Kind: captions
Language: en
Once you realize that life is constantly
and always evolving, you basically turn
on life and then you turn on this
endless story. The universe is too big
for my brain, but I'm really interested
in the story of our planet. When did it
start behaving like Earth? When did life
itself start? When did the oceans form?
When did the continents form? When did
the first fish evolve? I mean, this is
all heavy stuff for a paleobotist. I
want to tell you right now.
[Music]
[Applause]
[Music]
Hi everyone. Today I got to talk to Dr.
Kirk Johnson. He is s director at the
Smithsonian Institution National Museum
of Natural History, which is home to one
of the biggest natural history
collections on the planet. He's also a
paleobotonist and has hosted a bunch of
Nova documentaries like Polar Extremes
and Making North America. I love this
dude. We got into some really cool stuff
like how fossils form and where Earth's
oceans actually come from. You know,
stuff we all talk about right before
bed. So, if you get as much of a kick
out of this conversation as I did, I
need you to do me a favor and rate us.
or you can leave us a review or drop us
a comment and make sure you subscribe so
you never miss an episode because we got
more amazing stuff like this coming and
your support means everything. It helps
us to reach more curious minds just like
yours. So, let's jump into the
conversation.
Kirk, welcome to Particles of Thought.
Hakee, great to meet you.
>> Yeah, man. So listen, when I looked you
up, I saw two words, geology and
paleobatney.
I hadn't heard paleobatney before, but
when I think paleo, I don't think about
the diet. I think about paleontology,
which makes me think about dinosaurs.
Tell me about paleobatney. I've never
heard of paleobatney.
>> It's one of the obscure sciences for
sure. It's fossil plants. And the reason
I became a paleobotonist was I when I
was a kid, I loved finding stuff. Like
I'd find coins and egggots and rocks and
fossils. And once you have a thing you
can do as a kid and you find that it
works more than once, you do more of it.
And I became like my childhood
superpower was finding things.
>> Wow.
>> So I go on hikes with my dad. I'm like,
"What's this rock? What's that? Hey,
here's a fossil." And when we're driving
somewhere, I was like, "Mom, can we stop
here? I know there's some good stuff to
find here." Yeah. So, I started being
like this search kid detective. And
there were fossils around where I lived.
And there was a fossil site about a
15-minute drive from my house that had
cool things. It had fossil clams and
snails, but there was also fossil wood.
And then there was uh I found a fossil
walnut. And then I found a vertebrae
from a dolphin. I'm like, what's going
on?
>> Wait a minute, man. A fossil walnut.
>> Yeah.
>> So, it looked like a walnut, but it was
rock
>> even. Yeah. It was it was soft rocky,
but the shell was black and the meat was
white.
>> It looked like a walnut.
>> So I um I went to the museum in town,
the Burke Museum in Seattle, and the guy
said, "Yeah, there's a walnut specialist
you can mail this thing to,
>> a fossil walnut specialist." I'm like,
"Okay." So I mailed it to this guy. He's
like, "Hey, it's a walnut. You found a
fossil walnut." And then you know the
the part of the porpus, I found one
porpus vertebrae. It's like what where
in the world do you find walnuts and
porpuses together,
>> right? Well, at the edge of the sea
where there's walnut trees and purposes
swimming,
>> it's like a beachy deposit and it was
like 15 minutes from my house.
>> Sounds like you were set up to be a
paleontologist like young right out of
high school. You didn't need to get a
degree.
>> Like a paleobotonist even.
Yeah. Yeah. So, what what what separates
the um fossilized plants from I imagine
everything doesn't get fossilized,
right?
>> Yeah. Yeah. So, here's the key thing
that you have to know about fossils is
that in order to become a fossil, you've
got to die.
>> Yeah.
>> And you got to get buried.
>> Okay?
>> Right? And if you don't get buried, say
you just fall over in the forest
somewhere, you're going to rot away.
>> So, it's death plus burial. So, if
you're a dinosaur, you fall over and you
die, chances are you're not going to
become a fossil unless you live in a
place where stuff gets buried. And what
are those places? They're places like
Louisiana for instance, right? Right. If
you Louisiana, the whole landscape is
sinking slowly and the stream is always
dumping out sediment and putting more
layers on it. So an area that's sinking
is what I call DO or deposition world.
>> Ah, right.
>> And if you were to drill a hole beneath
New Orleans, you would go down almost
20,000 ft in layered mud that's only 25
million years old.
>> What?
>> That's literally miles of thickness.
Yes.
>> Miles. So if if a fish died in New
Orleans
>> 10 million years ago, it would be 10,000
feet down.
>> Wow.
>> And in the sediment it was buried in is
being compacted into rock.
>> So I've seen this p this image ge
geologically of the Gulf of Mexico and
how it goes out underwater. Then there's
like this big giant cliff. Yep. So all
of that stuff is from the river.
>> Yeah.
>> Whoa.
>> Yeah. And from rivers dating back to
millions of years. So the earth is as it
erodess mountain ranges all the sediment
ground up mountain ranges end up at the
edge of the continents and piling up in
thick layers of sediment or limestone or
other kinds of stuff and that's where
you create the fossils. You an animal
dies or animal plant dies is buried in
an area that's sinking which buries it
deeply and that turns the sediment into
rock. Yes.
>> And they're at depth and then eventually
what happens is some other first
phenomenon pushes that area back up. M
>> so areas that were depositional areas or
D world
>> right
>> become lifted up into what is called Eld
or erosion world.
>> So if you can look at North America for
instance most of North America right now
is erosion world or Eld.
>> It's getting eroded away.
>> Mountains. Anytime you see a hill or a
mountain you know that stuff's eroding
away. Look at the Mississippi River
time.
>> You see a river right?
>> Exactly. Yeah.
>> Some areas. And so there are are, think
about this, there are rivers in erosion
world like the Colorado River is cutting
the Grand Canyon. Yeah. Not a good place
to become a fossil. That's just grinding
away and taking it out to the sea.
>> And it goes side to side and meanders
and Yeah.
>> But that same river like Mississippi
when it gets down to New Orleans, great
place to make a fossil.
>> Ah,
>> so that's the Eld D world difference.
And the best place to find fossils and
like maybe the best place in the world
to find fossils is western United States
because most of the last 500 million
years that landscape was sinking. It was
D.
>> But then when the uplift of the Rocky
Mountains started, it pushed that area
back up and exposed those rocks in
EWorld.
>> So you want D.
>> So you bury them.
>> Bury them.
>> Then lift them and erode the stuff off
the top of them and now they're exposed.
>> Exactly. and and sometimes you uplift
them in an irregular way. So in one
place you might be able to see a
cross-section of the entire stack.
>> Oh,
>> and there's a place near Cody, Wyoming
where you can see from 2.5 billion years
to 60 million years in one spot.
>> Geez.
>> It's better than the Grand Canyon.
>> That is
And so because they've been lifted and
turned now, it's it's it's more
horizontal or at an angle rather than
Exactly. It used to be flat and then
turned up and they're almost vertical
and you just count the pages like this
all the way through.
>> Wow. And each layer has its
representative fossils.
>> Exactly. There like always there's sort
of local D world like the immediate area
around you like you're standing next to
a mud bluff and it it slumps down and
buries you. You just got buried in a
little narrowest piece of DO.
>> I see. But if you want to look at it at
the continental scale,
>> there most of North America is E-World,
but they're little local ponds and
little local lakes. But those local
things are not going to get preserved.
They'll eventually fill up in a roadway
too.
>> So the fossils are going to be in those
places where the whole landscape is
sinking.
>> Whole landscape. So what places would
that be on Earth today?
>> The edges of the continents primarily or
the shallow low elevation parts of the
margins of the continents.
>> Okay. Is that generally true throughout
history? Yeah. So, as a result, we
really don't have much of a fossil
record for mountains or hills.
>> Wow. So, so for example, right now,
humans are distributed primarily along
coastlines. So, so would it be the case
that land animals, even though it's a
it's it's geographically limited, it's
still a good representation because uh
that's where most life is going to
concentrate anyway. Is is that fair?
>> It's true. Probably the case, but like
you know, you're still going to miss the
mountain goats and stuff like that,
right?
the things that live only at high
elevations or you know even on the great
plains some of those things do get
preserved like the the animals of the
great plains are preserved because the
Rocky Mountains came up and all the
sediment coming off the Rocky Mountains
shed and buried things under river
sediments and then that area is still
coming up so those rivers are now being
exposed. Oh,
>> and so you have that kind of local D
world um is a source of good fossils on
continents. And we found an amazing site
in Colorado in 2012 that was a lake on
top of a hill at 9,000 ft.
>> Wow.
>> And it filled up with
>> Lake Tahoe. No,
>> no. Was at Snow Mass Skiary Snow Mass.
It's right 700 yards from the base of
the ski area. There's a little 12acre
lake that turned out to have been an ice
age lake
>> that filled up between 120,000 years ago
and 50,000 years ago. And we found 50
mastadons and 12 mammoths in this one
little lake in 70 days of digging.
>> It was an amazing thing. But that was a
a little tiny lake on top of a hill that
was a little temporary bit of deorld.
>> Yeah.
>> And in the future that'll erode away and
go away. But we got it before eroded
away.
>> Wow.
>> We just our timing was very good.
>> Good timing. But but over geological
history, a lot of those have come and
gone.
>> Yeah. Oh, yeah. Cuz that's at the top of
the hill. It's going to go,
>> right? It's going to go.
>> Hills go away. Mountains go away.
>> They're temporary.
>> Yeah. Never trust mountain ranges.
They're undependable. They rode away.
>> All right. All right. You can't depend
on them.
>> Yeah.
>> You know, later, man, we're going to get
back to this because one of the things
that I feel like as science
communicators, we don't do quite often
is we tell what the results are, but we
don't tell how we get them.
>> Yep.
>> But we'll get to that. But what I want
to go to first, man, is sort of like an
ultimate fossil.
>> A fossil from the foundation or the
formation of our solar system. I hear
you got an asteroid.
>> Well, we all share that asteroid. It's
asteroid Bennu, which is, you know, it's
a 550 meter diameter blob of rocks. It's
actually like a gravel pile that's all
held together by loose gravitation. And
NASA had the vision to send a a little
Osiris Rex out there to go take a look
at this thing. And they got there and
they orbited a whole bunch of times and
made a geologic map of the surface of
this thing and it's got boulders and
pebbles and things and then they had
this they moved the spaceship into
position and punched a little sampler
can the size of a tuna fish can
>> into this thing and it and it went way
in further than they thought. They like
they were they were when they got close
they're really scared because all these
huge boulders the size of buildings on
it and and they're like oh what if we
hit on a rock? They they they landed it
right where there's a spot and they just
punch it in and it was kind of like just
loose gravel in the air and they brought
back I think 150 grams okay
>> of samples that you know the spaceship
then left those Bennu flew back over
Earth they dropped it out it parachuted
down landed in the desert in Utah in
this little capsule was about this big
around and then they took off the lid of
this thing and here's like 150 grams
that look just like granola little
pieces little chunks of stuff
>> and those samples are untouched by
Earth's atmosphere.
>> So, they're subsurface of of the
asteroid. So, it's not is it surface
material or did they actually like cuz
you said it went in deeper than
anticipated?
>> Yeah, I think they it went in like I
don't know maybe the length of my arm
deeper. It wasn't a huge depth of my but
it was more than they expected. They
expected a hard surface but it was
really just loose material kind of
loosely held together. Yeah. And
>> so you have this all these particles
that they came back and at the
Smithsonian Natural Museum where I work
um we have Tim McCoy who was on the
Bennu team. So one of the very first
samples you know Tim was there when they
opened the can he got to bring home some
samples and we had acquired this great
analytical device so we could actually
look at these samples and within minutes
of these sample being in the building
and he had it under the equipment. We're
looking at this thing and he's like
there's hydrated minerals here. There's
all this incredible.
