Blubber, Part 2

In this two-part series from Stuff to Blow Your Mind, Robert and Joe discuss the science of blubber and some of the ideas surrounding cetacean insulation.

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Episode Transcript

Speaker 1 (00:03):
Welcome to Stuff to Blow Your Mind production of iHeartRadio.

Speaker 2 (00:12):
Hey, welcome to you Stuff to Blow Your Mind. My
name is Robert Lamb.

Speaker 3 (00:16):
And I'm Joe McCormick, and we're back with the second
part in our series on the biological prodigy that is blubber,
that subcutaneous blanket of the marine mammal world. A lot
of ways you could describe as kind of a dynamic
beer cooler worn underneath the skin of the whale and
seal alike. The interesting way that it's equipped with a

(00:38):
hot cold toggle switch that works by opening and closing
the inner floodgates of blood. So in part one of
this series, we started off by talking about a couple
of passages from the novel Moby Dick, One from a
chapter about whale blubber, where the narrator sort of does
a mental dissection of the body of the whale and

(00:58):
then marvels at what he calls this cozy blanketing of
his body, the blanket underneath the skin by which the
whale can quote be cool at the equator and keep
thy blood fluid at the pole. And the book deploys
this as a metaphor for a way that humans should
be ideally for how humans should try to cultivate a

(01:20):
sort of stoicism or a form of mental independence from
the influence of outside events. But in the literal sense,
this ability to carry your own weather with you is
indeed probably the most amazing thing about blubber. Blubber is
not just fat based insulation, but highly vascularized dynamic insulation,

(01:42):
which can keep the body core warm in freezing waters,
but open up those channels of blood flow within the
fat to dump excess heat when the whale is hot
from warmer water or from exertion.

Speaker 2 (01:54):
Yeah, it's no mere coat. If it were a coat,
it would be some sort of high tech living smart coat.

Speaker 3 (01:59):
Yes, yeah, it's like it's cyber. It's very cyber. But
in the last episode we also talked about a bunch
of the weird fascinating biological characteristics of blubber, its role
not just in thermal insulation, but energy storage, supporting fasting seasons,
long migrations, and extreme reproductive challenges for some marine mammals.

(02:20):
We also talked in particular about probably the blubberiest beast
in the seas, would you say, Rob the bowhead whale,
which uses thick, powerful walls of blubber insulation to survive
despite being a warm blooded mammal in the iciest of
polar waters. And we're back here today to talk about more.

Speaker 2 (02:40):
As promised, we're going to be getting into the culinary
uses of blubber a bit here, right.

Speaker 3 (02:45):
Yes, So if you are not from a blubber consuming
culture yourself, it might come as a surprise to you
that blubber plays a big role in multiple food traditions
around the world. One of the most interesting and important
of ways, which is the cultural use of blubber as
food known as muktuck, a traditional preparation of whale skin

(03:08):
and blubber made by the Inuit and other related peoples
of the Arctic Circle. So I've been reading about this
a lot today, and it seems like there is a
wide variety in how people enjoy muktuck. Traditionally it was
most often eaten raw or frozen, and still today it's
sometimes eaten raw. I've seen people compare it to, you know,

(03:30):
a preparation that's kind of like sushi. You know, you
would have these raw pieces of the whale blubber with
the skin together, served with a variety of different seasonings
and condiments according to people's tastes. I've read some people
talking about eating it with soy sauce, some people with
HP sauce, you know, the British brown sauce, different types
of seasonings people like. There are also recipes for pickled muktuck,

(03:54):
fried muktuck, boiled muktuck, aged, or fermented muktuck. The thing
that seems to be common between these is the source
of the product, of course, which is whale blubber, most
often from beluga or bowhead whales. So it's gonna be
whale blubber with the skin attached. So that's one thing

(04:14):
in common. And the other thing that seems to be
common is the way it is initially processed and cleaned
after the whale is harvested, and then after that you
can take it in a lot of different directions. I
was reading a short article in Mashed by an author
named Maria Sinto from twenty twenty three that was just
mentioning the various different flavors that people said muktuk reminded

(04:37):
them of, and the list is pretty diverse. Quote anything
from fried eggs to coconut meat to beef jerky and sardines.

Speaker 2 (04:47):
Yeah, that is a pretty wide ray.

Speaker 3 (04:50):
So muktuk is traditionally an important dietary source of vitamin
C and vitamin D for people living in the Arctic Circle.
I've seen some sources claim, or at least imply, I
believe inaccurately, that whale blubber and whale skin are the
only ways you can get vitamin C in the far North,

(05:13):
due to the lack of fresh fruit. From what I
can tell, this is not quite true, as some locally
available vegetable and animal sources will also supply you with
vitamin C. Examples could be algae, berries, meat, and various
organs from other animals, including from whales. But it is
true that muktuk is a good source of vitamin C,

(05:34):
I think, especially in the whale's skin, and traditionally for
the Inuit an important one. I was reading a bit
about the harvesting of the beluga and the processing of
the muktuk from an article from September twenty twenty four
hosted on the website of a marine conservation group called
Ocean's North, and this article was by an author named

(05:56):
John Noxana Junior, who is Nuvi alu It beluga hunter
who lives in a coastal hammet called Tukta Yaktuk, which
is right up on the coast of the Arctic Sea
in the Northwest Territories of Canada. Actually got to this
article backwards because I was first watching a video of
Noxana showing how to prepare the aged muktuk. So he

