Wisconsin Public Television University Place Chaos and Complex Systems Seminar  Jim Blair, "How Drifting Continents Jumped from Fringe to Core"  November 23, 2010 UP528     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]