1. So we've been talking about nutrients, the elements in the environment that are essential for living organisms to develop, live a healthy life and reproduce, some nutrients are quite scarce, there just isn't much of them in the environment, but fortunately they get recycled. When nutrients are used over and over in the environment, we call that a nutrient cycle, because of the importance of nutrients and their scarcity, nutrient recycling is one of the most significant eco-system processes that will cover in this course.
2. So would it surprise you to learn that many of the food that we today consider traditional European dishes that their key ingredients were not even known in Europe until quite recently, until the European started trading with the native people in North and South America? I mean, you probably aware that the Americas provide Europe and Asia with food like squash, beans, turkey, peanuts.
3. Although unlike potatoes, they weren't originally cultivated there, that seems to occur first in Central America, and even then the tomato doesn't appear to have been very important as a food plant until the European came on the scene, they took it back to Europe with them around 1550, and Italy was indeed the first place where it's widely grown as food crop, so in a sense, it really is more Italian than American, and another thing and this is true of both potato and tomato, both of the plants are members of Nightshade family.
4. But when corn came to Europe from Mexico, wow, now they had a much hardier crop that could be grown easily in more northerly climates and centers of power began to shift accordingly, and then, well as I said potatoes weren't really popular at first, but when they finally catch on which they did in Ireland around 1780, well, why do you suppose it happen?
5. Plus, potatoes grow on the single acre of land could feed many more people than say, wheat grow on the same land, potatoes soon spread to France and other Northern European countries, and as a result, the nutrition of the general population improved tremendously and population soared in the early 1800 and so the shift of power from southern to northern Europe continued.
网友评论