BIG IDEAS @ScienceStowers Featuring Neil Shubin, PhD


(gentle music) – My name is Neil Shubin. I’m a professor on the faculty
at the University of Chicago. I’m a paleontologist. I’m interested in the history of life. So my interest in evolutionary biology, genetics, paleontology, and all that stuff really
began with curiosity. I was a kid who had a
different passion each week, whether it’s astronomy or
geology or natural history. So I entered college to study animals. And, yeah, I was, like, in my early 20s. I get invited on this
expedition to the American West. And I remember finding
fossils for the first time. It was mindblowing to me. You know, here, digging in the rocks, we can uncover evidence
for the history of life. I just thought that was so
incredibly powerful, and so I was studying to be a
paleontologist in graduate school. And a number of scientific
papers were coming out from a whole other discipline,
from molecular biology, from studies of DNA. And not just any DNA, the
DNA that builds bodies. And people were making
incredible discoveries about how bodies were built
from egg to the adult and how DNA was involved in that process, and I remember looking at
those papers and thinking, wow. That is, that’s just such a
powerful approach to evolution. So ever since, I’ve been combining these
different disciplines. Going out and finding fossils,
working in the laboratory to understand the workings of DNA. To understand one particular
area of science, which that is uncovering the history of life. Obviously, we’re at a
technological moment. An explosion of technology
at the level of the genome, at the level of imaging. At the level of understanding
the workings of the Earth, at the level of understanding
and manipulating DNA. Those are all powerful. But what they are at the surface of is understanding diversity. Really, what it, what’s turning me on, what really excites me
everyday, is that we are now at the capability to understand
the diversity of life. Not just a small number of model systems, whether it’s mice or yeast. But exotic species of biologies that we can barely imagine, you know. So it’s really exciting to
understand the diversity of life with these different tools because now all these different
species become available to us as scientists to study. It wasn’t the same way
before, but then the thing about diversity, and
this has been the story of science since I’ve joined it, is it’s become much more diverse itself. More diverse and inclusive. We’re a now much more
diverse, sort of, set of scientists, different viewpoints. Very international. And, you know, as a lot of people say, you know better decision-making happens. More knowledge is gained
by having diverse teams, collaborative teams of
different kinds of people with different approaches and
perspectives and backgrounds. We’re at that moment of science as well. We have a long way to go,
but it’s much better than when I started. So underlined, diversity. Diversity for experiments,
diversity of scientists in themselves. (rhythmic music) (audience applauding) Thank you. Thank you very much. It’s a real pleasure to be
here with you in Kansas City at Stowers Institute. This is, if you don’t know,
this is just a treasure. This institution is a source
of discovery and exploration in biology, and it’s a true
privilege to be invited here to speak to the community today. We’re gonna be talking about
your inner fish this evening, and you’re probably
scratching your head saying, what is this whole inner
fish thing about anyway. But it probably behooves me to begin with how this whole idea of your
inner fish began for me. And like anything in our
world, it had many beginnings. I’m gonna give you two
of those beginnings. One of those beginnings was when I moved to the University of Chicago in 2000. I came to the university as the chairman of the anatomy department
in the medical school, and my main responsibility
was, at the time, to teach human anatomy to
first-year medical students. It’s an incredible experience. This first-year medical,
all of our medical students, that’s 100 of them have to
take it, they’re learning tens of thousands of new
names of the human body. Learning the structures and
the organs and the tissues of the body itself, and they’re doing it while dissecting human cadavers. So you can imagine the
room with 25, 30 cadavers, 100 medical students. It’s a world activity. And, in fact, for our students,
it’s often very stressful. You know, they’re
confronting their new career. They’re working very hard
to memorize new names, and they’re doing so, confronting their own
mortality often, over cadavers. So to kind of chill the
scene a little bit, I’d hang out over the tables and do the dissections with the students. And I’d get to know them, and
they would get to know me. Almost invariably, they would ask. Dr. Shubin, what kind of doctor are you? Are you a cardiologist,
are you a neurosurgeon? Are you a psychiatrist, whatever? I’d say, no. I’m a fish paleontologist. What? No! I want my money back. But it soon became clear
that being a paleontologist, and not just any paleontologist. A fish paleontologist, is
a powerful way to teach and learn human anatomy. Why? Because, often, some of the best roadmaps to our own bodies lie in other creatures. The best roadmaps to the
complex tangle of nerves in our head, the so-called cranial nerves. That’s in sharks and fish. It’s simpler, and I can teach it that way. The best roadmaps to basic
structures in our own brain, including its overall
organization are in creatures like reptiles and so forth,
and the reason for this is that in every organ, in
every tissue, in every cell, in every gene of our
bodies, we have artifacts of almost four billion years
of the history of life. That’s inside of us. What a wonderful story,
and the way we know this is by going around the world
and collecting fossils. Some of which I’ll show you
today, by studying embryos of living creatures and comparing them and studying the DNA that drives all that. The development that
we’re gonna talk about. It’s a wonderful story, and
that’s what I’m gonna try to unpack for you today. There’s another origin
for your inner fish, and that began when I was a student. I was a first-year graduate
student, and I was terrified of the whole student thing. I didn’t think I could do
this whole research thing, and the biggest problem
for me was finding a topic to work on. So I was in the first
year of graduate school, and I was with the professor. And the professor led a
class on the greatest hits in the evolution of life. And every week was,
like, another huge event in the history of life. It was like, it was like
speed dating with some of the great ideas and the
great events in billions of years of history. And I remember the professor
showing this exact slide in that course, and I
remember looking at that slide and saying, that is what
I wanna do with my career. And I literally spent the
last three decades working on this slide. It’s a sad life, I tell you that. There’s, so if you look
at this, it captures, in cartoon form, sort of
the essential question. The essential problem. What you see is a
cartoon on top of a fish. That right there is a
