cc >> Clint Sprott: I'd like to
welcome you to the Chaos and Complex Systems Seminar.
Those of you who have been attending regularly undoubtedly
know our speaker today, Jim Blair.
He's been a regular attendee and active participant in the
seminar for a number of years. His PhD is from the University
of Wisconsin in physical chemistry in 1963.
He had a number of careers, as he'll elaborate on briefly, but
his main occupation was a professor of physical sciences
at Milton College. He's now an emeritus professor
from that institution and with us today.
His topic will be the structure of scientific revolution.
Jim. >> Jim Blair: I'll begin
by explaining who I am. And then a little later, I'll
explain my connection to the story that I'll be telling you.
I came here in 1958 as a graduate student on a National
Science Foundation scholarship in chemistry.
Ended up with a PhD inform 1963. My thesis was on determining the
molecular weight of macromolecules using the
analytical ultracentrifuge. My first job was at DuPont Photo
Products in Parlin, New Jersey, on photographic, silver halide
chemistry basically, for two years.
Then I didn't like New Jersey and I moved back to Madison to
teach at Milton College. I began to teach the chemistry
curriculum, but before long, and as you'll see, I ended up
teaching geology, astronomy, oceanography, a series of short
courses, one semester, one month on each of the number
of short topics that were active in science at that time
like decoding the genetic code, which was a big deal at that
time, animal behavior, because Konrad Lorenz had just gotten
the Nobel Prize in studying animal behavior.
I also taught a course in science fiction, one of the
first in the country actually, and had a number of science
fiction writers come to visit the course.
Out of the oceanography class they instituted the calendar,
the 4-1-4 calendar with the month of January as a one-month
semester, and somebody on the board of trustees said how can
you teach oceanography if you don't have an ocean and what am
I going to do during January, that was my other problem.
So I put those two problems together to spend January taking
groups of students down to the Virgin Islands Ecological
Research Station to study the ocean.
And in conjunction with that, I got an open water diving scuba
certification. My first free summer at Milton,
I came in contact, and I can't remember exactly how, with Har
Gobind Khorana at the Enzyme Institute.
And he was making artificial DNA to decode the genetic code.
But he wanted to know how big his molecules were, and he had
access to an analytical ultracentrifuge.
So measuring the size of molecules, analytical
ultracentrifuge, I know how to do that.
So I got hired as a summer project sort of thing but I was
able to stay on during the free time that I have during the
academic year from Milton, and this project with Khorana ended
up with a Nobel Prize being given in medicine in 1968.
I don't know how anybody figured that what we were doing was
connected with medicine but when Khorana got his prize he went
off to MIT but I stayed on here and then worked with David Green
and Henry Lardy running the analytical ultracentrifuge doing
proteins of various kinds, mitochondrial structural
proteins and botulinum toxin protein.
Well Milton College closed and I had to go get a real job.
So at that point I got employed by what was then called Raltech
which later became Hazleton. That was a contract research
laboratory doing miscellaneous research things.
But the most interesting thing I ended up doing there was
developing a series of laboratory procedures in order
to predict the environmental fade of agricultural chemicals.
They spray these things out over acres and acres of ground,
insecticides, pesticides, herbicides.
What happens to them? How are they transformed and how
are they transported and can that be predicted from
laboratory procedures. But after five years there I was
able to switch over to the Wisconsin Occupational Health
Lab which is a subdivision of the State Laboratory of Hygiene.
And my projects there, I was miscellaneous industrial hygiene
analysis. Industrial hygienists go around
to workplace environments, factories, office spaces, around
the country and mail their samples here to Madison to be
analyzed for the various kinds of pollutants that they might
have to compare with OSHA standards.
And at the end we were even getting samples from Europe and
from South America. I retired from that 2006.
So, as I look back over my career what I see is a lot of
diversity. I've had experience in a lot of
different areas and not much depth.
I was never really an expert in anything except for the
analytical ultracentrifuge and that was 40 years ago.
Okay, the talk today is going to have three distinct parts.
Part one, the structure of scientific revolutions or how is
it that new ideas become adopted by the scientific community.
As kind of a specific application of that, how the
idea of drifting continents was transformed from a very fringe
idea in science, sort of ranked along with Atlantis and maybe
ancient aliens and flying saucers to become what's now the
central core of modern geology. And then the third part, which I
hope we have plenty of time to get to, is somewhat more
speculative, the first two parts I think are pretty
straightforward recitation of history.
The third part is a lot of speculation and probably more
controversial because a lot of it is my own speculation, and so
I'll talk more about that when we get to it.
Okay, for the beginning, when I first came to Madison in 1958 I
remember the elderly faculty talking about the earlier days
when they were having such a hard time getting the concept of
ions to be accepted. The scientific community
apparently was very resistant to the idea of ions.
Now ions had first been proposed by Michael Faraday in the 1830s,
but it was really Svante Arrhenius who wrote into his
thesis in 1884 and utilized the idea of ions.
And the skepticism went from, I overheard the comment like
around here we call him Erroneous Arrhenius and does he
think that there are dog ions that chase those cat ions
around. And even in the popular press
there was skepticism about ions. Quote here from Ambrose Bierce's
Devil's Dictionary. It has an entry talking about
under molecules. Molecule: the ultimate invisible
little unit of matter. It is distinguished from the
corpuscule, which is also the ultimate invisible little unit
of matter, and by its close resemblance to the atom, also
the ultimate invisible little unit of matter.