>> Wait a minute. Hydrated. Yeah. Water.
>> Yeah.
>> On a dry asteroid pile of gravel in it
system.
>> So there you go. Says water is the first
thing you're looking at. And what's cool
about rocks are that rocks are made up
of minerals and minerals are made up of
various things and some minerals have
water in them.
>> Well, that's what I was going to get at.
Right. There's a difference between
waterbearing minerals and there was
liquid water here.
>> Yeah. But but the water bearing minerals
has H2O in it.
>> Yeah. But it could be ice
>> or or in the molecular structure.
>> Molecular structure, right? Yeah.
>> So, but it's there. It's water. It's not
It wasn't a glass of water on the
>> Bennu did not have glasses of water.
>> Well, here's what I'm getting at. So, a
lot of uh asteroids are the remnants of
protolanets that collided and got broke
broken apart. That's why we get chunks
of iron out there, right? Exactly. Yeah.
And so I can imagine that could it have
been possible that one of those
protolanets actually had liquid water
and somehow that got incorporated into
Bennu or is it just the everyday kind of
space water?
>> So this was the big surprise on Bennu is
that the first glimpse is like wow we've
got these minerals we've got hydrated
minerals um other researchers in other
labs like hey we're getting some amino
acids out of this stuff. Wow. But what
our team discovered which was so amazing
was they they're uh museumbased
researchers. So we have the this amazing
collection of the world's minerals and
there's thousands of different kinds of
minerals on planet earth and a lot of
those minerals are med were formed in
conditions that formed on planet earth.
Some of them are mediated by life. For
instance, there's minerals that are
deposited by living organisms like
shells and clams and things like that or
humans and our bones. Those are
minerals, right? So life creates
minerals. So earth has a high diversity
of minerals because it has life.
>> So there's a, you know, it used to be
that whole animal, mineral, vegetable
kind of thing,
>> that's a little bit touching because
animals have minerals. So
>> they're like, "Let me wrap myself in
rock then you can't eat me."
>> Exactly. And some things do that like
right like turtles and things like that.
So, um, as they were inspecting these
grains, literally micron by micron with
their instruments and analyzing the
grains, they started noticing some
minerals that were familiar to them.
They're like, I've seen this mineral
somewhere before. And what they were
finding, they were finding evaporate
minerals. And these are the kind of
minerals that form when you take a lake
in a very warm area and you evaporate
the water like the Dead Sea or the Death
Valley
>> where there's a lot of sun, it's very
hot and the river is coming out of the
mountains carrying minerals and then it
evaporates and leaves those minerals
behind and think about the borax trains
of California,
>> right? Yeah. There's a whole sequence of
minerals that formed in Death Valley. As
the water comes off of the Sierra
Nevada, it evaporates, more water goes
back, you get a series of different
evaporate minerals. And they started
finding these minerals in the Bennu
sample.
>> So, is it that they come in a particular
combination? So, so it's sort of like a
signature of this.
>> Yeah. There's an evaporative series like
you evaporated off one kind of mineral
that leaves a different composition of
the water. The next time you evaporate,
you get a different mineral.
>> Oh.
>> So, it's actually an evaporative
sequence.
>> Yeah. and they start finding the
evaporative sequence which means that
you know Ben Venu was probably rubble
from some exploded planet.
>> Yeah.
>> Uh but on that planet there had to be a
sequence where water was evaporating and
creating evaporative minerals.
>> So that means a collection of liquid
water.
>> Yeah. So you got water now you have all
these different minerals. You have the
um amino acids and stuff like all the
things you need to make life are right
there
>> man. That's that's amazing because you
know one of the ideas that I've seen
about life you know where it might be
found. So we typically look at planets
and moons but there's this one scientist
who said comets if you have some
radioactive nuclides inside the comet
that could create enough heat to melt
the ice and create little water
reservoirs. But this is very different
because you have water that's liquid
then it dries then it's liquid then it
dries then it's liquid then it dries.
Now you think about Bennu. It's like
it's it's out there and it's exploded
from somewhere which means that and it's
from the beginning of our solar system.
>> Yeah. What's the age? Did it get an age
on it?
>> Well, I don't know. It's probably 4.567
billion more or less the age of our
solar system. Right. Right.
>> So you've basically got um debris out in
the solar system on a asteroid sitting
out there. That's a signal of what was
in the solar system when the solar
system founded. Which means that at the
beginning of our solar system, even
before Earth cooled,
>> you've got evidence for the conditions
for life before you have Earth, because
Earth, remember, it was a molten ball
and then it got hit by the body that
became the moon. So the the moon,
Earth's a bad place to be for his first
100 or 200 million years, right? You
starting to enjoy life, things are
cooling down, then bam, you get this
thing and then the moon forms. So the
rest of the solar system maybe has a 200
million year head start on the Earth. M.
>> So you've got conditions that could
maybe form life somewhere else,
>> right?
>> Out there. And then how does life get
onto Earth? Well, maybe some of that
stuff that was blown from somewhere else
lands on Earth.
>> Yes. Yes.
>> And you start the process.
>> Wow. So not necessarily from out. So
essentially what this suggests
potentially is that you don't even need
fully formed planets to get life. You
can at the protolanet stage, you can
have water. You're doing this complex
chemistry that results in amino acids.
So
>> what's to stop you?
>> What's to stop you? So So my
understanding of Oh, this is a good
question for you. So we look at the
origin of life
>> and the origin of the oceans. Yep.
>> Right. So what are the theories of where
the oceans originated? How did how did
we get them?
>> So So you don't have many options,
right? Because right now you've got the
planet where 70% of it's covered by salt
water, right?
>> And the you know it's it's even an
amazing question to ask or imagine what
the Earth didn't have oceans,
>> right? Amazing.
>> But you got to figure if it started out
as a molten thing, there was no ocean
there then. You have a giant blob of
molten water boiled away, right?
>> Yeah. So you've had that problem and
Earth's a big thing, too. Like it's got
a big diameter. It's got a lot of
volume.
>> So you got to you got to ask yourself
what's in the middle of that. And how
does how does the structure of the earth
itself form? How does its core and its
mantle and its crust form?
>> Yeah.
>> Where do the continents come from?
>> And where does the ocean come from?
These are like fundamental questions
about how our earth became this amazing
place it is today with lovely oceans and
great mountain ranges and all that kind
of stuff.
>> So, uh, you know, as you pointed out,
one idea is you have this molten blob.
It cools down and then it gets hit by a
bunch of comets which deliver truckloads
of water because the comet's got a lot
of ice. And so you come, it delivers the
water. Um, and there's ways to test
that. I don't really know how rigorous
those tests are. But the other option,
really the only other option is
>> the water was already there in the in
the rock of the planet and it was
inhydrated minerals that then somehow
outgassed and the water started to
accumulate on the surface. And the
question there is how do you keep the
water on the planet? Like what keeps
what holds the atmosphere and the oceans
to the planet? Obviously there's there's
gravity but
>> you know so you you basically have is
either was delivered or it was already
there. Those are your two options.
>> So I guess the question is you know if
you have a situation like Mars where the
atmosphere is incredibly thin because
it's been eroded by solar radiation. Y
>> so Earth's atmosphere doesn't erode as
quickly. My understanding from Jim Green
who's the um the uh who who who was the
chief uh scientist at NASA
>> is that it's being eroded but
geologically it's being replaced as
rapidly as it's being eroded away.
Right. But the the magnetic field of
Earth slows down the the erosion of our
atmosphere.
>> Do we know how early our magnet our
magnetic field kicked on the Earth's
magnetic field? I certainly don't know
the answer to that question, but I mean
that's you're you're basically asking
all the right questions, which is how
how does when does Earth start acting
like Earth? This is all heavy stuff for
a paleobotist. I want to tell you right
now,
right? Oh my goodness. Well, I would
imagine it's all mixed together, right?
So, you got the the planet's evolution
and life's evolution. So, it's almost
like life becomes its own geological
process that you know works together
with the planet.
>> Absolutely. And once you realize that
life is constantly and always evolving.
>> Yeah.
>> You basically turn on life and then you
turn on this endless story that we're
part of right now.
>> Yeah.
>> What things are and what's so cool I
think what I I kind of uh there's so
much cool stuff here that I kind of
restrict my knowledge to the planet
because I'm like the universe is too big
for my brain. But I'm really interested
in the story of our planet. How did it
start? How did the pieces come together?
When did it start behaving like Earth?
When did life itself start? When did the
oceans form? When did the continents
form? Right? When did the first forests
form? When did the first fish evolve? I
mean, in every one of those things, it's
got its own tale. But if you put it in
the context, we've got 4.5 billion years
to tell the story and then you just
start chipping away at every aspect of
the story.
>> Well, let's go back to that Earth
without water.
>> Yeah.
>> Sort of image because we do have
continents. So if you had an earth
without water, so I imagine that the the
you know the ocean is deep.
>> So do you imagine a world that's pretty
much you know if you look at
>> other bodies that don't have water
>> on them?
>> They appear to be more or less smooth if
you get rid of the cratering. It's not
like these giant, you know, you have the
places with volcanism like Mars and
Venus that have giant volcanoes, but
other than that, you don't have like big
basins and then huge continents sticking
up. Is that what we imagine?
>> Well, think about what you just said
because when you say the ocean's deep,
it's only 36,000 ft deep at its deepest
point. Most of the ocean is maybe only
8,000 ft deep. That's only a mile and a
half deep.
>> That's pretty damn deep if you ask me.
That's
>> Well, compared to the size of the Earth,
it's nothing. I'm like, if you look at
the Earth, if you drained all the water
off the planet right now, your highest
points Mount Everest, your lowest points
the Mariana's Trench, what's that?
29,000 ft and 36,000 ft. So like 60,000
ft. What's that? 10 miles only.
>> So that would from space, Earth would
look like a polished bowling ball.
>> Yeah.
>> And so there's really no topography
there to speak of at the the scale of
the planet.
>> And then you have to ask yourself, well,
how do you get that topography anyway?
How did you get the deeps in the ocean?
And how do you get the highs of the
mountains? Yeah,
>> that all happens because we have plate
tectonics and the continents are moving
and the plates are colliding with each
other and these deep part of the oceans
are where two oceanic plates come
together and make a deep subduction
zones. So the trenches are
>> Oh, the trenches are subduction zones.
>> Those are those are platetoplate
collisions and when you get a continent
colliding in a continent like India hits
Asia, you get the Himalayas. That's
where you get your high points. So you
can't even have um topography we have
until you turn on plate tectonics.
>> Yeah.
>> And then you you think about plate
tectonics that's ocean crust and
continental crust. It's like what came
first chicken or the egg
>> continents or the ocean
>> right? Do they form there?
>> And I guess another question is does the
weight of the water sort of segregate
the continents from the cont from the
oceanic crust? I'm just swagging here.
Scientific wild ass guesses. Well, the
thing about it is water weighs a lot
less than rocks and different rocks have
different um relative densities and
masses. So, you have a heavy rock and a
light rock.
>> The light rock's going to float on the
heavy rock.
>> Yeah.
>> Right. So, you have and also rocks
themselves, we think of rocks as really
hard things you throw out windows,
>> right?
>> But the reality is that rocks are the
pro like the products of any other
cooked item, right? Like they start out,
some of them start out liquid and they
cool to hard rock. Some of them start
out as sand, which cements become
sandstone.