(06:19):
starts with these pieces of a harvested beluga and showing
like how you clean it, how you cut it, and
how you soak it to get some of the blood out.
You go through these multiple stages of processing and then
eventually you pack it with these strips of fat from
the whale to age it over time, and it takes
a lot of care. And in this post on the

(06:41):
Ocean's North website, Noxana talks about inuvialuate beluga harvesting practices
for one thing, and how the catch is used to
feed the community. So you can use the different parts
of the whale for different things, like you can turn
the flippers into a grilled meat that he compares to bacon.
You can soak the large muscle in this solution to

(07:01):
extract blood and oil so that they can be used
as meat. And cooking. And this process also includes cleaning
and preparing these strips of skin and blubber to be
used as muktuck, and also the process of extracting an
oil called uzuk, which he says can be used with
other traditional foods that they harvest, like caribou and fish.

(07:23):
And so there's this video you can look up. I
think you'll probably find it if you google, like belugabytes.
But this video of him preparing aged to muktuck that's
very centered around I noticed making sure that the pieces
are clean and that all of the blood has been
removed from the layers of blubber and skin before it

(07:44):
gets packed in to age and the necessity of getting
the blood out. I thought was very interesting because it
put me back in mind of some of the biological
facts we were talking about in the last episode, the
biological characteristics that make blubber unique and so different from
other fat, the main one being that it is highly vascularized,

(08:05):
so that it has all of this ability to allow
throughput of blood for when the whale needs to dump
excess heat.

Speaker 2 (08:14):
That's right again, the idea that is not just not
just a coat, but a smart coat loaded with all
of these veins.

Speaker 3 (08:20):
So anyway, if you kind of like me, are addicted
to cooking videos and you would like to learn about
this subject from that point of view, this video is
a good thing to look up. I think you can
find it if you google belugabytes aged mooktok m u
k t uk and I think this will come right up.
That's the title of the video on YouTube. Yeah, and
it shows the processing of the whale blubber and skin

(08:42):
and how the how it's packed for fermentation. Has a
lot of interesting details about the whole process.

Speaker 4 (08:48):
Yeah.

Speaker 2 (08:48):
I was glancing at this video, and you know, I
don't currently eat meat, and I I've never had whale
meat or blubber either. But there's something very appetizing about
the look of the meat. It has like this really
like white coloration. You know, it reminds me. I guess

(09:09):
if I'm going to compare it to anything, I would
compare it to like calamari, like uncooked kalamari, or maybe
I've also seen tripe. I guess it's also this this
the same coloration, but it's almost like a You get
the sense of almost like a completely clean palate upon
which to build some sort of culinary creation.

Speaker 3 (09:29):
Though I do want to say that although mukduck is
clearly one of the most interesting and famous of these
blubber preparations as food, it's not the only one. People
eat blubber in a variety of cultures.

Speaker 4 (09:40):
It does.

Speaker 3 (09:40):
It does seem especially far northern culture is you know,
you will see whale meat and blubber in icelandic culture.
In I think there are some preparations in Norway or
Scandinavia generally, so.

Speaker 2 (09:54):
Yeah, yeah, Whale drife proteins have served as an important
food source in Norway, i Iceland, Greenland, the Faroe Islands,
as well as Japan, going back at least as far
as the Joman period, so we're talking twelve thousand BCE.
And I think it's interesting because you think about whaling,
and of course you can set aside more recent industrial era,

(10:19):
essentially modern whaling, and you get into these various indigenous
practices and you can still think about them as pretty
labor intensive hone skills that were involved to go out
and actually hunt and catch these animals and then bring
them back for processing. But for a very long time

(10:41):
for humans, and it's still this way for various opportunistic
non human carnivores. You have the bounty of the beached
live whale or a washed up dead whale, which is
an enormous caloric windfall. So well, before we humans had
the technology and the skills to actually go after many
of the whales of the sea, we were taking advantage

(11:04):
of opportunities like this. You're out there, you can just
imagine scraping together a living perhaps depending on the season,
you know, trying to find the nutrients and the calories
that you need, and then lo and behold, here is
a dead whale, or here's a whale that is yet
still alive but is beached, and you don't even have
to venture out into the water to take advantage of it.

(11:26):
You might have to fend off other humans or other
opportunistic carnivores, but you got a shot at least some
of that whale, meet some of that blubber.

Speaker 3 (11:34):
It is not just the sharks and the seagulls that
take advantage of a free whale.

Speaker 2 (11:39):
Yeah, you might have to deal with a bear or
some other organisms.

Speaker 3 (11:43):
Oh no, I was referring to us humans, where we
benefit as well, but I'm sure other Yeah, whatever is
around that likes the smell is probably going to get
in there.

Speaker 4 (11:51):
Yeah, okay.