And then it says the three great scientific theories of the
structure of the universe are the molecular and the
corpuscular and the atomic. The present trend of the
scientific thought is towards the theory of ions.
Ions differ from the molecule, the corpuscule or the atom in
that they are ions. Well, had he said in that they
are electrically charged he maybe would have been on to
something. Anyway, how did this resistance
become vanquished, how did people overcome this resistance?
Well, the theory that I heard from the faculty members was not
that the idea or data or logic changed the minds of the
skeptics, but rather that one by one the skeptics retired and
were replaced by younger faculty members that were comfortable
with the idea of ions. So I call this the generational
succession model. The alternative model which was
published in 1962, Thomas Kuhn's book called "The Structure of
Scientific Revolutions," is the paradigm shift.
And his idea or his model is there's an existing theory,
world view, structure, he called it a paradigm, and it explains
the observations in a field that had been made.
But over time more observations are made, maybe expanding the
range, new instrumentations, new experiments, whatever, and some
of the results of these new ideas don't really fit very well
with the existing paradigms. So they're referred to as
anomalies. And they're kind of accepted and
people adjust to them, but when enough anomalies begin to build
up, then people begin to question the original paradigm.
And eventually when there's sufficient number of anomalies,
think of like pressure building up along a fault line or
something, then there is a rather rapid and dramatic
paradigm shift to the new paradigm which explains all of
the old observations but also the anomalies that have occurred
since. So that's the paradigm shift.
I'll describe these as the top one A is slow, gradual uniform,
almost, build up. As opposed to the second which
corresponds to like a rapid dramatic shift.
Or you can think of it in terms of the tortoise and the hare.
I come back to this idea of distinguishing between slow
gradual versus rapid transitions a little later.
Okay, drifting continents and Alfred Wegener.
He was the first to propose the idea that the continents had
moved around. He was a meteorologist, which
probably didn't help his creditability in the geology
community, but everybody knew that the earth's structure was a
dark, dense basaltic sphere with lighter, lower density lighter
colored granitic rocks floating on top of it, sitting on top of
it. And it was a thought that there
really wasn't any force large enough to push these continents
around. So they were assumed to just be
locked in place. But there's a number of
anomalies that are associated with that.
The shape of Africa and South America, every grade school kid
when they look at the globe notices that those continents
look like they could fit together.
Geologically there's a number of places where the geology on each
side of the Atlantic looks similar.
And then of course the famous ring of fire.
The Pacific basin which has deep trenches and high mountains and
lots of earthquakes forming a very definite pattern.
So as, for example, Brazil obviously would like to fit
there, further south Argentina doesn't fit so well with South
Africa. This is just looking the coast
line. On the geological matches, you
have the Cabot Fault up here in Nova Scotia, New Brunswick area,
and over here on the other side you have the Great Glen Fault in
Scotland. And the geology of these two is
very similar. The age of the rocks, the
structure of the rocks. They kind of look like they
ought to go together except of course you got the Atlantic
ocean in between. Here is the rim of fire.
This is where earthquakes occur. And you see there is a very
definite pattern. And you have the deep trenches
of the Pacific over here, and these are like, what, seven
times as deep as the Grand Canyon and in distance running
the equivalent of New York to Kansas City.
They have mountains, they're always associated with mountains
and volcanoes and earthquakes. And likewise, over here,
trenches, mountains, volcanoes, earthquakes.
In standard geology, pre-paradigm shift, there was
really just no good explanation. That was the kind of thing
people learned to pass exams. They couldn't really offer an
explanation for why it was that way.
Then there's the tropical reef fish, and I'm going to show you
here, these are the butterfly fish of the Caribbean.
If you've done any snorkeling or scuba diving in the Caribbean,
you may recognize these fish. Four-eye butterfly fish looks
like he's trying to go the other way.
Notice the size and the shape of these fish.
They're relatively small. They all have these little
mouths. They feed off of coral and
little detritus that sticks to the rocks.
But they have a very characteristic shape and size.
The colors are all different. And the thing that's unusual,
not just about butterfly fish but about tropical fish in
general, is that from all the tropical oceans they all look
very much alike. Here would be the butterfly fish
of the Red Sea, for example. You notice the same size, shape
mouth. Same behavior patterns, the same
way they feed. But this is from an ocean that's
halfway around the world. And now can these fish just like
swim back and forth across the ocean to maintain their similar
looks? Well, no.
These guys cannot swim across large bodies of water like the
Atlantic ocean, for example, to get from the Red Sea or the
Mediterranean or over to the Caribbean.
So how did they do it? Well, marine biologists have
long speculated, and of course invoking Darwin's ideas of
evolution, that if you have a lot of species that look very
similar to each other, they like to think that there was some
sort of a common ancestor at some time in the past.
And they speculated something called the test sea.
A hypothetical worldwide tropical ocean from which the
butterfly fish, and I could have made exactly the same kind of
model for angel fish, for example, or any of the various
tropical fish. Groupers.
The similarity between the tropical fish of the various
oceans around the world is just one of those kind of
coincidences or anomalies, no explanation for it.
So, tropical fish in the test sea.
And now another anomaly was the fossils of Mesosaurus.
He's a lizard-like guy who only lived in two places in the
world. And we'll only find fossils for
him in two places: South America and Africa.
