Today, a progress report. The University of
Houston's College of Engineering presents this
series about the machines that make our
civilization run, and the people whose ingenuity
created them.
By the time this program
reruns, it may well be ready for updating. That's
because recent studies have been causing an old
question to shift under our feet. "Where did we
modern humans, we Homo Sapiens or
Cro-Magnons, come from -- and when?"
For over a century we'd thought that our
technological species had arisen in Europe and the
Near East some forty thousand years ago and then
(rather quickly) displaced the Neanderthals.
It's clear that we began creating sophisticated
cave painting and tool-making; and that we have,
ever since, been the only human species. But the
search for our mutual origins has recently shifted
away from Europe to artifacts and remains in
Africa.
Now, in South Africa, we are finding
seventy-thousand-year-old delicate bone awls and a
seventy-seven-thousand-year-old piece of ochre
engraved with a design. Most amazing are
ninety-thousand-year-old items from the Congo. An
early harpoon for spearing fish has sweptback hooks
along its shank. Several flat beads look like small
metal washers.
So the great explosion of art and technology
clearly began, not in Europe, but in Africa. DNA
evidence points back to the remains of a
modern-human African female whom we name Eve. She's about twice as
old as the oldest of these fine artifacts.
The current mystery is no longer where these people
and their art came from, but how they made their
way out of Africa. And here, two competing routes
have been on the table. Both begin with modern
humans who had moved north into Ethiopia. From
there, the favored route was up through Suez and
into the Holy Land.
But DNA evidence supports the second route. It
suggests that modern humans crossed the southern
tip of the Red Sea (where Ethiopia almost touches
Yemen today) and they continued through Arabia and
Persia into India. Then they migrated both eastward
and back to the northwest and Europe. They reached Australia some sixty
thousand years ago, maybe before they got to
Europe.
New York Times science writer John Noble
Wilford points to two factors that archeologists
think caused the sudden technological explosion
that these people created. One was population; the
other, adaptation. Population growth drove
migration, and it drove people to go after
harder-to-catch game. When there are enough of us
to eat up all the slow-moving turtles, we must
either move or invent means
for hunting more elusive animals.
Those same factors work in yet another way. As
populations increased, we sought out means for
expressing our individual selves to one another. "I
am me!" "Here is a picture of what
I am thinking." "Here is my new
invention." That's very important. It's the reason
that art has always preceded utility, in invention.
So we came out of Africa. Eve really did move off
to the east of her Eden. We carried our art -- our
inventions -- with us, and, for better and for
worse, we took over the world.
Cain, by Fernand Corman, 1880
(Artist's impression of Cain's expulsion)
I'm John Lienhard, at the University of Houston,
where we're interested in the way inventive minds
work.
(Theme music)
Wilford, J. N., When Humans Became Human. New
York Times, Science Times, Tuesday, Feb. 26,
2002, pp. D1 and D5.
