Anthropology What is the main purpose of the talk?

Human beings, like all animals, are territorial. The center of our territory is the home. Think about it. The home is where we spend most of our time. We begin and end our day there. We eat and sleep and bathe ... and relax ... and play with our children there ... and are most comfortable there. We keep our possessions there. We furnish our homes as an expression of our taste. We say-and generally believe-that "There’s no place like home" and "Home is where the heart is."
The human habit of building homes has a long history. Anthropologists think home building began with very simple round huts, similar to the shelters still built in parts of Africa today. Round huts probably started out like this: tree branches were leaned up against one another like the ribs of an umbrella; then the frame was covered with leaves or animal skins.
It’s from these round, tent-like structures that the first solid dwellings probably evolved. As the tents became larger and more elaborate, they became the center of family life, and the place where the family’s possessions could be kept. In other words, these structures became home, the heart of the human territory. Round huts progressed from being temporary shelters, made of wood and skins and leaves, into stronger, more permanent structures built of stone.
But even though stone structures were stronger, there was still a problem: the round shape made it difficult to combine it with other structures. This difficulty was overcome with the development of the cube, or box shape. The box shape was a major development in home construction. By making the sides of the house rectangular, and then covering the four walls with a roof, it was possible to place structures next to one another, and to join them with doorways. Thus, the room was invented.
After the room came the multi-unit dwelling: the apartment house. Nearly ten thousand years ago, this method of building led to the construction of clusters of rectangular buildings that made up the first complex human settlements. Today the box shape not only survives but also remains the basis of our domestic dwellings.
The homes of today still contain some ancient features. Around the house itself there’s an outer perimeter-the symbolic boundary of the ancient home territory. Today the boundary is often marked by a barrier, like a fence, a wall, or a hedge. Inside the boundary, we find the yard-where we keep our dogs-and the garden, where we-like our ancestors- grow a few fruits and vegetables. We surround our home with a grass lawn, like our ancestors surrounded theirs with pastures for their livestock.
Today, humans are more sociable than in ancient times, and so we allow others to enter the home territory, especially the outer boundary. For example, we let people bring letters and packages to our door. Sometimes we let outsiders enter the first of the private areas, the hallway, which is inside the solid wall of the home itself. But beyond the hallway, there are more boundaries. Each room you come to becomes more private and less available to outsiders.
Guests are allowed to enter the living room. Closer friends can go farther. We tell our closest friends to "make yourself at home" and allow them into the rooms where we cook and eat and pursue our hobbies. But ... up the stairs ... or down the hall ... somewhere less accessible in our home-this is where we find the bedrooms and bathrooms, the most private rooms of our home. These rooms are where we, the owners of the territory, feel most secure. This is where we retreat, like any animal to its den, whenever we are at our most vulnerable-for example, when we’re sleeping, bathing, or when we’re sick.