cartoon of a fossil fish, creature known as Eusthenopteron. It’s first found in rocks
about 390 million years old. And you look at that and you say, look at, that’s a good old American fish. That’s a fish, right? It doesn’t look like a, but
on the bottom is a cartoon of an early limbed animal. That’s a cartoon of a
fossil that was discovered in East Greenland in the
1920s and 1930s, and it’s one of the earliest creatures to walk on land. And this diagram captures
how do you go from a fish that lives in water to a
creature that walks on land? You just look at this! And if you look at the
end points, it seems so utterly impossible, right? Fish live in water. They breathe, they excrete. They reproduce, they move about in water. Land-living creatures, as
the name implies, do all that stuff on land. Totally different ways of making a living. Different kinds of anatomy. I saw this and I said, that is a first class scientific problem. That’s what I want to
study, and I was training, at the time, to be a
paleontologist, right? So what do paleontologists do? If they are good at their
jobs, they find fossils. And so I said, if I wanna find fossils, I’m gonna find fossils
that tell us about this. And so I, what I wanted to do
was find, say, something that, you know, it’s a cross. An intermediate between these two. Maybe a creature that has a
flat head like this with fins, with arm bones inside and stuff like that. I wanted to find an intermediate,
so that’s what I set off to do. And this was in the mid-1980s, and I did what paleontologists had
done a century before me. I followed the rule book,
the playbook of paleontology. And I’ll give you the playbook. I’ll give you, in conceptual form, kind of what drives the research program. It’s gonna sound very simple,
and it is in principle. In execution, it’s very hard. But in principle, if you
wanna find an intermediate between fish and land-living animal, or an intermediate between
reptile and mammal, bird and dinosaur, I don’t
care what the transition, these are the rules you follow, okay? It’s pretty simple. The first thing you do
is you look for places in the world that have
rocks of the right age to answer the question that interests you. Remember I told you the fish on top’s about 390 million years old? The land-living animal on
the bottom is about 365? So you want something
in that window of time between 390 and 365. That’s the late Devonian, and the interesting
thing is geologists from around the world, usually
for economic reasons, have mapped the rocks in their borders. So you can obtain maps
that show where rocks are of a particular age in
a particular country. So you can get those, that information. The next thing is, it’s not just rocks that are the right age. It’s rocks of the right
type to hold fossils. Not every kind of rock
holds fossils, right? I mean, in Hawaii, that’s
volcanic rock, right? Volcanic rock lava is
not gonna hold fossils. It’ll destroy whatever’s in
there or nothing will fossilize. Metamorphic rocks. Rocks that are twisted
and highly pressurized, that’s not gonna, anything
in there will be destroyed. So what you look for
are the kinds of rocks that will hold fossils and from the kinds of environments that creatures
likely lived in millions of years ago. In this case, I was looking
for sandstone, siltstones, shales from rivers and
streams that’ll hold it. So rocks the right age,
rocks the right type. But it does me no good
if my wonderful rocks of the right age and the right type are buried
five miles underground. They have to be exposed
to the surface, right? So we need to expose rock. When you open the pages
of National Geographic or see a documentary with paleontologists, where are they working? Typically, they’re working in deserts. And the reason why we like deserts is it’s
all exposed bedrock, right? You can work on the rock,
and you can see the bones that are weathering out. There you have it. Honestly, in conceptual form,
that’s the toolkit we use to design new expeditions. We look for places in
the world that have rocks at the right age. Answer whatever question interests us. Rocks at the right type
to hold those fossils, and that’s some nuanced geology there. But you get good at it. And, finally, rocks that are accessible, that are exposed. That’s, so now you can run
out and be my competitor. And it’s all good. There’s a fourth variable I
didn’t know about at the time, but I was a young scientist. I was very naive, and it’s the
fourth variable, in my case, that started everything,
was money or lack of it. So I started, so I had saw that
slide right in the mid-80s. And I got my first academic
job in the late 80s, and I’m all, like, hot. I wanna find my, I wanna find
my flat-headed fish with fins. My first academic job was
in Philadelphia right here. In the Southeastern corner
of the state of Pennsylvania. I was at the University of
Pennsylvania for 10 years, and I remember thinking, I want a research program I can do on turnpike toll gas
money and do it totally on the cheap, right? I didn’t have the ability
to lead exotic expeditions around the world. I couldn’t raise money. I wanted to get in my
Subaru and drive, work, and find fossils. So I dug a geological map of
the state of Pennsylvania out, and I’ve stripped it of
everything unimportant. And what you see here is
the state of Pennsylvania, and look at this in purple. What do you see in purple, all throughout mapped by the Pennsylvania
state geological survey? Devonian age rocks. Remember I told you
rocks of the right age? Devonian is a window of time. That’s it, right? Three, 90, 365. So I had, within about a
three-hour drive of my home in Philadelphia, I have rocks that are in the right shooting
match in terms of age. The next thing is were they
rocks of the right type? And, to give you a sense
of that, they were perfect. These, if you wanna get a sense of what Pennsylvania looked
like 365 million years ago, get Pittsburgh out of your brain. Get Harrisburg out of your brain, get Philadelphia out of your brain. And think Amazon delta. This is a cartoon of what Pennsylvania looked like 365 million years ago. It was done by the Pennsylvania
state geological survey. We know this from the rocks. There’s a package of rocks
that have a signature of this. It was an ancient delta! The idea was, in the Eastern
part of Pennsylvania, kind of where Scranton and
Wilkes-Barre are today. You had a series of Highlands mountains. In the Western part of Pennsylvania actually extending into Ohio,
you had an ancient seaway called the Catskill Sea. So, if you look in that area,
you’ll see Devonian rocks, and they’re marine. They’re formed in ancient oceans. And draining from east to west across the state of Pennsylvania
were rivers and streams draining from the Mountain Highlands all the way into the sea. And you could see that in
the rocks of Pennsylvania. Pennsylvania geological
survey mapped this. Now if you’re a paleontologist
interested in finding fossils at the cusp of the transition from life in water to life on land, this is absolutely perfect. Why? Because if you have the exposures, you can sample fossils
from the ancient seas, from the ancient estuaries
all the way upstream. You have all the relevant environments that the creatures that
