Today, we find out why humans hang together. 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.
Two anthropologists, Malcom
Smith and Robert Layton, tell a strange tale about
the integrity of the human species. They begin by
visiting an African lake that teems with strange
fish. They're called cichlids. The cichlids in the
lake come in 200 different species. They're all
pretty similar. Only their lips, jaws, and teeth
have all evolved differently.
Some have evolved into fin eaters -- some into worm
eaters. Some cichlids eat snails. Each has evolved
into a tiny niche of the ecology. That kind of
subdividing is pretty common. That's why we count
25,000 species of fish, 9,000 species of birds, and
4,500 species of mammals.
So why haven't we splintered like that? Humankind
is only one species. One young hunter can chase
down a rabbit. Another can spear a fish. Yet we
haven't specialized into one race of rabbit
catchers and another of fish spearers. Why are we
alike in all but the most minor features -- things
like skin color?
We're not like the fish in that African lake. We've
faced every environment on earth. It certainly
seems plausible that we too would've divided in
that way, and become different species with
The reason we haven't lies in one key attribute.
Humans share! We share in complex ways that no
other animal does. Back in camp, the rabbit chaser
and the fish spearer exchange food. We've done that
as long as we've existed.
Of course, it helps that we're very omnivorous. We
eat almost anything. If it lives, we've eaten it at
one time or another. More important, we've also
Our sharing goes beyond food. Most societies have
taboos about mating across the lines of clan,
ethnicity, or race. But the important thing about
those taboos is that we break them. Intermarriage
is another kind of sharing that holds our species
Sharing goes beyond food and beyond mating. We also
share the techniques for gathering food and
fulfilling other needs. One cichlid fish had to
develop its own specialized jaw for crushing and
eating snails. We can share our knowledge of snail
catching, of rabbit chasing, or of fish spearing.
That's what technology is. It's the lore, or
science, of technique. Technology is our primary
act of sharing. Technology shapes us into one body,
instead of a thousand subspecies. We're bound in a
unique and instinctive tether of generosity. And
our technologies are right at the core of that
I'm John Lienhard, at the University of Houston,
where we're interested in the way inventive minds