Mike Wazowski's Eyeball

 How do zebras get stripes? How does Mike Wazowski keep his eyeball moist? And how come a group of crows is called a "murder?" I answer your questions! 

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Episode Transcript

Speaker 1 (00:07):
Welcome to Creature Future production of iHeartRadio. I'm you're a
host of many parasites, Katie Golden. I studied psychology and
evolutionary biology, and today on the show, we are answering
some listener questions, and by we, I mean me and
all of my parasites. Uh, Guys, you send to me
your wonderful questions and I try my best to answer them.

(00:30):
If you have a question and you're thinking, wait a minute,
I want my question answered, why don't I get my
question answered? Well, listen, it's easy. You send me an
email at Creature Feature Pod at gmail dot com, and
I answer as many of them as I possibly can,
which is often all of them. And so yeah, just

(00:52):
send me your questions, and thank you to everyone who
has sent me questions. I'm going to answer some of
them today. So here we go, Hi, Katie. I read
somewhere that tigers have white spots on their ears to
act as eye spots to frighten predators. Is that true?
And if so, what preyed on tigers in the past. Also,

(01:13):
I just saw the spotless giraffe and it is super
cute and got me thinking, what color would a stripeless zebra?
Be all white, are all black? I love your show
and I have been listening two past episodes from Taylor. Hi, Taylor,
thank you so much. I really appreciate your question and
for listening to the show. Yeah, this is a great

(01:33):
This is an excellent question. So the eye spots on
tiger ears, I don't necessarily want to call them eye
spots because they may not necessarily be that. They certainly
look that way because they have a contrasting black and white,
So they do kind of appear to be similar to
eye spots. But what are they for? They may serve

(01:56):
several functions. One hypothesis is that it is a clear
signal that makes it easier for conspecifics, which means members
of their own species, which means other tigers to identify
each other. It could be useful for cubs to follow
their mother, or to for adults to find a mate.

(02:19):
Another non mutually exclusive theory is that it is used
to threaten rivals, which would be other tigers. I really
find the positive signaling theory a bit more compelling, you know,
or perhaps some kind of protection for tiger cubs. I

(02:40):
don't think the adults necessarily need to use them for protection.
And if it's something where it is to intimidate rivals,
it would be a little odd given that if tigers
are used to being around conspecifics, it would seem like
that signal would not necessarily scare off other tigers. But
perhaps early in their evolution there were genes for icepot contrast,

(03:03):
which was indeed used for defensive signaling, but as they
became larger, it was used more for communication with members
of their own species. So onto the question about a
stripeless zebra. So a stripeless zebra, in my opinion, it
would most likely be black or brown. But saying a

(03:28):
stripeless zebra, let's dig into that a bit so zebras,
in addition to having black skin, also has these black
furry stripes. But they also have these white furry stripes.
So it seems that on average, mutations and zebras that
alter their stripes usually caused them to lose white fur

(03:51):
and default to being melanistic. The exception would be an
albino or lucistic zebra. So there have been zebras documented
with a color mutation that turned its white stripes into spots.
It's very cute. If you look up spot at zebra,
you can probably see an image of it. The real answer, though,

(04:13):
in terms of being stripeless, is that stripes on a
zebra aren't so much painting on a blank canvas, but
rather a complex diffusion of melanocytes and other pigment creating
cells that occur during zebra's evolutionary history. So the extinct
zebra cousin, the quaga, shows a more complex picture of

(04:35):
how zebra coloration may have come about. So the quaga
has brown, white, and black coloration. The stripes appear to
be white given that brown is the predominant color, but
it also has a white belly. So really what we're
seeing in terms of zebras or the quaga is the
distribution of pigment producing cells. So is a zebra white

(04:59):
with black stripes or black with white stripes? I would
say it's neither or both. Let's actually look in to
how stripes and spots and other patterns form as an
animal develops. So obviously this is a result of genetics
and evolution. There may be selective pressures put upon animals

(05:22):
to form these patterns, either as defense or camouflage, or
in the case of zebra, potentially disruptive coloration. There's a
couple things that the stripes may help out with. One
is that it makes it difficult for a predator to
pick out an individual zebra and to understand which direction

(05:42):
the zebras are running in. And also it may make
it more difficult for a mosquito to land on a zebra.
The disruptive stripe coloration confuses mosquitoes and other bugs, and
so that may protect the zebra both from large predators
and tiny predators. So how do these patterns get printed
out on animals? Right? Like? You have your zebra stripes,

(06:05):
you have your spotted giraffs, you have fish that have
stripes and spots. How do these patterns come out? Right? Like?
Obviously nobody's going in with a paintbrush to give these
animals their patterns. So there's actually some really interesting and
complex physics and math at play here. So Alan Turing,