Speaker 3 (12:02):
I also wanted to revisit a source that we talked
about in the last episode. That was the Biological Overview
of blubber in the Encyclopedia of Marine Mammals from Academic Press,
two thousand and nine. This entry was written by the
marine biologist Sarah J. Iverson. Last time, we talked about
the summary of the role of blubber in thermoregulation and

(12:24):
energy storage, but I wanted to come back to Iverson's
article briefly to talk about the role of blubber in
low commotion and moving from one place to the other. Obviously,
getting around in water presents challenges that we don't have
to think about much on land. A major example here

(12:45):
is drag. Drag is the force that opposes the motion
of an object moving through a fluid like air or water.
Drag is the main reason it's harder to walk through
water than it is to walk through air. Though both
water and air do exert drag on us, water usually
exerts hundreds of times as much drag as air at

(13:08):
sea level. Though drag is not static for each type
of fluid, it's not just like drag in water is
one number and drag in air is another. Drag varies
depending on the density of the fluid, the speed you're moving,
and notably on your shape, which is an interesting thing.
Two objects of the exact same mass and the exact

(13:32):
same volume, moving at the exact same speed through the
exact same fluid can experience dramatically different levels of drag
depending on how their external surface is shaped and which
way their bodies are facing when they move. And that
might sound complicated, but you can actually illustrate it with

(13:54):
very simple examples. The human body experiences less drag diving
head first into the water, then it does belly flopping.

Speaker 4 (14:03):
Into the water.

Speaker 3 (14:03):
So same mass, same volume, same water, same everything. It's
just like how your body is trying, what part of
your body is facing, the direction you're moving into the
water hugely changes the amount of drag you experience. I
assume you have a lot of experience with this in
your swimming rob.

Speaker 2 (14:22):
Oh yeah, I mean it's I mean it's almost kind
of in the background ones thinking when you're swimming laps
and so forth. But yeah, I mean you're dealing with
with drag all the time with your the shape or
the imperfection of your strokes, the you know, whatever kind
of swimwear you're wearing, you know, is it something that's
form fitting and tight or is it baggy like a

(14:44):
pair of beach swim trunks. You know, And then you know,
other folks take advantage of it, people who are jogging
in the water like they're doing so to use that
drag of as part of their exercise resistance.

Speaker 3 (14:57):
I've never been good enough at swimming that I had
that I got to the point where thinking about hydrodynamics
made any sense. I never I've always just got the
baggy board shorts because like you know, I can't swim
good enough anyway that it matters. But I guess, yeah,
once you're moving pretty fast and you're trying to maximize
how fast you're moving, you really do think about like
what you're wearing, whether do you wear do you wear

(15:18):
a cap when you swim?

Speaker 2 (15:19):
I wear a cap, but mainly it's to just keep
from having to wash my hair each time. Oh I see,
so yeah, I'm I've never been a fast swimmer, so
I've never been too concerned with how streamlined I am.
But you know, sometimes I tend to wear shorts. I mean,
I wear swim trunks when I when I swim, and
it can at times you're like, this just seems like

(15:41):
an undignified way to do things. You know, You've got
like a draw string and you're having to I have
to keep retying it, and like so sometimes I feel like,
especially as the swim trunks get older and are wearing
out and they need to be replaced, I feel like
I'm wearing a bag in the swim pool and I
think to myself, I should really buy something a little
more streamlined and in a way dignified, but I never

(16:02):
do well.

Speaker 3 (16:04):
So the same kinds of considerations that people have in
mind when choosing what to wear when they get in
the pool trying to swim fast, those same considerations figure
into evolution. The bodies of fish and other water dwelling
animals are shaped by evolution to maximize hydrodynamics, so that
they usually I mean, there might be different considerations in

(16:25):
play depending on what your ecological niche is. You know,
maybe you're trying to hide more than move fast or
something like that. But with a lot of fish and
marine animals, the deal is that you want to be
able to glide easily through the water with as little
drag as possible, allowing you to swim faster or to
use less energy and movement. Marine mammals need to maximize

(16:48):
hydrodynamics on their external surface as well, and it turns
out blubber is a great tool for doing this. This
might be counterintuitive to people because you might just think
like having extra blubber sounds like something that would slow
you down, but no, actually having extra blubber, especially in

(17:08):
the right place, can make it easier to move through
water by changing your shape to make it closer to
the optimally hydrodynamic shape to go diving and swimming. Ierson
gives some examples of this, and my favorite one that
she mentions is seal butts. So the blubber at the

(17:29):
back end of a seal is often thicker than it
would need to be for insulation alone. So you know
a seal all around its body, it's going to have
a layer of blubber. This blubber helps keep its body
heat in. It has the right amount for insulation, but
then toward the back end of the body, it's got
extra Why is this well? Iverson writes that this extra

(17:51):
blubber quote serves to taper the animal more gradually than
would be dictated by the musculoskeleton. So, okay, you've got
the working parts of the seal's body, the bones and
the muscles needed for movement. If the blubber just wrapped
those parts at an even thickness all the way around

(18:12):
the body, what you would end up with is a
seal butt that narrows and terminates too fast. And rob,
I've got some illustrations for you to look at here
in the outline. I don't know if you care to
comment on these, but for example, I've got the skeleton
of a harbor seal next to a nice fleshy, plump
harbor seal with all of the soft tissue wrapped around it.

(18:36):
You can kind of see that the full fleshy harbor seal,
it tapers nicely, you know, it kind of like narrows
to a point, very gradually, going back towards the back flippers.
But if you look at the skeleton, you've got like
the big rib cage, and then you've got just a
very narrow section around the lower area of the spine
and this pretty narrow looking pelvis, and then the back flippers.

(18:58):
It looks like it would it would sort of bulge
in the front and then narrow really fast.

Speaker 2 (19:03):
Yeah. Absolutely, the image of the harbor seal too. Once
we're really focusing in on how streamlined the creature is,
I really do get a sense of like a commercial
airline looking at it, you know, it looks like like
an airline fuselage.

