In fact it has been river water that has been crucial
to the history of
civilization in the Near East. This gives the advantage to southern
Mesopotamia, which benefits from the relatively abundant winter
rainfall of the north which flows into the Tigris and the Euphrates.
There is no similar river system in Arabia.
It stands to reason that the Near East is likely to
have been the
earliest region outside Africa to be colonized by modern humans, and it
is clear that people were present at least forty thousand years ago.
Yet what gave the region its central importance in history was not the
relatively early arrival of people, but rather the speed with which
they developed farming. This does much to explain why the earliest
known civilization should have emerged there.
The environment of southern Mesopotamia gave to these
lands the
potential for large scale irrigation to produce an agricultural
surplus. A disadvantage was that other critical resources were lacking,
and could be procured only through long-distance trade. In the case of
southern Mesopotamia, these included materials as basic as timber,
metals, and even stone. Thus in the fifth millennium B.C. the
cultivators were using clay sickles, which were later replaced, first
with flint and then with copper, both of which had to be imported. A
noteworthy feature of the archaeological record in this connection is
the greatly expanded commercial horizons of southern Mesopotamia in the
centuries leading up to the emergence of civilization.