first walked on land likely lived there. They’re not living at
the bottom of the ocean, they’re living somewhere along these. Perfect, right? My problem was I had rocks, more or less of the right age, rocks probably of the right type, but Pennsylvania is not
known for its rock exposures. It’s not a desert, right? That’s good for the residents, lousy for the paleontologists
who work there. So it turns out that my
entire research program on the paleontological
side in the early ’90s came from thinking about
finding new exposures, and in Pennsylvania,
new exposures are made by Pennsylvania Department
of Transportation. When the Pennsylvania
Department of Transportation made a new road in the late ’80s, and early ’90s what would they do? They would widen the road. They would make a road, they blow up rock, right? And if I got really, really, really lucky, Penn Dot would be blowing
up rock in Devonian areas where that is mapped, Devonian. So we got really good, and really tight with the Pennsylvania
Department of Transportation. I signed my life away
to work on these sites. And it’s, you know,
they’d blow up the rock, and my colleague Ted, who you’ll hear about
throughout the story here, Ted and I would drive
out to to these sites, and we would look for fossils. And this is one of them. This is called Red Hill, Pennsylvania, ’cause it’s a hill, and it’s red. We’re not clever with our names,
we didn’t actually name it, but they, the Penn DoT in the late ’80s, and early ’90s widened the road. When they widened the road, they created this huge road cut. Look at this. We’re on state route 120, about an hour and a half north of State College, Pennsylvania. So this is an active roadway. You could see our car’s all
the way on the right hand side. There’s a human being for scale. Now this is a wonderful road cut, because this is a road cut that the Pennsylvania
Department of Transportation just really gashed through Devonian rocks. So you’re seeing all this red rock, and look at these layers, see all these different
layers here, running across. These are the layers. These are layer after layer
of Devonian Age, rivers. What you’re seeing in cross
section is an ancient delta. These are ancient rivers, and streams that you could see cobbles, and fine grain sediments. This is just the whole delta
system captured in time, you know, in the Devonian time. And what’s amazing about this place, I actually, pretty much where
this gentleman was working, is as soon as we got to this spot, we started to find fossils. The first fossils we found were teeth the size of railroad spikes, or a large thumb. Think about that for a second. Huge. And then all of a sudden we
start to find, this is Ted, holding the front end of a
jaw of one of these creatures. The jaw’s as long as your arm, you know, so we’re pulling
up these big monstrous fish with teeth the size of railroad spikes, jaws the length of your arm, the whole body, about 15 feet long, giant Devonian monsters coming out from this
roadside in Pennsylvania. Now think about that for a second. Think about the juxtaposition
of presence, and past, present day roadside, Pennsylvania. Right outside State College, Pennsylvania, in the rocks, an ancient Amazon Delta
with giant monstrous fish. You know, so trucks are
whizzing by, honking at us, and we’re pulling out these giant monsters going, check it out. Anyway, so we started, we started to find all
these other lobe fin fish, like with bodies, and heads, and squash. I know this looks like a
Devonian roadkill to you, but this is beautiful to me. It’s a body of of a gorgeous fish. And then we started to find limbed animals, and bits, and pieces of limb bones. We found shoulders, we found leg bones. We found this is an upper arm bone, a humerus, of an early walking animal. And it’s identical in some ways. Remember that cartoon I showed you of the limbed animal from Greenland? It’s identical to that. We were discovering
plants, and invertebrates, and fish and, and limbed vertebrates. So we worked with National
Geographic to reconstruct what these ancient
ecosystems in Pennsylvania looked like 365 million years ago. And this is it. Isn’t that amazing? You know we had some of
the earliest forests, and you could see the trees right here. We see them as fossils. You have some early shrubs. Look at those. They’re really kind of shrubby things, but they’re important, because they stabilize these banks, and then in the water, and the fresh water we have those giant monstrous fish, remember the one with the teeth
the size of railroad spikes, the jaws the length of your arm. Then we had all kinds
of little armored fish, dozens of those species, and then all kinds of
different limbed animals. Really an amazing ecosystem. All in rocks, about 365 million years old, Ted and I were really loving it. This is in the mid ’90s, but we realized we had a big problem. A really big problem. We were finding lots of
limbed animals, right? But they were very advanced. We were finding a great ecosystem, but we were likely in rocks too young to find that intermediate, that cross between fish, and tetrapod. In fact, limbed animals, in fact, if we looked
at scientific papers, we were probably in rocks. We were in rocks about
365 million years old. We had to go back in time to rocks about 375 million years old. So the action was all a great ecosystem. But we were finding tetrapods,
limbed animals already. We had to push it back in time. To give you a sense of
what we’re looking for, let me go back to what
started all this, right? And you can look at the fish on top, and the animal on the bottom, and you can see lots of differences. Let me give you a few salient ones, cause it gives you a sense
of what we’re looking for, and why we had to move back in time. Look at the head of that fish. These fish are so-called lobe fin fish. They’re cousins of limbed animals. They’re fossils. But look at that head. It’s conical, right? And the eyes are on either side. But if you look at the
head of the limbed animal, and look at that, it’s a
flathead with eyes on top. And the nostrils, paired
nostrils, sit on top as well. So the geometry, the proportions of the head is different. So you have a flat wide head with eyes on the top dorsal, okay? The other thing is if you look at this, look at that fish on top. That head is connected to
the shoulder right here by a series of plates of bone. There is no neck in fish. When the fish wants to look around, it can’t swivel its head
independently of its body. It moves around in
three dimensional space, you know, in the water. Whereas if you look at a limbed animal, they have a neck where the head
is separated from the body, and can swivel independently. That’s a really good thing, right? To have a head that moves
independently of the body. We love that, right? That’s what I’m using right
now to talk to you with. And it’s particularly important in creatures that are on legs. And the other big thing is fish have fins with finned webbing. I’m sorry, whereas the
limbed animals have limbs, as you can tell with fingers, and toes, and wrists, and ankles. And look, that’s a big transformation. And you think about it,
this is all of a piece. Well, think about that neck. That neck is important on a creature that is
