of the horse realize that hoofs require
special care, and that this care could in fact be
preventative care, so the hoof, like the human foot, could
be protected and reinforced.
Speaker 3 (32:50):
This is one of those things like drinking animal milk,
that's the questions like who's the first person who tried
to do this, You really got to wonder.
Speaker 1 (32:59):
Yeah, and again this kind of gets into sort of
the everyday nature of the horse and horse related technology.
It just seems so common. You know, it's the stuff
of westerns and fantasy shows, fantasy shows in which the
horse is not the most fantastic element. You know, we're
focusing on the dragon, but meanwhile, here's this animal running
(33:21):
around on its on its single toes, and we have
augmented this creature with various contraptions and straps and bits.
And also we have we have nailed these these shoes.
We call them a shoe, but you know, it's like
it's like an iron loop onto the bottom of their
their hoof walls in order to make them more capable
(33:43):
of keeping up with what we need them to do.
Technologically enhanced. Is the horse cyborgs? Yeah, yeah, yeah, and
in some respects now, there have been many different approaches
to this over the ages, because again, like the Bay Sick,
none of it is the realization that, oh man, we're
rough on these horses. We should we're having to clean
(34:07):
up and take care of them after we use them
too hard. Let's try and protect that hoof a little bit,
and there have been various ways to sort of address
this again in different times.
Speaker 3 (34:17):
In different places.
Speaker 1 (34:18):
Some early examples from parts of Asia have been based
in apparently in medicinal organic wrappings to treat injuries. So
you're working your horse too hard, the horse is suffering
various injuries or ailments of the hoof, so you start
wrapping it up in things to protect it and to
(34:38):
heal it. And then it seems to be a case
of treatment becoming preventative, where it's realized, oh, you know,
let's just keep something wrapped around the hoof or at
least when we're using the horse, or at least in
certain environmental circumstances, and that can help make the hoof
last longer.
Speaker 3 (34:56):
That's interesting.
Speaker 1 (34:58):
Then there's this whole area of early hoof boots. Now
these are not to be confused with the hoof boots.
Humans make and wear themselves so that their own feet
can look like hooves. If you're not familiar with these,
treat yourself, go do an image search. A lot of
them are cloven hoofs for like sador costumes, but other
(35:18):
times they are horse hooves for horse related dress.
Speaker 3 (35:23):
When you i didn't realize at first. You meant like
that these were for costumes or recreational I was like,
what is the functional reason to make your foot into
a hoof?
Speaker 1 (35:32):
To be a satyr or to be a horsey? And
you find that, you know, some of them are very
goth looking, some of them more and more on the
furry end of the spectrum. But yeah, I saw some
of these recently at a at a Renaissance festival that
I went to with my family. There's a sadar guy
over there walking around on hoof boots.
Speaker 3 (35:50):
Man, you think being in high heels for a long
time is rough? It turn your foot into a hoof.
Speaker 1 (35:55):
I know it. It looks, it looks unpleasant, I mean,
but I guess it's like really awesome high heels, right,
I mean, nobody's wearing those for comfort. You're wearing them
to look cool. And the same goes for those those
weird goat boots you might be wearing to the renfest.
All right, So what we're talking about here not those
sorts of hoof boots. These are basically different approaches where
(36:18):
you would take like essentially like a leather sheath for
the hoof, sometimes augmented with metal studs on the bottom,
essentially making you know, you think about basically the same
sort of adaptations you would make to a human boot.
You know, well, it's like wrap that, let's wrap that
foot up in leather. Or it's a little slippery, let's
put some studs on the bottom of that so it
(36:39):
doesn't slip around. And it's also worth noting that modern
hoof boots exist as horseshoe alternatives. You see a lot
of this, particularly in the realm of natural horsemanship, sort
of like modern backing away from some of the the
aspects of horsemanship that might be considered a little bit
(37:02):
too rough or unnecessarily rough, especially for what we might
be asking of our horses in the modern age, and
so you might see a hoof boot, which in many
of these cases they look like like little like sports
shoes for a horse. They can slip those on, and
I'm to understand that also sometimes they're used in addition
to a normal horseshoe. Equestrians out there listening to the episode,
(37:23):
if you have some thoughts on hoofboots right in, we
would love to see them. Same goes for people who
just like dressing like satyrs. We also want to see
your hoof boots. Nobody needs to feel left out. But
then there's also the hippo sandal, and this is exactly
what it sounds like. It is a sandal of sorts
for horse hooves. These were especially common in the northwestern
(37:46):
Roman Empire and it was I think largely a temporary solution.