And the only way by the standard model you could get between
these two places would be to go all the way up to North America
and around across the Bering Sea and come all the way down across
Siberia and they didn't leave any fossils.
So they assume, and nobody really knew or remembered prior
to the Challenger expedition in 1872 there was very little
understanding of what the undersea world was like, what
the sea floor looks like. So they postulated that there
must be some kind of a land bridge that connects these two
because nobody had done, but as soundings began to come in
determining what the undersea looks like, nobody found any
land bridges. And the more they did soundings
and not find it, the narrower the land bridges had to become
to fit between the places where they'd done the measurements
until eventually they became so skinny that the Mesosaurus would
practically have to tight rope walk across them.
Now, as more data comes in, you get data on the fit of the
continental shelves, and instead of finding land bridges in the
Atlantic, you start finding a mountain ridge, for example.
I'll talk about those two for a moment.
If instead of plotting the shore line, which is the lighter line
here, you plot the edge of the continental shelf, which is the
depth of about 900 meters, the continents, a lot of what's
under water appears to part of the ocean is not very deep, it's
just the continental shelf. It's continental rock, gritty
type rock, not the basaltic sea floor type of rock.
This just happens to be flooded because the sea level is sort of
high now, but if the sea level dropped a little bit, you'd
begin to see what the continents actually looked like and the fit
here becomes almost incredibly close to be a coincidence.
You see where it's overlapped or there's a gap, but if you use
the edge of the continental shelf rather than the water
line, the fit of the continents is pretty hard to pass off as
just coincidence as it had been before.
And instead of finding these land bridges, you find an
mountain range that splits, almost winds around between the
two continents on this side and something similar over in the
Pacific. Finally we come to the last,
the anomalies are starting to become too big to ignore but
still the idea of drifting continents was still held up by
the idea of what force could be strong enough to push the
continents around. Well, when they begin to climb
mountains and find that there were marine fossils up in the
mountains, and in fact there are marine fossils on the tops of
the highest mountain, you have to have some kind of explanation
for that. Of course way back before the
1800s the explanation for the shape of the land was a single
cataclysmic event. A great worldwide flood of,
shall we say, biblical proportions that was responsible
for shaping the land. And of course that would give an
explanation for why you might marine fossils on the tops of
mountains. But in the mean time the
geologists were promoting the idea of uniformitarianism.
There's gradual changes taking place over eons of time rather
than single catastrophic or cataclysmic events.
So they came up with something called the geosyncline theory.
Now, at this point I'll introduce my connection to this
story. When I started teaching down in
Milton it was to teach chemistry but very soon, the first couple
of years, the word that was that the professor who was teaching
geology was going to retire. And so the dean said would I be
interested in teaching geology, and I said sure, the only
problem is I don't know anything about it.
But other than that, yeah, I'll be glad to teach it.
But they were going to teach it one more time before the other
guy was going to teach one more time before he retired.
So I thought I'll sit in on his class.
And as it turned out, Milton college had been in business for
over 100 years, but this was the last time that geology was
taught under the old paradigm and the next year when I taught
it was the first time it was taught in the new paradigm.
I was right there at the paradigm shift, straddling it so
to speak. So I sat in on the class and
very much of it was perfectly appropriate no matter what.
They had a lot of nice field trips in the Milton area because
it's right at the edge of the glacier.
So I could go and find out where the drumlins and the kettles and
the eskers were. We had a field trip to Parfrey's
Glen which is a fantastic place to take a geology field trip.
And of course we had a lot of lab stuff, looking through thin
sections of rocks with microscopes and polarized light
and identifying lots of minerals and things.
But when we got to the part about the marine fossils on the
tops of the mountains I heard an explanation of this geosyncline
theory and it just didn't sound very plausible to me.
I was pondering over that when one of the students in one of my
other classes said, Dr. Blair, I hear you're going to be teaching
geology next year. And I said, yeah, are you going
to take it? And he said, no I already took
it last year at, it was Cornell or some prestigious school.
He was a transfer student. And I said, oh, good, tell me
why there are marine fossils on the tops of mountains.
And he went through exactly the same geosyncline theory that I
heard in the class at Milton so I figured that's got to be the
story then because if you get to from somebody who learned it at
a prestigious school like Cornell it's not like Milton is
out of the loop here. And the explanation is basically
just that the sea floor is concave, that's the geosyncline,
there's concave area that's an ocean, and the marine creatures
die and leave fossils on the bottom, and then it pops up and
becomes a mountain. And I said why does it become a
mountain? And they said well, nobody
knows. Maybe it's because the earth is
shrinking and causes it to come up.
And I said the sea floor is generally basalt and how come
the mountains are mostly granite?
Anyway that was the theory and it just didn't seem to fit very
well with anything else. There's a very good film that I
showed and that I saw in the class called Time Changes the
Land. It must have been made in the
early 1960s right before this paradigm shift, and it's really
an excellent film, but it incorporates the whole idea of
uniformitarianism. Uniformitarianism is sometimes
explained as the present is the key to the past or to find out
how things happened in the past, look at what's happening today
in the world. So this movie is presumably
showing what happened over millions of years in some area
of the US west, not too far from the Grand Canyon because a lot
of the layers in the Grand Canyon were used to explain.
So they'd say at one time it was a shallow sea.
But then they went to the Bahamas to film a shallow sea.
And then at a later time it was desert dunes.
