Big History—Humans in the Cosmos .............................................

Lecture 48

Agriculture appeared about 10,000 or 11,000 years ago. Before the

appearance of agriculture, all human beings were foragers.

I

f asked (perhaps around a camp¿ re) to explain how everything got to be
the way it is, how might we respond? Let’s begin with human history. We
live in the largest and most complex human community ever created. Six
billion humans, often in conÀ ict with each other, are linked through trade,
travel, and modern forms of communications into a single global community.
This community was created in just a few hundred years. About 300 years
ago, human beings crossed a sort of threshold as human societies became
more interconnected and began to innovate faster than ever before. For 5,000
years before this, most people had lived in the large, powerful communities
we call “Agrarian civilizations.” They had cities with magni¿ cent architecture
and powerful rulers sustained by large populations of peasants who produced
most of society’s resources. Innovation was slower, so history moved more
slowly, and there were fewer people than today. Two thousand years ago,
there were about 250 million people on Earth.

The ¿ rst Agrarian civilizations appeared in regions such as Mesopotamia,
Egypt, and China. During the previous 5,000 years, humans had increasingly
lived in small peasant villages governed by local chiefs. Yet many still lived
by foraging, gathering what they needed as they migrated through their
home territories. The appearance of agriculture, just over 10,000 years ago,
counts as a fundamental historical threshold because agriculture increased
the amount of resources humans could extract from a given area. By doing
so, it stimulated population growth and innovation and laid the foundations
for the ¿ rst Agrarian civilizations.

In the preceding 200,000 to 300,000 years, all humans had lived as foragers,
in nomadic, family-sized communities. Slowly, they spread through Africa
and around the world. For most of this time, humans were only slightly more
numerous than our close relatives, the great apes, are today. Our species,
Homo sapiens, appeared about 200,000 to 300,000 years ago somewhere in