>> Man, you're triggering me. I remember
elementary school, you had to learn
metamorphic, ignous, sedimentary.
I don't remember what's what anymore.
>> I'll tell you using a food analogy. How
about that?
>> The simplest one is sedimentary. Those
are just like particles of sediments,
sand grains, and things. So, the food
analogy there is salad. It's just a
bunch of stuff thrown in a bowl.
>> Got it?
>> You know, whatever is coming downhill,
it's just a bunch of stuff. That's
salad. Is it always in association with
water?
>> Uh, no. It can be blown in wind too.
Okay. Yeah. Wind dunes, sand dunes for
instance. So water or wind, both. And
you have Mars, you have
>> dunes. Oh, they have
>> they have wind. Right.
>> Right. So there and there's also on Mars
evidence of waterborne sedimentary
rocks. So you have both kinds. Then
there's the um the ignous rocks which
are the rocks that started out their
life melted. Ah
>> right. Yeah.
>> And the food analogy there is a fondue.
>> Melted cheese.
>> Melted cheese is a molted thing and it
cools to a blob and you eat it when it's
a little bit harder, but you know
whatever. So that's it. And then the
tricky one is the third kind, the
metamorphic rocks. These are rocks that
got heated and squeezed, but they didn't
melt.
>> They didn't go all the way back to being
fondue, but they were heated and pressed
enough that their crystal structure and
even its content changed. And so the
food analogy for a metamorphos is a
lasagna.
>> You start out with, you know, your
noodles and your sauce and your burger
and all that stuff and then you cook it
>> and it changes a bit. You can recognize
it a little bit. Um but since we only
cook lasagna to a certain temperature,
you only get lasagna looks like that. If
we cranked up the temperature in
lasagna,
>> Yeah.
>> Um you know, it might have a different
form even still. So all three states can
turn into the other state depending on
what happens to them. And this is why we
don't have the oldest rocks on planet
Earth because Earth is always baking
itself, melting itself, and grinding
itself up.
>> Wow.
>> It's like its own factory that's
churning away.
>> Yeah.
>> And cranking away on that thing.
>> The other piece is that we have a lot of
unique minerals on planet Earth because
they're formed by interactions with
living
>> organisms,
>> right? Yeah. Yeah. My mind went there as
you were saying that that life must play
a role also.
>> Yeah. And this is this took surprisingly
long to figure out for people, but like
this whole idea that that there are lots
of minerals that wouldn't exist if they
didn't have some living organism that
was mediating the formation of those
minerals. The study of the earliest life
forms really only got going in 19 the
1950s when they started looking at
>> precamprian rocks and slicing them open
and finding little things that look like
cells or little filaments and things. So
so much of what we know has been acred
in about the time that you and I have
been alive.
>> Wow.
>> I mean the understanding of our planet
is leaping forward in great bounds all
the time. But so much of it um if we'd
had this conversation when we were 5
years old.
>> Yeah.
>> There's a whole bunch of stuff that we
wouldn't have known collectively. Right.
So that's the thing that always blows me
away is if depends on when you stop
paying attention to science. Uh, don't
do that because science moves forward
moves fast every day. Every day.
>> It absolutely does.
>> This podcast is from the producers of
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[Music]
So, you've been chasing these fossils
since you were a kid. Where has that
taken you on the planet? and tell me
some of the coolest surprises that
you've encountered.
>> So, I have found about a thousand fossil
localities in my time on all continents.
>> Um, and my favorite continent is North
America because I'm from North America,
but because the western part of North
America, the Rocky Mountain region was
for a very long period of time primarily
deorld. So it accumulated layers and
layers and layers um from the Cambrian
all the way up to the present almost
present. So
>> So let's define the Cambrian for those
who who might not know.
>> So the Cambrian period starts at 542
million years ago
>> and that sort of starts the you know
it's not the very beginning of of big
life forms but it's sort of much the
starting gun for the the evolution
event. It's the first time you see
actual animal fossils for instance is
the the very bottom of the camber. So
542 million.
>> And so at this time is it 100% in the
oceans?
>> Um well there's land. It's just there's
not I mean life.
>> Yeah. Yeah. There's it's not clear
what's on land. There's land but it's
not clear if there's anything living on
land at all. That's one of the
unanswered questions.
>> I see.
>> Um there's probably some
>> kind of microscopic microbes on land,
but hard to know. Yeah.
>> Um but it predates certainly any plants
or anything on land. So then then you go
through this sequence where you
eventually evolve a diverse ecosystem in
the oceans and then then you see land uh
start to be populated by some very early
land plants and some very early land
animals but again probably little insect
like or spider-like things and little
tiny plants that might be only three
inches tall or two inches tall,
>> right?
>> And then eventually you start to get uh
bigger plants in the first forests. So,
wait, wait. You know, one of the things
I saw on YouTube,
>> of course, that I discovered were these
big giant fungus things.
>> Yeah.
>> Yeah. So, that's a it's a fossil known
as prototaxes.
>> Okay. That's a mouthful. Um, it is a
like most fossil names are mouthfuls.
I'm going easy.
>> It's not like in my field of
astrophysics. Black hole.
>> No, no, no. We We got some good names
for you. So this prototaxes
uh very weird enigmatic because it's a
it's a
>> looks like it's a fungus of some sort.
>> And they are these big trunklike chunks.
>> Yeah.
>> And that's all you get.
>> Yeah.
>> And then you can look at this in
cross-section and you slice them up and
look in cross-section and you can see
things that kind of look like fungal
threads and fungal hygiene.
>> Um but they're way bigger than anything
else around there. And
>> when they first appeared, how big they
got, and what they actually related to
is pretty much at the hairy edge of what
we know.
>> Yeah.
>> Because they're only known from a few
places in the world.
>> And how big they got, well, there's a
couple that look like they might have
been pretty big. So you see
reconstructions of them, but that's just
somebody saying, "Well, I'm going to
paint some big thing that looks like a
big thing." So, a lot of debates on this
stuff. And so much of early life is like
that. We have fragments of these things,
>> right?
>> And you have preservation that doesn't
show all the details. Yeah.
>> And it's like it's likely that they're
fungi.
>> Yeah. Yeah.
>> They might be something else, but who
knows what else it would be.
>> They could be neither plant nor fungi.
Could be something different
potentially,
>> but they're organic. You know, they're
not an animal. So, you're kind of like
in a realm of the things that we know
about, fungi seem to be a reasonable
interpretation. And I think the further
back you go in time,
>> the blurrier the view is. And there's
plenty of things in the fossil record
where we know we've seen this thing
before. We've given it a name. We don't
know where it fits on the tree of life.
>> So, so here's the question then. If
you're a paleobotonist, is there are
there paleo fungicists?
>> There are. There are.
>> Wow.
>> So, I mean there's paleo anything you
want because any living thing has it has
its fossil story and you know science
like we all specialize and specialize
and I'm I I
>> became a paleobotonist because you got
to get a PhD in something.
>> Yeah.
>> But I love the whole story. the whole
story of ancient life, ancient earth.
Yeah.
>> And everything's in context. So,
paleobotney is in the context of where
were the first plants,
>> right? Yeah.
>> Right. And uh and so and then when were
the first forests and then when the
first leaves and the first seeds and the
first walnuts.
>> So, is there a case of
plants becoming, you know, is it a
something that happened a single time
and spread out or is it something that
just kept popping up and then was able
to survive? It's a hard question to
answer because um but one thing is very
clear and important thing to realize is
that it looks like because of the
presence of DNA that all life forms are
related to each other. They all have
DNA.
>> Yeah.
>> And so when you start to evolve a
complex life form, no matter what it is,
Yeah. it it's got its own DNA.
>> It still implies it's related to the
other things that formed,
>> right? And the further you go down the
evolutionary tree, um, the less likely
it is you're going to reproduce the same
thing because it's had its pathway that
you've already gone down.
>> So the the new stuff
>> Yeah.
>> takes the blueprint from the older stuff
and builds on that,
>> right?
>> Yeah. Yeah. But a lot of the old stuff
is still here, right?
>> It's true. But then this is this is why
we're so worried about extinction
because let's take for instance a um
bison.
>> Yeah. If a bison goes extinct,
we're kind of done because you can't
re-evolve a bison.
>> You can't go back to the start. The
extinction is when you lose that whole
lineage.
>> Yeah. It's a whole process that you've
lost,
>> right? You and it's like, you know, it's
it's it's, you know, it's genealogy goes
back all the way back to those first DNA
molecules back in the ocean. So, um, and
the fossil record is full of things
where you lose things like the big
dinosaurs, like the long neck dinosaurs.
>> Yeah.
>> They're not just going to pop up one day
again. They're we had them, they're
gone.
>> They're gone. They're gone.
>> Right. And that's that's the cruel thing
of evolution and extinction is things
are the ends of lineages. So, when you
lose them for whatever reason,
>> Yeah.
>> Um, they're not coming back.
>> So, what do we represent then? All life
forms today. So I read somewhere that
something like 99% or higher of all life
species have are no longer here. Yeah.
But then I think what does that really
mean? That doesn't mean they necessarily
like there's extinction that comes from
uh you know birds are still here but yet
they are dinosaurs and we say dinosaurs
are extinct. So you evolve to something
new. You didn't die off. So it's not the
end of the lineage. So when you say that
sort of phrase that 99% of all species
are gone, does that mean that uh you
know what what percentage of them
evolved into something else and what
percentage of them just died off?
>> Again, hard to say because we have no
idea how many things were alive at any
point in the past because the fossil
record is so incomplete.
>> Right.
>> Right. So you don't really know. And
your point's well taken. Certain things
do have descendants, but you can destroy
entire lineages. So for instance, if the
birds go extinct Yeah. Yeah.
>> Then dinosaurs will be truly extinct.
>> Mhm.
>> Right. And birds were just one branch of
dinosaurs. So all the other branches of
dinosaurs went extinct
>> except for the bird branch.
>> Yeah. Yeah.
>> So you know and there were some really
cool dinosaurs. I mean there's this
thing called Patagot Titan that is 100
ft long and its head's 60 feet above the
ground and its one leg bone is taller
than I am. Man, it is so hard for me to
imag I I I step into the museums like
yours and I see these giant animals and
I just cannot
envision that thing walking around,
right? It's it's hard enough when you
see an elephant lumbering along, right?
Something many times the size of an
elephant like the mechanics of that, you
know, are they fast moving cuz they were
warmblooded, right?
>> Do the big ones? Who knows? Maybe, maybe
not. I mean, this is like a good theory.
Some of the some of the more birdlike
dinosaurs almost surely were
warm-blooded, but the big ones, you
know, they're big animals and there all
sorts of mysteries about those animals.
And I I will say that
>> were it not for fossils,
>> we'd never have an idea that those
animals existed, first of all,
>> and when you see them in museums, like,
I can't believe that thing existed. But
I'll tell you what, when you are digging
and you find one of those things,
>> that's where your brain gets rung hard
because
>> you dig out a 7 foot long femur.
>> Yeah.
>> And you know that you dug it out.
>> There's zero doubt in your mind that
that was a living animal.
>> Yeah.
>> And those long neck, longtailed
dinosaurs, the sorapods,
>> they were around on planet Earth for
like 150 million years. Humans are
300,000 years.
>> Geez. Yeah. So, here's a kind of animal
that and they're found on all continents
that was a very successful kind of
animal. So, even if we can't imagine how
they walked,
>> they walked.
>> Yeah. They walked 150 million years of
lineage.