So the idea is, this is not something that was
nailed on. It was something that was strapped on, and
if you look at examples, it looks like basically like
a strap on horse hoof. You can see that like
these were generally made out of iron. They would cover
the bottom of the hoof wall and then you would
(38:08):
strap it on, but it wasn't going to be on
their long term. Once you got wherever you were riding to,
or I don't know, after battle or whatever the scenario is,
then it's time to take these hippo sandals off. And
then eventually we get to the proper iron horseshoe, which
everyone knows what this looks like because it exists in
(38:28):
the public mind outside of mere equestrian interests, and even
outside of its use on the horse, it has become
an artifact of some significance across multiple cultures. It is
this U shaped twist of iron that is actually nailed
into place in the horse's hoof walls. The origin of
(38:49):
this particular invention or artifact is also difficult to well
nail down, if I guess you could say, with different
possibilities emerging, I've read that the Gulls are thought to
have possibly innovated this. Others have said the Celts may
have done it, or being among the first to do it,
and there's some evidence stemming from ancient grave sites. But
(39:12):
one thing to keep in mind here is that initially
you might think, oh, well, they're made out of iron,
at least they're going to keep longer. But then we
have to realize iron would have been precious, and therefore
iron would often be reused or even re forged, thus
robbing us of evidence in many cases of these particular artifacts.
(39:33):
But it's possible that the use of iron horseshoes go
back to perhaps four hundred BCE. But like a lot
of this, the use of iron horseshoes is rather broadly
difficult to define and nail down because their use often
bumps up against and coexists with other forms of protecting
the hoof. So you might have a period of time
(39:56):
and a part of the world where some people are
using a horseshoe, using the hippo sandal or some other innovation,
or or indeed where there'll be a whole culture that's
not using anything and they're depending on stage just switching
out horses and find you know, realizing that they can't
and shouldn't just run the horse to death. But they
(40:18):
may realize, well, we just need to switch them out more,
and this is going to be our approach to making
the most out of a given hoof and making the
hoofs and therefore the horse itself lasts longer for us.
(40:38):
Now the horse shoe itself has a life all its
own at this point outside of merely nailing it in
place in the bottom of a horse's foot. As we've
touched on a bit already, the horseshoe has long been
seen as a good luck icon in many different cultures,
in many different times, and it's only kind of interesting
(41:00):
chase down like why this is? Like why did people
start admiring the horseshoe and nailing it up and attracting
some level of significance to it?
Speaker 3 (41:10):
Very good question. I often find myself wondering about things
like this, like how did a certain item or image
come to have good magic or bad magic associated with it?
Speaker 1 (41:22):
Yeah, yeah, So one of the first places I turned
to for an answer on this is the book Magical
House Protection by Brian Hoggard, a former guest on the show.
I think it was on last October while you were
on a parnal leave. But the book deals with various
things that people have hidden away in their walls and
(41:42):
under their floorboards throughout Europe, in the US predominantly, but
also just throughout the world as a way of protecting
the house from bad luck, evil spirits, and what have you.
And Hoggard wrote that, yeah, you find horseshoes being associated
with good luck throughout the British Isles, Europe, the United
States quote, and it would seem the rest of the world.
(42:04):
He writes that the horseshoe is sometimes displayed pointing upward quote,
so that the luck doesn't run out, which I thought
was fun. You know this idea that it's like, well,
don't have it facing down, because then all the luck's
going to run out of the ends of the horseshoe.
But meanwhile, in other areas, other traditions. It is common
to display the horseshoe with the points down.
Speaker 3 (42:24):
I think of it with the points down, I think
because I think of it hanging up just by a
nail through the middle.
Speaker 1 (42:30):
Yeah, that's the easiest to do, right. If you hang
it the other way, you's a little more complicated or well,
I guess it depends. I mean, you g The thing
about the horseshoe, I guess too, is it is made
to be nailed in place, and therefore it can be
nailed in its intended place, the bottom of a horse's hoof,
or it can be nailed in place on a barn
wall or above your door or what have you. Anyway,
(42:53):
Hoggard highlights two main reasons for the horseshoes perceived power. One,
and it's certainly a big one, is the closer relation
between humans and their horses. You know, these are animals
that were highly important to the people who owned them
and or used them. They were animals that we ultimately
cared about, and we also had various, you know, supernatural
(43:16):
traditions concerning them. And if not your actual mundane horses,
you have these ideas of mythic horses and so forth.