(06:26):
the famous computer scientist, came up with a diffusion theory
when it comes to animal skin patterns. The idea is
that pigment cells would diffuse like die diffuses through water
throughout the tissues of the animal as it is developing.
The problem with the diffusion model is that it generally
would result in fuzzy patterns, not the sharp crisp patterns

(06:50):
we see from zebras to zebra fish. So currently biological
engineers are looking into this. So researchers Benjamin Alessio and
Akurgupta at the University of Colorado, Boulder have tested a
model of pigment distribution called diffusiophoresis the movement of molecules

(07:14):
through different mediums, which can result in patterns with crisp edges.
If you've ever tried to do suminagashi or paper marbling,
you know that you can let ink float on water
and then use alternating brushes of ink and surfactant something
that decreases water tension like soap, and you create these

(07:36):
rings of ink on the surface of the water, and
then you can dip your paper or fabric in it
and then get this beautiful pattern. Of course, biological development
does not use this kind of technique to get those patterns,
but the interesting idea that is similar is that there
may be different chemical concentrations that the pigment cells are

(08:00):
moving through, meaning that it is interfering with the movement
and diffusion of these pigment cells, which could result in
these crisp lines. So researchers think that certain chemical agents
present during development diffuse through tissues, polling melanocytes or chromatic
fes or other pigment producing cells with it. So the

(08:23):
patterns then would be formed by differing concentrations of chemical
agents that either poll or reject the diffusion of pigment cells.
So if you've ever tried to clean a couch or
a chair or some kind of upholstery and accidentally formed
a ring of dirt on it while trying to clean it,

(08:43):
you are basically doing a version of diffusiophoresis. So this
is a theory that has been tested in mathematical models.
It's yet to be completely proven as the way in
which animals get their stripes in their spots, but I
think it is really interesting and really promising. Follow up

(09:06):
to Alan Turing's original theory, onto the next listener question.
A question posed on the Internet was how would Mike Wilkowski,
that little green cyclops monster from Monsters, Inc. How would

(09:26):
Michael Kowski cry two streams of tears on either side
or one in the middle bottom. Of course, in media
shorthand animators would likely do the two streams. Is that
would be the least distracting from the emotions of the scene.
But tear ducks on the side seem insufficient for an
eyeball that big, and while I can come up with
multiple plausible methods of keeping that eye hydrated, nature is

(09:48):
often weirder than fiction. But the only things from nature
I could find were geckos who licked their eyes or
creatures who have eyes that don't need to be hydrated
and cleaned. So are there other animals with weird methods
lubricating eyeballs? So ah, this is from Tegreja, Thank you
so much. I love this question. So I hardly realize

(10:08):
that Michael Kowski has one eye because every time I
see him his face is covered by a logo. But anyways,
cyclops animals are actually really rare, so having two eyes
is a huge advantage. You have this bilateral symmetry. It's
really useful in depth perception and navigation and having a
wide range of visions. So the cyclops is not a

(10:31):
super advantageous design, and so we don't see it very often,
but there are a few cyclopses. When you get really tiny,
there are cyclops copapods who have a single median eye
in the middle of their heads. Copapods are tiny teeny
teenyeniuenie crustaceans and members of these Cyclops copapod genus are

(10:52):
about the size of a grain of rice or smaller.
If you've ever seen a silverfish, which is one of
my least favorite insects, Actually they kind of look like that,
but really tiny and microscopic. In terms of tear ducts,
it doesn't seem that they have any. The eye spot
is extremely simple and they are aquatics, so there's not
much need for a tear duct. So while some aquatic

(11:15):
animals have tear ducts and cry, like crocodiles and sea turtles,
by the way, sea turtles cry out excess salt to
protect their kidneys, so their crying is not necessarily out
of emotion or cleaning their eye, but to expunge excess salt. Anyways.
Cetaceans also have oily glands that protect their eyes, but

(11:36):
fish and many other species that live in the ocean
or in bodies of water do not need tears, as
their eyes are well adapted to salt water or fresh water,
and they do not need extra moisture or lubrication. But
most terrestrial animals have to come up with a way
to keep their eyes moist and clean. So how do

(11:59):
various land animals cope with the dryness of air? And
what do I think a terrestrial cyclops like Mike Wakowski
would do. Well. There's a lot of things that we
see in terms of eye protection, like eyelids, eyelashes, and
tear ducts of course that help protect eyes from irritants,

(12:19):
but some species have different solutions. So, like you mentioned
to greyha, most gecko species lack eyelids, so to moisturize
their eyes they have to give them a good lick
with their long, flexible tongue. But you also have species
like snakes who do not have eyelids and they can't
really lick their eyes with their tongue to keep them hydrated.