supporting itself on all fours. Think about this. Think of doing a pushup
without a neck, okay? You could do a pushup, you
can’t look around, right? So this origin of limbs of animals that walk on the
land with legs is actually, we see coincident, and time
with the origin of a neck. Okay, but look at that. I’ve gone through all these things, but Ted and I were
already finding fingers, and toes, and wrists, and
ankles in the fossil record. We had to move back in time. We wanted to find, say, a flat headed fish with fins, with arm bones inside. To do that, we had to push
it back like 10 million years to 375 million years ago. And that meant going into a time period of the Devonian called the Franconian. I know that doesn’t make sense to you now, but it’s gonna make a
ton of sense in a second. So Ted and I sort of pulled out the
paleontological playbook again, looking for rocks of the right age, rocks of the right type, rocks that are exposed. But this time, not 365 million years old, now 375, older in time
to find a flathead fish. We had an idea to work in Brazil. We had an idea to work in Montana. Everything changed in my
office one day in late in 1997, Ted and I had an argument. This is the true story. Talk about the way discovery can happen. Ted and I were having an
argument about geology, and to settle the debate, I pulled out my college geology textbook. This is a true story. Now this book is, and this
was the second edition, this is when I took it, it’s now on the 17th edition. That gives you a sense of how old I am. But this, you know, and
I settled the debate with the textbook. I forget what the debate was about. It was just a friendly
banter, that kind of deal. But you know, we’re
just talking afterwards, you know, chewing the fat, and I’m just sort of turning
the pages of the book. And I saw another diagram
that was to change my life. This one launching 13 years of expeditions to near the North Pole. And I’m gonna show you that diagram, and we’ll work through it. It’s going to look a little complicated. We’re gonna work through it a little bit, cause it gives you a sense
exactly what we were looking for. This is the diagram. This launched 13 years of expedition. Got us to really think
about it in a new way. So this diagram says upper
Devonian sedimentary face. Now what that means is upper Devonian, remember, that’s the window
of time we’re interested in. So more or less the right time. Sedimentary rocks. Remember, these are the rocks that are, can possibly hold fossils. What you see as a map of
north of North America, there’s the United States, there’s Canada. And you can see Central America
down here at the bottom. Superimposed on that
map is an interpretation of the environments that
the Devonian age rocks were formed in. I’ll give you a sense of that. So in the western part of North America, these guys, these folks mapped that there were marine oceanic rocks in the western part of North America. That’s not what was interesting to us. What they identified were
three areas that were formed in ancient delta systems. So the first is in the
eastern part of North America. I looked at the diagram,
and oh I know that one. That’s the Catskill rocks. That’s what Ted and I have been working on for the last, you know, five, six years. Been there, done that, right? That we knew about that. That confirmed that they, that this is sort of on the right path with the diagram. The next area shown in red was also formed in ancient delta systems, and been there, done that too. Remember that cartoon
of the early limbed animal. I’ve been showing you from, from Greenland, that’s here. That was discovered here in
the 20s, and ’30s by Danish and Swedish teams working, really under
primitive conditions. And then you could see where I’m going, extending 1500 kilometers, east to west, across the Canadian Arctic
was a series of maps, Devonian Age rocks, from they’re called the Frasne formation,
from the Frasnian age. I looked at Ted, I said, Ted, do you know anybody
who’s worked these rocks? He says, I don’t know. Do you know anybody? I said, Ted, I just
asked you that question. So boom, back, nobody worked these rocks. So it’s like, wow, what an opportunity. So we ran to the library. This is the mid, late 1990s, 1997. Now, libraries, as you
may know, or may remember, have things called
books that have paper, you know, so at the time
we looked at journals, and there was paper journals. We had opened the paper, and look at the pictures. And we found an amazing, from using the bibliography of this undergraduate geology textbook, missed by us and all my colleagues. But these writers found it,
cited a paper by this gentleman, Ashton Embry. Ashton Embry is a modern day explorer. Ashton had one of the world’s great jobs. What he was hired by the
Canadian government to do was to map the rocks
in the Canadian Arctic to produce those maps to
tell us what rocks are where in the Canadian Arctic. And so what Ashton would
do is every summer, he would fly to the Canadian Arctic, with an Inuit guide, and a sledge, and basic hand tools, a compass, brought compass, hand axes, and so forth. You know, a sledge,
sledge dogs, canned food, and then they take off, and leave him with the
Inuit there for a month, or more to map the rocks. Hopefully they’d leave him a can opener, and he would map the rocks. And what he did was produce
an amazing scientific paper, and I’m gonna show you
the scientific paper, and there’s a method to my madness. I know you think I’m crazy, but this is the paper. This is the scientific paper that in a nutshell
captures what we look for. It doesn’t have a title that you know you’re gonna go to the
movie for it, but it’s like, The Middle-Upper Devonian Clastic Wedge of the Franklinian Geosyncline,
by Embry and Klovan. It was published, in the mid ’70s, ’76. And in this paper was one page that captures exactly what Ted and I were looking for, Ted Deshler. This page, people ask me all the time, how do you know where to look? And I point them to this
page from Emory and Klovan, page 548, Emory and Klovan. When they talk about the age of the rocks of the Devonian rocks
in the Canadian Arctic, they say the available
data indicate an age of early to middle Frasnian. Remember I told you
we’re looking for rocks in that age window early
to middle Frasnian, 375 million years ago. As soon as I saw that, I knew these rocks were
at the perfect age. Then when they talk about
what the kinds of rocks are, remember Ted and I were working in the Catskill formation of Pennsylvania, finding tons of fossils. But you know, we were wondering if this
new formation in the Arctic, the Frasne formation,
had any fossils in it, and then this sealed it. Okay, this is what like
sent us to the moon. So there’s the Frasne formation, similar to the Catskill
formation in Pennsylvania. Okay, so I had rocks that
were like old friends, right, of the right age. Is there any, like, mystery
why I then spent 13 years working in the Canadian Arctic? And then he showed pictures like this, which show us kind of how they fall, how the rocks are exposed. This all happened in a morning in 1997, and Ted and I were so
excited we missed lunch. So we ran to a Chinese food restaurant down the street from the library at Penn, where I was in Philadelphia