So they went to the Sahara Desert to film dunes.
They put those together. That's uniformitarianism.
It's to know how things were in the past, you'd look around to
see how things are today and assume that in the past these
places are like they are today. And they could assume in this
movie that practically everything about this piece of
geography, this piece of real estate, has changed.
It's been sea floor and it's been desert and it's before
forests. About the only thing that can't
change is the latitude and the longitude.
But everything else has been subject to change.
But then the movie ends up by talking about what to predict
from the age of the sea floor because it's well known that the
rocks on land get pushed up and pushed down and eroded and
become sedimentary rocks. So the earth was known to be
like four and a half billion years old but the rocks on the
land, and particularly in and around the Grand Canyon, weren't
nearly that old. In fact the rocks at the bottom
of the Grand Canyon are only about two billion years old,
roughly half the age of the earth.
In fact, the story is that when an ranger in the Grand Canyon
Park is explaining that the rocks at the bottom of the Grand
Canyon are only two billion years old, one of the tourists
sticks up his hand and says actually they're two billion and
forty-two years old. And the ranger says, two billion
and forty-two, how do you know that?
He said, well, 42 years ago I came out here to the Grand
Canyon and the ranger said that the rocks were two billion years
old then. I thought this was appropriate
here. This is usually the story I tell
when we're introducing the idea of significant figures, but it
seemed to fit here too. Okay, the movie ends up by
saying when we drill down through the sediments on the sea
floor, which really hadn't been done yet, we would expect to
find the oldest rocks on earth because the sea floor is that
basaltic dense thing that the continents are sitting on top
of. The continents are doing their
churning but the sea floor presumably is not being affected
by this. So we should expect to find the
oldest rocks, four billion years or whenever the earth first
solidified, oldest rocks on the sea floor.
When they started drilling through and finding the rocks on
the sea floor, what they found was of course exactly the
opposite. The rocks on the sea floor are
younger than any other rocks. The oldest rocks on the sea
floor are only about 200 million years which sounds old unless
you're a geologist and you realize that that's only roughly
five percent of the age of the earth.
And furthermore, the oldest sea floor rocks are up near the edge
of the continent and the youngest ones, as you go towards
this mid-ocean ridge, the rocks get progressively younger.
Now this should have been enough of a tip off to make them think
that something was happening here.
But no. Before we get to the final blow
to the conventional static continents model, I have to tell
you about what the poles do. The earth has four poles, as you
probably know. North and south, east and west?
No, no. There's magnetic north and true
north, and then there's magnetic south and true south.
True north is sometimes called geologic north or geographic
north. It's the spin axis.
The axis the earth rotates around, that's true north.
If you laid on your back on true north all year round, you'd see
the same star above of all the time, the north star, Polaris,
doing a very, very tight little circle, probably hardly
measurable. Or in Antarctica if you laid on
your back year round, you'd see the center of the southern cross
year round. The earth rotates around that
axis. But magnetic north is the
compasses point. And when I was in high school or
somewhere, one theory was the compasses point north because
there's a big load of iron ore up there that's magnetic and
attracts them. It wasn't clear exactly why
compasses point north, they don't exactly point north
because true north and magnetic north are not exactly aligned.
And the maps, boy scouts, when they learn to read maps with
compasses, there's a correction factor on the map that corrects
between true and magnetic north. But, with time the poles do two
things. On a long time scale, how do you
know what the poles are doing anyway?
Well, when lava, when there's a volcanic eruption and lava flows
out, little particles of magnetic iron materials orient
with the earth's magnetic field because it's a liquid and they
line up the same way compasses point north.
So when there's a recent volcanic eruption, those little
needles are all pointing towards magnetic north.
If you turn the clock back a long time, in this case 500
million years, over that time as seen from North America, the
north pole appears to have wandered very slowly over
millions of years out to some place down by the equator over
there in the middle of the Pacific ocean, near the eastern
edge of the Pacific ocean. And so it was taught in the
class that I was going to at Milton about how the north pole
500 million years ago was down by the equator in the Pacific
ocean. I was a little disappointed none
of the students raised the question did the magnetic north
pole left the true north pole and wandered out here or did
both poles move out into the Pacific ocean?
The assumption seemed to be that it was both poles, that the
earth's spin axis was also aligned with the magnetic pole
but nobody really, we had really no direct data on that.
The story gets worse because when geologists in Europe and
Siberia started doing the same kinds of studies, orienting
where the north pole was, they were getting a different answer.
They had the north pole, as seen from Europe 500 million years
ago, over here. So you have the north pole in
two different places 500 million years ago depending upon whether
you're living in North America or Europe.
And by golly, even that didn't seem to be enough to destroy the
paradigm of the fixed continents because there was still the
problem of overcoming the question of what can push the
continents around. Well the other thing that the
pole does is it flips. When I said the north pole moved
out there what I mean is a pole moved out.
Sometimes north, sometimes south.
The movement of the pole that I was showing is a very, very slow
kind of thing. This is, from a geologic
standpoint, very rapid. Black means the north pole
magnetic aligned the way it is right now, and white means the
compasses, instead of pointing north, would be pointing exactly
south. The tail end of the compass
would be pointing north. And you'll see very sharp bands.
They're not gray. There is no measurements on any
of the lava flows where the pole was pointing anywhere other than
directly either north or south. This is all very modern type of
thing before the poles have wandered down to the equator.
