Lecture 34: Long Trends—Rates of Innovation
Feeding these growing populations depended on a constant trickle of mini-
innovations, some of which were almost certainly driven by population
pressure. Peasants or their masters sought out new lands to farm and
encouraged settlement in new regions. That meant adapting to new soils,
climates, and neighbors and adopting new farming techniques and crops.
Examples include new crops such as the strains of rye that allowed farmers
migrating from eastern Europe to begin settling the lands of modern Russia
some 1,500 years ago, or the slow spread
of windmills, which are ¿ rst recorded in
Persia late in the 1st millennium C.E.The increasing size and variety of
exchange networks could also stimulate
the spread of innovations. Roughly
speaking, the larger and more diverse
the networks of exchange, the larger the
pool of ideas they contained, and the greater the chances for the spread of
signi¿ cant innovations. In the later Agrarian era, the most important large
exchange networks were the “silk roads,” which crossed most of the Afro-
Eurasian world zone.As early as 4,000 years ago, innovations such as horse-riding and the use
of chariots may have diffused from the steppelands to the Mediterranean
region and also to China, while Indo-European languages, which probably
originated in modern Russia, were spreading toward China, India, and
Mesopotamia. Two thousand years ago, trans-Eurasian exchanges became
more common. Chinese governments traded with Central Asia, Chinese silks
entered Mediterranean markets, and Buddhism traveled from India to China.
The travels of Chinese envoy Chang Ch’ien to Central Asia in the reign of
Han Emperor Wu-ti (141–87 B.C.E.), or the astonishing military campaigns
of Alexander the Great (365–323 B.C.E.), provide vivid illustrations of how
Agrarian civilizations from different ends of the Eurasian landmass came
into closer contact with each other. Sea trade also increased between the
Mediterranean, India, Southeast Asia, and China, as mariners learned to
exploit the monsoon winds of the Indian Ocean. By 2,000 years ago, and
perhaps earlier, most of Afro-Eurasia belonged to a single “world system.”
(The term “world system” is derived from the work of Immanuel WallersteinDespite their hostility to
commerce, tribute-taking
rulers could also stimulate
innovation and growth.