Narrator: Listen to part of a lecture in a sociology class.

Professor: Have you ever heard the one about alligators living in New York sewers? The story goes like this: a family went on vacation in Florida and bought a couple of baby alligators as presents for their children. Then returned from vacation to New York, bringing the alligators home with them as pets. But the alligators would escape and find their way into the New York sewer system where they started reproducing, grew to huge sizes and now strike fear into sewer workers.

Have you heard this story? Well, it isn’t true and it never happened. But despite that, the story has been around since the 1930s. Or how about the song ‘twinkle, twinkle little star’, you know, ‘twinkle, twinkle, little star, how I wonder what you are’. Well we’ve all heard this song.

Where am I going with this? Well, both the song and the story are examples of memes. And that’s what we would talk about, the theory of memes. A meme is defined as a piece of information copied from person to person. By this definition, most of what you know, ideas, skills, stories, songs are memes. All the words you know, all the scientific theories you’ve learned, the rules your parents taught you to observe, all are memes that have been passed on from person to person. So what? You may say. Passing on ideas from one person to another is nothing new. Well, the whole point of defining this familiar process as transmission of memes is so that we can explore its analogy with the transmission of genes.

As you know, all living organisms pass on biological information through the genes.

What’s a gene? A gene is a piece of biological information that gets copied or replicated, and the copy or replica is passed on to the new generation. So genes are defined as replicators. Genes are replicators that pass on information about properties and characteristics of organisms. By analogy, memes also get replicated and in the process pass on culture information from person to person, generation to generation. So memes are also replicators.

To be a successful replicator, there are three key characteristics: longevity, fecundity and fidelity. Let’s take a closer look. First, longevity. A replicator must exist long enough to be able to get copied, and transfer its information. Clearly, the longer a replicator survives, the better its chances of getting its message copied and passed on. So longevity is a key characteristic of a replicator. If you take the alligator story, it can exist for a long time in individual memory, let’s say, my memory. I can tell you the story now or ten years from now, the same with the twinkle, twinkle song. So these memes have longevity because they are memorable for one reason or another.

Next, fecundity. Fecundity is the ability to reproduce in large numbers. For example, the common housefly reproduces by laying several thousand eggs, so each fly gene gets copied thousands of times. Memes, well, they can be reproduced in large numbers as well. How many times have you sung the ‘twinkle, twinkle song’ to someone? Each time you replicated that song, and maybe passed it along

to someone who did not know it yet, a small child maybe.

And finally, fidelity. Fidelity means accuracy of the copying process. We know fidelity is an essential principle of genetic transmission. If a copy of a gene is a bit different from the original, that’s called a genetic mutation. And mutations are usually bad news. An organism often cannot survive with a mutated gene. And so a gene usually cannot be passed on, unless it’s an exact copy.

For memes however, fidelity is not always so important. For example, if you tell someone the alligator story I told you today, it probably won’t be word for word exactly as I said it. Still, it will be basically the same story, and the person who hears the story will be able to pass it along. Other memes are replicated with higher fidelity though, like the twinkle, twinkle song. It had the exact same words 20 years ago as it does now. Well, that’s because we see songs as something that has to be performed accurately each time. If you change a word, the others will usually bring you in line. They’ll say, ‘that’s not how you sing it’, right?

So, you can see how looking at pieces of cultural information as replicators, as memes, and analyzing them in terms of longevity, fecundity and fidelity, we can gain some inside about how they spread, persist or change.

Narrator: Listen to part of a lecture in an Astronomy Class.

Professor: Last week, we covered some arguments against going back to the Moon. But there are compelling reasons in favor of another Moon landing too, um… not the least of which is trying to pinpoint the moon’s age.

We could do this in theory by studying an enormous impact crater, known as the South Pole- Aitken Basin. Um…it’s located in the moon’s South Polar Region. But, since it’s on the far side of the moon, it can only be seen from space. Here is an image of…we’ll call it the SPA Basin. This color-coated image of the SPA Basin, those aren’t its actual colors obviously, this image is from the mid 90s, from the American spacecraft called Clementine. Um… unlike earlier lunar missions, Clementine didn’t orbit only around the moon’s equator. Its orbits enable it to send back data to create this topographical map of … well, the grey and white area towards the bottom is the South Pole, the purples and blues in the middle correspond to low elevations – the SPA Basin itself, the oranges and reds around it are higher elevations.

