Today, we cross Wallace's line. The University of
Houston's College of Engineering presents this
series about the machines that make our
civilization run, and the people whose ingenuity
Physiologist Jared Diamond
makes a pilgrimage to Wallace's line -- an
imaginary line separating Borneo and Java from the
Celebes and other islands to the southeast.
"[Crossing] that line," he says, "may have been
what made our ancestors truly human."
Alfred Russel Wallace was the now-almost-forgotten
co-discoverer of the theory of evolution. Darwin
had pretty well formulated the theory when he
learned that Wallace was about to publish a similar
idea. When Wallace heard about Darwin, he politely
stood aside and let Darwin publish first.
Among many contributions, Wallace identified the
demarcation between species of southeast Asia and
completely different species in Australia and New
Guinea. There are other such regions. The Sahara is
one. A band from northwest India through the
Himalayas and Indochina forms another such zone of
separation. But Wallace's line has special
For a long time, we've known that modern humans
evolved in Africa 100,000 or so years ago, and that
they began making dramatic art and tools in Europe
30 or 40 thousand years ago. But we've paid scant
attention to the world southeast of Wallace's line.
The so-called Java Ape Man fossils make it clear
that ancestors of modern humans reached southeast
Asia a million years ago. Java Man got as far as
Borneo and Java over land links that existed before
the glacial epochs. But those links ended there,
and he couldn't get to New Guinea and Australia.
Yet modern humans have occupied Australia for
60,000 years. Somehow, modern humans appeared in
Java Man's world, and they managed to go
island-hopping all the way to Australia. There they
practiced advanced art and technology that rivals
what we find in the caves of central Europe. The
catch is, they did so much earlier than
the European Cro-Magnons.
And so, Jared Diamond observes, we were the one
species that lived on both sides of Wallace's line.
The crucible of human creativity might well have
been Australia. He believes the art and technology
of Australian aborigines slowly trickled back and
eventually reached Europe. Diamond thinks that
crossing Wallace's line was the giant step that
made us into a technological species.
Eventually, the vast geography and resources of
Eurasia allowed the aborigines' cousins to run
ahead -- to invent writing and the wheel, to build
canons and cathedrals. Eventually, when Dutch and
English navigators found their way back to
Australia, all they saw were shockingly primitive
humans. They had no way to see the sophistication
of their survival strategies.
And they had no idea they should be saying "Thank
you" to their ancient teachers.
I'm John Lienhard, at the University of Houston,
where we're interested in the way inventive minds
Diamond, J., Mr. Wallace's line.
Discover, August, 1997, pp. 76-83.
For more on Wallace's line, see the following
The Engines of Our Ingenuity is
Copyright © 1988-1997 by John H.
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