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GENETICIST PARDIS SABETI
Video Summary
This video profile adapted from NOVA
scienceNOW profiles the life and work
of Harvard geneticist and biological
anthropologist Pardis Sabeti. Although
Sabeti spends many of her evenings on
stage, fronting her band Thousand
Days, her true passion is unraveling
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scientific puzzles. In 2006, Sabeti
developed a method for analyzing the human genome in search of genes that may
have arisen through natural selection. Her method is now widely used among
geneticists and evolutionary biologists in an effort to better understand how genetic
traits have evolved.
Topics Covered:
Recommended for Grades 6-12
– Life Science:
Genetics and Heredity
Media Type: QuickTime Video
Video Length: 5m 04s
Evolution and Diversity
Permitted use: Download, Share
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Discussion Questions
 What did Pardis Sabeti figure out? Why do you think it was considered a
scientific breakthrough?
 Why do you think she describes her breakthrough as a “wonderful
scavenger hunt”?
 What is meant by the term “resistant” in the context of disease-causing organisms?
Background Essay
Evolution and genetics once seemed worlds apart. While evolutionary biologists
generally charted the paths that organisms had taken in the past, geneticists attempted
to catalogue the present state of a species’ genetic makeup, often with the aim of
curing some human diseases in the future. By developing a system to analyze genetic
information through an evolutionary lens, Harvard scientist Pardis Sabeti has helped to
bridge the divide between these two scientific disciplines. Now she hopes that these
new tools may one day help eliminate some of the world’s deadliest diseases.
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Scientists have known for more than a century that evolution proceeds through a
process of natural selection. Traits that are beneficial to an organism and improve that
individual’s chances of survival and reproduction are more likely to be passed on to
future generations. Traits that are detrimental to survival are less likely to be passed on.
The concept of genes and their relation to an organism’s traits and to inheritance was first
suggested by Gregor Mendel in the 1860s, based on his studies of pea plants. Despite
tremendous advances since then in our understanding of what genes are and how they
function, the way in which genes are selected for and become more common in a
population has remained something of a mystery. In addition, hypotheses regarding the
path of evolutionary change have proven difficult to test.
Pardis Sabeti helped to resolve these two mysteries by developing a method to analyze
the human genome in search of the signs of natural selection. Although the genetic
difference between one person and the next is a scant 0.01 percent, the differences that
exist can be telling. Scientists think that common genetic variations that have arisen
relatively recently are clear signs of the work of natural selection. The method that Sabeti
developed analyzes such common variations to determine how long ago they arose in
the population. In this way, she has identified several variations that have likely been
favored by evolution. As an example, Sabeti points to the mutation that causes sickle cell
anemia. Although this mutation causes disease in people who inherit a copy from both
parents, it offers malarial resistance to individuals who possess only one copy. Indeed,
Sabeti found that the sickle cell mutation became prevalent quite recently in evolutionary
terms in regions were malaria is prevalent.
Sabeti has more recently turned the focus of her analysis from human evolution to the
evolution of disease-causing organisms, including the parasite that causes malaria. She
hopes that by identifying regions of a parasite’s genome that have been favored by
evolution, the analysis might also reveal genetic vulnerabilities that could be more
effectively targeted by medicine. The malaria parasite and many other disease-causing
microorganisms have proven their ability to adapt quickly and become resistant to
medications used to fight them. Sabeti’s hope is that by identifying a vulnerability in this
process, scientists will one day be better able to fight, and perhaps eliminate, diseases
including malaria, tuberculosis, and HIV/AIDS.
To learn more about he connection between natural selection and genetics, check out The
Common Genetic Code, Mendel’s Laws of Genetic Inheritance, and Some Genes Are
Dominant.
To learn more about the rapid evolution of microorganisms, check out Microbe Clock.
Curricular Standards Correlations:
Geneticist Pardis Sabeti
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NSES, Project 2061, MCREL, and state standards correlations available at
www.teachersdomain.org. (Free registration required for your specific state standards correlated to this resource.)
Source: NOVA scienceNOW: “Profile: Pardis Sabeti”
Materials used courtesy of:
Pardis Sabeti and Ben Fry.
Attribution to be distributed with this media asset: Geneticist Pardis Sabeti.
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Geneticist Pardis Sabeti
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