And this is something that also influenced the use of
horse skulls and things like that in other traditions. The
other key fact that he highlights is that these are
made of iron, and iron was thought to provide protection
against quote witchcraft and the fairy folk. Yes, and as
(43:40):
Hoggard chronicles in that book, iron horseshoes and iron nails
were often used in these household productive magics, hidden in
walls and so forth. I also looked at this was
an older paper, but I thought it highlighted some interesting concepts.
This is an eighteen ninety six paper by Robert M.
Lawrence published in the Journal of American Folklore titled The
Folklore the Horseshoe, and Lawrence points out that the horseshoe,
(44:03):
though shaped the way it's shaped for practical reasons, obviously
it would have essentially stood in or resembled pre existing
and potent symbols in different traditions and in different cultures,
and he highlights some of the key ones here. So
picture the horseshoe, just a standard horseshoe, and then think
about these. The first one he mentions is the idea
(44:25):
of an arch, just a protective arch, something that would
be even in an age before horseshoes positioned above a
doorway or on a threshold. I believe he highlights the
I want to say a Scottish tradition of having an
arch shaped from from just the branch of a tree
would sometimes be used like this.
Speaker 3 (44:46):
Well, this may be saying the same thing as saying
that it sort of resembles an arch, but it also
sort of resembles a doorway, which is like an arch
and good luck symbols of various kinds are often put
on or around a doorway.
Speaker 1 (44:57):
Yeah, yeah, I think that's a pretty solid one. The
next one he brings up is that a horseshoe is
also reminiscent of a serpent, and therefore it could tie
into various traditions and involve the use of some sort
of a serpent symbol. Be that a serpent, that's you know,
I guess it depends what your snack is doing. It
may be it may be straight, it may be coiled up,
(45:18):
it may be eating its own tail. I mean, there's
so many different ways the snake has been utilized in
different iconography over the ages, but this one seems sensible.
The idea of like the horseshoe as a serpent. Another
big one the horseshoe is the crescent moon. Now the
next one is one that he writes that he thinks
the evidence is mediocre for this, and he's kind of
(45:39):
begrudgingly mentioned that. He's like, I'm gonna mention it, but
I don't like it. And that's that the horseshoe could
also stand in for various ophallic imagery. So the horseshoe
as thallus.
Speaker 3 (45:51):
Huh, I need to have the case made for that.
It's not evident to me. Yeah.
Speaker 1 (45:58):
I looked around for more horses on this to see
if there was anybody advocating for this, and I didn't
find anything. Maybe it's out there and I just couldn't
find it. I did see some images of some Roman
phallic icons and charms that maybe kind of remind like
I could maybe see it, like there's more than one
way to create a phallic symbol, and some of them
(46:20):
are I guess, more horseshoe like than others. But still
I think maybe Lawrence is right and saying that maybe
there's not as much sense behind this. This one I
thought was interesting. The prong shape of the horseshoe as
a deterrent to evil spirits or as a kind of trap.
So the idea that the horseshoe is either the thing
(46:40):
that's gonna kind of like catch the limb of an
evil spirit, you know, you know, like, oh, you put
your limb, your arm in there, and now you can't
get it out, or kind of like the prongs of
some sort of a poking fork.
Speaker 3 (46:54):
Okay, Yeah, that the horseshoe does have a shape that
seems to contain yeah.
Speaker 1 (46:59):
In this this lined up with a lot of what
Hoggard wrote about concerning witch bottles, which bottles would often
have a bunch of nails in them, and the idea
that like, here's this evil spirit coming into your house
and then it smells some of your hair that's in
this bottle that's buried.
Speaker 3 (47:14):
Under the floorboards.
Speaker 1 (47:15):
Oh, it went into that bottle after that hair smell,
and now it's found a whole bunch of nails. Good
luck getting out of their spirit.
Speaker 3 (47:22):
Iron nails maybe.
Speaker 1 (47:24):
Yeah, yeah, yeah, I believe they would have been in
most of these cases. Now, Lawrence also points to the
sacred nature of the horse and the virtues of iron,
as Hoggart did. He points to examples from various cultures
and traditions, including the ancient Romans, Arabic traditions, Chinese and
Scottish traditions. So again, it's one of these things when
you start, it's just it's spread all over. Some other
(47:46):
ideas that he mentions include the horseshoe is a thing
that captures traps or transmits bad luck. The position is
sometimes important here, and like it could be a situation
where it's like, Okay, here's the horseshoe. You got all
your bad luck in that. Now leave it on the
ground and see if someone picks it up and catches
(48:07):
all that bad luck you just put into it. Then
there's an idea of numerology coming into it, particularly concerning
the number of nails in a horseshoe versus the number
of nail holes. He writes, quote in Northumberland, the holes
free of nails are counted as these indicate, presumably in years,
how soon the finder of the shoe may expect to
(48:29):
be married. And I guess in this case they're like,
you know, you're out in the field, you find a horseshoe.