where I was at the time, and I had whatever, you
know, my hot and sour soup, or what have you. But then I had a fortune cookie. Yeah, that fortune cookie, I had, and it’s moved with me
from Philly to Chicago. I would carry it on my body
if it wasn’t glued to my door. It said, soon you’ll be
sitting on top of the world. (audience laughing) I was like, Ted, you won’t believe this. I got this fortune
cookie, we’re out of here. I’m not like, you know, spooky. Although I, you know, I haven’t lived a life
of a ton of regrets. I actually, you know, I
don’t, not many regrets. One huge one is, I’ve
never played these numbers in any lottery. So, but anyway, so Ashton’s paper, so I’m gonna show you
some of the diagrams. Actually we’re gonna drill
into it a little bit more in a little more detailed to show you kind of what we’re doing. So this is the kind of
diagram we work with, this paleontologists, this
is from Ashton Emory’s paper. So we now, we knew we were
on the right track right? Now, it’s a matter of
like finding the islands, and getting the money,
and getting the permits, and getting a team together. All the nitty gritty. So we’re here we are, up
in look on the upper left. This is a Nunavut territory in Canada the northernmost province of Canada, and let’s zoom in on it. You can see lots of little islands there. So let’s zoom in on those islands. That’s what composes
the bulk of the slide, where my pointer is now, okay? One thing you should see
is look at the scale, 100 kilometers, it’s big country, right? And everything circled in red are where Ashton mapped the Devonian rocks of the perfect age, and the perfect type. This is an enormous
amount of area to look at to find fossils, and the Frasne formation right there is this time column, so-called stratigraphic column. It sits perfectly. This was perfect right? Now the question became,
how are we gonna do this? I mean, I was used to driving my like, station wagon to central Pennsylvania. Now I’m leading expeditions here, a 500-600 miles from the North Pole. You know, it’s daylight 24
hours a day in the summer. It’s dark in nighttime, 24
hours a day in the winter. We are, it’s cold, right? There are polar bears up there. Polar bears eat people. That was on my mind all
the time for 13 years. And plus, you know, we’re really remote. We are about 200 to 300 miles
from the nearest community. It’s an Inuit village known
as Grease Fjord Canada, one of the northernmost
settlements in the world. It’s small, 150, 170 Inuit
year-round living there. This is a picture of the big
city, in spring, all right? So that’s kind of the nearest
civilization to where we work. So, so much of what we have
done working in the Arctic, and later Antarctica,
is relying on aircraft. And it’s a really remarkable thing that I spent so much time trying to think about how to get there. So where our sites are,
are beyond the tank of gas of a helicopter, okay? So to get there, we use
these planes, twin otters, which are amazing bush planes. They have a stall speed
of 55 miles an hour, which means in a headwind they
can like vertical takeoff, and landing. It’s like spooky. You’re like pulling your
seat up is to try take off, and they can land. They can land right on
the Tundra, super slow. So what they can do is
bring in the fuel, and food, land on the tundra, and then the helicopters
can leapfrog to our sites. Now what this means is
this affects our science. There’s a reason why I’m
telling this story is, because since the terminal
end here is the helicopter, helicopters have strict weight limits. So we can’t bring a lot of people, we can’t take a lot of fossils home because fossils are heavy. So a lot of decisions have
to be made both in advance, and while we’re on site
about what comes home. So I take a small crew, we
don’t take a lot of people. They tend to be very small. We don’t take a lot of stuff. So, this is it. This is kind of like one of our years. This is camp for a month and
a half before it’s set up. All our food goes in these
tubs, these white tubs, they seal up almost airtight, because that’s good news ’cause
the polar bears are out here and they good noses. We take, you know, a lot of students then we take an Inuit,
usually an Inuit youth from the local village. It’s Brian at a good time to work with us, and then graduate students,
postdocs, and so forth. But the idea is we optimize everything. We don’t take a huge
crew, because we can’t, we just can’t do it. So anyway, let me work
you through the logic. The Antarctic is huge, right? Think about the vast scale of this thing. How do you know where to look? How do you start? And how do you narrow it down, this vast arctic to a small
place to find fossils? Well, you make a lot of mistakes. It’s what you do, and you learn from your failures. And that’s the story here. So we started in 1999 right here in the western
part of the Arctic. And this is what camp looked like in 1999. This was my home for six weeks. We each live in a little
mountaineering tent. These tents, when you build
wind walls around them, can withstand winds of
about 70 miles an hour. It’s really remarkable
what they can withstand. This is our kitchen tent that first year, this was a remarkable tent, and it can withstand winds
of about 30 miles an hour. So that first year I was in the Arctic, I chased this tent all around
the Tundra during storms. It would literally blow. We had to like weight it down
with all kinds of stuff. But you know, you can’t
put the base of these. We camp at the base of
these in snowfields. You can literally drink the water as it comes out of the snowfield. So some people carry water
bottles when they camp. I would carry a mug. It was a really amazing thing. Just put a mug there, and you’re drinking this incredible water. Anyway, this gives you
a sense of what we do. This is all what you’re seeing
here at the top of the slide. That’s all Devonian rock. That’s the rock that we work on. It’s very flow lying in this place. So it was a tough place to work. So what you do as you get
out of tent each morning, and caffeinate, or don’t
caffeinate as your choice, and then look at these rocks, and basically we would
walk back, and forth, back, and forth, back,
and forth over miles, looking to see where
bones are weathering out. So we’re looking to see how the bones are weathering out of the rock, because think about what happens here. You have a freeze – thaw. Then in winter it’s really, really cold. In summer it’s less really, really cold. So it goes from really, really cold. The less really, really cold. And what you have is this freeze – thaw. And what that does is
it breaks up the rocks. You could see they’re
sort of broken up here, and it can spit the fossils out. So if you’re lucky, you
can actually find fossils, weathering out on the surface here. And that’s exactly what we did. But there was a problem. We were finding deep water organisms. We’re finding deep water sharks. We were in the middle of an ancient ocean. Do you think I’d find limbed animals in the middle of an ancient ocean? Uh-uh, ain’t gonna happen. So by the second week of this expedition, you know, not only was I chasing