Speaker 3 (19:17):
Yeah, exactly, and even much plumper seals. I mean, you
can see some seals that look very plump with blubber,
but still they taper at a nice gentle ratio. You know,
the way that their body narrows as it goes towards
the very end is a gentle sloping down of the
thickness of the body. So instead of the way that

(19:39):
the seal would taper off very quickly if it was
just wrapped tightly around the bones and the muscles, Iverson
says that to maximize hydrodynamic efficiency, marine organisms tend to
be adapted one way or another to have a gradually
tapering tail end, aka the spindle shape. This reduces the
wake behind the animal and thus reduces drag. And it's

(20:02):
not just seals. Whales, porpoises, and dolphins all apparently use
blubber to thicken and gradually taper the tail stock for
maximally smooth glide through the water.

Speaker 2 (20:15):
Yeah, and if I recommend, if you haven't had a
chance to see a seal or sea lion, especially moving
through the water, definitely check it out because it can
be quite impressive. I was in Vancouver with my family
a few months back when we went to the excellent
Vancouver Aquarium where they have different varieties of seals and
sea lions that you can observe from above the water

(20:38):
and also below the water via some viewing areas. And
oh man, especially the stellar sea lions, especially the male
stellar sea lions, such an enormous creature and just moving.
It's such an incredible click through the water.

Speaker 3 (20:52):
It's quite impressive, especially at hilarious contrast to how they
sometimes move on land. I mean, different seals are different
in this sort, but a lot of times you see
a seal moving on land and it's it's adorably awkward.
It's kind of scooting along, you know, like like you
would imagine job of the Hut moves.

Speaker 2 (21:09):
Yeah, there's like big furry hot dogs kind of rolling around,
flopping around. But then when they get and then they
can move around. Not to say they can't move in
a very intimidating fashion. Yes, on the ground when they
need to, but in the water, of course, they're completely.

Speaker 3 (21:25):
At ease, undulating plump worm sausage, just kind of like
scooting around on the beach. But then yes, once they
get into the water, suddenly it's totally different story, graceful, rapid,
agile movements. They're like, this is a strange comparison, but
I think of them flitting around like fairies in a movie.

Speaker 2 (21:45):
Mm. Yeah, yeah, I've had a similar experience with with
other creatures that you think of as being you know,
from our terrestrial land based view we think of often
we think of sea turls this way sometimes, and I've
been in the water where there'll be a sea turl,
like a smaller variety that suddenly zooms away from me,
and I'm just a little astounded because it moves with

(22:06):
such not only speed but ease through the water.

Speaker 4 (22:09):
Yeah.

Speaker 3 (22:10):
So that's a big part of blubber in the marine
mammal's body. It's used to help shape the body to
be its ideal tapering ratio, generally to shape the body
for maximum hydrodynamic efficiency. In addition to all the other
things we've talked about energy storage and most importantly thermoregulation,
but there are a couple of other locomotion possibilities that

(22:35):
Iverson talks about in this overview. One thing she mentions
is that there's also some research indicating that cetaceans may
I think this is less firmly established, it's more speculative,
but cetaceans may use blubber as a form of biomechanical spring.

(22:55):
So I went looking elsewhere to try to find more
detail about this. I found an article in in Science
from January two thousand by Elizabeth Panissi talking about this research. Essentially,
the idea is studies conducted in trained dolphins showed how
blubber may help contribute to a spring like phenomenon that

(23:15):
increases efficiency in swimming. So, if you look at a
dolphin or a porpoise, the blubber lining in the mid
section of the body near the dorsal fin is quite stretchy,
but the blubber at the end of the tail is
relatively stiff. And remember we talked about in the last episode,

(23:35):
blubber has a lot of collagen and elastic fibers that
make it much bouncier and tougher than regular fat tissue,
and so this article talks about how researchers and Pabst
and John Hamilton associated with the University of North Carolina
at Wilmington found in this research. I think this was

(23:57):
first published in the nineties that when a dolphin swims, quote,
the stiffer blubber hardly bends at all, while the blubber
closest to the dorsal fin bends quite a lot, reaching
its maximum distortion at the bottom of the tail's downstroke
and then bouncing back. Because remember, the dolphin's tail does

(24:17):
not stroke side to side like the tail of a fish,
but up and down, bending like the spine of a
land mammal, because of course dolphins ancestors were land mammals.
All marine mammals evolved from land mammals, so they still
have that up and down flexing spine, unlike fish and reptiles.

(24:39):
So as the dolphin swims, its spine flexes up and down,
and its tail pushes with these powerful downstrokes and then
flexes back up with the return stroke. And at the
extreme of these strokes, it seems some extra energy, instead
of being wasted, is stored in the deformation of the

(25:00):
elastic mid section of the animal's body, which when it
springs back from the extreme of the stroke, puts that
energy back into locomotion. So it's of course it's muscle
powered undulation of the body where it's flexing and producing
these strokes, but some amount of that energy may get
stored in the elastic tension of the body when it

(25:22):
reaches the extreme and then bounces back, which helps propel
each stroke. And because of its elastic properties, the idea
here is blubber itself may be contributing to this. It
wouldn't be just the blubber that is storing this potential energy,
but the blubber itself may be contributing, storing and then
releasing some of this energy along with other parts of

(25:43):
the body.

Speaker 2 (25:44):
Wow, it makes you wonder where they would be without springs.