It's like, oh, I found a horseshoe. Let's find out
how long I'm going to be single? Which and again,
you know, we're not familiar with this tradition and we
can kind of snicker at it. But I guess there
are a lot of things like this. I mean, it's
kind of on a very very like slender level. It's
almost like you know, not stepping on a crack, right,
(48:50):
you know, like we know that's not there's not accurate,
but we can't help but think about it when we
do it. And so I can imagine there could be
this tradition whereas, oh I found a horseshoe exciting for me,
Maybe I'm going to take this home and put it
up over my doorway for good luck. But also what
if it's right? What if I am three years from
finding my wife that sort of thing.
Speaker 3 (49:10):
Well, also, I mean things like this are done for fun,
even if people don't necessarily believe it's literally predictive. I mean,
you know, she loves me, She loves me, not on
flower pedals and stuff.
Speaker 1 (49:22):
Yeah, catching the flowers at a wedding and so forth.
The other thing you mentioned is that you could consider
the horseshoe in its resemblance to a halo. M Okay, yeah,
so I don't remember that coming up at all in
our episodes about the Halo. We did a series on
the Halo, and there was a lot of fun. But
I guess again, we might just think of it like,
(49:42):
what are some major icons and symbols within any given
culture that could then here comes this artifact, this, here
comes this horseshoe. What does that horseshoe remind us of? Now,
outside of all these superstitions and so forth and older traditions,
the emblem of a horseshoe, I think really potent. One
(50:03):
example of this that came to mind is the various
cartoon interpretations of this, as well as how it's presented.
Sometimes in science textbooks. The horseshoe magnet has become a
kind of fixed symbol for magnetism, despite the fact that
horseshoe magnets are technically obsolete, since like the nineteen fifties,
you don't need a horseshoe shaped magnet. All the magnets
(50:25):
on your fridge are likely not horseshoe shaped.
Speaker 3 (50:27):
I was thinking about the horseshoe magnet, and especially when
you were talking about the various magical powers associated with them,
because of the way horseshoe magnets are represented in cartoons,
as like emitting beams of magic power or with like
zigzagging lightning of magnetic I don't know what, you know,
the like zappiness coming out of them.
Speaker 1 (50:49):
Yeah, yeah, I mean, it might be a scenario where
you've stopped to think and maybe you're like, hey, do
I know how magnets work? And then instantly you're struck
with that cartoon image or that or that little icon
your science textbook growing up, where oh, yeah, there is
horseshoe lightning bolts. Now I got it, Now I can
move on.
Speaker 3 (51:06):
Now.
Speaker 1 (51:07):
Another concept that some people may be thinking of, there's
also this horseshoe theory of politics, which I'm to understand.
I didn't know a lot about it previously, but it's
my understanding. It's also it's not something that's really that
much of a thing within actual political science, but you
sometimes see it in a lot of popular discourse about
(51:27):
people's political leanings and their ideologies. This idea that instead
of it being like a sliding linear scale between on
one on one end, like leftist extremism and on the
other end right wing extremism, and then in the middle,
you know, just just you know middle of the road,
you know, neutrality and so forth. Then instead of it
(51:49):
being shaped like that, we should really curve it, and
then it's more of a horseshoe, and that by virtue
of this horseshoe shape, it's illustrated that the extremes of
either side are actually closer than you might think. And
this is generally it's employed to talk about like either
like an overarching theme, like perhaps that in the extremes
there's more of a draw towards like a strong leader
(52:12):
type or totalitarianism or something, or that you might find
particular sentiments, say like an anti vaccine sentiment in both
the far left and the far right, despite these groups
having little else in common in terms of their ideology.
Speaker 3 (52:26):
Yeah, I've heard people using this analogy in different ways.
I mean, in I think in one sense it is
often used to mean that people think that at the
far extremes of the political spectrum people actually come to
share some political ideas. And then I think the other
idea is that is that at the furthest extremes of
(52:47):
the political spectrum, people have more i don't know, sort
of personality based or epistemic things in common apart from
political positions. And I'm not sure which version of the
of the model people are really talking about when they
invoke it often.