Very relatively frequent, very rapid flips.
The poles are sort of bi-stable. They have two stable positions
that they flip flop back and forth between, sometimes
spending a long time with one orientation and sometimes a
rather short time and not very predictable.
And last thing on this graph to point out is this is the
Cretaceous, this is 65 million years ago.
And this is the boundary between, it's usually called the
K-T boundary because this whole set of epics was called the
Tertiary. So K for Cretaceous, T for
Tertiary, the K-T boundary. Very important boundary in
geology and I'll have more to say about it later.
More recently people have been trying to rename it is the
Cretaceous-Paleocene boundary. Instead of K-T it then becomes
K-P something. If it's been the K-T boundary
for 65 million years, I don't know why they want to change it
now. But anyway, you sometimes see it
expressed the other way. I'll have more to say about this
boundary in the last section. Finally the thing that did in
the existing geological paradigm was these pole flips because
looking as they developed kind of a magnetic device that they
could drag from a ship just along above the surface along
the bottom of the ocean and measured the magnetization
orientation of the iron inside that lava.
And what they found was a symmetrical pattern.
This is the current orientation for these lavas on either side
of this is the mid-ocean ridge, that mountain range we saw, but
then reverse polarization, reverse flip, equally spaced, or
almost exactly equally spaced, either side of the rift.
And notice the patterns are just symmetrical on either side of
the rift. Now this was just too much to
accept as coincidence. Finally it comes through that
this paradigm of fixed continents just can't be true.
There was still the question of what can push it though.
There were papers written in Scientific American in the early
1960s, some people say that it's the lava squirting up here that
pushes this. That didn't seem very
reasonable. It's like trying to push a rug
across the room by trying to push one end of it.
It wouldn't happen. It would crumple.
Another paper said it's the weight of the sediments.
You have all these sediments down here that are weighting it
down and they're pulling on it, and even if you combine pulling
on this end from the sediment weight and pushing on this end
with the lava extrusion you still don't get a very likely
picture of what can be happening.
But if you accept the idea of this moving it does explain a
lot of the things that we saw before.
Why are there marine sediments up in mountains?
Well because this was the sediment and as the plate moved
it got pushed up and made a mountain.
Why are there volcanoes next to deep trenches?
There's a deep trench, there's mountains and volcanoes.
But what can power it? Well, of course, this is a
fluid, this is a melted fluid. It's very hot.
Roughly the temperature of the surface of the sun.
You can see that when volcanic lava is exposed it's roughly the
same color, bright orange yellowy, almost like the sun
which means it's pretty much the same temperature of the sun.
But it circulates because heat is being lost here as it comes
in contact with the cold ocean water.
So if heat's being lost and heat's being generated down
here, you'd expect the fluid to flow.
And so the model that you have now is the continents are not
exactly being pushed through the basaltic lithosphere, it's like
a conveyor belt, they're riding on it.
The whole system is being powered, well what generates all
the heat down here of course is radio activity.
You have a lot of uranium in the earth and thorium and
radioactive decay of isotopes like that.
They generate heat. So basically the thing that
powers the movement of the continents is atomic energy.
We got nuclear powered continents moving.
And once this became accepted, the final comment on it is in
the context of the current global warming CO2 thing, I was
just reading somebody who was saying you can't believe what
those scientists say because when I was in college and I took
geology they told me the continents were fixed and can't
move. Now the scientists are saying
the continents are moving around all over the place.
Those scientists don't stick to their story.
They're a bunch of flip floppers.
You can't believe what they say.
If I reconstruct, accepting now that continents are moving
around and I reconstruct where they were 180 million years ago,
sure enough there was a worldwide tropical sea for all
of the ancient ancestors of the butterfly fish and the angel
fish and all to have been living here and as the continents get
separated they separate from each other then they diversify
into the closely related similar kinds of species that we see
right now. Okay, part three.
Dialectics. Friedrich Engels proposed this
idea of dialectics which was if you have two conflicting things,
a thesis and an antithesis, that somehow they can be reunited
into a synthesis. Engels, if you're not familiar
with the name, is usually associated with Marx.
Marx and Engels are like Laurel and Hardy or something.
Names that go together. And dialectics was usually named
in the context of dialectical materials.
And Engels was really talking more about the social classes or
something but I'm applying it here, too.
We have the original idea of geology, we'll just look at the
top part of it here. This is the geology part.
Originally it was a single cataclysmic event that shaped
the land, the great flood. That was replaced by
uniformitarianism, gradual change over eons of time.
Time changes the land. Gradually, more or less uniform
and continuously. But cataclysmic events got
revitalized with the recognition that at this K-T boundary
65 million years ago there was in fact a large catastrophic
event, an asteroid collision. And I was going to go into an
explanation of all the evidence that supports that but I
realized that would be a whole other lecture.
So I have to say that it was quickly accepted by the
scientific community that in fact there had been an asteroid
impact. The first skeptical response to
it was, gee it's too much of a coincidence to believe that an
asteroid would just happen to hit at the transition point
between two geological epics. Until you realize that you're
thinking about it exactly backwards.
The asteroid didn't just happen to hit at this transition, the
asteroid caused the transition between the two epics.
When I first begin, this was in the 1980s, they first
popularized the idea of dinosaurs being wiped out.
The Cretaceous was the age of the dinosaurs, and the one above
it is the age when mammals first appeared.
