36 DISCOVERMAGAZINE.COM
CLOCKWISE FROM LEFT: JASON EDWARDS/NATIONAL GEOGRAPHIC CREATIVE; STEPHEN ALVAREZ/NATIONAL GEOGRAPHIC CREATIVE; TON KOENE/ALAMY STOCK PHOTO; AFRIPICS.COM/ALAMY STOCK PHOTOfor example, the Hamar people use ochre to clean
their hair. “They use ochre for aesthetic as well as
hygienic reasons,” says Rosso, who spent a few days
among the Hamar. “There really isn’t this limit to
functional or symbolic. They’re combined.”
And in South Africa, Hodgskiss says, ochre
is widely used as sunscreen. “You can buy it at
hardware stores and in traditional medicine shops,”
says Hodgskiss, where the sunscreen is known as
ibomvu, the Zulu word for red.The archaeological record suggests ochre had
some other practical uses, turning up on tools
and weapons. Experimental archaeologists,
who seek to understand how our ancestors used
different materials by replicating the processes
involved, concluded that ochre was mixed with
other substances to create a hafting adhesive used
to attach, for example, a stone arrow point to its
wooden shaft.
Riaan Rifkin, an archaeologist at the University
of Pretoria in South Africa, has been one of
the leading proponents of a new, functional
interpretation of ochre in the story of human
evolution. For nearly a decade, his experiments,
along with those of colleagues, have pointed
to prehistoric use of the material not just as a
sunscreen and adhesive but also an insect repellent
and leather preservative.
Rifkin believes, in fact, that ochre’s functional
applications may have contributed directly to
H. sapiens’ greatest early achievement: spreading
across the world. “The use of red ochre as a
sunscreen must have enabled humans to traverse
longer distances without getting excessively
sunburnt. This was an amazing adaptive advantage.
They could forage longer and explore further,” says
Rifkin. He suspects ochre sunscreen evolved about
the same time humans began using ostrich eggshells
as containers for water and other provisions, about
65,000 years ago. “As soon as we could carry water
with us, had a good [ochre-based] sunscreen and
mosquito repellent, and warm [ochre-tanned]
clothing, we were able to expand from Africa.”last common ancestor of Homo sapiens and
Neanderthals collected pigment,” Zipkin says.
“Things like this don’t arise out of nowhere.”
Ochre use appears limited to the genus Homo,
but the material’s attractiveness is likely rooted in an
adaptation that occurred about 23 million years ago
in an early primate ancestor: trichromatic vision.
Old World monkeys, apes and hominins — the
branch of the ape family tree that includes humans
— inherited that ancestor’s ability to see red,
particularly against a green background.
Detecting the color red likely helped our distant
ancestors discern which fruits were ripe and ready
to eat, and which leaves were young, tender and
more easily digested. As our own hominin lineage
became both more social and more exploratory, the
ability to see red would have provided a particularly
useful advantage.
“If you’re going to walk into someone else’s
territory, you want to signal that you’re a friend,
not a foe,” says George Washington University
paleoanthropologist Alison Brooks. “Anything red
is extremely visual.”
Brooks adds: “There are lots of rocks that come
in powdery form that aren’t red and didn’t get used.
Ochre has importance because it signals to others.
... Its use is extremely widespread, even in the
modern world. Why do we color our world when
our world is colorful already? It could be a lot of
reasons, but it’s a form of communication.”
That communication, or signaling, is what
archaeologists and anthropologists call symbolic
behavior, and it’s why ochre use is often cited as
a proxy for the cognitive ability of the people
who used it. Collecting ochre, turning it into a
powder or paint, and then applying it to the body
or surroundings to express something to others
is a multistep process, done to convey something
to another individual who possesses the ability to
understand the signal.
In addition to being highly visible over
long distances by our species, red is also the
color of blood, charging it with even more
symbolic significance.
It’s no coincidence, Brooks says, that “some
languages have only two words for color: red and
not-red. A language may not have a word for green
or blue, but there is always a word for red.”THERE’S AN APP FOR THAT
But some archaeologists have begun to challenge
the idea that ochre was primarily symbolic for
early humans. Instead, they believe ochre had a
number of functional applications, some of which
traditional societies, particularly in Africa and
Australia, still employ.
In the arid environment of southern Ethiopia,