Behind the Science

The fossil record places human origins in Africa, but science continues to search for details about the incredible journey that took Homo sapiens to the far reaches of the Earth. How did each of us end up where we are? Why do we have such a wide variety of colors and features?

Such questions are even more remarkable in light of genetic evidence that we are all descended from a common African ancestor who lived only 140,000 years ago.

Through the eons of time, the full story remains clearly written in our genes. 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 random mutations, which become what are called genetic markers. The order in which these markers occur allows geneticists to trace our common evolutionary time line back many generations.

Different populations carry distinct genetic markers. Following the markers through the generations reveals a genetic tree on which today’s many diverse branches can be followed backward to their common African root.

The markers still present in our genes allow us to chart ancient human migrations from Africa across the continents. Through these markers, we can see living evidence of an ancient trek to populate the globe.

The GenoChip

In 2012 the Genographic Project developed a cutting-edge tool called the GenoChip, which has been designed for the study of genetic anthropology. In 2015, we updated the chip to a new, and larger version. Using scientific information gleaned from the first phases of the Genographic Project, the new GenoChip included a unique collection of more than 750,000 markers that we believe offer the richest ancestry-relevant information. Both chips were created in collaboration with our lab partners at Family Tree DNA.

Next Generation Sequencing

In collaboration with Helix laboratories, Genographic is now also using next generation sequencing to achieve a product called Exome+. Instead of scanning the genome for mutational spots using a chip, next generation sequencing reads the code written in your DNA, thus allowing more in depth analysis. The “exome” is comprised of all the DNA that encodes for proteins—and because proteins are the machinery of your cells, the exome represents the most important and well-studied pieces of your DNA. Exome+ is the largest and richest data set available to consumers today, and represents 100 times more data than previously available products. The Helix technology is the same technology used by hospitals and researchers around the world. By participating, consumers contribute to the larger community, taking part in a real-time research project and, in the process, learning something new and fascinating about themselves.

Both of these advanced technologies enable us to determine new components of ancestry, with thousands of newly-identified markers on the Y chromosome, and provides the highest mitochondrial DNA resolution. It allows us to decipher the regional affiliations of mixed populations, enabling you to learn what percentage of your genome is affiliated with specific geographic regions around the world.