Speaker 3 (25:49):
Wait is that an mst short?

Speaker 2 (25:50):
I think it's.

Speaker 4 (25:52):
Gotta be no springs.

Speaker 2 (25:54):
Oh yeah, yeah, now that don't never wish such a thing,
don't wish.

Speaker 3 (26:01):
And then one last thing for blubber and locomotion is
this one's fairly obvious, but buoyancy. This is a huge thing. Obviously,
marine mammals use blubber to manage buoyancy. Fat tissue is
generally less dense than water, while lean body mass is
generally denser than water. And then the ratio between these

(26:22):
two things within your body helps determine how easily your
body sinks or floats Iversen writes quote. Studies have demonstrated
that seals descend faster during diving when they are more
negatively buoyant than when they are less negatively buoyant, providing
evidence that seals adjust to their diving behavior in relation

(26:42):
to seasonal changes in buoyancy. So during the fattening season
and then the lean season, how buoyant you are in
the water will actually change because of your relative level
of blubber compared to the lean muscle and you know
the rest of the mass of your body. So as
that buoyancy changes, you will also have to go through

(27:05):
some behavioral changes. But this could contribute to this could
be adaptive for the marine mammals in some cases as well.

Speaker 2 (27:23):
All right, Joe, well, are you ready to talk about
reptile blubber?

Speaker 3 (27:27):
Oh? I cannot wait. You told me you were going
to go down this avenue and I got so excited.

Speaker 2 (27:32):
Yeah, yeah, And I didn't know to be excited about
it because I'll be honest, I was not expecting to
discuss prehistoric reptiles in an episode on Blubber because, as
we've been discussing, it's generally considered a hallmark of aquatic mammals.
But we've discussed convergent evolution before on the show, particularly
in the way that certain body plans can be found

(27:53):
in both prehistoric reptiles and mammals, birds and fish.

Speaker 3 (27:58):
Yeah, So sometimes there is a common problem presented by environments,
and different evolutionary lineages get too roughly the same solution
to that problem.

Speaker 2 (28:07):
Yeah, Like if multiple different creatures had to open cans
of beans, they would evolve different appendages that carry out
the same task, and they might appear rather similar to
each other, and then they might have key differences as well.
So you can consider the similarities and differences between the
wing plans of birds, mammalian bats, and reptilian pterosaars. You

(28:31):
can consider the similarities between the mammalian dolphin and the
reptilian ichthiosaar. In both cases we see morphology that evolved
to tack all the engineering and life challenges of locomotion
through a particular medium. So you know, why not blubber
as well, makes sense, and this does seem to be
the case with ichthiosaurs. So these were the ancient Mesozoic,

(28:58):
largely Mesozoic marine rep tiles whose story so closse closely
resembles that of the dolphin, the descendants of land based
organisms that took to the ocean and evolved into effective
marine predators. Plus again, in many respects, the two organisms
have a lot in common when it comes to general morphology.
Like if you look at even just the skeletons of

(29:20):
a nichthyosar or certainly paleo art depicting them, you get
the idea that, oh, these were reptilian dolphins, these were
lizard dolphins, you know, And I think the more evocative
imagery kind of captures that. You're like, you recognize the
outline of the thing as dolphin shaped or you know,

(29:42):
large fish shape. But then when you get closer you
see the differences. You know, you can you can tell
there's something about it that stands distinct from any kind
of mammalian legacy.

Speaker 3 (29:51):
Yeah, it really is striking how much they look like
whales and dolphins. I mean, we can be aware of
their their heritage if your pitch during something in your
mind and that doesn't match what you're picturing.

Speaker 2 (30:04):
You might be.

Speaker 3 (30:05):
Thinking of applesiosaur, which I think looks more distinctly reptilian
or more like a dinosaur the ichthiosaur. It has just
such strong dolphin energy.

Speaker 4 (30:17):
Yeah.

Speaker 2 (30:17):
Yeah, And we know that the ichthiosaurs, this is an
order containing various genuses by the way, we're also warm blooded,
air breathing, and that they bore live young, and based
on excellent fossil evidence, they may have also benefited from
the thermal protection of blubber or a blubber like tissue. Johann

(30:38):
Lindgren from Lund University in Sweden is one of the
prime researchers on this topic, with a big major publication
from this research came out in twenty eighteen Soft tissue
Evidence for homeothermy and crypsis in Jurassic Ichthiosaur, as well
as some more recent publications that have followed up. This
is very much an area of continual study as our

(31:01):
tools and our technology continues to improve in this area.
Twenty twenty two's A review of Ichthyosaur soft tissue with
implifications for life reconstructions published in Earth Science Reviews. This
is one that I looked at more extensively, and Lindgren
and his co authors walk through a number of the

(31:22):
key points here. So for starters, yes, most of what
we know about prehistoric reptiles in general comes via the
inherently incomplete fossil record that consists largely of mineralized hard tissues.
This is like the basic scenario where you go to
the museum and you realize that the skeleton of a

(31:42):
particular dinosaur, for example, is based on a number of
actual fossil bone finds, and then we've kind of filled
in the missing pieces based on other finds and also
just extrapolations about what the rest of its skeletal system
would look like. However, with the ichtheos are due to
a combination of biological factors, rapid burial processes, and specific

(32:06):
and oxic marine environments, we have some great representation of
these creatures in the fossil record, and it includes not
only hard tissues but soft tissues as well, and this
means we're afforded just far more insight into the anatomy
of these creatures and how they lived, of more so

(32:29):
than many of the prehistoric reptiles of their age.