>> Yeah. And Okay. So I I' I've studied
human history a bit and one of the
things that is mindblowing to me is
during Homo erectus's time of two
million years brain volume went from
like 600 cc's to 1200 it doubled right
in 2 million years. So now you're
talking about something a lineage that's
150 million years.
>> The difference be before the the before
state and the just before the meteorite
hit like what were the major changes
that happened? Was it just the evolution
into small mammals and different
reptiles or
>> did some of them become smart? Like
what? So here's here's the thing that's
so incredible is that the the state of
the planet does change from time to
time. like there the planet is in orbit
around the sun. It's got the moon. The
moon gives us its months. The earth you
know it's rotation around the sun gives
us our seasons. We have these things
that are there but but certain things
have changed like the earth is slowing
down in its rate of rotation for
example. So there used to be 480 days
per year.
>> Wow.
>> Now there's only 365 days per year
because
>> so as the earth is orbiting the sun it's
spinning. So it would go get 480 spins
in by the time it made one complete
orbit.
>> Right. Yeah. So the days are a little
bit shorter
>> and so things like that happen or
>> we get a little bit closer to the sun so
the climate's a little bit warmer or a
little bit further away.
>> What is that? The Melankovich cycles or
something like that.
>> Yeah. And those are pretty like those
happen on these sort of 20,000 40,000
100,000 year cycles.
>> And if if nothing else was changing at
all on the planet, if just the
Mankovich, you'd have this cool warm
cool warm tick- tock thing going back
and forth on these cycles. And that's
what's driving things like the most
recent glacial periods, the advances and
retreats of the the big ice sheet that
covered North America, for instance.
Yeah. And today, um, we sit here and
enjoying our weather in Boston and
Seattle and New York. But if we were
here 20,000 years ago, there was 3,000
ft of ice on top of Seattle, New York,
and Boston. 3,000 ft.
>> Wow.
>> That's six Space Needles, you know. It's
like it's And that was only 20,000 years
ago. or it's like more than half a mile
ice on top of what we call cities today.
So there's there are processes that are
happening over time and and when you
shift a major process for whatever
reason that then challenges the life
forms to respond,
>> right?
>> But those long neck dinosaurs which
first appear, you know, sometime in the
Jurassic period, maybe 180 million
years, they kind of disappear at the
asteroid impact at 66 million years.
They've got well over a hundred 100 plus
uh million years of time. They were
living in a time when there were no
polar ice caps.
>> The entire 100 million years or so.
>> Yeah. There was some times where it
cooled down a little bit, but the
evidence for polar ice caps there is
very sparse. Which means that um and I
see the world of the last 400 years, I
see the world as a view between the
battle between trees and ice. Ooh.
>> Cuz when there's lots of ice, there's
not so many trees.
>> When the ice retreats, there's more
trees.
>> I see.
>> So, and uh today, for instance,
Antarctica is covered by 10,000 ft of
ice.
>> And Greenland, the same.
>> Yeah.
>> Dial the clock back 50 million years.
Antarctica was completely forested.
Greenland was completely forested. There
were no ice caps on the planet. So, you
have a tree world
>> versus an ice world. So,
>> how many years ago was that? Well, 56
million years ago was a high peak. 100
million years was even a higher peak of
temperature. But remember, dinosaurs um
first appear in the geological record
around 230 million years ago and they
disappear at 66 million years except for
the birds, right? That one lineage that
survived. So, you have this nice long
chunk of time where
>> dinosaurs um
>> these long neck dinosaurs, they
survived. That lineage had a long time,
but it lived in a world that wasn't all
that different. It was a forested world.
>> Yeah.
>> And to become a big herbivore, what do
you need?
>> You need like endless salad.
>> So, Mr. Paleo botnist.
>> Now, we come back to it.
>> Were trees hella big to feed all these
big dinosaurs? Is it a different forest
world than in the forest worlds we have
today than like the Amazon or the Congo?
>> So, the now you're talking about
language here.
>> All right,
>> we've gotten rid of all this earlier
stuff. Now, we're on to the plants. But
the the thing is that um think about
trees. People don't think about trees
very much at all. I mean, I find that
people are they love animals and they
just ignore plants. Yeah. Now, there's
gardeners, of course, that like growing
plants.
>> Wait a minute, man. Let's get back to my
Mississippi upbringing. So, one of the
things I used to be proud of that I
can't do anymore was, you know, the
ability to identify trees by their bark
and leaves like because, you know, we
haul pulp wood and, you know, you had to
get this for firewood and you, you know,
you ate this or that. So, you knew your
forest. Today I just I lost it all.
Yeah. Yeah.
>> And if you go to Mississippi, there's a
nice diversity of trees. You know, if
you went out and walked in the forest
and down if you walk in the swampy
areas, a lot of bald cypress every and
sweet gum and sour gum and that kind of
stuff.
>> Uh but if you go to the Amazon today,
>> you walk in one acre of forest, you
might have two or 300 species of trees.
>> Wow.
>> Like Mississippi might have 20 or 30.
Wow.
>> Amazon might have two or 300. It's just
an interesting thing. It's like we ask
now the question when did the first
tropical rainforests form?
>> Okay.
>> When did the first uh pine forests form?
When did the first redwood forests form?
Because there's different kinds of
plants. There's about on planet Earth
today. There's about 400,000 different
species of plants.
>> Okay.
>> Now, about that maybe 100,000 different
species of trees.
>> Okay.
>> All right. So, there's a lot of
different kinds of trees. And trees are
very interesting because um the
different kinds of trees have long
lineages. So there is a thing known as
the GKO tree
>> behind GKO fossils that go back 180
million years.
>> Wow.
>> So the Genko trees are alive with the
dinosaurs. So there actually are some
kinds of trees that are alive today
>> that were alive with those dinosaurs.
>> And this is the kind of cool thing is
that the the planets always changing,
but some of the some of the cast members
in the play
>> Yeah.
>> have long roles. How long can a seed
last? Like I can imagine that if there's
some big disaster, you know, seeds can
even though if even if all the trees get
burned up, you know, the seeds may
survive for some like what's the
longest?
>> There's some examples of very old seeds
like archaeological sites that have
germinated. So thousands of years maybe
in some rare cases,
>> but that gives you enough time.
>> Yeah. you preserve the seed and we have
these seeds that were frozen in a seed
bank in in the Swallbard and the Arctic
Islands. Now we're like freezing seeds
to preserve them from the future. So
depending on what kind of seed it is, it
can last a while. I would be pretty
surprised to see an ice age seed
germinate. Okay.
>> Um but
>> I'm not going to say it's not going to
happen. I'm just going to say I'd be
surprised if it was frozen at the time.
Maybe it
>> comes back. But trees um there's so many
things to say about trees that I'm going
to
>> Well, you are botist is in your
educational heritage though.
>> Yeah. I mean I think my point is that
most people just don't pay attention to
trees and they have so much to tell you
because trees have growth rings so you
can cut them down and tell how old they
are. Some trees are,
>> you know, typical age of a tree is about
the same age as a person. A typical tree
lasts about 60 or 70 years. But some
kinds of trees last thousands of years,
like the, you know, the pines go back
like 4,000 years. So, they're good at
telling time. They're good at telling
time in human kind of stories. And we
often use trees with growth rings to
tell us about archaeological sites
because there's a thing known as
dendrochronology or using tree rings to
measure time.
>> It's one of the many ways we measure
time back in the past. But if you go to
the tropical rainforest and cut a tree
down,
>> it has no rings.
>> What?
Yeah, because there's no seasons.
>> Oh,
>> a ring is when the tree slows grows slow
in the winter. So, it's like tree rings
are something that's very familiar if
you live in a temperate region. But if
you go to the tropics and you saw a tree
down, it's like, huh, looks like butter.
>> It's ringless.
>> Yeah.
>> And so in the tropics, if you want to
measure how old a tree is, you can't
count the rings. You have to watch it
grow
>> to so to know the growth rate. So you
have
>> you measure it every year and see how
back it's growing. So we have a
Smithsonian has a plot in Panama called
the Smithsonian Tropical Research
Institute and we have this place called
Borrow Colorado Island which is 50
hectares where they've measured every
single tree every five years for the
last 50 years.
>> Well here here's the question. Are those
trees the the human lifespan type trees
or do they live much longer? Because if
it lives much longer, you would imagine
that it would have to undergo different
environmental conditions which would
increase or decrease the growth rate.
Right.
>> Exactly. So, um, what we're finding is
that in tropical rainforest, it looks
like the average tree lasts about as
long as a human 70 or 80 years because
trees get diseases, too.
>> Yeah.
>> They get knocked over by windtorms.
>> Yeah.
>> They get burnt by forest fires.
>> Wait a minute. Let's talk disease. So, I
can imagine fungal. Yep.
>> I can even imagine bacterial. Yep.
>> Do they get viruses?
Like, can a tree catch a cold?
>> I should know that, but I don't.
>> I love that about you, though, man. I I
I feel like one of the best answers a
scientist can ever give is I don't know.
Because
>> to me, the hallmark of when you cross
the threshold of being a scientist is
when you know the difference between I
know and I don't know.
>> Yeah.
>> And even know is a little bit of a
stretch because I think I know.
>> Well, I know with some uncertainty,
right? There's going to be an error bar
on my no. Exactly. Yeah,
>> exactly. Because as but that's why you
got to keep reading, right? You keep
studying. You keep watching what's
happening because the world there's so
many scientists. There's now 10 million
scientists in the planet.
>> Thank you for that. Is that cool?
>> That is amazing. I have no idea because
what I tell people is what I've been
telling people is that you know when you
look at scientific knowledge, it's not
like the good old days where you had
like this one lone person. Every country
has armies of scientists. Yeah. And now
10 million people that I never had a
number to attach to that.
>> No, it's interesting cuz I think there's
8 billion people.
>> Yeah.
>> So what scientists are one in a
thousand?
>> One in a
>> That's a lot higher than I would have
imagined.
>> Yeah. It's like
>> one in a thousand is a
>> right. Did you do my math right?
>> Billion 8 billion is 10 to the 9
>> and 10 million is 10 to the 7.
>> Yep.
>> So it's one Wait, it's one in 100.
>> Can't be.
>> Can't be. So we're gonna turn 8 billion
into 10 billion. And so now we're at 10
to the 10 compared to 10 to the
>> 100,000. Thousand.
>> All right.
>> Yeah. Yeah.
>> Well, let me ask you this other question
then. The fossilization process. So, you
know, I've been to the um painted desert
in in in Arizona with all the fossilized
trees and they're rock. So,
>> pretty much fossil equals not organic
stuff in its current composition. It's
minerals, right? Is that always the case
or do you actually get some organic bits
here and there?
>> So I would define fossils different.
What you've described is a petrified
fossil where the fossil has been turned
into rock. That's one type of fossil.
Okay.
>> A fossil can is basically anything old.
It's a very
>> Okay, it's broad.
>> It's very broad because we have um
fossils that are almost unaltered
entirely. I can show you, for instance,
a site that we worked up in the Canadian
Arctic Islands that was 5 million years
old.
>> And the wood looked like driftwood off a
beach.
>> So, it's still wood.
>> It's just wood.
>> It just happens to be 5 million years
old. Wow.
>> I have a site in North Dakota that I dig
called Ginko Salad. And the reason we
call it GKO salad is when you crack the
rock open, this is 67 million year old
rock.
>> The ginko leaf peels off the rock. It's
a leaf.
>> Wow.
>> You can eat it. It's like the pressed
leaf in your that you
>> It is
>> but it's encased in rock.
>> Yeah.
>> Wow.
>> Right. So, and petrified wood is
petrified wood is wood that's been
invaded by silica rich water. So, it
turns the it turns the wood or the wood
is replaced with glass effectively.
