India is a part of the old supercontinent of Gondwana
that has joined
Eurasia. India separated from the rest of Gondwana over a hundred
million years ago, and until it collided with Eurasia, about fifty
million years ago, it was an island. This is reflected in that the
Indian subcontinent is a peninsula, not a land bridge. There are
nevertheless some broad physical similarities with the Near East. Like
the southern Near East, India overall is relatively flat. Inland from
the coastal plains of the south there are mountain ranges arising from
the rifting that brought the region into being, and between them are
the highlands of the interior. But there is nothing in the south to
compare in altitude to the combination of mountains and plateau by
which India is closed off to the north. Much as in the northern Near
East, this massive uplifting is the product not of rifting but of
collision. Yet the scale of the uplifting dwarfs anything the Near East
has to show; indeed, there may have been nothing on earth to match it
in the last half billion years. By contrast, it is between the northern
mountains and the southern highlands that India is at its lowest and
flattest, with alluvial plains comparable to those of Mesopotamia.
One of the most significant differences between India
and the Near East
is climatic: India gets much more rain. The high terrain to the north
and the open ocean to the south generates the monsoon, the wet summer
so alien to the Near East. But the distribution of summer rainfall in
India is very uneven. The wettest regions are the coastal strip in the
southwest and a large area in the northeast; by contrast, the southern
highlands are dry, and the northwest shares the aridity of the Near
East, of which it is in effect a climatic extension. As a result, the
two great rivers that rise in the northern mountains have somewhat
different effects on the lands through which they flow. Both of them
deliver a valuable agricultural resource, namely silt. But in the
northeast the Ganges takes its water to a jungle region of abundant
rainfall; whereas in the northwest the Indus brings life to a land much
of which would otherwise be desert.
