A recent article in The American Journal of Human Genetics reveals a stunning new finding uncovered by Family Tree DNA, a subsidiary of Gene By Gene, Ltd., in regards to the lineage of the human Y chromosome. Gene By Gene, Ltd. is based in Houston and specializes in genetics and genomics testing. The report in the Journal is entitled “An African-American Paternal Lineage Adds an Extremely Ancient Root to the Human Y Chromosome Phylogenetic Tree” and is based on the study by Gene By Gene’s staff scientists Drs. Thomas and Astrid-Maria Krahn, as well as a member of the company’s advisory board, Dr. Michael F. Hammer of the University of Arizona. According to a recent press release the DNA sample that led to the discovery 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 Bonnie Schrack noticed that the sample was very unique and advocated for further testing to be done…The discovery took place at Family Tree DNA’s Genomic Research Center, a CLIA registered lab in Houston 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.
According to Dr. Hammer the results show that when the first anatomically modern humans began appearing approximately 195,000 years ago, the last common Y chromosome ancestor had already expired some years before. Dr. Hammer is quoted as saying that the sample in question, “which came from an African-American man living in South Carolina, matched Y chromosome DNA of males from a very small area in western Cameroon, indicating that the lineage is extremely rare in Africa 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 directto-consumer DNA testing companies can play in science; this might not have been known otherwise.” The published study appeared in The American Journal of Human Genetics earlier this month.