>> But that also happens. I have places
where fence posts are petrified because
of the water. Groundwatering has
silicate or calcium carbonate in it. And
you can actually take a chunk of
petrified wood in some cases
>> and put it in hydrofuloric acid, which
is an acid that dissolves silica. It
dissolves glass. So don't put
hydrofuloric acid in a glass jar cuz it
will
>> wait. HF?
>> Yeah. HF?
>> Oh man.
>> Nasty stuff.
>> Nasty stuff. I used to work in a
semiconductor field. And then we had to
watch these horrible videos of HF
accidents
>> that kills people.
>> Yeah.
>> So you take uh a piece of petrified wood
and you put it in hydrofluoric acid. It
will dissolve the silica out and give
you the wood back.
>> Wow.
>> The wood structure is still there.
>> So, we're talking like tens of millions
of years old.
>> Could be less. I mean,
>> I'm saying up to, right? That would
could that work with something that's
>> Oh, yeah. Oh, yeah. I mean there there
are plenty of fossils from 400 million
years old where you can um dissolve away
the rock and get the organic material
that like the coal seams of West
Virginia. They're these things called
coal balls which are concretions made up
of calcium carbonate that formed around
these plant parts. What you do is you
saw them in half. You dip the flat
surface in a light acid which etches
away the calcium carbonate. And then you
lay a little bit of acetone on there and
I put a sheet of acetate and peel it off
and you can get a peel of the cell
structure of the plant.
>> Wow. And look at it under a microscope.
>> Cell by cell. And that's 400 year old
plant.
>> 400 million.
>> 400 million. Sorry. 40 million. So this
is the Now you're starting to get the
joy of paleobiology here, right?
>> This is dope, man. This is dope. Yeah.
>> So, you said something and this is
something I've always wondered. I see
these videos, they're walking in a
stream or they're out in some place
where there's all these big rocks and
they're like, "Ha." And they grab a
rock, hit it with a hammer, open them
up, and there's a fossil right there.
I'm like, "How do you know? How do you
know that that rock had a fossil in it?"
And then what is the rate? Like, like
you're I you've been doing this a long
time. You're probably good at it. Like,
is it one out of 10? like, you know, how
how does this work, man? We want the
secret. I want to find fossils in my
backyard.
>> Perfect. There's several secrets here.
One is um you don't find anything unless
you look for it. So, that's a pretty
obvious thing. And so, uh certain kinds
of fossils are in the rock and fossil
leaves are in the rock. And if the rock
erodess away, it just erodess away the
fossil. Because you think about it,
here's how a fossil leaf gets formed.
>> Leaf is on a tree, leaf falls off the
tree into the stream. leaf gets buried
by sand at the bottom of the stream.
It's in a deworld situation. The stream
gets buried by more streams. After a
while, that layer is so deep it becomes
a hard sedimentary rock. Then later on,
that area is uplifted. Now, that rock's
exposed to the surface.
>> That leaf is in the rock. So, I go
walking along with my pickaxe and I'm
digging holes and digging holes. I'll
split a chunk of rock and crack it open.
And I do this when I I'm hunting for
fossils. I might do that a hundred a
thousand times a day. Just look, crack a
rock. Nothing. Nothing. Nothing.
>> But you have some sort of uh criteria to
determine which rock you're going to
crack open. Right.
>> I do, but sometimes I when I have like
young interns, I say just go dig holes
because sometimes my criteria
>> locks me into missing things.
>> Ah, I see.
>> Right. Like I I think I know where
things are when I think I do.
>> Yeah.
>> But I don't know what I don't know as
always. And so I sometimes have the
uneducated people digging holes too. And
sometimes they find amazing sites by
random and I'm like, "Oh, I could find
fossils there, too." But say you find
you crack the rock open and
>> remember there was a leaf that was
there, but the leaf is usually rotted
away, leaving a leafshaped hole
>> in the rock, which means when you hit
the rock with a hammer, it wants to open
up there because that's a plane of
weakness.
>> Ah,
>> so it's going to it's predisposed to
open up where the fossil is.
>> I see.
>> So when you crack a rock and there's a
leaf or even a fragment of leaf, you're
like, "Ah, okay. Now remember this.
Leaves are like potato chips. You don't
just get one.
>> Oh,
>> right. It came off a tree.
>> A typical tree has hundreds of thousands
of leaves.
>> And I know this because I once cut down
a tree and counted the leaves.
>> Man, you you are committed to the art.
>> I wanted to know.
>> You are good at it.
>> I wanted you to know. Hey, you know
what? I I believe it now because you
know what I did? You know, I have a
bunch of trees. I'm I'm kind of in a
country place. And so, I bought one of
these extendo
>> auto automatic cut the limbs off cuz
they're get they're growing into the
areas they don't they shouldn't.
>> Yep.
>> And man, when it came time to get all
that stuff and put it in bags, I was
thinking they got to be a 100,000 leaves
on this tree.
>> Not a bad guess. Here's here's I I had
this thought. I said, I want to do this
because I really just want to know. And
I I selected a 50- foot tall red maple
tree that was about this big around at
the base.
>> Yeah.
>> And I saw it down with a buddy of mine
and we um then we cut off all the
branches and stacked them all up. And
then we sat down and we had a counting
system where um we had a pile of sticks
and every time you counted 100 leaves,
you put a stick in the pile so you
wouldn't lose count.
>> Yeah.
>> And we took 18 hours and we counted
leaves for 18 hours. And this tree had
99,284
leaves on it. So your 100,000 leaf was a
good guess.
>> Well, that I just say that cuz you you
you already said it. But you reminded
that you planted that, right? You led
the witness. It reminds me of that that
thing where they show up with the jelly
beans. You're like, "Guess how many
jelly beans are in the jar." So you did
that for a tree and you got the
>> Exactly. So So that was just one tree,
but it was it was the average tree in
this forest. I'd measured all the trees
in the forest. I here I'm going to hit
the average tree.
>> Well, let me tell you, a physicist would
never do it that way. There's two ways
we would do it. Okay. One way is either
we would like
>> chop off all the trees, chop off all the
leaves, put them in a big pile and weigh
it and then weigh one leaf
>> divide it. Or the other way is we'll say
like, oh, let me take a meter by meter
by meter volume, count the number of
leaves in there and then estimate the
volume of the entire canopy.
>> Well, you know what I had done actually
before then was I had um his leaves all
in in the northeast all the leaves fall
off in the in the fall. They all fall in
the fall. So, I had gone to that same
forest where there was leaf litter in
November. So all the leaves are off the
tree and I had measured 1 meter square
and counted the leaves in 1 meter square
and I divided that by the number of
trees in the area and I'd come up with
an estimate of 103,000 leaves.
>> So tree. Yeah.
>> Yeah. So there's more than one ways to
skin a cat or count leaves on the tree.
>> Right. Yeah.
>> But um so now whenever I look at a tree
I'm like that's a 1 million leaf tree or
there's a 600,000 leaf tree. There's a
100,000 leaf tree. But my point is when
you're looking for flowers,
>> you have an intuition about it now.
>> Well, yeah. I mean, it's a useless
intuition. Who cares about how many
leaves are on a tree?
>> You don't know, man. That might save
your life someday. You know, you're out
in the If only we had a tree with
200,000 leaves.
>> There it is.
>> So, but get back to the fossil.
>> Gilligan wish he could have known that.
>> Remember the professor?
>> Yeah, the professor. Of course.
>> So, when you're digging fossil leaves,
it's rare that a leaf is going to be
there by itself
>> because it came off a tree that had
100,000 leaves. So if you find one leaf,
you're going to find more.
>> Yeah.
>> So when I find a single leaf, then I
stop. I get the other tools out and I
dig a hole. And almost always when I
find one leaf, I can find hundreds of
leaves.
>> So that what you're telling me then is
that the material doesn't move far
>> over this over these long time periods.
>> Well, yeah. I mean, and so I've done a
lot of work in modern forests and asking
the question, what happens to the leaves
when they fall off the tree?
>> Yeah.
>> Like what happens to leaf litter?
>> Yeah. And if you know in leaf litter in
a forest it rots away by the next year
because it's gone by the time the next
year. But if that forest floor was
flooded by a stream you bury those
leaves.
>> So and then the question is how much
does the leaf litter of the forest floor
reflect what's actually in the forest?
Can you take fossil leaf litter and make
a description of the forest?
>> Um so all those are like tools we use
now when we're building ancient forests.
>> So wait a minute this reminds me of
something that I learned which was also
a mind-blowing thing but I never
verified it. Right. And that was was
that uh you know it was about coal and
the statement was oh yeah you know uh
there's different way you know there are
some petroleum products that form in the
oceans and there's some you know when I
say not petroleum but I don't know what
you call oil gas fossil fuels right
>> and they're like but there are when it
comes to coal
>> when the forest material fell to the
floor a tree died leaves fell
>> so it kind of sat there and built up and
so I always try to imagine you know is
if that was real. What did that florest
floor forest floor look like? And then
also, you know, it made me think about
these coal seams. They have a thickness
to it. So, does that tell you the story?
So, tell me what you know about that.
>> So, this I've been thinking about coal
for a long time.
>> Okay.
>> And the ticket is is that you know what
a swamp is technically,
>> man. I was born in New Orleans.
>> Okay.
>> Trees and water.
>> There we go. It's a forest. It's wet.
>> Yeah. And when you a tree falls over in
the water, it's protected from being um
ground up by organisms because it's
underwater, these low oxygen situation.
And so the tree sits there and then it
gets more trees will pile up on it and
that's how you accumulate layers of
unrotted trees because if you let a tree
on a forest floor,
>> the termites will go at it and it'll
turn back into carbon dioxide.
>> Yeah.
>> And it's gone. Like you walk around in
the forest say, "Where are all the trees
that fell over?" They've all gone back
up into the air as carbon dioxide. Yeah.
So, so but having a swamp means that
it's that's not happening and your trees
are getting preserved. If you have a
swamp that accumulates over time,
>> you'll get a coal seam and
>> so you got to be in D world.
>> You got to be in D world
>> and you got to be in a swamp.
>> Yeah.
>> To make it make a coal. And even then,
we don't really understand coal
formation that well because there's two
major time periods of coal formation in
planet Earth history. There's one called
the Carboniferous,
>> right,
>> which is sort of like the 350 million
year time range.
>> And then there's one that happened
during the um end of the Cretaceous
period and into the Paleo gene, the
Paleocene. So like 100 million to about
50 or 40 million years old. Those are
the two big times when there's lots of
coal on the planet.
>> Okay?
>> And you say like what's going on in the
planet that's burying lots of trees in a
way that they don't rot away
>> and we get these huge coal seams. And
the really thick coal seams are in that
second phase. And there are places in
Wyoming where the coal can be 80 or 100
feet thick.
>> Wow.
>> So,
>> so that meant that there was trees dying
>> and it built up to at least that
thickness.
>> Yep.
>> Before it got buried and turned into
coal.
>> And when you bury it, it's probably
going to squish down because of the
weight, right?
>> And it stuff. So, you know, 100 foot
coal might have been a 300 foot thick
pile of dead trees.
>> Wow. And of course, you know, burning
that is where we get the electricity for
this country.
>> Yeah. Yeah. You know, that that that
that's one thing that interests me is
that we power our societies on life.
>> Yeah.
>> We're like,
>> we call it fossil sunlight, right?
>> Fossil sunlight. Yeah.
>> Yeah. Cuz I mean, it's basically
photosynthesis 60 million years ago.
