This great crack
in the Earth's crust

extends for 4,000 miles,
from Mozambique in the south

to Lebanon in the north.
Where the continent fractured
some 20 million years ago

an escarpment plunges 2,000 feet
to the sunken rift floor.

The remains of great volcanoes
dominate the Rift Valley

eroding monuments to
the continent-splitting forces

still at work beneath.
On the floor of the Rift Valley
roam remnats of the great
animal herds of Africa.

They run where valley floor
did not yet exist

ten million years ago...
where a sea may exist
in ten million more...

or a great ocean
in a hundred million.

And here, in the eroded gorges
of the rift floor

in the exposed sediments
of three million years

we have unearthed
the clearest record

of the genesis of man.
For here,
anthropologist have discovered

the oldest fossil remains
spanning human evolution.

Life has been profoundly shaped
by the movement and separation
of the continents.

Had not the continents been
continuouly raised and renewed

life would never have adcanced
from the sea.

Had not the continents separated
Life would not have been
isolated in separate preserves

to proliferate
in a thousand directions

which evolution explored.