this tent around in storms, I was finding sharks, which is great. I love sharks, but that’s
not why I was there. We needed to move upstream to places where we can find fossils. So think about it. We were in the middle of an ancient sea. We needed to go upstream. And what that meant, geologically was the next
year we had to go east. So we went east the next year, and this is what camp looked like. Look at that new kitchen tent, yay. But we also now got into
a little more montane areas. These aren’t, these cliffs
aren’t as steep as they look. They’re actually, you can
walk up them, and down them. But what was great about this site was, as soon as we got there, we realized we were in
ancient rivers and streams. And as soon as we got to this, these rocks, since we’re
here east, more easterly, they were the estuary, ancient estuaries, ancient streams, and rivers. And we started to find bits, and pieces of fish that we’re looking for. Bits, and pieces of lobe fin fish, nothing I’d be here to talk to you about, because it’s bits and pieces. We needed a place where we
can find whole skeletons, and that meant finding places
where there are small rivers, and streams. So how do we do that? Well we found a new valley. So we went back in later years, and I’m gonna show you, give you a sense of how
everything changed for us. This is one of the roast remarkable slides that I will show you today, and it looks completely boring. And at one level it is, but at another level it
is mind-numbingly amazing, because it caught a moment in time that we’re still
scratching our heads about. So Ted took this picture. Ted had just finished lunch in this new valley we were working in, and we’re beginning to find
bones there, bigger bones. It’s not bits and pieces. We knew we were on the right trail, and in this photo, Ted had just
taken as he loved this view. We just finished lunch, he stretched out, took this picture just
because he liked the view. And in this picture he
caught something amazing, just by accident. This set of blue pixels right there. I don’t know if you’d see, it’s that set of blue pixels right there. I’m just gonna blow it up. That is young Jason Downs, okay? So young Jason Downs had just finished his lunch
as well, and he stood up. If you look carefully,
you can see him standing. And he was about to walk off the slide, as was Ted, to walk the other way, to give you a sense of things, our camp was about a
mile to the right, okay? Here, Jason walked off here
all the way to the left. We didn’t know that at the time. What happened was we
spent the rest of the day after lunch, working. I’d met Ted back in the main camp. We’re about to main camp. We’re making dinner. And I look at Ted, and I said, Ted, have you seen Jason? He goes, I haven’t seen Jason. Have you seen Jason? I asked you that question. We went back, and forth like, no Jason, where’s Jason? Now, Jason was a college
student who joined us for, for the summer, and he, you know, he wanted to be a paleontologist, and here we lost Jason, right? Right! And now those of you who are educators know what happens if you lose a student. It’s like paperwork like this. I mean, you know me for years. Anyway, so we lost Jason. Oh, we lost him… And so all of a sudden I hear
outside of the tent, footsteps, and the fly of the tent opens, the body of the tent opens. Jason’s eyes are like globes. He goes, he’s like, I found it. I absolutely found it. So what’d you find Jason? A polar bear or what? And in his parka, and his rain pants, he pulls out bone after
bone, of fossil fish. These are his hands. I got them. They weren’t shaking enough, too much. I look to him to set his hand out. And these are all bits,
and pieces of lung fish, and other lobe fin fish, which are the kind of fish
we were looking for. So what happened was this, Jason walked off this
slide right to the left, then to go back at
night, he got separated. And the reason why he got separated is he started to go back to camp, and walked over the slide this way, going from left to right, because remember I told you, camp is all the way on the right. He walked over this patch right here. Now look at that patch. Do you see it’s a slightly
different color, right? Know why it’s a different color? Because it’s thousands upon thousands of fragments of fish bones, weathering out of the rocks. That’s what stopped Jason, he called that. So we’re like Jason, you did find it, wow. And so we you know, to
stay 24 hours a day, we grab cliff bars, chocolate bars, bars, and bars, and bars. We ran to Jason’s site. This is us at two in the morning, and crawling Jason’s
site on the upper right, looking not only picking up the bones, but looking for the layer
that Jason’s bones came from. It was remarkable, and it took us about a
year to find that layer. It was not easy. We’re patient. And this is Ted on the
left, with Jack Henry, and we finally found Jason’s layer, and it turns out here’s
Jason’s layer right there. You can see, and it formed a
layer about 20 to 30 feet long, and we’d form a line of us, and we basically dig into there. And you know what was happening? It was layer upon layer
of fossil fish skeleton piled one on top of the other. That’s why there was
that carpet of fragments, because those skeletons
were weathering out. That’s what stopped Jason. And now what we had was,
we had a whole layer that we could work one year after another looking to see skeletons as they came up. So we’re pulling out the skeletons about, you know, two feet long, three
feet long, four feet long. And this is kind of what
the site looked like after we dug our very big hole, digging that layer. And we work this layer for a long time. We’re pulling out lung fish, we’re pulling out armored fish, fish on fish, on fish, and
everything changed one day, July 14th, 2004, I’ll
never forget the day. We’re all working next to each other in line pulling out skeletons. My colleague Steve Gates,
who’s here in blue, sorry Steve, you’re not in the slide, but he pulls out
something from right here, right there. And he says, you see
something funny in there? It’s like hey guys, what’s this? And as soon as I saw that, I knew we had found
what we had spent years looking for, countless dollars,
countless sprained ankles, and so forth. What you see here is a
V right there like that. It’s the same color as the rock, but you can see it’s a V. And I looked at this V, and I saw that this V sits
on top of a bunch of teeth right there. That little crack there
had a bunch of teeth in it. That’s one jaw, that’s another jaw. It had the texture of fish, clearly fish. But this other side, where the teeth were on
top of, that was a snout, and not just any snout, the snout of a flat headed fish. I had the snout of a flat headed fish staring at me in the Canadian Arctic. Now you’re looking at this thinking, this guy is truly crazy. Where’s the exit? But I’m telling you that
this was a flat headed fish. Remember I told you,
conical head to flathead. We found a flathead staring right at us. I’m gonna show this to you in a second. You’re gonna see it. Then there’s the method to our madness. And so what Steve did
is he roughed it out. You can see rough the pedestal out. And we wrapped it in plaster, and brought it back to Chicago. As in Philadelphia. As we did that, we found four more of
