The Genographic Project recently released the most refined evolutionary tree of the human Y chromosome, which every male inherits directly from his father. The new Y tree was created in part through the help of the 300,000 male participants that have joined this one-of-a-kind project to trace their own ancestry and become citizen scientists.
As more people participate in the Genographic Project, we are able to fill in branches and gaps on the entire human family tree, and gain new insights on our ancient past. We wanted to outline how this new tree affects our understanding of our shared ancestry, and what it means for current and future project participants.
Why should I be excited about the new tree?
Each human male carries a series of DNA mutations in his Y chromosomes that records a portion of the story of humanity. The story begins with a common ancient ancestor that lived in East Africa more than 150,000 years ago. The paternal tree, or “Y tree,” is a map that illustrates this deep-rooted relationship, and how billions of his descendants have expanded around the world. During that expansion, these descendants acquired and maintained mutations or changes in their DNA that occurred at particular times and places. The new Y tree illustrates the progressions of these known mutational events showing the many ways all people are related. The new tree is particularly exciting if you are a male and a Genographic Project participant, since you will see that your own results are now even further refined!
How did Genographic Project Participants help create the new Y tree?
The Geno 2.0 DNA Ancestry Kit invites participants to test their own ancient ancestry by submitting a DNA sample to the project. Participants can then choose to opt into Genographic Project scientific research to have their DNA results compared to those of thousands of other participants. When comparing the DNA, Genographic scientists look for changes or mutations in participants’ results that help determine when new lineages may have begun. Since changes accumulate over time, a large number of differences between two DNA samples would indicate the two lineages diverged long ago. Few differences would indicate a more recent split.
How different is this Y chromosome tree to the previous versions used by the Genographic Project? The number of branches nearly doubled from 667 to more than 1,200 on our new paternal tree. As a result, new connections and new bifurcations (branch splitting) have since emerged. For example, haplogroup C (a male lineage common in South Asians) now shows patterns of deep-rooted relatedness among East Asians, Aboriginal Australians, and Native Americans.
The overall structure of the tree remains consistent with past versions, thus not affecting major haplogroup (or lineage) designations. However, more branches mean greater geographic specificity–helping us narrow down where specific lineages are found and when they originated.
What does this mean for Genographic Project Participants’ results? Male results may have changed slightly since we gained greater insights into the paternal migratory paths and discovered new branch tips on the shared Y tree. In particular, we gained a new understanding of internal branching patterns of the tree and of events that occurred between 10,000 and 60,000 years ago as humans moved to populate every corner of the earth.
What’s next? We are looking at the maternal ancestral tree right now and should have additional information featuring your input in the weeks to come.
This is an exciting moment for The Genographic Project as we can actively show the power of participant involvement in advancing genetics and anthropology. So, thank you again, and please continue to reach out to us with your questions and your stories.