Speaker 3 (32:34):
The soft tissue prints are a real gym.

Speaker 2 (32:36):
Yeah, yeah, Yeah. There's sort of two major areas for
key ichthiosr fossil finds. That's Pasidonia Shale and holds out
in Germany and the Zapota Formation in Patagonia. So the
first ichthiosaur fossils were described as far back as sixteen
ninety nine, and the first known discovery of fossilized soft tissue,

(32:58):
this would be patches of scaleless skins, were made in
eighteen thirty six. So over time, just in general trying
to understand what the ichthyosaurs were, paleontologists gradually went from
this idea that well, maybe they were sort of like
big crocodiles and they crawled back on land periodically. We
kind of moved away from this to realize that no,

(33:18):
they were essentially like modern dolphins. They lived out in
the water and they were not coming back. They weren't
crawling up on the land of lay eggs or anything
like that. But yeah, like I was saying, the fossilized
soft tissue here has apparently been just amazingly revealing, like
to the point where we've had we've had an indication

(33:42):
of what was inside of their guts, inside the abdominal cavity,
we were able to tell that, in particular, they may
have lived on a diet of cephalopods. And this in
addition to just a general body outline as well. So
when you look at especially modern images of ichthiosaurs, we're
not just doing the exercise that we do with other

(34:06):
prehistoric animals. We're like, Okay, we know what the skeleton
looks like. We're gonna lay some skin over that and
just sort of imagine it. No, we know with a
great deal of accuracy that they were their shape like
the way we think they were shaped. They have this
dolphin shape to them, or the ichthyosaurs might say, well,
that's the ichthyosaur shape, not the dolphin shape we had
it first.

Speaker 3 (34:24):
Oh yeah, good point.

Speaker 2 (34:26):
The blubber find came about in twenty eighteen. This was
a specimen discovered in the Hole Mountain area, and I'm
going to read the description of it here from the
paper that the fossilized remains provided evidence of a quote
layer of condensed, densely laminated organic material enriched in hydrocarbons,

(34:46):
including potential fatty acid moieties. Situated in between of phosphatized
fibers and overlain by distinct epidermis and dermal layers, and
this the is can tend provide strong evidence that they
were home themic or intothermic like birds and mammals in
order to sustain the high energy lifestyle they would have

(35:10):
required in the ancient ocean. So again, it's living essentially
the life of what a dolphin lives today. So it
has to be out there as an active hunter in
the water, chasing after things that are moving around with
a great deal of speed.

Speaker 3 (35:24):
But that also means it cannot tolerate its body temperature dropping.

Speaker 2 (35:28):
Right right, It needs to maintain yeah, right, it has
to maintain quote insulating blubber would have kept ichthiosaurs warmed
during deeper dives into colder mesoplagic zones in pursuit of prey,
but also help them tolerating excursions into frigid waters at
higher latitudes, explaining their occurrence in polar regions. Back in

(35:50):
twenty eighteen, there was a BBC article about some of
this work by Paul Runken, and it has a wonderful
side by side illustration. Everyone out there can look this
up at Your Leisure included the image here for you, Joe.
It shows a comparison between matured modern porpoise blubber and
skin and the equivalent from the fossil ichtheos are. And

(36:13):
I'm not going to lie and say that I'm well
versed in interpreting this kind of kind of imagery, but
it's you know, everything's labeled here, and you know, side
by side, I can see it, you know. And I
should say that the contemporary blubber images remind me of
some of these other blobber images we've been looking at,
particularly culinary preparations.

Speaker 3 (36:33):
Yeah, I wonder what the what people would say the
ichtheos or blubber tastes like I'm looking at this and
I'm trying to see is there any indication whether it's
vascularized in the same way that marine mammal blubber is,
you know, infused with all of these blood vessels that
can sort of toggle on the blood gates, so to speak,

(36:55):
when the animal is overheating, or whether it's it's less
dynamic than the installation of modern marine mammals.

Speaker 2 (37:02):
Yeah, I think a lot of these answers. They stress
in these articles that as the tools of molecular paleontology
continue to improve, we're going to be able to tell
even more about a fossil soft tissue fossil remains like this,
and tell yeah, just how robust was the quote unquote
blubber of the achthiosar compared to the blubber of modern

(37:24):
day aquatic mammals.

Speaker 3 (37:26):
That we're getting a picture of the blubber of an
animal that went extinct to this long ago is amazing
on its own. Just that you're getting this level of
granular detail on the soft tissue is pretty remarkable.

Speaker 2 (37:41):
Yeah. When I first was doing some searches and this
came out, I was like, that doesn't sound right, this
sound this this Yeah, prehistoric reptile blubber is surely not
a thing. But lo and behold here it is. Now.

(38:05):
I want to move on to one last topic here,
but it connects because none of this concerning ichthiosaur blubber
is really all that shocking when you consider that penguins,
avian descendants of the reptilian dinosaurs also have blubber of
a sort generally referred to as blubber. But as we'll discuss,
there are some distinct differences between the quote unquote blubber

(38:27):
of the penguin and the blubber of a whale. Joe,
you've seen a penguin before, right, a few times? Yeah, yeah, yeah,
so you can agree that they have a little bit
of that chalk going on. We've been discussing. They have
a little bit of a blubbery body build that certainly
aids them well when they're swimming underwater.

