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Family That Walks on All Fours
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Classroom Activity
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Activity Summary
Students
use a viewing guide while watching a program about members of a Turkish family
who walk on four limbs and discuss program themes after watching.
Learning Objectives
Students will be able to:
- copy of the "Handwalkers Raise Questions" student handout
(PDF or
HTML)
Background
In
early 2005, scientists discovered five of 11 siblings in a Kurdish family
living in southern Turkey who walked on all fours. Uner Tan, the Turkish
scientist who first reported the discovery, believed that studying the family
could shed light on evolution. He suggested the family members were a
"throwback" to a much earlier time in human prehistory. Many scientists
disagreed with his conclusions.
A team of German scientists thinks there may be one or a few genes responsible
for bipedality. Most scientists believe that a complex trait like walking
upright is a consequence of changes to many genes over a long period of
time.
Some scientists believe that brain damage caused by a genetic mutation may have
influenced how the family members walk (all five siblings are mentally
handicapped). Some scientists also think that environmental influences played a
role, including the idea that the siblings may never have made the transition
from an infant "bear crawl" they used to move around.
In this activity, students will track four themes within the program and
prepare a presentation sheet on each assigned theme and consider some of the
ethical issues of studying and filming this family.
Organize students into four teams. Assign each team one of the following
themes to take notes on as they watch the program:
- Possible reasons for why some family members are handwalkers.
- Treatment of the family by outsiders (e.g., villagers, scientists, and film producers).
- Neurological tests that were performed and the conclusions drawn.
- Interactions among family members and the beliefs they hold.
Distribute a copy of the student handout to each team before viewing.
Discuss appropriate background information with students, and explain that
sensitive issues related to culture and physical challenges faced by the family
are addressed in the program. Show the program and have students individually take notes on the theme
their team has been assigned. After watching the program, have students meet in their teams to discuss
their notes. Have each team prepare a presentation sheet that includes
information and ideas from each team member. Have teams share their presentation sheet and any questions that came out of
their teamwork. (See Activity Answer on page 4 for possible theme presentation
material. Accept all reasonable answers.) Ask students in the rest of the class
if they agree with what the team has presented. If students don't agree, ask
them to explain why and provide evidence from the program that will support
their opinions. Based on the evidence presented in the program, which of the
hypotheses presented do students think best explains the siblings' condition?
Why? To conclude, discuss some of the ethical issues related to studying and
filming a family with challenges such as those of the family in the program.
Assign each team one or two ethical issues to explore. Ask students to include
in their discussion how studying this family may be helpful to scientists and
others, and how it could be both helpful and hurtful to the family. Have teams
share what they discussed. As an extension, have students research and present information on Turkey
and Turkish culture.
Suggested
points related to themes listed on the student handout:
Possible reasons for why some family members are handwalkers.
One scientists thinks the family members are "throwbacks" exhibiting
traits that have resurfaced after being absent for generations. Most scientists do not believe that ancient genes resurface in living
organisms. A team of German scientists believe there may be a gene or small set of
genes for bipedality. Many scientists believe bipedality cannot be traced to a
single gene, thinking that evolution usually proceeds more gradually and
involves many mutations. Some scientists think that brain damage may contribute to the five
siblings' inability to walk on two legs, although others with this sort of
damage have been known to walk on two legs. Some scientists think that environmental factors played a large role in
how the family members walk.
Treatment of the family by outsiders.
Family members experienced isolation and ridicule from members of their
community. Children threw rocks at family members, who were outcasts because of
their challenges. After they rebuilt their house and ran out of water, they
received no assistance from the community. The visiting scientists and film crew placed a spotlight on the family,
perhaps adding to the local tension. The crew and scientists working on the film brought the family walkers
and parallel bars, arranged for them to work with a physical therapist, and
took them to the beach.
Neurological tests that were performed and the conclusions drawn.
The neurologist gave family members simple tasks to complete. A
discrepancy arose between how well the siblings performed in front of the
neurologist and the skills they exhibited in private. For example, Safiye
didn't perform well using a pegboard, but later she was observed tying her
scarf. MRIs were used to study family members' brains. It was discovered that
Huseyin, Hacer, and Safiye each had a shrunken area in the middle of the
cerebellum. However, the presence of a small cerebellum may not be
enough to explain why these siblings walk on all fours, as other people with a
similar condition can walk upright.
Interactions among family members and the beliefs they hold.
Family members cared for and supported each other. The family believed God was testing them, and that they would be rewarded
after death for doing God's deeds in life. The family is Muslim and does not believe in evolution. The father felt
being compared to other species was degrading to his family.
Web Sites
NOVA—Family That Walks on All Fours
www.pbs.org/nova/allfours/
Find articles, interviews, interactive activities, and resources in this
companion Web site to the program.
Cerebellum
www.sci.uidaho.edu/med532/cerebell.htm
Explains the cerebellum's role in walking.
Laboratory of Neuroimaging
www.loni.ucla.edu/About_Loni/education/AB_Cerebellum.shtml
Describes the function of the cerebellum.
Turkish Culture Foundation
www.turkishculture.org
Provides information on many aspects of Turkish culture.
Books
The
Brain Explained
by Daniel Drubach. Prentice Hall, 2000.
Describes the structure and function of different parts of the brain and
disorders that can affect the brain.
Turkey
by Chris Eboch. Lucent Books, 2003.
Includes information on the geography of Turkey and Turkish culture.
The "Handwalkers Raise Questions" activity aligns with the following National
Science Education Standards (see
books.nap.edu/html/nses).
Grades 9-12
Science Standard C
Life Science
Biological Evolution
Classroom Activity Author
Developed by WGBH Educational Outreach staff.
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