these flatheaded fish. Every one of them remarkable. We now have 20 of them, and they come back the
bottom of helicopter, there’s the fish at the
bottom of helicopter, in nestling, wrapped in plaster. There’s a first year
graduate student for scale. I love it. Anyway, so this thing comes
back, or a hundred miles, and now the real work begins, because they come back to the laboratory, and they come back to the laboratory and these fossils are, you know, prepared somebody
in 2004, five, and six, sat with a needle, and a pin vice removing
rock grain by grain. And this is what Steve’s
specimen looked like after four months. Look at that. Look at that, it looks like
we have a top of the head, doesn’t it? There’s one orbiter eye hole, there’s another orbiter eye hole. Doesn’t it look like a skull
is coming out of this thing? Another five months go by, boom, flathead. Look at one orbiter. There’s another, wait a minute. There’s a shoulder,
there’s another shoulder. It looks like this thing has a neck. Remember what motivated this? We wanted to find a flat
headed fish with fins, with arm bones inside. So what did we do? We look for rocks that are at the right age, rocks that are the right
type, made a prediction, and this is the flat headed
fish with arm bones inside. It took us a number of years to find, and I brought just for fun,
which we can talk about. I can bring it down to
the reception later. This is a cast of the head
of this particular specimen. It’s about four feet long. Now, if I was to hold
this in front of you, what you would see,
just look at the slide, and look at the specimen. It has scales on its back. Fish fins with thin
raise, fin rubbing fish. If you look at the shoulder,
aspects of the shoulder, and the bones in it are very fish like, but like a limbed animal, has a flat head with those eyes on top, has a neck that can swivel
independently in the body. And guess what? When we cracked open those
fins, what did we find? An upper arm, a forearm,
even parts of a wrist, shoulder, elbow, wrist, in a fish, in fin webbing. And this creature had
both lungs, and gills. Amazing. Now to give you a sense
of how he found it, I told you there’s method to our madness. Let’s go back. Remember that V that you
thought I was utterly nuts? This V is this. See there’s a crack. There’s one part, there’s another. This is what we first saw
staring out at us like that. So I saw the texture of a fish bone. I saw a flat head snout. I knew we found what we’re looking for. So it was really sort a
remarkable moment for us. So now the creature, and now this is where the
science really begins. So now like this critter
had, like a lobe fin fish, had fins, had scales, had a primitive jaw. In fact, I could make a
list of fin fish features that go all the way to the floor, like a land living animal
had a neck, wrists, flathead, and expanded ribs. Truly amazing. Now when you discover a new species, you get to name it. That’s one of the things
that’s really important here. And we were working, you know, with the indigenous people, with the local Inuit population, and we felt it really important
to include them in our, in our work. So we had a naming project with the Inuit. And so we worked with the
annual council of Elders. And this is the, this is the committee as it was in 2005. And, we had working with them, we wanted to come up with
a name for the fossil that really had two properties
that were important. One was the name that
was meaningful to them, and to us, right? And so we had to be
meaningful to everybody. And the other is to have a
name that we could pronounce. The name of the committee did not land me a nod of confidence that we can come up with a
name that we could pronounce. So I was talking to the
gentleman in the middle. This is a really amazing moment. You know, I was in Chicago,
and he was in Greece Fjord, you know, we were talking, you know, he was in this small village in the middle of winter. And interestingly, it was very
hard to come up with a name that meant something to both of us. They didn’t have a
concept for fossil, right? So I told him, you know,
we found this fish, so we’re just fine if they don’t. We found the rocks, it’s like hunters don’t
find fish in rocks. I know that, it’s a fossil, we went back, and forth, eventually he got really
frustrated with me. He said, okay, stop. Just tell me what it is,
and where you found it. I said, oh, it’s a large freshwater fish. He said, why don’t you say so? You got yourself a Tiktaalik. I said, Tiktaalik, what’s that? He says a large freshwater
fish in our language. So that stuck. So that was that the name. So Tiktaalik was in the name that stuck, and so now, so that was 2004, 2005. Now we have higher energy CT scanners, where we can actually use x-rays
to blow high energy x-rays to blast through the rock. And we can see, we can
look at the fins inside. We can see it in great detail. We can look at the humerus,
the upper arm bone, the radius, and ulna,
we can see the fin rays. We can reconstruct the vasculature. There’s so much we can do in these, the technologies that have
really come to the fore in the last decade and a half. But check this out here on the left are the joints in the fin. In A, what you see as the shoulder, there’s the socket on a
bone called the glenoid. There’s the ball on the humerus, in B, you see the elbow of the fish. This is a fish with an
elbow with a radius, and ulna. It could flex, and bend, and pronate. And then it has a proximal
carpus and a distal carpus, that are very similar to the
ones that we see in amphibians. Really, really, I mean at
the cusp of the transition from life in water and life on land. So Tiktaalik is an animal
that has lungs, and gills, has fins with arm bones
inside, has shoulders that are part fish, part limbed animal. It’s a really beautiful
window into this great moment into the history of life. But the central point for
us is not just the Tiktaalik is a great window into
the history of into this, this great moment of time, but this moment of time, where fish began to walk on land, is not some esoteric
branch of the tree of life. It’s inside each one of us. I could trace structures that
first came about in Tiktaalik, and its cousins to us. Look at this. We can trace an upper arm bone
from Tiktaalik to amphibians, to reptiles, to other mammals, to people. We can trace the radius, and ulna from fish to
amphibian to reptiles, to mammals to people. I could trace this wrist
we see for the first time in Tiktaalik, and its cousins
living in the Devonian to us. I could trace the neck
we see in Tiktaalik, and its cousins in Devonian
first time all the way to us. So what that means is every
time you bend your wrist, every time you shake your
head, you can thank Tiktaalik, and other fish, evolving in the Devonian 375 million years ago. And we know that craziness, we know that when we could
trace it through the fossils, we know it as I’ll show you in a second by looking at embryos, and by the DNA that drives the
development of those embryos. It’s a amazing story that connects us to the
rest of life on our planet. And once you see it, it changes how you look
at the natural world, changes how you look at