(12:42):
But they do have a hard, clear, protective eye cap,
one that they can actually shed and regenerate along with
the rest of their skin. And flies clean their eyeballs
with their forelegs. You may have actually seen them doing this.
When you watch a fly carefully as its lands, you
see its little fore legs going around cleaning its head,

(13:03):
cleaning its eyes. So you can give it a good
just rub down with your hands if you need to
clean your eyes. Don't do that, You'll hurt yourself. Our
eyes are very sensitive. So personally looking at Mike Wakowski,
I don't think Mike Wolkowski would have tear ducks. I've
never seen him cry or his eyes water in a movie.

(13:24):
Someone let me know if I'm wrong about that. But
given the shape of his eye, it's very bulbous, it's
very large, it seems like it'd be really difficult for
a tear duck to cover that whole eye and to
actually keep that moist and given the size of the eye,
also there'd be a lot of danger of debris getting

(13:46):
into that eye. Just the probability of something smacking him
in that eye is so high that I do think
he probably would have a hard clear eye cap similar
to a snake basically like a permanent large contact lens,
but it covers his whole eye and something that maybe
he sheds with his skin. Mikeawelkowski probably does shed his

(14:09):
skin on sort of a monthly maybe bimonthly, right, I
can only think how he can keep his skin so
clear and moisturized other than frequent shedding. But also I
think Mike Wolkowski would have to use other cleaning techniques.
I mean, it is a big eye. I don't know
if an eye cap is enough. He'd probably have to
wipe it with his hands or his tongue. Maybe if

(14:32):
Michaelkowski is like a species. It's unclear to me exactly
how monsters inc works. If they're each unique, if they're
members of a species, if they're all the same species
but they all have extremely different phenotypes, it is a mystery. Nevertheless,
I would think that for all of these monsters who

(14:53):
have huge cycloptic eyes, they probably would have some kind
of like contact solution. He could squirt on there to
keep his eye cap clean. Maybe he uses his hands. Uh,
maybe he has a nictitating membrane underneath his eyelid. We

(15:14):
know he has an eyelet, he's very expressive, But a
nictotating membrane is a third semi transparent eyelet that runs
horizontally across the eye, helping to clean it. So many
bird species and reptiles have a full nictitating membrane, and
mammals like cats and dogs have a partial membrane. That's
sometimes like when you have a very sleepy cat and

(15:37):
you see it wake up and it's got that weird
white thing covering half of its eye. That's the nictitating membrane,
and so yeah, I think Michael Kowski would probably have that.
And uh, I mean the other I guess eyeball cleaning
protection moisturizing thing is something that you see in say,
land snails, terrestrial snails, where their entire ey stock can

(16:00):
invert and roll back into their head, kind of squish back,
and that's a way to clean it and to also
moisturize it with some mucus. I don't think Michaelkowski would
do that. I can't imagine. It doesn't seem like his
body is big enough to contain that. I don't even
know that his eyeball can move in his socket. It

(16:23):
seems too big. It seems like he has to move
his whole body to change his field of vision, which
might be pretty big considering the size of his eye.
You actually see that in say owls, or actually this
little primate called a tarsier. They have such huge eyes
they can't really move them in their sockets, so they
have to move their whole heads. Mike Wwikowski does not

(16:45):
have a neck, so I imagine he has to move
his whole body in order to get that full range
of vision, which you know, at least he's getting a
little more of a workout. So this is a question
that actually talks about a bonus episode that I recorded

(17:07):
with my friend Alex Schmidt. We have a podcast together
called Secretly Incredibly Fascinating. If you enjoy this show, I
am very confident you would also enjoy that show, so
please check it out. All right, here is the question. Hey,
Katie was listening to the Crows bonus episode with Alex,
and it had me wondering the weird Victorian dude in

(17:27):
their garage that came up with all these group animal terms.
Is there any chance they were fans of corvids and
gave them names on purpose that people would avoid eating,
because it sounds like this perception of them being murderous
and unkind saved countless lives. This is from PK. Thank
you so much for the crow's question. So there's a
lot of crows based phrases like murder of crows, right,

(17:49):
which is the term for the group of crows. But
there's also phrases like eating crow or crowing about something
or other. So where did these phrases come from and
what do they have to do with crows. So in
terms of the phrase murder of crows, most biologists sort
of ignore the silly name conventions for specific species of animals,

(18:11):
most of us just for fun. There's just a few
general terms that are used for certain orders or clades
of animals that biologists actually use, like herds of ungulates,
flocks of birds, troops of primates, packs of dogs, schools
of fish, et cetera. So I don't know if a
crow researcher or covid researcher would refer to them as

(18:33):
anything other than a flock, but crows have long been
associated with death in the West, and so it is
very unsurprising that they got this term of a group
of crows being a murder of crows. So crows are scavengers,
but they're omnivores, so they will eat carrion, and this

(18:56):
is seen as kind of gross, right, two people, So
they may have been seen in places where there were
dead humans as well, like graveyards or battlefields where you
have or maybe even after a plague or illness, right,
and you have a bunch of human corpses. So things
that we have an aversion to, right, a bunch of

(19:17):
human bodies or you know, moldering carrion. We don't really
appreciate that as humans, and so if we see a
lot of crows around it, the association is probably going
to be pretty negative. They're also all black, and they
have these guttural calls, which may have added to their
Gothic mystique. I think they're really beautiful, and I think

(19:40):
that the sounds that they can make are really really interesting,
because they can make a lot of sounds other than
just that calling sound, so it can ravens really really cool.
But there were all sorts of other negative superstitions about crows,
like how they might peck out your eyes, or that
they're omens of death. Of course none of this is true.