The basin measures an amazing 2,500 km in diameter, and its average depth is 12 km. That makes it the biggest known crater in our solar system and it may well be the oldest. You know planetary researchers love studying deep craters until learn about the impacts that created them, how they redistributed pieces of a planet’s crust and in this case, we especially want to know if any of the mantle, the layer beneath the crust, was exposed by the impact. Not everyone agrees, but some experts are convinced that whatever created the SPA Basin did penetrate the Moon’s mantle. And we need to find out, because much more than the crust, the mantle contains information about a planet’s or Moon’s total composition. And that’s key to understanding planet formation. Um… Dian?

Dian: So, the only way to know the basin’s age is to study its rocks directly?

Professor: Well, from radio survey data, we know that the basin contains lots of smaller craters. So it must be really old, about 4 billion years, give or take a few hundred million years. But that’s not very precise. If we had rock samples to study, we’d know whether the small craters were formed by impacts during the final stages of planetary formation, or if they resulted from later meteor showers.

Dian: But if we know around how old the Basin is, I’m not sure that’s reason enough to go to the Moon again.

Professor: No…, but such crude estimates…um…we can do better than that. Besides, there are other things worth investigating, like is there water ice on the moon? Clementine’s data indicated that the wall of the south-polar crater was more reflective than expected. So some experts think there’s probably ice there. Also, data from a later mission indicates significant concentrations of hydrogen and by inference water less than a meter underground at both poles.

Student: Well if there’s water, how did it get there? Underground rivers?

Professor: We think meteors that crashed into the moon or tails of passing comets may have introduced water molecules. Any water molecules that found their way to the floors of craters near the moon’s poles, that water would be perpetually frozen, because the floors of those craters are always in shadow. Um…furthermore, if the water ice was mixed in with rock and dust, it would be protected from evaporation.

Dian: So are you saying there might be primitive life on the moon?

Professor: that’s not my point at all. Um… o.k., say there is water ice on the moon. That would be a very practical value for a future moon base for astronauts. Water ice could be melted and purified for drinking. It could also be broken down into its component parts – oxygen and hydrogen. Oxygen could be used to breathe, and hydrogen could be turned into fuel, rocket fuel. So water ice could enable the creation of a self-sustaining moon base someday, a mining camp perhaps or a departure point for further space exploration.

Student: But holding tons of equipment to the moon to make fuel and build a life support system for a moon base, wouldn’t that be too expensive?

Professor: Permanent base, maybe a ways off, but we shouldn’t have to wait for that. The dust at the bottom of the SPA Basin really does have a fascinating story to tell. I wouldn’t give for a few samples of it.

Narrator: Listen to a conversation between a student and a professor.

Student: Hi, I was wondering if I could talk with you about the assignment in the film theory class.

Professor: Of course, Jill.

Student: It seems that pretty much everyone else in the class gets what they are supposed to be doing but I’m not so sure.

Professor: Well, the class is for students who are really serious about film. You must have taken film courses before.

Student: Yeah, in high school, film appreciation.

Professor: Um…I wouldn’t think that would be enough. Did you concentrate mainly on form or content?

Student: Oh, definitely content. We’d watch, say Lord of the Flies, and then discuss it.

Professor: Oh, that approach, treating film as literature, ignoring what makes it unique.

Student: I liked it, though.

Professor: Sure, but that kind of class. Well, I’m not surprised that you are feeling a little lost. You know, we have two introductory courses that are supposed to be taken before you get to my course, one in film art, techniques, technical stuff and another in film history. So students in the class you are in should be pretty far along in film studies. In fact, usually the system blocks anyone trying to sign up for a class they shouldn’t be taking. Ur who hasn’t taken the courses you are required to do first as prerequisites.

Student: Well, I did have a problem with that but I discussed it with one of your office staff, and she gave me permission.

Professor: Of course. No matter how many times I tell them, they just keep on… Well, for your own good, I’d really suggest dropping back and starting at the usual place.

Student: Yes. But I’ve already been in this class for 4 weeks. I’d hate to just drop it now especially since I find it so different, so interesting.

Professor: I guess so. Frankly I can’t believe you’ve lasted this long. These are pretty in-depth theories we’ve been discussing and you’ve been doing OK so far, I guess. But still, the program’s been designed to progress through certain stages. Like any other professional training we build on pervious knowledge.

Student: Then maybe you could recommend some extra reading I can do to… catch up?

Professor: Well, are you intending to study film as your main concentration?

Student: No, no. I am just interested. I’m actually in marketing, but there seems to be a connection.