When they first begin to accept the idea that dinosaurs were
basically wiped out by an asteroid, there was a very
interesting little cartoon thing on one of the late night talk
shows, or maybe it was "Saturday Night Live," of Barney the
dinosaur singing his little song, I love you and you love me
or whatever it is, and then a big rock comes and hits him on
the head. And that's how the dinosaurs
were wiped out by an asteroid. When I first heard that
I thought that's too dramatic. I was programmed to think
uniformitarianism. The asteroid probably kicked up
a lot of dust which would cool the earth and then the dinosaurs
would have a harder time adjusting to the cooler climate
and it would slowly, over eons of time, lose out in competition
to the mammals that were warm blooded.
No, no, no. Barney getting bonked on the
head was probably the closer model, because as they found a
crater for the asteroid impact in the Caribbean not too far off
of Yucatan, it's a rather large crater and that is a very large
asteroid. So people starting figuring how
much energy is a large asteroid going to impart to the earth.
And it turns out it's a lot. And in fact when the asteroid
hit, it presumably kicked up lots of debris that then
re-entered all around the world as meteor showers, and all of
these are generating heat. And their calculations indicated
that there was enough heat being generated as a result of the
asteroid impact to raise the surface temperature of the earth
up to around a thousand degrees for a short period of time.
Now that's blast furnace temperature.
Like putting the earth in a blast furnace for a period of
weeks maybe, days, hours at least.
And of course the dinosaurs lived on the surface.
So it's very likely that all of the dinosaurs on earth were dead
within a few hours of that asteroid impact.
And of course the vegetation would burn off.
They did a test by going to San Antonio and using a blast
furnace to put in the kind of soil, the kind of plants, the
kind of things that they thought existed at the time and of
course the plants were all burned off.
Do you have a question? No? Okay.
So presumably the dinosaurs were literally wiped out in one
catastrophic, catastrophic for them, it actually turned out to
be good for us, catastrophic event.
How did the little mammals, mammals at that time were little
burrowing things like shrews and mice and such, how could they
have survived? Well, one of the things that
they found from the San Antonio experiment is if you're very far
under the surface of the earth, even a few inches, you could
probably survive it. The heat didn't last that long.
It didn't penetrate soil. Soil is fairly temperature
resistant. Burrowing animals could probably
survive. Well when they came out what are
they going to eat? Well they got lots of roasted
dinosaur meat around all over the place.
They were omnivores. They could come out and feast on
roasted dinosaur until such a time as the plants would
recover. How long does a take plants to
recover from a massive worldwide fire?
Not very long. Actually plants, as you know
from the say the forest fire in Yellowstone Park a few years
ago, the plants snap back fairly quickly.
A lot of the prairie grasses have deep roots, and they'll
come right back the next year. The cooling effect right after
the asteroid impact, the dust, you go from a thousand degrees
Fahrenheit blast furnace temperatures down to around
freezing temperatures for a while, well that just preserves
the dinosaur meat for the little mammals until the grass can grow
back. Presumably that's how they
survived. And that was now the accepted
idea that this is bringing back the idea of cataclysmic events.
Well, go back one, do I have anything else to say about this?
Notice the scale here looks quite different than the first
one I showed you, and this is because this is scaling it in a
linear fashion. This is like the four and a half
billion year age of the earth and this is proportionately, you
see the asteroid impact is right here, that's pretty modern times
compared to the age of the earth because sometimes people would
get the idea of an asteroid used to hit the earth a long time ago
when it was first forming and when they hit the moon and
things and it doesn't happen anymore.
Well, looking on this scale, a mere 65 million years ago for a
major asteroid impact, that's actually relatively recent.
If it's happened fairly recently, maybe it will be
happening again sometime soon. Something to worry, if you
didn't have enough things to worry about.
Now, the last section-- >> How many other times did
it happen? >> Well prior to that I don't
think anybody really knows. A mere 65 million years ago the
crater was still detectable. Of course we have little meteor
impacts all the time like the one out in Arizona.
But I'm talking about a really catastrophic one.
Presumably none since. There was the big one in Siberia
in 1908 that knocked down a few trees and maybe killed a few
people and cows, but fortunately it didn't hit over a major city.
So I'm talking the kind of really worldwide catastrophic
events apparently don't happen, may have happened a lot back
here but not in the last 65 million years but maybe
we're due for another one. Now, jump down to, this has
revived the idea of cataclysmic events.
This was clearly a cataclysmic event.
This trumps a worldwide flood. So this is sort of like maybe
when old theories die sometimes they come back like zombies and
have a second life. So we have uniformitarianism and
cataclysmic events, both acting, apparently now, so you put them
both together like Engels wanted to do and you say maybe you have
both. Let's call it punctuated
equilibrium. The time changes the land,
there's gradual transitions over long epics of time but every so
often there is a cataclysmic event that's superimposed upon
that long uniformitarian change. Now we come to the last part,
and I'm going to apply this same dialectic idea to evolution and
creationism. Now of course originally
creationism was the theory. God created the world and then
he created all the animals on the fourth or fifth day.
And each individual species was created independently and out of
nothingness, so to speak. When I grew up, I was in Kansas
City in the 1950s, although I didn't actually take a high
school biology class, I picked up my ideas from evolution, I'm
not sure where, but I came away with a complete misconception of
what evolution was all about. I thought that it was like this
uniformitarianism thing. Gradual change over eons of
time. Animals were selected out to fit
into their environment and this adaptation took place slowly,
gradually. And the evidence that was given
for this, the examples that were given to me seemed to make
sense. One of them was the moths in
England. Maybe you've heard this story.
