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Bushmen have
more diversity
By Tina Hesman Saey
An archbishop and four Bushmen walk
into a lab. What emerges is no joke, but a
more complete picture of human genetic
diversity than ever seen before.
A new study of five Africans has identified more than 1 million new human
genetic variants and could contribute
to a better understanding of the genetics underlying many human diseases.
The data might also lead to more effective medications for Africans, who often
derive less benefit from drugs than the
people of European ancestry who are
the most common test subjects in drug
development trials.
Archbishop Desmond Tutu and four
Bushmen leaders from Namibia contributed their DNA for the new study, published in the Feb. 18 Nature. Researchers
decoded the complete genetic blueprint
of Tutu, who belongs to the Bantu ethnic
group, and !Gubi, one of the Bushmen.
The international team also deciphered
the protein-coding portions of the three
who was not involved in
the project.
The new research
also reveals evidence of
mixing between hunter-gatherer Bushmen and
agricultural Bantu people. Tutu has a female
heritage marker usually found only in Bushmen, indicating that the
archbishop has a female
Bushmen ancestor. And
one of the Bushmen has
a type of Y chromosome
often found in Bantu
men, indicating a Bantu
male ancestor.
The new study could help scientists
assess newly discovered links between
genetic variation and disease, says
Stephan Schuster, a geneticist at Pennsylvania State University in University
Park and one of the project’s leaders. For
instance, a variant in the LIPA gene has
been linked to a fatal lipid metabolism
disorder called Wolman syndrome. But
three of the Bushmen carry the variant
and are still in good health at approximately 80 years old, possibly indicating
that the change is not actually disease-causing or that other genetic variants
might counteract it.
!Gubi is one of four Bushmen who participated in a
study of genetic diversity in southern Africans.
other Bushmen’s genomes.
The data confirm that the Bushmen
are among the most genetically diverse
people in the world and reveal about
1. 3 million previously unknown variations in all five men’s genomes. These
variations, called SNPs, change a single
nucleotide, or chemical building block,
of DNA.
Because African populations are not
well represented in genomic studies,
this research “is going to set the stage
for future studies in Africa,” says Sarah
Tishkoff, a human geneticist at the University of Pennsylvania in Philadelphia
Driving hazardous to cell phone use
Operating a car impairs drivers’ ability to recall information
By Bruce Bower
Phones don’t just interfere with driving — it turns out the reverse is also true.
Driving dents the capacity to describe
and remember information in cell phone
messages, at least for some of the young-
est and oldest drivers, a new study finds.
These subjects had a harder time relay-
ing stories they had heard in cell phone
messages while driving, say psychologist
Gary Dell of the University of Illinois at
Urbana-Champaign and his colleagues.
Driving skills also took a hit while subjects retold the stories, the investigators
say. Earlier studies have found that driving worsens while talking on cell phones
or sending text messages.
This new research challenges the
notion that conducting important business conversations while driving boosts
productivity.
“Safety concerns aside, if the quality
of a conversation matters to your business, then it is best to reserve your conversation for times when you are not
operating a motor vehicle,” remarks psychologist David Strayer of the University
of Utah in Salt Lake City.
S. SCHUSTER
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