>> So, speaking of which, you know, one
place I hear about North America all the
time, I was like, what makes that is
Burgess shell. Oh, yeah. Why, you know,
first off, what makes shale? And you
know why is that so fossilri?
>> This is so random because yesterday
>> no
>> I went and I you know I'm the director
of the national museum and it's one of
our most famous collections is the
Burgess Shale collection
>> in 13 years I'd never gone and looked at
the actual Burgess Shale collection
itself and I went there yesterday.
>> Wow.
>> This is true. This is like man
>> I mean timing is good.
>> We're we're connected. So, I've been
I've been to the Burgess Shale in
British Columbia and looked at it and
it's an amazing site. It's it's Cambrian
in age. So, it's like 505 million years,
I think, is the date. It's over.
>> Wait, I thought I thought it was in
America, but it's in it's in it's in
Canada.
>> Yeah, in Alberta.
>> No, British Columbia.
>> British Columbia.
>> And um it's a place that was in the
seafloor.
>> And the way you make a shale, shale is
made out of mud. when mud sinks to the
bottom and if it's and the the particles
in mud are clay particles which are
platey and when you squish them the
plates flatten out so you get a what's
called a fistle or very layered material
that's shale shale is file or
>> so is it a is it a um are the layers
created by some seasonality
>> no they're just they're just layers
they're just that the the if you imagine
if you have these plateike crystals and
you squish them they become flat so the
rock's always going to split on planes
>> right
>> and that's a shale and you have shale
from lakes or from the bottom of the
ocean. Anytime anywhere you're putting
mud down where mud sinks and still
water.
>> And in the Burge of Shale was this very
unusual situation where
>> there was looked like an underwater
um slump where a whole bunch of mud slid
down the bottom of the of the seafloor
and buried an Cambrian ecosystem on the
seafloor
>> like in a in a single event.
>> It seems like it. Yeah. It's like a
slump that kind of came in
>> and there are but there are layers of
the muds and you split these and it's a
black shale. It's like black rock. You
split it and on it are these flattened
>> um fossils of all these seafloor
creatures. And the key thing about this
is that remember you have to kill it to
fossilize you have to kill it and bury
it. Yeah. And there are certain times
when you do the killing with the
burying.
>> It's like a landslide kills and buries
at the same time. Right. zero chance of
rotting away.
>> Yeah.
>> Death and burial.
>> And that's what happened. And so here,
instead of having just the shells of the
organisms, you actually see their
tentacles and all their soft parts.
>> Oh wow.
>> And this site was discovered in 1909 by
um a guy named Charles Dittle Walcott.
Guy that had my job.
>> 1909. Oh, no way. Smithsonian. Yeah, he
was a Smithsonian guy. And um he found
this site and the site is full of all
these little creatures that we never no
one had ever seen before because no
found an underwater landslide that
killed and buried things in fine grade
mud and they're all these really cool
weird things and people have been
finding fossils of that age for many
years.
>> Yeah. So how big of an area are we
talking because
>> oh you know about the size of the studio
that's it?
>> Yeah. It's the size of a big room. It's
it's on the face of a big mountain range
but it's this one quarry where they've
been digging. That's just one quarry,
>> man. And so for all these decades, it's
even though it's so small, it's still
yielding Oh, yeah. Lots of fossils.
>> Well, like you know those layers going
to the side of the mountain, there's
fossils there forever.
>> Oh jeez.
>> I mean, lots of fossil sites. Once you
find it, you can go back to the candy
machine again because the fossils,
>> they're there. And and so um these
slabs, you should come to the museum.
I'll show the slabs to you. They will
blow your mind.
>> Um but they are exquisite. They're
little things. I mean there's an animal
called anomalis which means
>> I think anomalous body or something like
that and they got up to about this long
which like a you know three or four feet
long which is big because most of the
animals in this time period are a few
inches long or even smaller.
>> I see.
>> And so the burg shale is famous because
it's a window
into a well preserved ecosystem that was
flash frozen in a moment. And so we we
have a name for those kinds of things.
We call them logger or just loads of
life basically. And the bird of shale is
the most famous one and it was a
Smithsonian one and it is old enough
that it tells us a story about the very
beginning and it really tells us how
much we don't know.
>> Cuz you see all these Yeah.
>> Every bit of new information just paints
a picture of like oh yeah now now you
know even less than you thought you
knew,
>> right? Yeah. Yeah.
>> So what you just said reminds me of a
particular place where there is always a
lot of life and so and those are coral
reefs. Yep. So, are there like, you
know, fossil
just banks of ancient coral reef that,
you know, just preserves
life from Well, first off, I don't know
when corals came about.
>> Yeah.
>> So, so I'm kind of making an assumption
built in there. But, you know, do you
have
records of ancient coral reefs in the
fossil record?
>> Absolutely. I mean, like most
emphatically, yes. Because coral reefs
are like structures, right? And to keep
the fish and uh
>> so you know we have the and remember
that there are you can have reefs that
are made of other things besides corals.
>> Right.
>> Right. But oh is that right?
>> That's true. So the first corals do go
way back. Their corals way back into the
Cambrian orient time period. But and but
there have been many different kinds of
reefs through geological time. So reefs
are made of clams. Reefs are made of
brizzoans.
>> What are bryzoans? Ra zones are a very
primitive kind of animal that's um that
it's a specific group of animals that
have just the little pores and they're
very simple animals. They're like almost
like sponges in their simplicity. Oh, I
see. Right. So, some of them have
>> So, they're rooted. They're fixed.
>> Yeah. They tend to they tend to they can
be on stems. They can glue onto things,
but they're a one type of marine
organism that's still alive today.
They're still brizz because clams tend
to occur in clusters as well. So, it's
that whole idea of clustering and
affixing yourself to the bottom.
>> Exactly. So, and there are many many
many different known fossil reefs
because they are where the organisms are
making calcium carbonate or oreganite
shells and so they're basically
fossilizing themselves if you want to
think about it that way.
>> That's one way to think about it.
>> And um if you go to Miami, all of
southern Florida is sitting on top of
fossil coral reefs.
>> Oh,
>> the whole state of Florida has got coral
reef fossils underneath it. Anywhere you
go, you dig a hole
>> except the sink holes.
>> Well, the sink holes are holes in the
coral reefs.
Why would that exist?
>> It's Look, I was just in Florida three
months ago and I had the best sinkhole
experience.
>> That may be the first time that sentence
has ever been uttered on planet Earth
because sinkhole experiences are
typically tragic. Yeah. Well, I'm going
to h Now, we're going to talk about
sinkholes in Florida. All right. Oh,
man. So, the um bedrock of most of
Florida is limestone. That's about 35
million years old.
>> Wow.
>> So, it was deposited at the bottom of
the sea and there's a thick layer of
limestone and when
>> forms limestone
>> limestone are fossil reefs.
>> Oh, okay. It can be can be lots of
different things, but in Florida they're
fossil reefs. They're coral heads and
just what you're talking about,
>> right? So, why why is the word lime in
there?
>> Cuz it's calcium carbonate. And when you
bake calcium carbonate, you get lime
which is used to make concrete,
>> right? And it's so it's a lime is sort
of an old English word for this
>> calcium carbonate.
>> Calcium, right? And we use and so um
lime stone
>> is calcium carbonate. Yeah.
>> And you um so it forms in ocean
situations can also form in fresh water
it turns out. But in ocean situations
organisms build these reefs or just
layers of microorganisms that make
limestone. Like the cliffs of do for
instance. Oh yeah. Are a sort of
non-reef version of the reefs. But
Florida is these reef ones and you can
go to the outcrops anywhere in Florida
and you'll see the coral sticking right
out of the rock. I mean it's it's like
there it is. It's just takes
>> 35 million year old.
>> Yeah. Takes zero imagination to see it.
You're looking at the reef and
>> I used to live in Florida and I don't
ever remember seeing that. So
>> you don't look at the ground enough.
You're looking at the stars too much.
>> Yeah, I'm looking up.
So, so, um, I went to Florida because
I'm working on this fossil atlas of the
United States. And I had heard that
Florida had great fossils. And I went to
University of Florida Gainesville where
they have a great museum. And I went out
with um to a limestone quarry where
they're quarrying limestone to make
concrete and all this stuff.
>> And we first stopped at piles of the
ground up limestone. And I was looking
around. I found a beautiful fossil crab,
like a fossil stone crab that was like
that big. And lots of chunks of snails
and clams, all the kind of things you
see living around a reef. But then
here's the kicker. That reef was 34
million years ago. Over time, the earth
goes up and down depending on different
things where the continents are. So like
the surface goes up,
>> the surface goes up and down. And the
sea level is also going up and down. So
if you live near the coast, either the
sea level can go up and flood the land.
Yeah.
>> Or the land can go up and drain the sea
or both happen over time quite a bit. So
the limestone of the 34 million year old
limestone from Florida which used to be
under the sea
>> is now you know above the sea. It's
maybe 30 or 40 or 100 feet above the
sea.
>> Limestone is dissolved by rainwater
right because it's the rainwater's got a
little bit of dissolved carbon dioxide
in it which makes it carbonic acid.
>> When so raindrops got carbon it hits the
limestone and it dissolves a little bit.
So limestone get um forms caves.
>> Yeah. That's where you find all the big
caves like like Mammoth Cave in Kentucky
or you know Carl'sbad Cavern in New
Mexico.
>> Wait a minute. Wait a minute. Wait a
minute. So Mammoth Cave is an old reef.
>> Yes. In Kentucky,
>> dude.
>> Yes. Yes. Now you're getting it. You're
with me on this one. So So you have this
landscape now that the rain is making
holes and these caves can get huge.
You've seen Mammoth Caves.
>> Oh, yeah. I've been in a few caves. I
haven't been in Mammoth. Yeah. Yeah. All
of those caves are formed by uplifted
ancient God. Now that you mention it, I
was I was in this island in the South
Pacific in the Cook Island. It's Mangaya
and it's an ancient
>> it's a coral island of course full of
caves.
>> Exactly. Right. So, but think about um
marine limestone that's been uplifted.
Think about the best analogy back to
food. Yeah.
>> Is Swiss cheese.
>> Swiss cheese.
>> It's a block of cheese with holes in it
all over it. Right. So now what a
sinkhole is is when you put some weight
on the top of a part of the sinkhole
because when you lift it up and you
limestone is formed these holes in there
they often fill up with ground water. So
it's like a Swiss cheese that's full of
liquid
>> and that gives a support as well.
>> Support but so but the little see the
top of the sink hole is there and you
park your car on it and your car weighs
enough to crack the hole and suddenly
the whole thing collapses in on itself
and you have a round lake. And that's
the thing is they're they're circular.
That's
>> because they're round holes and they
become round lakes. So So now you have
this thing that's there and um it's a
lake that's got steep walls on it
because you've collapsed in the side and
if you're a a turtle or an alligator,
you find your way in there and they fill
up with turtles and alligators are
living happily in there. If you're an
animal walking by and you like go for a
drink in the water or you fall in, you
can't get out because of the secret
walls. So it become a trap.
Now, over time, dust and stuff fills it
up and the sinkhole fills up with mud
and bodies of all the animals that got
buried there.
>> And northern Florida has got I mean, we
went to this one limestone quarry and
you could see where they're cut in the
wall, you can see cross-sections of
infilled sink holes full of fossil
mastadons and rhinoceroses and giant
ground sloths and manatees and
alligators and turtles.
>> And so I'm like, this is the coolest
thing I've ever seen.
>> Right. So it's a big cylinder of
>> it's a cylinder full of skeletons.
>> Jeez.
>> And so and and the museum is chocker
block full of skeletons. All of them
younger than the age of the limestone 34
million years all the way up to the ice
age 2 million years ago.
