March 26, 2013
Gene By Gene, Ltd.
-based genomics and genetics testing company, announced that a unique DNA sample submitted via National Geographic's Genographic Project to its genetic genealogy subsidiary,
Family Tree DNA
, led to the discovery that the most recent common ancestor for the Y chromosome lineage tree is potentially as old as 338,000 years. This new information indicates that the last common ancestor of all modern Y chromosomes is 70 percent older than previously thought.
The surprising findings were published in the report "An African American Paternal Lineage Adds an Extremely Ancient Root to the Human Y Chromosome Phylogenetic Tree" in
The American Journal of Human Genetics
earlier this month. The study was conducted by a team of top research scientists, including lead scientist Dr.
Michael F. Hammer
University of Arizona
, who currently serves on Gene By Gene's advisory board, and two of the company's staff scientists, Drs.
Thomas and Astrid-Maria Krahn
The DNA sample had originally been submitted to National Geographic's Genographic Project, the world's largest "citizen science" genetic research effort with more than 500,000 public participants to date, and was later transferred to Family Tree DNA's database for genealogical research. Once in Family Tree DNA's database, long-time project administrator
noticed that the sample was very unique and advocated for further testing to be done.
"This whole discovery began, really, with a citizen scientist – someone very similar to our many customers who are interested in learning more about their family roots using one of our genealogy products," said Gene By Gene President
. "While reviewing samples in our database, she recognized that this specific sample was unique and brought it to the attention of our scientists to do further testing. The results were astounding and show the value of individuals undergoing DNA testing so that we can continue to grow our databases and discover additional critical information about human origins and evolution."
The discovery took place at Family Tree DNA's Genomic Research Center, a CLIA registered lab in
which has processed more than 5 million discrete DNA tests from more than 700,000 individuals and organizations, including participants in the Genographic Project. Drs.
Thomas and Astrid-Maria Krahn
of Family Tree DNA conducted the company's Walk-Through-Y test on the sample and during the scoring process, quickly realized the unique nature of the sample, given the vast number of mutations. Following their initial findings, Dr. Hammer and others joined to conduct a formal study, sequencing ~240 kb of the chromosome sample to identify private, derived mutations on this lineage, which has been named A00.
"Our findings indicate that the last common Y chromosome ancestor may have lived long before the first anatomically modern humans appeared in
about 195,000 years ago," said Dr.
. "Furthermore, the sample, which came from an African American man living in
, matched Y chromosome DNA of males from a very small area in western
, indicating that the lineage is extremely rare in
today, and its presence in the US is likely due to the Atlantic slave trade. This is a huge discovery for our field and shows the critical role direct-to-consumer DNA testing companies can play in science; this might not have been known otherwise."
Family Tree DNA recently dramatically reduced the price of its basic Y-DNA test by approximately 50%. By offering the lowest-cost DNA test available on the market today, Gene By Gene and Family Tree DNA are working to eliminate cost as a barrier to individuals introducing themselves to personal genetic and genomic research. They hope that expanding the pool of DNA samples in their database will lead to future important scientific discoveries.