Professor: Oh…well, in…in that case, if you’re taking the course just out of interest, I mean I still highly recommend signing up for the introductory courses at some point, but in the meantime, there is no harm I guess in trying to keep up with this class. The interest is clearly there. Eh, instead of any extra reading just now though, you could view some of the old introductory lectures. We have them on video. That would give you a better handle on the subject. It’s still a pretty tall order, and we will be moving right along, so you will really need to stay on top of it.

Student: OK, I’ve been warned. Now, could I tell you about my idea for the assignment?

Narrator: Listen to part of a lecture in a chemistry class.

Professor: Okay. I know you all have a lot of questions about this lab assignment that’s coming out so … I’m gonna take a little time this morning to discuss it.

So, you know the assignment has to do with Spectroscopy, right? And your reading should help you get a good idea of what that’s all about. But, let’s talk about Spectroscopy a little now just to cover the basics.

What is Spectroscopy?

Well, the simplest definition I can give you is that Spectroscopy is the study of the interaction between matter and light. Now, visible light consists of different colors or wavelengths, which together make up what’s called spectrum, a band of colors, like you see in a rainbow. And all substances, all forms of matter, can be distinguished according to what wavelength of light they absorb and which ones they reflect. It’s like, um, well, every element has, what we call, its own spectral signature. If we can read that signature, we can identify the element. And that’s exactly what spectroscopy does.

Now, Laser Spectroscopy, which is the focus of your assignment, works by measuring very precisely what parts of the spectrum are absorbed by different substances. And it has applications in a lot of different disciplines. And your assignment will be to choose a discipline that interests you, and devise an experiment. For example, I’m gonna talk about art. I’m interested in the art and to me it’s interesting how spectroscopy is used to analyze art.

Er… let’s say a museum curator comes to you with a problem. She’s come across this painting that appears to be an original – let’s say, a Rembrandt. And she wants to acquire it for her museum. But she’s got a problem: she’s not absolutely certain it’s an original. So, what do you do? How do you determine whether the painting’s authentic? Okay. Think about the scientific process.

You’ve got the question: Is the painting a Rembrandt? So first, you’ll need to make a list of characteristics the painting would have to have to be a Rembrandt. Then you have to discover whether the painting in question has those characteristics. So first of all, you’ll need to know the techniques Rembrandt used when he applied paint to canvas – his brushstrokes, how thickly he applied his paint. So you’d need to work with an art historian who has expert knowledge of Rembrandt’s style.

You’d have to know when he created his paintings, um… what pigments he used, in other words, what ingredients he used to make different colors of paint, cause the ingredients used in paints and binding agents plus varnishes, finishes, what have you, have changed over time. Since you’re trying to verify that’s a Rembrandt, the ingredients in the pigment would need to have been used during Rembrandt’s lifetime – in the 17th century. And that’s where chemistry comes in. You’ve got to find out what’s in those pigments, learn their composition, and that requires lab work – detective work really – in a word, Spectroscopy.

So, how do we use Spectroscopy? Well, we put an infrared microscope – a spectroscope – on tiny tiny bits of paint. And using ultraviolet light we can see the spectral signature of each component part of the pigment. Then we compare these signatures with those of particular elements like zinc or lead, to determine what the pigment was made of. So, you can see why this type of analysis requires a knowledge of the history of pigments, right? How and when they were made? Say we determined a pigment was made with zinc, for example. We know the spectral signature of zinc. And it matches that of the paint sample.

We also know that zinc wasn’t discovered until the 18th century. And since Rembrandt lived during the 17th century, we know he couldn’t have painted it. Now, Spectroscopy has a very distinct advantage over previous methods of analyzing our works, because it’s not invasive. You don’t have to remove big chips of paint to do your analysis, which is what other methods require. All you do is train the microscope on tiny flecks of paint and analyze them.

Now a word or two about restoration. Sometimes original art works appear questionable or inauthentic because they’ve had so many restorers add touchup layers to cover up damage, damage from the paint having deteriorated over time. Well, spectroscopy can review the composition of those touchup layers too. So we can find out when they were applied. Then if we want to undo some bad restoration attempts, we can determine what kind of process we can use to remove them to dissolve the paint and uncover the original.

Narrator: Listen to part of a lecture in a literature class.

Professor: Now we can’t really talk about fairy tales without first talking about folk tales because there’s a strong connection between these two genres, these two types of stories. In fact, many fairy tales started out as folk tales. So, what’s a folk tale? How would you characterize them? Jeff?

Jeff: Well, they are old stories, traditional stories. They were passed down orally within cultures from generation to generation, so they changed a lot over time. I mean, every story teller, or, maybe every town, might have had a slightly different version of the same folk tale.