human’s place in nature, and it changes how you do your research. You look at this gentleman, and you see what? A pinnacle of human achievement. You see Albert Einstein, I look at this, I’m somebody who’s worked
on fish for 30 years, and I see, yes, I see a big
fat old bipedal fish. And when you, you can compare professor
Einstein to the fish. I labeled it here, Einstein’s on the left by the way. You can compare professor Einstein in so many ways, by the
fossils that connect us, but importantly through how they develop. Let’s look at this. Let’s look at Einstein’s head
a few weeks after conception. What did our head, what did
Einstein’s head look like? And this is sort of a
cartoon snapshot of it. What you see here is the top of the head. You could see paired
primordia for the eyes. This are where the eyes
are going to develop. But then I’ve color coded several areas, where you see these swellings
in the pharyngeal area, and sort of throat area. You see paired swellings,
which I’ve color coded left and right here. Light blue, dark blue, green, and yellow. Those swellings are filled with cells, and there are cells that
are dividing in there, but also cells that are moving, and migrating in there. It’s an amazing thing
that goes on in there, but these swellings have clefts
between them on the outside, and inside they have pharos. It’s an amazing set of structures. Guess what? If you look at anything that has a head, and let’s look at a shark. Guess what you see doesn’t look identical. The human embryo looks a
little bit different, but they have some very similar features. They have paired primordia
for the eyes as a shark embryo, and look down lower in the pharyngeal area you have these swellings, light blue, dark blue, green, and yellow,
paired clefts, and so forth. That’s the starting point. A common ground for
development for a lot of, for creatures with heads. Now let’s trace these things. You could trace the cells,
you can mark the cells, and can see where they end up, and if you’ll look at this,
or you’d like a shark embryo, that first one, the light blue becomes portions
of the upper and lower jaw. The other ones become portions that support the gill apparatus, and this includes the skeleton, the nerves, the muscles as
well as the vasculature. So it’s really muscles,
nerves, arteries, and bones. What happens in people and other mammals? Well, check this out. That first one in light
blue, you trace the cells, the one in light blue becomes bones that form part of our jaw as well
as two bones in the middle ear. The dark blue ones become a portion of a
throat bone on the hyoid, as well as one bone in the middle ear, and then the other ones become
a portions of the voice box. What does this mean? This means in a developmental sense, many of the muscles, and nerves, and bones I’m using to
talk to you with right now. And then any of the muscles, and nerves, and bones you’re using to hear me with, correspond to gill structures
in sharks, and fish. And how do we know this? We know this by comparing the embryos. We know this by seeing their
common part of development. We know this also by the fossil record. I could trace the
history of this gill bone in a shark through fish, and creatures like Tiktaalik to become the staples of the middle ear. Once you know how to look, you start to see our
connections to life everywhere. And this is really remarkable, because you know, when you think about some of the great puzzles of biology, what researchers here in particular, at Stowers are thinking about, you know, we think about a fertilized egg, a fertilized egg as a single cell, right? But all of us trace back
to that single cell, right? But all of us sitting here
are trillions of cells all packed in the right place. You know, maybe four trillion
cells of our own cells. There are microbes all around
us, I’m seeing more of them. But of our own cells, we
have trillions of cells, eye cells, muscle cells,
bone cells, gut cells, all kinds of different, and they all are in the right place. And things can go really wrong when they’re in the wrong place. But that formation from a single cell to a creature with trillions
of cells in a body. We call that bodybuilding, right? Going from the thing on the
left to thing on the right, but this diagram captures
one of the great challenges, and one of the great puzzles of biology. How does a single cell
contain the information to build a body with this
incredible organization, which we take for granted, and that’s been where some
of the great breakthroughs in science have happened
in the last 30 years. Understanding the DNA recipe, the DNA toolkit that builds bodies as different as people, flies, fish, worms, and so forth. It’s a remarkable story. One area of this story is showing that many of the genes
that build the basic architecture of our body are also present in other creatures. So if you look at say our
vertebrae, or backbone, we have a regular pattern
of different vertebrae, cervical, thoracic, lumbar, and sacral that exists in our bodies, and our limbs always pop out
in the same place in the body. We have a basic architecture of backbones, and limbs that stick out on the right way. It turns out that whole process
depends on certain genes being turned on and off in the right way, at the right time in development, and interacting with one another to make the body plan come about. One of the remarkable stories is that these genes were
originally discovered in flies, in embryos of a flies, and what were they doing in flies? Versions of the same genes are building the basic
architecture of flies. It’s a remarkable story. It’s an incredible thing, and it’s not just bodies. It’s organs of all kinds of different of different kinds in the body, that we share a basic toolkit with other creatures on the planet. So you can ask the question, who really cares about your inner fish? Well, I care a lot, but it turns out the places like the Stowers Institute for Medical Research
care a lot. The Nobel Prize Committee in medicine, and physiology cares a lot. Because think about this, where have basic
breakthroughs that happened that led to research that is, has changed human health, and wellbeing? Well, Nobel prize in the last 30 years, gone to people working on flies, gone to people working on
mice, working on yeast. In fact, two Nobel prizes
awarded in the last 15 years have gone to five people working on Caenorhabditis elegans,
a tiny little worm, the size of a comma on a piece of paper. Yet that little worm is providing insights into how our cells are
programmed to naturally die. How our genes can be turned on and off, in particularly off, and what goes wrong in
diseases like cancer. I like to think that as we discover cures to everything that ails us, from Alzheimer’s, to different cancers, that the breakthroughs that will extend, and enrich our lives, will in
some way be based on flies, worms, mice, species yet to be discovered. And yes, in some cases, even fish. I can’t imagine a more powerful, or more beautiful statement on the importance of our
connection to the rest of life on our planet than that. Thank you very much. (audience applauding) (upbeat electronic music)

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