OFFICIAL10 What is the main purpose of the lecture?

[00:00]Narrator: Listen to part of a lecture in a European history class.
[00:06.37]FEMALE PROFESSOR: So would it surprise you to learn that many of the foods that we—uh, today—consider traditional European dishes—that their key ingredients were not even known in Europe until quite recently—until the Europeans started trading with the native peoples of North and South America? [00:24.24]I mean, you’re probably aware that the Americas provided Europe—uh, and Asia—with foods like squash…beans…turkey…peanuts… [00:33.80]But what about all those Italian tomato sauces, Hungarian goulash  or—my favorite—French fries—[00:40.52]those yummy fried potatoes?
[00:45.22]MALE STUDENT: Wait—I mean, I knew potatoes were from—where, South America—?
[00:50.23]FEMALE PROFESSOR: South America, right—the Andes Mountains.
[00:52.84]MALE STUDENT: But you’re saying…tomatoes too?  [00:54.83]I just assumed, since they’re used in so many Italian dishes…
[00:58.33]FEMALE PROFESSOR: No, like potatoes, tomatoes grew wild in the Andes—although unlike potatoes, they weren’t originally cultivated there; [01:06.22]that seems to have occurred first in Central America. [01:09.46]And even then the tomato doesn’t appear to have been very important as a food plant until the Europeans came on the scene. [01:16.41]They took it back to Europe with them around 1550, [01:19.96]and Italy was indeed the first place where it was widely grown as a food crop. [01:25.34]So, in a sense, it really is more Italian than American.
[01:29.68]And another thing—and this is true of both the potato and the tomato—[01:34.17]both of these plants are members of the nightshade family. [01:39.19]The nightshade family is a category of plants which also includes many that you wouldn’t want to eat…like oh, uh, mandrake, belladonna, and, uh…and even tobacco! [01:52.25]So it’s no wonder that people once considered tomatoes and potatoes to be inedible too, even poisonous—[01:59.04]and, in fact, the leaves of the potato plant are quite toxic.  [02:04.08]So it took both plants quite a while to catch on in Europe, and even longer before they made the return trip to North America and became popular food items here.
[02:14.32]FEMALE STUDENT: Yeah, you know, I remember…I-I remember my grandmother telling me that when her mother was a little girl, a lot of people still thought that tomatoes were poisonous.
[02:25.34]FEMALE PROFESSOR: Oh, sure—people didn’t really start eating them here until the mid-1800s.
[02:30.26]FEMALE STUDENT: But, ah—seems like I heard…didn’t Thomas Jefferson grow them or something?
[02:36.00]FEMALE PROFESSOR: Ah! Well, that’s true…but, then, Jefferson is known not only as the third President of the United States, but also as a scholar who was way ahead of his time—in many ways! [02:47.08]He didn’t let the conventional thinking of his day restrain his ideas.
[02:53.19]Now, potatoes went through a similar sort of, ah—of a rejection process, especially when they were first introduced in Europe—[03:02.14]you know how potatoes can turn green if they’re left in the light too long? [03:06.10]And that greenish skin can make the potato taste bitter—even make you ill. [03:10.96]So that was enough to put people off for over 200 years! Yes, Bill?
[03:16.31]MALE STUDENT: I-I’m sorry, Professor Jones, [03:17.85]but—I mean, yeah, OK, [03:19.52]American crops’ve probably contributed a lot to European cooking over the years, but…
[03:24.46]FEMALE PROFESSOR: But have they really played any kind of important role in European history?  [03:29.68]Well, as a matter of fact, yes, I was just coming to that. [03:33.39]Let’s, uh—let’s start with North American corn, or maize, as it’s often called. [03:39.72]Now, before the Europeans made contact with the Americas, they subsisted mainly on grains—grains that often suffered from crop failures—
[03:48.55]And it’s largely for this reason that political power in Europe was centered for centuries in the south—around the Mediterranean Sea, which was where they could grow these grains with more reliability. [03:59.73]But when corn came to Europe from Mexico…well, now they had a much heartier crop that could be grown easily in more northerly climates, and the centers of power began to shift accordingly.[04:12.58]And then—well, as I said, potatoes weren’t really popular at first, [04:17.61]but when they finally did catch on—which they did first in Ireland, around 1780—
[04:23.47]well, why do you suppose it happened?  [04:25.77]Because potatoes had the ability to provide an abundant and extremely nutritious food crop—no other crop grown in northern Europe at the time had anything like the number of vitamins contained in potatoes. [04:38.36]Plus, potatoes grown on a single acre of land could feed many more people than say, uh, wheat grown on that same land. [04:47.40]Potatoes soon spread to France and other northern European countries, [04:51.84]and as a result, the nutrition of the general population improved tremendously, and populations soared in the early 1800s. And so the shift of power from southern to northern Europe continued.