Professor: That’s right. There’s local difference. And that’s why we say folk tales are communal. By communal, we mean they reflect the traits and the concerns of a particular community at a particular time. So essentially the same tale could be told in different communities, with certain aspects of the tale adapted to fit the specific community. Um, not the plot, the details of what happens in the story would remain constant. That was the thread that held the tale together. But all the other elements, like the location or characters, might be modified for each audience. Okay. So what about fairy tales? Th…they also are found in most cultures, but how are they different from folk tales? I guess the first question is: what is a fairy tale? And don’t anyone say “a story with a fairy in it” because we all know that very few fairy tales actually have those tiny magical creatures in them. But, what else can we say about them? Mary.

Mary: Well, they seem to be less realistic than folk tales…like they have something improbable happening – a frog turning into a prince, say. Oh, that’s another common element, royalty – a prince or princess. And fairy tales all seem to take place in a location that’s nowhere and everywhere at the same time.

Professor: What’s the line-up? How do all the stories start? Once upon a time, in a far away land… oh, in the case of folk tales, each story teller would specify a particular location and time, though the time and location would differ for different story tellers. With fairy tales, however, the location is generally unspecified, no matter who the story teller is. That land far away… We’ll come back to this point in a few minutes.

Student: Um… I, I thought that a fairy tale was just a written version of an oral folk tale.

Professor: Well, not exactly, though that is how many fairy tales developed. For example, in the late 18th century, the Grimm Brothers traveled throughout what’s now Germany, recording local folk tales. These were eventually published as fairy tales, but not before undergoing a process of evolution. Now, a number of things happen when an oral tale gets written down. First, the language changes. It becomes more formal, more standard – some might say, “Less colorful”. It’s like the difference in your language depending on whether you are talking to someone, or writing them a letter. Second, when an orally transmitted story is written down, an authoritative version with a recognized author is created.

The communal aspect gets lost. The tale no longer belongs to the community. It belongs to the world, so to speak. Because of this, elements like place and time can no longer be tailored to suit a particular audience. So they become less identifiable, more generalizable to any audience. On the other hand, descriptions of characters and settings can be developed more completely. In folk tales, characters might be identified by a name, but you wouldn’t know anything more about them. But in fairy tales, people no longer have to remember plots. They’re written down, right? So more energy can be put into other elements of the story like character and setting. So you get more details about the characters, about where the action takes place, what people’s houses were like, ur, whether they’re small cabins or grand palaces. And it’s worth investing that energy because the story, now in book form, isn’t in danger of being lost. Those details won’t be forgotten. If a folk tale isn’t repeated by each generation, it may be lost for all time. But with a fairy tale, it’s always there in a book, waiting to be discovered, again and again. Another interesting difference involves the change in audience. Who the stories are meant for? Contrary to what many people believe today, folk tales were originally intended for adults, not for children. So why is it that fairy tales seem targeted toward children nowadays?

Narrator: Listen to a conversation between a student and an employee in the university’s career services office.

Student: Hi, do you have a minute?

Employee: Sure, how can I help you?

Student: I have a couple of questions about the career fair next week.

Employee: OK, shoot.

Student: Um …well, are seniors the only ones who can go? I mean, you know, they are finishing school this year and getting their degrees and everything. And, well, it seems like businesses would wanna talk to them and not first year students like me.

Employee: No, no, the career fair is opened to all our students and we encourage anyone who’s interested to go check it out.

Student: Well, that’s good to know.

Employee: You’ve seen the flyers and posters around campus, I assume.

Student: Sure, can’t miss them. I mean, they all say where and when the fair is, just not who should attend.

Employee: Actually they do, but it’s in the small print. Uh, we should probably make that part easier to reach, shouldn’t we? I’ll make a note of that right now. So, do you have any other questions?

Student: Yes, actually I do now. Um …since I’d only be going to familiarize myself with the process, you know, check it out, I was wondering if there is anything you could recommend that I do to prepare.

Employee: That’s actually a very good question. Well, as you know, the career fair is generally an opportunity for local businesses to recruit new employees, and for soon-to-be graduates to have interviews with several companies they might be interested in working for. Now, in your case, even though you wouldn’t be looking for employment right now, it still wouldn’t hurt for you to prepare much like you would if you were looking for a job.

Student: You mean, like get my resume together and wear a suit?

Employee: That’s a given. I was thinking more along the lines of doing some research. The flyers and posters list all the businesses that are sending representatives to the career fair. Um …what’s your major urge you to have one yet?