>> Wow.
>> And we went digging. We went to this
other place called Montbrook and you
give you a little knife to dig with and
I dug myself on. First I found um a
beautiful fossil turtle with a skull
intact. And then
>> so do you get to keep this stuff or
>> No, it goes to the museum there. Okay.
Like whenever I go I'm always like some
museum I'm working for. Usually my
museum, but I'm always like this cool
stuff.
>> But is there like how does that work? If
there is there regulation around that
like Okay.
>> If you own the property, you own the
fossils.
>> Got it.
>> Which means that if you I mean which is
a good argument to buy property,
>> own a lot of fossils, right?
>> So but I was this is a piece of property
that's owned by a private citizen who is
letting the University of Florida dig
there. They've been digging for 10
years. They have from this one little
top of a little sinkhole extracted
something like I don't know hundred
different rhinoceroses.
>> And when I was there I dug on to a
rhinoceros.
>> Wow. Wow. So, I tell you, I left Florida
a changed person because I I've been
going down to Florida a lot looking at
fossils and things, but I had I didn't
really realize the Swiss cheese thing
and there are thousands of those sink
holes and they're all full of amazing
fossils. And as a result, Florida has
one of the best fossil records of early
mammals.
>> Wow.
>> In the country. If you want a fossil
mammal between the ages of 34 million
and now,
>> Yeah.
>> Florida and Nebraska are your two top
places. the the I remember you saying
something about uh Earth's memory.
>> Yeah.
>> The fossils are the memories of our
planet.
>> Yeah.
>> And the rocks are the pages on which
those memories are written.
>> So anytime I see layered rocks because
sedimentary layer rocks are layered.
Wherever I'm in the world I see
sedimentary rocks. My first question is
how old are those rocks? Mhm.
>> And then are they marine rocks or rocks
that were deposit on land?
>> That tells me what kind of fossil to
look for.
>> Well, let me ask you a question. So,
there are certain intuitions you get
that as a professional that seem
impossible before you become a
professional. For example,
>> looking at the periodic table looks like
a million different elements, but then,
you know, once I started working in
material science and things, I got to
know a lot of those elements personally,
right? Same with the starry sky. It's
only 6,000 stars you can see with the
naked eye. and but it seems like it's a
million but once you start studying it
you get them you know you know them by
name basically
>> when you I understand that in different
geological layers
>> there are fossils that occur at specific
times y
>> so do you have the ability because
you're a professional in this you're
looking at a sedimentary layer like oh I
see this fossil is this age can you do
that is that a thing
>> just just off the top of the head
>> oh yeah
>> oh wow yeah
>> I could do it when I was 13 years No
way, dude.
>> I mean,
>> oh man.
>> Cuz you know, there are certain kinds of
fossils that are common and known.
>> Trilobytes.
>> Yeah.
>> And trilobyes, the first trilobyte shows
up at 542 million and it's the last
trilobytes gone by 252 million. So, they
were around for about a quarter of a
billion years.
>> Yeah.
>> They're marine animals and they are
different ones. There's there's
literally
>> hundreds I think thousands of kinds of
trilobytes.
>> Oh, wow. But the the common ones are
quite recognizable. So you could flash
me a trilobyte and I'd say that one's
from New York State and it's Deonian,
>> right?
>> That one's from Oklahoma. Because they
preserve different ways, too.
>> Wow.
>> Um and so trilobytes and ammonites are
the other ones. The coiled show guys and
>> tentacles sticking out.
>> Yeah. Yeah. Yeah. Both of those are sort
of like the poster children um
invertebrate fossils that are poster
children for extinction because they're
both extinct. Trilobytes went extinct at
the Peran Triacic boundary. Ammonites
went extinct at the Cretaceous Paleogene
boundary. Got it. And they're both
exquisite things. And you can find them
and they come in all sizes. Like the
biggest trilabyte is like this long.
>> Yeah.
>> The biggest ammonite is like 9 ft in
diameter. Wow.
>> But both of them have lots of little
tiny ones, too. And so you can And they
and they have
>> hundreds of hundreds of species.
>> Yeah. Wow.
>> So you can slice time very finely with
these.
>> Geez. Geez. What about this uh thing I
heard about Teen Rex?
Oh, that was awesome. What? What? Tell
me that story.
>> This is the best This is maybe the best
story ever because it's so surprising.
So, this guy Tyler Lisa, I met him when
he was 12 years old and he lived in this
little town in North Dakota and he was
um a very curious kid. We love curious
kids. And I was there digging with my
team. I'd been going there for a long
time. I've been going there for at least
>> um 15 years before I met him, I think.
And um and I so I was in my early 30s.
he was 12. I said, "Come dig with us."
He dug with us and stuff. Eventually, he
went and got a PhD, became a paleon
vertebrate paleontologist. He's a turtle
expert.
>> Wow.
>> Um and he works at the Denver Museum
where I used to work at. So, like, you
know, it's great. He's like my intern
turned good kind of thing.
>> But he goes, his family still lives in
that little town where all the fossils
are. And um his high school friend had
two sons and a daughter. And the two
sons who are like nine and 11 like we
want to be like Tyler, we want to find
dinosaurs. And they live out there. What
911 year old doesn't, right?
>> Right. So, they live out there and they
they went on this hill that was close to
their house. They called up Tyler and
said, "Hey, um, we think we found a
dinosaur." So, Tyler's like, "Well,
we'll come look at it." And I was with
Tyler. Tyler and I went to look at it.
And we get up the top of the hill, these
two nine-year-old, 11-year-old kids. And
sure enough, it was part of a knee-bone.
There was a two leg bones attached.
>> But different dinosaurs have different
um
>> paint the picture for me. So this
looking at a cliff side and a flat on
the ground.
>> No. So you know what Badlands are?
They're sort of these rounded melting
rock kind of hills. It was a rounded
hill and at the very top. These are
right at the very top. So it was like
this tabletop and there was a chunk of a
leg like this and another chunk of leg
looked like the knee. And and different
kinds of dinosaurs have different bone
textures. So like a triceratops versus
an admonosaurus versus a Tyrannosaurus
Rex.
>> So that's like the pattern and the grain
that you see.
>> It's like the bone. You could tell it
was bone and like and but the the
T-Rexes have a kind of a shine to them.
It's hard to describe.
>> And I looked at it and Tyler looked at
it. We looked at each other like like
>> these kids found a T-Rex.
>> Wow. So, wait a minute. We we but we
didn't like we weren't
>> you know that's that's the mind-blowing
thing you know when when you talk about
the how you get information quite often
like you said all you have is a tooth
and you know all you have is a piece of
a pinky bone or something like but the I
but the the the idea that you can look
at just a piece of bone and know the
entire animal.
>> It's just years of experience. Right? If
you looked at if you looked at hundreds
and hundreds of parts, pretty soon you
can say, "Oh, that's the left femur of
an alligator." I mean, it just
especially if it's common stuff, right?
>> Yeah. They're that unique one from the
other. Like is is are there ones that I
want you to get back to the T-Rex story,
but that but just the fact that you just
went by that like it's an everyday
thing, man. You can't.
Oh, I see the surface of a bone. It's a
triceratops.
Well, I mean, this is the thing, like
you become, especially if you focus on a
certain time period and a certain
formation, you get to know it really
well.
>> And people are like, "How did you know
that?" It's like, "Well, I I looked at I
don't know, thousands of them or
whatever." And it's like I, you know,
it's like you recognize the Hershey bar,
you know,
>> I'll tell you one of the things that we
used to do in Mississippi as a kid
>> because we did so much manual labor.
>> Yeah.
>> Somebody could hold up a wrench and you
could and everybody, you know, any young
boy, right? You knew what 9/116, 58.
>> Yeah. same example. It's just that it's
just familiarity, right?
>> Familiarity.
>> And so I was like, "And you look at
wrenches, I look at turtle bart."
>> So, but we, you know, we're like, it
looks I was like, "It looks like T-Rex."
Tyler's like, "It looks like" So, we're
looking at each other going, "What do
you think?" I'm like, "Yeah, that's what
I think, too." So, we um and just
coincidentally, this is a crazy
coincidence. A couple of weeks before,
this company was making an IMAX film
about T-Rex, and they'd called up Ter
and said, "Hey, do you know anybody
who's excavating a T-Rex?" And Tallyy's
like, "No, I don't." But these kids have
found a dinosaur. It's probably not a
T-Rex, but we'll call you if it think it
is. So after that, Tyler called and
said, "Hey, we actually do think it's a
T-Rex." So they said, "Don't dig
anything. We're going to come with the
IMAX camera." So they came to the IMAX
camera and the two little kids and Tyler
were there. And they start scraping away
at next to the bones. And within 20
minutes, appears a T-Rex tooth.
>> Wow.
>> Right there. It's like it was a T-Rex.
So then that was great because now
there's this great story like my interns
interns
>> found this your grandchildren.
>> Yeah. My grand interns.
>> They're great interns. Yeah.
>> So So grand. So, so then they um they
got a big team up there to chip around.
And what you do is you uh sort of dig
around a site and and you you kind of
expose where the bones are and you dig
around and you trench down around all
sides and then you cover the whole thing
with u plaster a pair of soaked burlap
strips and you build like a plaster
jacket around it and on a big block and
this block was about a six or 7,000
pound block. Then you tunnel underneath
it and you run some steel beams under
that and you keep chipping away and
adding more plaster and burlap and more
steel beams of wood to reinforce it.
>> Reinforce it. So end up you end up
having this giant thing which is now
free from the rock below because you've
chipped all the rocks the beams and it
weighs 6,000 lbs. You got to figure out
how to get it off the top of the hill.
>> Geez.
>> And sometimes you can um build a road or
you can drag it down or whatever. In
this case it was like this is a huge
thing. So what they did was they um got
a helicopter like a big Blackhawk
helicopter.
>> Wow.
>> We rented that because it was
>> rented a Blackhawk helicopter.
>> It cost a lot.
>> So you put that in your grant
application. We anticipate.
>> This is where donors come in.
>> A donor rented the helicopter. Thank
you.
>> And then we we they uh I wasn't there
when this happened. That was this is
happened after cuz they left after they
started digging. They tied a a cable to
the back side of the thing and over the
top and ran the cable down the hill to a
car and they used the car pulling the
cable to tip the block up over turned it
upside down so it flipped it into a
helicopter net.
>> Oh wow.
>> Okay. So it was in the helicopter net
and then they brought the helicopter,
clipped it up, lifted it up on a big
thing and put it on a flatbed truck.
>> Yeah.
>> They drove it to Denver.
>> Yeah.
>> And put it on display in the museum and
started shipping. Now remember they've
turned it upside down. So the original
bones which were on the top now are on
the bottom. So there's nothing at all in
view
>> looking down at the top.
>> Yeah.
>> And they started chipping away at the
top to see what was there.
>> And they found what is the most amazing
fossil I've ever seen. And I have seen a
world of fossils.
>> But as they chipped out, what came into
view was the entire face of a
Tyrannosaurus Rex. The lower jaw with
all the teeth in it. The upper jaw with
all the teeth in it. It was like mouth a
gape.
>> Wow. And adjacent to it was a 7 foot
long palm frond with the whole palm leaf
there.
>> Wow.
>> So here's the It looks like the T-Rex is
like is basically a squished head on the
side. Yeah.
>> It looks like he's eating the palm
frron. Of course, he was just buried
next to the palm frron.
>> But you know, and the and the block is
about the size of four of these tables.