Back before the Industrial Revolution the moths in England
were white, mostly. A black moth would stand out
against the pristine environment and get eaten by birds.
With the Industrial Revolution and a lot of soot being put into
the air, the environment turned black and all the sudden being
black if you're a moth became an advantage.
So the population of moths shifted and you saw mostly black
moths, and the white moths were the ones that were getting
eaten. Then in the 1980s when Margaret
Thatcher took England off a coal-based economy and
transformed it over to an oil-based economy, not so much
because she was an environmentalist who wanted to
clean up the environment they would say but because she wanted
to break the coal miners union, but for whatever reason the
effect was to transform England back to this pristine days when
white moths had the advantage because the environment was much
cleaner, black moths stood out. And this was given as an example
of evolution. Also, antibiotic resistant
bacteria like tuberculosis that are immune to penicillin.
If penicillin is around, the ones that are immune to it
survive. And this is example of
evolution. And then there's the story of
the horses. Back a few million years ago
horses were primarily little dog-sized animals.
And then, and I had this wrong image, over the years the bigger
horses were better adapted to the environment, maybe because
they could outrun saber tooth tigers or whatever.
So the bigger horses survived and their offspring were bigger
yet and over the years horses got bigger and bigger until they
looked like the modern horse. I thought this right up until I
heard a lecture by Stephen Jay Gould in the 1980s over in the
Memorial Union's auditorium there.
And he set me straight. Looking at the fossil records,
it's more like creationism really.
A species appears suddenly in the fossils.
It's never been there before. It appears.
It exists in the fossil for umpteen million years,
10 million, five million, however long, and then it goes
extinct and it's not there anymore.
And a new species appears. The new species just sort of
appear. And I thought my God that's
creationism. You don't dare call it that for
political correctness reasons. And these horses, these horses
are not the children of those horses.
These are separate species that each one of which just appears
in the fossil records and some of them overlap during their
time. They coexisted at the same time.
So how do we get gradual changes, mutations occur pretty
much in a gradual kind of thing, one base pair at a time being
substituted for another one, how do we get slow, gradual
change giving rise to rapid, what I would call cataclysmic
transitions like from one species to another?
Well, here is just to show a few animals.
How do you tell one species from another anyway?
Well if they're around and you can look at them and say a horse
looks different from a cow, that's how you can tell the
difference. But that's not necessarily a
very good guide when you think about it.
This guy, you might say he's a kangaroo.
No he's not, actually, he's a wallaby.
It's a separate species. He looks like a kangaroo, but if
you just go by looks you can be deceived.
And this guy, he looks like a llama, doesn't he?
Well he looks like a llama but he's not.
He's an alpaca. Just because two things look
alike doesn't necessarily mean they are.
On the other hand, you take things like dogs.
You've got a Pekingese and a Chihuahua and you've got
a Great Dane and a St. Bernard, they don't look very
much alike. I think anybody who wasn't
familiar with dogs and didn't know anything about them would
not necessarily recognize a Great Dane as being the same
species as being a Pekingese. They look more different than an
alpaca and a llama to me. Or to take the example of
elephants. Say I went to the zoo and I saw
an elephant. And I say, what kind of an
elephant was it? And a lot of people will give a
blank stare to that. They don't seem to recognize
that there are two distinctly species of elephants.
And just off hand, if you walked out on the street today and you
saw an elephant, would you recognize it as being African or
Indian? How many people would know the
difference if they saw them? Just a couple.
I guess I would have expected a little more than that.
When I see the GOP icon symbol on television, that's not clear
that they understand the difference, it's usually kind of
a generic elephant. It isn't clearly identifiable as
African or Asian. >> They don't believe in
evolution. >> Yeah, maybe.
So anyway elephants, two distinctly different species
that look enough alike apparently that a lot of people
don't even notice that there are two different species.
If you know what to look for, it's pretty obvious to tell them
apart. But looking at an alpaca and a
llama, since I'm not very familiar with either of those,
what I'll say is alpacas and llamas both live in South
America, and wallabies and kangaroos both come from
Australia. So animals, different species do
tend to look like the species that are around them but yet
they're different. So how do we get over this
transition? Well, lately a lot of
information has been learned about the genome.
So I'll go back, this is my schematic diagram of a genome,
and I'll comment that decoding the human genome was really a
big project. It was like going to the moon,
or the Manhattan Project or something.
It took 10 years. It was actually projected to
take 15 years; it only took 10. It cost $3 billion.
Now just two months ago in September, I looked up a mammal
of that size can have its genome determined today in two weeks at
a cost of $50,000. So we've gone from a 10 year
$2 billion project to a two week $50,000 project.
And one of the things we've learned about the genome, and
what's the genome? Well it's the genes.
One of the surprising things was that most of the genome is not
genes. And by gene I mean the sequence
of bases that codes for the production of a particular
protein. Only somewhere around 2% to 4%
of the genome is actually genes, and the other 98% to 96% was
dismissed as junk DNA. And people were saying, gee, why
would we invest so much of our genetic material into junk that
doesn't do anything? Well, it turns out this junk
isn't really junk after all. First of all, there's the genes.