Student: Well, I haven’t declared a major yet, but I’m strongly considering accounting. See, that’s part of the reason I wanna go to the fair, to help me decide if that’s what I really want to study.

Employee: That’s very wise. Well, I suggest that you get on the computer and learn more about the accounting companies in particular that would be attending. You can learn a lot about companies from their internet websites. Then prepare a list of questions.

Student: Questions, hmm… so, in a way, I’ll be interviewing them?

Employee: That’s one way of looking at it. Think about it for a second. What do you want to know about working for an accounting firm?

Student: Well, there is the job itself, and salary of course, and working conditions, I mean, would I have an office, or would I work in a big room with a zillion other employees, and…and maybe about opportunities for advancement.

Employee: See? Those’re all important things to know. After you do some research, you’ll be able to tailor your questions to the particular company you are talking to.

Student: Wow, I’m glad I came by here. So, it looks like I’ve got some work to do.

Employee: And if you plan on attending future career fairs, I recommend you sign up for one of our interview workshops.

Student: I’ll do that.

3. What does the woman imply about the small print on the career fair posters and flyers

Narrator: Listen to part of a lecture in a biology class.

Professor: Ok, I have an interesting plant species to discuss with you today. Um…it’s a species of a very rare tree that grows in Australia, Eidothea hardeniana, but it’s better known as the Nightcap Oak. Now, it was discovered only very recently, just a few years ago. Um… it remained hidden for so long because it’s so rare. There are only about 200 of them in existence. They grow in a rain forest, in a mountain rage…range in the north part of New South Wales which is a…er… state in Australia. So just 200 individual trees in all. Now another interesting thing about the Nightcap Oak is that it is…it represents…er…a very old type…er…kind of tree that grew a hundred million years ago. Um, we found fossils that old that bear remarkable resemblance to the tree. So, it’s a primitive tree. A…a living fossil you might say. It’s relic from earlier times and it has survived all these years without much change. And it…it’s probably a kind of tree from which other trees that grow in Australia today evolved. Just to give you an idea of what we are talking about. Here’s a picture of the leaves of the tree and its flowers. I don’t know how well you can see the flowers. They’re those little clusters sitting at the base of the leaves. Okay, what have we tried to find out about the tree since we’ve discovered it? Hum…or how…why is…is it so rare? That’s one of the first questions. Um… how is it…um…how does it reproduce? This is another question. Um, maybe those two questions are actually related. Jim?

Student: Hum …I don’t know. But I can imagine that…for instance, seed disposal might be a factor. I mean if the…er…you know, if the seeds cannot really disperse in the wild area, then, you know, the tree may not colonize new areas. It can’t spread from the area where it’s growing.

Professor: Right. That’s…that’s actually a very good answer. Um, of course, you might think there might not be any areas where the tree could spread into, er…because…um…well, it’s very specialized in terms of the habitat. But, that’s not really the case here. Um…the suitable habitat, that is, the actual rainforest is much larger than the few hectares where the Nightcap Oak grows. Now this tree is a flowering tree as I showed you. Um…um…it produces a fruit, much like a plum. On the inci…inside there’s a seed with a hard shell. It…it appears that the shell has to crack open or break down somewhat to allow the seed to soak up water. You know, if the Nightcap Oak remains…if their seeds remain locked inside their shell, they will not germinate. Actually, the seeds…er…they don’t retain the power to germinate for very long, maybe two years. So there’s actually quite a short window of opportunity for the seed to germinate. So the shell somehow has to be broken down before this…um…germination ability expires. And…and then there’s a kind of rat that likes to feed on the seeds as well. So, given all these limitations, not many seeds that the tree produces will actually germinate. So this is a possible explanation for why the tree does not spread. It doesn’t necessarily explain how it became so rare, but it explains why it doesn’t increase. OK, so it seems to be the case that the species, this Nightcap Oak is not very good at spreading. However, it seems, though we can’t be sure, that it’s very good at persisting as a population. Um…we…there’s some indications to suggest that the population of the Nightcap Oak has not declined over the last. er…you know, many hundreds of years. So it’s stayed quite stable. It’s not a remnant of some huge population that is dwindled in last few hundred years for some reason. It’s not necessarily a species in retreat. Ok, so it cannot spread very well, but it’s good at maintaining itself. It’s rare, but it’s not disappearing. Ok, the next thing we might want to ask about the plant like that is what chances does it have to survive into the future. Let’s look at that.