Speaker 3 (38:46):
I mean, we were just talking about the beautiful chonkiness
of the seal earlier and the way that that translates
to actually almost Elvin Grace in swimming. There's a similar
thing going on with the penguin. It's like the bird
version of that chonky grace. And for the record, my
daughter thinks penguins are adorable, and so I think the

(39:07):
chonkiness helps there.

Speaker 4 (39:08):
Yeah. Yeah.

Speaker 2 (39:10):
Penguins, of course are pretty much synonymous with cold environments
and cold waters. They of course can and do live
in less chilly areas as well, and also just they
can live much further north than the Antarctic. One example,
of course is the Galapagos penguin, the only penguin found
north of the equator, though the waters of the Glapgos

(39:30):
tend to be quite cold as well due to the
Humboldt and Cromwell currents. But on the whole, yes, we
have a variety of bird here that has evolved to
thrive in cold and semi aquatic conditions, and you know
it needs to dive into the water and go down
to certain depths in order to obtain its food.

Speaker 3 (39:51):
And we talked in the last episode about mammals that
do not have blubber as such, they don't have like
vas uscularized marine mammal blubber, but they still do rely
on a lot of fat as insulation. One example would
be the polar bear, which, despite some differences, you could
think of as having some ecological similarities to the penguin.

Speaker 2 (40:14):
Yeah, I think that's very fair. That's a very fair comparison,
and we'll get into exactly how this plays out here.
I was reading a twenty twenty two New York Times
article titled How Penguins Beat the Heat and Went South
by Jack Demsia, and the author here points out that
some prehistoric penguins lived in tropical waters off the coast
of Peru. Others had long legs and might have stood

(40:36):
seven feet tall, but as they pushed south into Chilier waters,
various adaptations kicked into eid them, and we've been able
to study these changes by looking at their genes. And
these include the transition of wing into flipper, the increase
of low oxygen tolerance for deeper dies, boosted immunity, and

(40:58):
that ability to pack on blubber or blubber like tissue. Now,
blubber is not their only adaptation to cope with cold
weather and cold water. And this is where we get
back to that polar bear comparison, because penguins also have
a dense layer of feathers, and they're so dense. If

(41:21):
you didn't know what you were looking at, if you
did not know that a penguin was a bird, you
might look at it and think of it as fur.
It almost reads more as fur.

Speaker 3 (41:28):
It doesn't look like feathers to me, at least in
most cases. Maybe in some varieties. But the penguin I'm
picturing in my mind looks fairly smooth to the touch.

Speaker 2 (41:38):
Yeah, And it's because of the density, more feathers per
square inch than almost any other bird, layered and oiled
and trapping that crucial layer of air insulation that we
referenced in the last episode. You know that serves this
is just a little barrier to help keep them insulated.

(42:00):
So and more on that in just a second. But
their circula story systems also evolve to conserve heat by
better warming the cold blood that's returning from their extremities,
and they also adapted to form these rotating huddles which
we've all seen in documentaries where some varieties of penguins
will share their body heat but also keep cycling around

(42:22):
so that the penguins on the outside also get some
time closer into the inside. So penguin blubber here. Again,
it's not quite the same, but one of the reasons
it's not quite the same is that it's essentially a
second line of defense against the cold right behind their
specialized feathers. So it's primarily the feathers, but then especially

(42:44):
during deeper dives, this is going to cause this is
going to you know, the deeper you dive, you're going
to get greater pressure, and that pressure is going to
collapse the layers of the feathers, and this is where
the blubber really comes in and does its role. And
so it's you get into the texture of the blubber.

(43:04):
And actually, you know, comparing penguin blubber to mammalian blubber,
and rather than the sophisticated, fibrous and highly regulated organ
that is mammal blubber, penguin blubber is more it's a
little simpler in its structure. It's still it's crucial again,
but it is more of a subcutaneous fat.

Speaker 3 (43:26):
Layer, less of the vascularization exactly the tough collagen kind
of meshing.

Speaker 2 (43:33):
Right, because they have not abandoned the feathers. The feathers
are still doing most of the work.

Speaker 3 (43:39):
Yeah, and you can see that also still with some mammals.
I mean, this is why it's good comparison to polar
bears because some people have said, you know, creatures, you have,
like you know, whales that have fully made the transition
from terrestrial mammal to aquatic mammal, and then you've got
polar bears and that are you know, that are somewhere

(44:02):
on the beginning of that journey kind of you know,
they're they're more fully terrestrial adapted, but they they you know,
in millions of years, their descendants could be fully aquatic mammals.
And then somewhere in between you have seals, which are
basically they're you know, they're halfway there to being fully aquatic,
but they still many seals do still have fur, and

(44:24):
that you know, so they're using both blubber and fur
at that point. But there is an evolutionary transition that
has been documented from fur to blubber in these mammals,
and so you can see a similar thing going on
here with the feathers to to fat.

