Discover more about your ancestors by learning approximately when a particular ancestry entered your family tree in a new feature called Ancestry Timeline. This feature, located within the Ancestry Composition report, was made possible through pioneering work by 23andMe Research Scientist Kasia Bryc, whose previous research provided insights into the American melting pot.
The Ancestry Timeline feature analyzes the pattern of ancestry in your genome by looking at both the number and size of segments that came from a particular ancestry as well as their distribution across your chromosomes. Large segments of ancestry in your genome that all come from the same population suggest a recent ancestor, while shorter segments suggest a more distant one. It is important to note that the Ancestry Timeline algorithm makes a notable assumption—that each ancestry was inherited from a single ancestor. For individuals from highly admixed populations, including Latinos and African Americans, the assumption that all of your ancestry from each population comes from a single ancestor may not be true.
Since the Ancestry Timeline feature uses only your DNA-based Ancestry Composition results and the pattern of ancestry in your genome to estimate when an ancestry entered your family tree, there are few key points you should keep mind when viewing your Ancestry Timeline.
Key Information about Ancestry Timeline
How To Use Ancestry Timeline
By analyzing the pattern of ancestry in your genome, Ancestry Timeline provides an estimate of how many generations ago you may have had a single ancestor who descended from a single population. This feature may be useful for:
- Learning about your genealogy.
- In figuring out which ancestors a particular ancestry may have been inherited.
- To help piece together the history of their likely migrations.
You can find out more ways to use this feature, by checking out our blog post.
When viewing your Ancestry Timeline, start on the left and work your way back in time as you move to the right. The estimated generation is presented as a range to allow for the randomness of how DNA segments in one person’s genome are passed down from an ancestor.
If you are using a desktop or laptop computer, you can also see the estimated birth year for each generation. This translation from generations to dates may be helpful in providing a timeframe for events in your family history. The generation birth dates are determined using the birth date you listed in your profile and an average generation time of 30 years*. It’s important to note that this generation length represents a population average and may not be accurate for your personal genealogy.
To print your Ancestry Timeline, click the Print button in the upper right corner of the page.
*Population geneticists have estimated that the number of years, on average, between the birth of an individual and their child’s birth is about 29 to 30 years. This estimate seems to be accurate even going back in time hundreds or thousands of years.
Using Ancestry Timeline When Multiple Ancestors Had the Same Ancestry
The Ancestry Timeline algorithm assumes that each ancestry was inherited from a single ancestor. For individuals from highly admixed populations, including Latinos and African Americans, the assumption that all of your ancestry from each population comes from a single ancestor may not be true. In these cases, the estimated number of generations for that ancestry should be used as a place to start rather than a definitive answer since the estimation may be more or less recent than expected.
You can explore the estimations provided in Ancestry Timeline by looking at where each ancestry is located on your genome in the Chromosome Painting feature.