"...National Geographic and IBM are now in the midst of the international "Genographic Project" documenting the genealogy of hundreds of thousands of people around the world..." MISSOURI, High school project traces students' genetic roots, Steve Giegerich, St. Louis Post-Dispatch, February 17, 2008.
The National Geographic Society, IBM, geneticist Spencer Wells, and the Waitt Family Foundation have launched the Genographic Project, a five-year effort to understand the human journey—where we came from and how we got to where we live today. This unprecedented effort will map humanity's genetic journey through the ages.
The fossil record fixes human origins in Africa, but little is known about the great journey that took Homo sapiens to the far reaches of the Earth. How did we, each of us, end up where we are? Why do we appear in such a wide array of different colors and features?
Such questions are even more amazing in light of genetic evidence that we are all related—descended from a common African ancestor who lived only 60,000 years ago.
Though eons have passed, the full story remains clearly written in our genes—if only we can read it. With your help, we can.
When DNA is passed from one generation to the next, most of it is recombined by the processes that give each of us our individuality.
But some parts of the DNA chain remain largely intact through the generations, altered only occasionally by mutations which become "genetic markers." These markers allow geneticists like Spencer Wells to trace our common evolutionary timeline back through the ages.
"The greatest history book ever written," Wells says, "is the one hidden in our DNA."
Different populations carry distinct markers. Following them through the generations reveals a genetic tree on which today's many diverse branches may be followed ever backward to their common African root.
Our genes allow us to chart the ancient human migrations from Africa across the continents. Through one path, we can see living evidence of an ancient African trek, through India, to populate even isolated Australia.
But to fully complete the picture we must greatly expand the pool of genetic samples available from around the world. Time is short.
In a shrinking world, mixing populations are scrambling genetic signals. The key to this puzzle is acquiring genetic samples from the world's remaining indigenous and traditional peoples whose ethnic and genetic identities are isolated.
But such distinct peoples, languages, and cultures are quickly vanishing into a 21st century global melting pot.
That's why the Genographic Project has established ten research laboratories around the globe. Scientists are visiting Earth's remote regions in a comprehensive effort to complete the planet's genetic atlas.
But we don't just need genetic information from Inuit and San Bushmen—we need yours as well. If you choose to participate and add your data to the global research database, you'll help to delineate our common genetic tree, giving detailed shape to its many twigs and branches.
Together we can tell the ancient story of our shared human journey.
But what about the disappearing languages and diluting cultures? What can be done to help preserve and perpetuate those stories? Proceeds from the sales of the Genographic Public Participation Kits support the Genographic Legacy Fund, a primary component of the overall Project. Through the extension of grants, the Fund aims to empower indigenous and traditional peoples trying to revitalize their communities on a local level while at the same time helping to raise awareness on a global level of the challenges and pressures facing traditional communities around the world. Learn more about the Genographic Legacy Fund and the grant application process >>
Learn more about the power of genetics and the scientific work going on at the Genographic Project. Our Computational Biology Center (CBC) team, part of IBM’s global Research organization, will provide regular updates here at CompBio Central.
A genetics refresher
For our introductory CompBio Central article, we thought it would be helpful to describe some of the key concepts behind the Genographic Project and the use of genetics to study our migratory history.
DNA-matter of heredity
The most significant biological material we inherit from our parents is the DNA that we carry in our cells. The DNA, which carries our genetic instructions, is wrapped as chromosomes. In humans, there are 23 pairs of chromosomes-one set from the mother, the other from the father. Of these, 22 are like pairs, but the 23rd pair is different. In females this pair has two like chromosomes called X. Males have one X and one Y. The Y chromosome is transmitted from fathers only to their sons.
In addition to the DNA in our chromosomes, we also inherit the DNA carried in mitochondria, a structure within each cell, which we inherit exclusively from our mother.
It takes two
As cells divide to produce new cells, they replicate the DNA within to give each new cell a genetically identical copy of the parent cell. The cell division that produces eggs (female) or sperm (male) in our reproductive system is different in two ways.
- The resulting new cell (egg or sperm) has only one set of chromosomes, not a pair.
- The composition of each chromosome in the new cell is a recombination of segments from maternal and paternal chromosome pairs in the parent cell.
Each resulting egg or sperm is genetically distinct. But a major fraction of the Y chromosome does not undergo such recombination, since it is passed only from father to sons and is unaffected by the X chromosome from the mother. It is this unique feature that makes the Y chromosome useful to genealogists.
DNA sequence variations
Occasionally, the DNA copying process introduces mutations or variations in the DNA sequence, making the egg or sperm differ in sequence from the parental source. These mutations are carried into future generations and serve as markers of descent.
Markers of descent
Looking at non-recombinant portions of the human genome, it is possible to associate specific genetic variations to a population group and infer that they must share a common ancestor. We can also conclude that this common ancestor was the first individual with that mutation and has passed it on to all his or her descendents. Such markers of descent have been identified on the Y chromosome and mitochondrial DNA.
- The markers on Y chromosome describe the paternal line of ancestry-the father's father.
- The markers on mitochondrial DNA describe the maternal line of ancestry-the mother's mother.
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Consumers turn to their own DNA
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Roots of the family tree
March 12, 2006