Speaker 2 (44:38):
Yeah, and it can get reasonably thick. With the penguins.
I was reading the for the Emperor Penguin. The blubber
layer can be three to four centimeters or one point
two to one point six inches thick. Now, I know
a number of you are asking, well, what does it
taste like? Well, I looked into this a little bit.
So first of all, penguin fat can be used to
create oil, so in the same way that whale blubber

(45:01):
has been used to create oil, certainly penguins have been
exploited for the same purpose. But then when it comes
to the eating of penguins, just penguin meat in general,
they are like basically two ways to look at it.
I mean, first of all, you have the accounts of
Antarctic explorers, and then you also have indigenous practices, you know,
people who for much longer lived within the range of

(45:23):
different penguin species. The Antarctic explorers, the generally Europeans, would
sometimes eat penguin meat out of desperation, but pretty much
across the board disliked it strongly thought it was oily
and fishy. Meanwhile, the indigenous groups on the whole would
eat penguin meat as a supplementary but not primary soon

(45:45):
a food source, and this was due to a few
different factors, slow yield, limited range involved, but also potentially
taste of versions as well. So I didn't go too
deep on this, but it seems like the best recipes
on either the indigenous end or the European end of
the spectrum, they all seem to lean heavily on masking
the natural flavor of the meat. So it's pretty much

(46:09):
always been considered a famine food or supplementary food source,
depending on the availability of other protein sources, with the
eggs being much more desired than the meat of the
actual bird.

Speaker 3 (46:22):
Yeah, to humans at least, I'd imagine if you're like
a leopard seal, they're great.

Speaker 2 (46:27):
Yeah, So I'm about to lean far more heavily on
the European accounts.

Speaker 4 (46:32):
Here.

Speaker 2 (46:32):
I couldn't find a good indigenous account of describing the
treatment or impression of penguin meat. But in this one
we have an individual who is both a harsh critic
of penguin meat but also perhaps its greatest defender among
European voices.

Speaker 4 (46:50):
And I read yeah, And.

Speaker 2 (46:53):
I was reading about this in Peter Smith's twenty twelve
Smithsonian Magazine article A Different Kind of Dinner Bell in
the Antarctic. This concerns doctor Frederick Cook, who served as
a physician on the Belgica Expedition eighteen ninety seven through
eighteen ninety nine. This was when the ship was trapped
in the Antarctic ice, which, of course that means that

(47:13):
it put a great strain on the cruise ability to survive.
And during this time he observed that penguin meat tasted
like quote, a piece of beef odoriferous codfish and a
canvas back duck roasted together in a pot with blood
and cod liver oil for sauce.

Speaker 3 (47:34):
Is that good or bad?

Speaker 2 (47:36):
I think he means it to be bad. And yet,
as the ship's crew faced the as yet not fully
understood threat of scurvy during the harsh winter, he landed
on penguin meat as their deliverer. And I think part
of this too was based on, you know, observations of
how indigenous peoples lived in extreme regions. And so again

(47:59):
he did not have nice things to say about the flavor,
but ultimately ended up prescribing it to crew members and saying,
what you need is some meat of the penguin. And
this is where the dinner bell part comes in. They
learned that they could summon penguins and seals to their vessel,
apparently by playing the cornett. Yeah, and Cook himself wrote

(48:20):
about this, saying, quote, at meal time, a cornet is
used to call them in together. And the penguins, it
seems also like the music, for when they hear it,
they make directly for the ship and remain as long
as the music lasts, but leave once it ceases. In
this manner, we have only to wait and seize our
visitor to obtain penguin steaks, which are just at present

(48:40):
the prize of the menu.

Speaker 3 (48:42):
That's I'm feeling so many things. That's sad and funny
and degree.

Speaker 2 (48:47):
Yeah, yeah, yeah, it becomes the prize of the menu
when it is one of the only things on the
menu obviously, but also yeah, a key to their survival. Again,
they were consuming it as a survival meat. The author
here of that Smithsonian piece also notes that Ernest Shackleton
backed him up on this, saying, yeah, yeah, the penguins

(49:10):
come when you play the cornette, but also observed that
if you play the bagpipes drives them away. So do
not try and lureen penguins to eat with a set
of bagpipes. That's the lesson.

Speaker 3 (49:21):
Should we have some kind of stinger or tag for
when our biology discussions inevitably turned to what does it
taste like?

Speaker 2 (49:30):
Yeah, well, you know, it's kind of inevitable, you know,
omnivores that we are. That is one way that we
have always connected with the natural world. What happens when
we eat it? Is it good? Is it bad? Does
it kill us? Does it make us stronger? The answer
varies tremendously, and you mean to a large extent, like

(49:51):
the human stomach, the human taste buds. These were all
one of the first laboratories by which we began to
understand the natural world.

Speaker 3 (50:00):
Yeah, and as we've talked about in other contexts. It
remains a kind of crude chemistry laboratory for the geologists,
for the chemists sometimes when they don't have other equipment.
Not recommending people taste things to discern their chemical properties,
but people can do this and do sometimes. Yeah, see
our old Ignobel episode about licking rocks if you want

(50:22):
to learn. All right, does that do it for Blubber
Part two?

Speaker 2 (50:27):
I think it does. Yeah, that's Blubber Part two. But
we'd love to hear from everyone out there. You have
additional insight on any of this, be it the meat
of the penguin or the blubber of the whale, or
how chonky prehistoric bosrs were, whatever the case, right in,

(50:48):
we would love to hear from you. Just a reminder
to everyone out there. The Stuff to Blow Your Mind
is primarily a science and culture podcast with core episodes
and Tuesdays and Thursdays, but on Wednesday's we run a
short form episode, 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 (51:06):
Huge thanks as always 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 at stuff to Blow
your Mind dot com.

Speaker 1 (51:27):
Stuff to Blow Your Mind is production of iHeartRadio. For
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