(20:00):
You may see a crow with an eyeball in its mouth,
but that is just because that crow got lucky and
scavenged and eyeball. They are just as likely to enjoy
a nice berry or nut, being omnivorous. So the murder
of crows terminology probably came from the general spooky vibe
that crows give off. Despite them not being particularly murderous

(20:22):
at least to each other or to humans, they will
kill small prey like insects, rodents or baby birds. But
you know that's what a cat does, So why aren't
we calling them a murder of cats? But yeah, crows
are not completely murder free, but they don't murder people.
They don't generally murder each other. They're not the most
murdery of animals. I think if we make a hierarchy

(20:43):
of murder animals. I don't think that the weird Victorian
who came up with the name was protecting the crows.
I think the crows already likely had many superstitions surrounding
them that protected them from being hunted for their meat.
Superstitions also probably just sort of as an aside, This

(21:04):
probably did save the lives of albatrosses and other seabirds
because sailors thought it was bad luck to kill an albatross.
In fact, the term an albatross around your neck, meaning
like an issue that is a big pain that keeps
following you around, is from Samuel Coleridge's nineteen seventy eight
poem The Rhyme of the Ancient Mariner, in which a

(21:27):
mariner kills an albatross, causing bad luck in the winds
to die down around the ship and stranding him and
his fellow sailors. As punishment, his fellow sailors string the
dead albatross around his neck, which is a reminder of
his crime that doomed them. So onto the other phrases

(21:47):
about crows. Where do these other sayings about crows come from?
Like eating crow? So eating crow means having to admit
to being wrong. This phrase likely originated in the eighteen
hundreds and was probably just to evoke disgust at the
idea of eating something unpleasant. There's a possible short story,

(22:09):
a kind of humorous story that originated the phrase, printed
in eighteen fifty under the title eating Crow. It's about
a New York farmer who claims he's not picky about
food and could eat anything, and so, of course, he
is provoked by his chums who tried to get him
to eat a crow laced with snuff, which is a

(22:31):
type of tobacco, And after he eats this dish, he says,
I can eat a crow, but I be darned if
I hanker after it, which basically means I can eat it,
but gross yuck. So it is this possibly this short
story that popularized the phrase eating crow, but essentially for
a while the idea of eating crow was unpleasant to

(22:55):
people because crows are scavengers and they eat carrion. This
was thought to be kind of a gross food. So
the idea being you are eating something that may have
eaten a dead body, maybe even human remains. Its quicked
people out. So that idea that crows are not good
for eating probably did save some of their lives, right,

(23:17):
Because apparently I've read that crow meat actually does not
taste bad. I wouldn't know. I've never eaten a crow.
I love crows too much. So what about crowing about
something or other, meaning someone is bragging, Well, this actually
has nothing to do with crows. Crow also means the
call of a rooster, and so the idea that someone
is being loud and obnoxious in a proud way is

(23:40):
supposed to be evocative of a rooster crowing proudly right,
sticking out its little chest, and crowing in the morning.
So the name crow for the bird we know and
love probably came from the automotopia of the Old English
word crawl, which was probably used for multiple bird calls.

(24:01):
But stuck is the name for crows, probably because their
call is very, very distinctive and they are also quite
present around human society. So there you have it, all
the crow etymology facts that I can think of. If
you have more questions about animals, animal behavior, your pets,

(24:21):
why are we got certain ideas about animals, or if
certain myths or superstitions about animals are correct or wrong?
Anything about animals or evolutionary biology, you can write to
me at Creature Featurepod at gmail dot com and I
will do my best to answer your question. I will
either do it here on the show in these listener

(24:41):
questions episodes, or I will write back to you, or
maybe even both. Who's to say, uh, but yes, I
really do appreciate your questions. They are really interesting and
often they have me off on a little research spree,
right Like, I didn't know about the etymology of all
these crow terms, and tell you ask this question, and
I looked all this up so it helps me learn.
I hope it helps you learn. Thank you guys so much,

(25:04):
and yeah, I will see you next time. Creature Feature
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shows I do not judge you, and I'm not your mother,
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do love you all very much. See you next Wednesday.