Speaker 1 (53:04):
Yeah, and I do. It kind of comes comes back
to our discussion earlier though about like how do we,
you know, interpreting data and thinking about like the underlying
truth of a given situation or a mystery. Like obviously,
the way people think about the world. They're different ideologies
and their political viewpoints. I mean, there's a lot of
complexity going on here, and that complexity can be overwhelming.
(53:25):
I mean, as we try to make sense of the
world's around us, the larger world and perhaps even the
closer world of our friend circles and our families and
so forth, and it might be tempting to say, but hey,
look at this horseshoe, Look at this. I think this
explains it all. You know, it provides maybe a simple
model that may I mean, maybe it provides some insight,
(53:47):
but also a level of insight that at least you
can sort of nod your head at and think like, Okay,
well this kind of lines up with some of the
things I'm observing.
Speaker 3 (53:55):
Well, yeah, I think another twist, for example, is whether
or not it is useful to think about political beliefs
as a spectrum at all, meaning that they extend along
a single dimension, or whether it's more useful to decompose
political beliefs into a number of different types of I
(54:18):
don't know, preferences and personality traits. And then in a say,
a representative democracy with two major parties we represent, we
discover that political behavior manifests in varying degrees of like
or dislike for those main two parties. But you know,
that doesn't fully explain people's the depths of people's beliefs
(54:42):
and preferences.
Speaker 1 (54:44):
Yeah, though in isolation it can at least seem to
make some sense. I had a case of this over
the weekend. I was in a city that has a
lot of crystal stores, so I wasn't necessarily out to
venture into a crystal store, but by virtue of where
I was, I just was going to wind up in
one eventually, and I was looking looking around at them.
Crystals are beautiful, you know, I think they can. They're
(55:07):
nice to look at, and maybe they're a nice focus
sometimes to take you out of the past in the
future and put you into the present. But they have
all these little notes on them about what they're good
for and what focus in the crystal will allegedly do
for you. And on one table I found one that
it was promised would help me connect with quote Christ consciousness,
and on the other it would help me communicate with extraterrestrials.
(55:30):
And so generally speaking, I don't know. I would expect
that people looking to connect with either would have rather
different world views, you know, the person with the Christ
crystal and the person with the extraterrestrial crystal, Like maybe
they want different things out of life. But also they
may have both wandered into this crystal store, which makes
me think that think of the you know, the ends
(55:52):
of the of the horseshoe, you know, arching towards each other.
Speaker 3 (55:56):
Every crystal store I go in, I ask for their
Nixon consciousness crystal, What will help me communicate with Nixon?
He's out there somewhere.
Speaker 1 (56:06):
Oh man, there's got to be a crystal. There's got
to be one that will do it. Unrelated to Nixon, though,
in discussing this, I am also thinking I don't think
Lawrence mentioned horns or antlers, but this would seem at
least just you know, off the top of my head,
this would seem to be like a potent symbol to
jump to and we're interpreting, like how people connected with
this horseshoe with this, you know, for all intensive purposes,
(56:30):
this new artifact that lines up with various symbols of
potents like the horns and antlers have long been and
still are things of symbolic power.
Speaker 3 (56:43):
In a quite literal sense in their biological context, but
then in a metaphorical sense to humans.
Speaker 1 (56:48):
Yeah, yeah, all right, Well, on that note, we're going
to go ahead and close this episode out, but we'd
love to hear from everyone out there if you have
thoughts about the horse, whof the horseshoe, interpretations of the horseshoe,
the use of hoof boots, be they equine hoof boots
or human hoof boots. Everything is fair game.
Speaker 3 (57:06):
Right in.
Speaker 1 (57:07):
We'd love to hear from you. In the meantime, you
can find all of our core episodes, so Stuff to
Blow your Mind on Tuesdays and Thursdays and the Stuff
to Blow your Mind podcast feed. On Mondays, we do
listener mail, Wednesdays we do a short form Monster Factor Artifact,
and on Fridays we do Weird House Cinema. That's our
time to set aside most serious concerns and just talk
about a weird film.
Speaker 3 (57:24):
Huge thanks to our excellent audio producer JJ Posway. If
you would like to get in touch with us with
feedback on this episode or any other, to suggest a
topic for the future, or just to say hello, you
can email us at contact stuff to Blow your Mind
dot com.
Speaker 2 (57:46):
Stuff to Blow Your Mind is production of iHeartRadio. For
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