This is my symbol for a gene. This would be a sequence of base
pairs in the DNA that codes for the production of a protein.
But these genes get switched on and off.
And there are sequences within the genome that simply serve to
switch genes off and on. And of course you realize there
have to be switches because the same enzymes that you need at
different times of development are different.
You need something but then you don't want it anymore.
Something has to turn that gene off.
Take, for example, when people lived in Africa having dark skin
was of no disadvantage, it probably gave you an advantage.
When people moved into northern Europe, however, dark skin
became a disadvantage because vitamin D deficiency becomes a
problem. You're not getting enough
sunlight and you want light skin so you get more vitamin D.
So people made the transition from dark skin to light skin,
the people who moved into northern Europe, by turning off
some of the genes that make melanin, the skin color.
Now, like our black and white moths, white skin and black skin
were the same species. Some racist opinions to the
contrary, it's not a different species just because you switch
some of these genes on and off. Or take lactose tolerance or
lactose intolerance. When we had a big famine in
Africa and they sent them powdered milk which sounded like
a good idea, they didn't realize that a lot of the people in
Africa do not metabolize lactose.
And the word I heard was they don't have the gene metabolize
lactose. Well, wait a minute, that's not
true. Everybody when they're an infant
can metabolize lactose or they wouldn't survive.
They eat their mother's milk. So what happens is that that
gene to metabolize lactose, to make lactase and to metabolize
lactose gets switched off. If you don't have a culture that
has access to milk from a domesticated animal, that's no
big deal. Cultures that have domesticated
animals that produce milk, they preserve the ability to
metabolize lactose into adulthood because they have that
as a milk source, as a food source for them.
So people who domesticate cattle or goats or yaks or whatever
maintain the ability to metabolize lactose, but people
who for thousands of years of culture are hunter/gatherers and
don't have domesticated sources of milk, they lose the ability
when they're infants. Now, in addition there seems to
be control areas, I won't call these genes, there seems to be
control areas that switch off whole sets of genes.
With a small change down here in the control, maybe a few base
pairs or even a single deletion, it sort of shifts all the ones
downstream, all the base pairings downstream of it so it
can have a significant impact. A single change down here might
trigger to activate or deactivate whole families of
genes. One of the things that came out
of, if you remember the talk that was given here a couple of
weeks ago by Andrea Gargas, was that her name?
Yeah, she had a slide that showed a close connection
between whales and hippos. Closely connected genetically.
When they went into the whale genome and they deciphered the
whale genome, one of the things they found is that a whale has
all of the genes necessary to grow hind legs but they're
switched off. The control mechanism got
switched off. They don't grow hind legs but
they could. They even have the bone
structure to support it. But those genes got turned off.
So how is it you can go from a small gradual change in the
genome, base pair or two here or there, to create a new species?
So I'll end up by telling you the story of Willie the happy
hippo. This is pure speculation but if
it happened it happened 50 million years ago when you have
a group of hippos, a colony I guess you'd call them or herd,
let's call them a herd of hippos.
Not exactly hippos like we have today but you'd recognize them
as hippos. Live partly in the land, partly
in the water but largely in the water.
And little Willie is born with a defective, maybe his father got
hit by a cosmic ray and it turned off that control
mechanism for hind legs or something.
But he's born as a little deformed hippo.
He doesn't have any hind legs. He's like the swan, the ugly
duckling. The other hippos kind of
ridicule him and he doesn't have hind legs.
But he discovered that he doesn't really need hind legs
because he can swim pretty well. He learned a new swimming
technique of wiggling his body. He finds that the legs would
just drag through the water and slow him down.
He can actually swim faster without legs to slow him down.
So he can go out and eat lots of food, maybe start catching more
fish and getting lots of protein.
He grows up to be a big, strong hippo even though he's deformed
with no hind legs. And in fact he's kind of like an
athlete in the hippo society. He'd be like we'd view an
athlete. Let's call him the Tiger Woods
of hippos. And you can see where this is
going. And the lady hippos are really
impressed by his abilities. He's big and strong and he can
move around fast. So he fathers lots of children.
This is not a gene now but let's say that the control mechanism
is passed on to the offspring as though it was a dominate gene.
That all of his children are born with the same deformity
that he had. And they can swim fast and move
around. And they grow up to big and
strong. And they go back and to the
hippo colony and all the lady hippos are interested in all of
his sons, and his daughters are also big and strong and the male
hippos are attracted to them too.
So you have now within the hippo community those without hind
legs and those with hind legs. But pretty soon the ones that
don't have the hind legs and can swim better, they forage out
further and further into the ocean to get their food supply,
and pretty soon they don't bother to come back to the hippo
colony on land anymore. And there's plenty of them now
and so they mate with each other.
And 50 million years later, make it 50,000,035 years later,
a paleontologist going through the shales thumbs across the
fossilized remains of our Willie.
And he says, I've discovered a new species.
It doesn't have hind legs. It doesn't look like a hippo.
Going by what things look like, he thinks it's a new species.
And after that in time there's lots of fossils that look like
Willie, all his descendants, but we've made the transition of
slow gradual changes to the quantum leap of a new species.
And of course other changes take places later that made them
unable to interbreed anymore and that's how the new species got
there, at least that's my speculation as to how slow
gradual changes can lead to quantum, catastrophic if you
want, cataclysmic leaps. The end.
[APPLAUSE]