TV Program Description
Original PBS Broadcast Date: November 14, 2006
An intense scientific debate has ignited around a quiet but
extraordinary family living in rural Turkey—a family
with five adults who walk on all fours. Since bipedalism has
long been considered one of the defining characteristics of
modern humans, such a discovery raises fascinating questions
about genetics, society, and the evolutionary history of our
species. Is this the anthropological find of the millennium,
or simply a unique medical case? NOVA sets out to unravel the
controversy and meet the individuals who have captured the
imagination of scientists around the world.
While no one knows exactly when our ancestors stood up, there
are clues. One of the most haunting is a trail of
human-looking footsteps unearthed in Tanzania. Whoever made
them walked on two feet more than three million years ago.
Now, shaped over the millennia by evolution, the human body is
exquisitely built for bipedal movement—from the
proportion of its limbs and spine, to its breathtaking sense
of balance. Walking, hands on the ground, is a painfully
difficult task, so much so that the U.S. Marines use it as an
endurance exercise. So why are adult members of a Turkish
family walking in this way? This program takes viewers through
a fascinating examination of the leading theories.
The family, comprising the parents and their grown children,
lives in a poor and remote area of Turkey. Five of the adult
children, ranging in age from 18 to 34, walk with their feet
and palms on the ground. They were first "discovered" in 2005
by scientist Uner Tan, who created a sensation in the popular
press by characterizing the handwalkers as "genetic
throwbacks." Intrigued by Tan's theory, German geneticist
Stefan Mundlos has searched for a genetic mutation that could
be connected to the emergence of bipedality. But NOVA checks
in with geneticist Sean Carroll and anthropologist Brian
Richmond, two prominent researchers who believe that to view
these family members as a kind of missing link is both deeply
insulting and scientifically incorrect.
Many experts reject the idea that ancient genes can simply
"switch on," causing traits to resurface after an absence of
generations, or even that any one gene could be responsible
for complex physical traits and structures they believe
involve multiple genes modified over millions of years and
many speciation events (see
The Genetic Factor). By comparing a quadruped chimp skeleton to a bipedal human
skeleton, anthropologist Brian Richmond shows NOVA how the
pelvis, hip, knee, and foot had to dramatically change for our
ancestors to walk upright—changes that could not have
occurred through a single mutation (see
Compare the Skeletons).
Spending time with the family in Turkey, researcher Nicholas
Humphrey and psychologist Defne Aruoba also doubt the single
gene theory, believing instead that the answer to the
scientific puzzle lies in the very fabric of the family's
life. Through interviews and observation, they learn that the
parents are closely related; that fearful neighbors in their
fundamentalist Islamic community have left them socially
isolated; and that the handwalkers have never had the benefit
of physical therapy—treatment that would be standard
protocol, for example, in the U.S. or Britain.
Personal interviews and footage of time spent with the family
are emotional and telling (see
The Family and Me). Villagers turn a blind eye as their children taunt the
adult handwalkers. NOVA's film crew takes the family on their
first-ever visit to the ocean, a mere hour-long ride from
their home. Cameras capture their efforts to stand and walk
upright when presented with equipment they have never seen
before—simple aluminum walkers. Whatever view these
individuals end up providing of our ancient past, it is clear
that they are a striking example of how people are shaped by
the world around them.
Program Transcript
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