>> So here's a 7 foot long palm frron and
the whole face of a T-Rex found by this
9-year-old kid, 11-year-old kid. And
then there was another 11-year-old was
with them when they found it. So, if I
Google this, can I get a picture?
>> Yeah, I can show it to you right now.
>> Well, it's not going to work for the
camera.
>> All right. We'll send you a picture put
on there. But you will see an
unambiguous palm frron next to an
unambiguous Tyrannosaurus Rex face.
>> Wow.
>> It is the most beautiful fossil.
>> And so, you can go to the museum and see
this. Anybody?
>> It's in Denver. Denver.
>> That was in Denver. The Denver Museum.
Yeah. You can go see. It's on public
display right now as they're chipping it
around. And And they have a problem
because the palm frron is so beautiful.
They they want to dig under where the
palm frond is. They don't want to
destroy the palm frron. So, they're
trying to figure out what to do. That's
the T-Rex.
>> So, you have had the ability to see
Earth through time
>> and there's been a lot of change, right?
You know, you talked about ice coming
and going, continents moving. And so,
right now, we're again in a time of a
lot of change. There's this rapid
advancement of technology and science as
we mentioned, but also, you know,
there's climate change happening. Um,
you know, there are the ring of fire.
The continents are still moving. Uh, one
question I want to ask you really
quickly though. Do you have future
Earth? How the continents are going to
move? How the atmosphere is going to
evolve? And how granular is it? You
know, are you looking at it on
million-year time scales, thousand-year
time scales, hundredyear time scales?
Like what does how does your knowledge
of the past and seeing that past movie
inform the future? And what do you see
coming?
>> There's things that we can predict,
things we can't predict.
>> Yeah.
>> At the scale of climate. Yeah,
>> that's an important one because there we
now have some pretty good predictability
and it's really tailored to how much CO2
we continue to emit and you can see from
CO2 itself as preserved in the ice cores
which go back as far as 800,000 years or
in the um fossil marine calcium forams
the plankton in the seab bottom which
goes back 200 million years
>> or um marine organisms preserved on land
which go back 500 million years. You can
actually build a climate record for the
last almost 500 million years. Wow. And
the team at the Natural Stream Museum
did that and published the first ever
>> climate curve for the last 485 million
years back in September.
>> No way. In science. So you should check
it out. It's a it's an amazing record
because it what it shows you very
clearly is is that more than half of the
last 500 million years the planet has
has no polarized caps.
>> Unless tends warm.
>> Yeah. Tends warm.
>> And what it means it tends warm it means
that the poles are forested.
>> So if we can think about what climate is
doing right now, it's warming as a
direct result of human activity.
>> Well, let me ask you a question. What
kind of makes sense to me? If you have
warmer temperatures, that sounds like
you'd have more evaporation and more
precipitation which would then
>> dissolve with rain the carbon dioxide
out of the atmosphere which would then
cool it back off. Is that a real thing
or am I just am I just making that up?
>> Well, I think that what we see from that
curve is that there are bounds to the
maximum and minimum temperatures. It's
like you know there and there were times
>> before the Cambrian. So like 600 and 700
million years ago where we had a thing
called snowball earth where the entire
earth got covered by ice. That hasn't
happened since we have large life forms.
And the arrival of forests
>> and a lot of other organisms that are
cycling carbon seems to have kept the
planet inside of a range of
temperatures.
>> And so what is that?
>> So the range gets quite a bit higher
than it is now. Like the mean annual
temperature of planet Earth right now is
about 57 degrees Fahrenheit. Okay.
>> Right. That's if you average the whole
thing over the year.
>> Yeah. Um, it's gone in the Cretaceous
time when the dinosaur time, it's gone
as high as in the 90s.
>> Really?
>> Yeah. That's what this curve shows.
>> Wow. That's like over a 30°ree
>> Yeah.
>> swing. Fair. Exactly. So,
>> they have air conditioning. Like
>> they had no but they also didn't die.
Like this is the thing is like the
planet has had these these
>> right they also cold periods. It's sort
of like there's cool cold and warm hot
>> and the hot periods are quite a bit
warmer than they are now. And the cold
pillars are colder than is now.
>> So what would you call it? A current
period, a warm or cold.
>> I call it a cool period. Yeah.
>> Cold would have had the ice sheets on
Boston and Chicago and Seattle.
>> Warm, you start to melt the ice caps.
Hot, they're gone. And you have
subtropical forest at polar latitudes.
>> So that's kind of our range. And we now,
you know, for the last two and a half
million years, we've been in a cool cold
cycle.
>> Cool. Cool. many times in the last two
and a half million years cool cold
>> and now we appear to be going cool warm
>> okay is that because of uh humans or is
that
>> it's it's directly because of humans
it's you know that we we've left because
the cool cold cycle was a melankovich
cycle kind of thing
>> and now what we've done is we've
titrated the atmosphere with excess CO2
yeah
>> and we've we've turned around because
like in the the famous study by um
Charles Keeling who was measuring CO2 on
the top of Monaloa in Hawaii since 1957
when he started measuring it was 300
parts per million CO2.
>> When was that?
>> In 1957.
>> 57.
>> So, and I I know this because I was born
in 1960. So, he basically started
measuring the CO2 the year my mom and
dad met each other.
>> Okay.
>> And here I am. And right now it went
from 315. Right now it's 430 parts per
million.
>> Okay.
>> So, the CO2 concentration in the
atmosphere has gone from 315 to 430.
>> So, that's like a 33% increase roughly.
A 35% increase. in my lifetime.
>> Wow. Wow. So, we don't see that in the
past on those time scales.
>> Well, not on those time scales. So, what
we're doing is humanity has become a
geologic force or an atmospheric force.
>> And that's that's what's happening. So,
we're in a point where we get to choose
what we do next. Like, we can just say,
do we want to
>> just do the experiment, run the
experiment, and destabilize the
cryossphere?
>> Well, let's say we don't. Let's say we
don't. Okay.
What has the record shown the impact on
life has been when you go from cold,
cool, warm, hot?
>> Yeah. So, when you go to those
temperatures, what you end up doing is
you take away the ice. Yeah.
>> So, if you melt all the ice,
>> um you're going to get a couple hundred
feet of sea level rise because you
Antarctica and Greenland. So, the sea
level change is one thing.
>> Yeah. Second thing is you're going to
have migrate um organisms will migrate
to the north as they're they're being
chased
>> and also new habitat opens up.
>> Life moves poleward
>> poleward. Yeah. So you get forest in the
poles. The equator becomes pretty hot
and um it would be difficult uh you know
we're looking at areas where a little
bit more warmth. It becomes difficult to
be outside and do agriculture outside in
the equatorial regions because you just
can't shed your heat.
>> So everything becomes Phoenix.
>> Yeah. Well, no. Exactly.
>> The equator becomes Phoenix.
>> Yeah. And that has an impact if you It
also decreases the the polar to
equatorial air currents and ocean
currents, right?
>> It decreases them. It decreases. So you
get less mixing.
>> Yeah. Because you have right now we have
a big gradient from the very cold the
frigid polar regions and the very warm
tropical. So there's there's a something
that's driving currents is that
temperature difference. And you're
basically decreasing the temperature
difference.
>> I see. In a warm world, what happens is
the a warming world, what happens is
that the poles
>> warm or let's just say they they are
less cold. Yeah.
>> Much more than the equator warms. So the
temperature gradient flattens out.
>> Right. Yeah.
>> And so you have less gradient from pole
to equator.
>> A hot stagnant world.
>> Exactly. Rather than in a a um hot cold
dynamic world,
>> right?
>> And that's kind of the trend. And how
fast that happens
>> um is still kind of unknown, but it's
pretty clear that it's happening.
>> And it seems to be surprising us because
from what I understand, the changes are
occurring faster than anticipated.
>> Let's think of all the things you've
heard of recently like atmospheric
rivers or like the Gulf Stream doing
that meandering thing that dumps a lot
of snow. You know, all these things are
like once you see them like, "Oh yeah,
we predicted this." It's like you didn't
predict it.
>> You predicted instability and
instability is manifesting itself in the
present. You don't know exactly what
that instability is going to look like.
>> Yeah.
>> But I think the the key point that came
from this big paper that was published
in the 485 million curve is that the
driver is CO2.
>> All right, man. So everything I'm
hearing, you know, working at the at the
museum, you sit in this place where you
get to see many different areas of
science and all of these have been
rapidly
um just increasing knowledge, increasing
data. So, I imagine that you have some
sort of like holistic view now of the of
science, where it's at, where humanity
is going, where the planet is going.
How do you summarize
your view from your perch in your
position?
>> You know, I think the the key points are
this one. I think science is an amazing
human endeavor. And it's because we
>> are curious primates that we pay
attention to things. And what science
has done is we we do experiments, we
observe things, we share the knowledge,
we move it forward. So knowledge gets
grows as a collective human endeavor.
Yeah.
>> So you and I are both scientists, but we
know what we know. We don't know what we
don't know. But you put all 10 million
scientists in the world together
>> and all the discoveries that are being
made every week by all those 10 million
scientists. Humanity is getting smarter
very fast.
>> Yeah.
>> And so and we're understanding this and
there are things we there are a lot of
things we don't know. A lot of basic
things the planet we don't know. But the
planet is so incredibly interesting
whether it's the couple million to 10
million species of living things or
whether it's the geology whether it's
the meteorology or the patterns of how
it all works together and um one
attribute of there being so many
scientists is that most scientists are
focused on one very specific aspect of
the scientific knowledge base right
>> and I think the great privilege I have
as being the director of the National
Museum of Natural History the world's
largest natural history museum is I get
a bird's side view of a whole bunch of
the scientific world and it it is just
endlessly fascinating, overwhelming,
thrilling and uh you know just I just am
thankful every day for the ability to
see what I see
>> experience what I experience.
>> I I still see the same joy that you know
like and curiosity. I was that kid too
in a different kind, you know, for me it
was relativity and Einstein. For you it
was looking down and finding things. And
I imagine, man, you know, I still have
it. Looks like you still have it. Oh,
yeah.
>> You're just it's like coming to you.
You're like feeding from a fire hose of
scientific knowledge and you just have
this perch where you you're you're like
in in the Marvel comics, they had the
Watchers, right? You could just look at
all knowledge going around in the
universe. You're like Earth's equivalent
to that.
Well, that's an awesome statement,
>> right? Yeah.
>> I definitely don't want to sleep ever.
>> Oh, man. Yeah. Well, you know, you get
to synthesize all this stuff in your
sleep and and and does that ever lead to
like I see it now. Right.
>> Well, you you get these steps and often
it'll be somebody makes a different
discovery which makes your observations
fit into place.
>> Yeah.
>> Like there's a lot of things where
you're confused about like what goes on
here. Like the Benu thing was I learned
so much from the guys doing the Beno
project. I didn't do any of that work,
but I was proximal to them when they
were doing the work and I could ask them
questions. So, I love interviewing
scientists and understanding because
>> it is hard to understand all of it. I
mean, no one can do it. There was this
there was a book called The Last Man Who
Knew Everything,
>> right?
>> I love that. I love that
>> like 1850, you know, back when there was
25 scientists or whatever. But, but now
it's, you know, we're in this collective
endeavor and it's been so fun talking to
you because your knowledge set
>> is quite different from mine.
>> Yeah, man. You're blowing my mind.
>> We can we can talk for another 12 hours.
No problem. No problem.
>> And we will now that I got you. Now that
I got you, man. Yeah. I'm
>> This has been amazing, Kirk. I'm so
happy the opportunity to chat with you.
This is
>> And I You will be seeing me showing up
at your doorstep.
>> Perfect. Looking forward, I love it.
Thank you, man. Thank you.
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