A 23andMe DNA test offers several features for researching your ethnicity and DNA relatives. These features have different limits on how far back in time they can go.
The 23andMe Ancestry Timeline goes back over 320 years to the year 1700, which represents from 8 to 11 generations.
The Recent Ancestor Locations in 23andMe’s ethnicity estimates go back 200 years.
23andMe DNA relatives extend to 5th cousins with common ancestors at 6 generations.
This article looks at the time spans of each feature in turn.
How Far Back Does The 23andMe Ancestry Timeline Go?
The Ancestry Timeline report gives an upper limit of the year 1700. 23andMe also labels this oldest section as being 8+ generations.
The report above is my 23andMe Ancestry Timeline. You read the timeline from left to right. I’ve highlighted the upper end i.e. the oldest section which is marked as starting from the year 1700.
The 23andMe white papers use an average of 30 years to represent a generation, so I’m not sure why they don’t label this as 10+ generations.
How to view the 23andMe Ancestry Timeline
The Ancestry Timeline is available from the Ancestry Overview page.
- Expand the Ancestry menu at the top of the page
- Choose “Ancestry Overview”
- Click the “View Report” link in the section titled Ancestry Timeline
How does the Ancestry Timeline go back several hundred years?
The Ancestry Timeline is based on your Ancestry Composition.
So, let’s take a look at how 23andMe goes back as far as the 1700s to estimate your ancestors’ ethnicities.
23andMe Reference Samples Attempt To Represent Older DNA
When 23andMe analyze your ethnicity, they compare your DNA to reference samples that they have grouped into 45 smaller regions. Here are some examples of these regions:
- Britain & Ireland
- Spain & Portugal
- Sudan
- Congo
- China
- Vietnam
- Southern Brahmin
- Melanesian
The reference DNA samples come from living (or recently living) people. But if these DNA samples are so recent, how can 23andMe say that they go back over 300 years?
The justification is in how they choose the reference DNA samples used to compare with your DNA test.
Choosing reference samples that represent several hundreds of years
23andMe choose their reference samples from academic genome studies and from their own customer base.
If you opt in to participate in 23andMe research, one of their questions is whether your four grandparents were born in the same country. They are trying to identify if your DNA represents a single ethnicity going back 80 to 100 years.
The next step for 23andMe is to review whether this country is likely to have a very settled population or whether there was a lot of inward migration from other areas.
So, if your four grandparents were born in the Americas or Australia, then you may not be a good candidate for a reference population.
However, if your four grandparents were born in the west of Ireland or in Finland, then your DNA may be typical of the local population going back many further generations.
23andMe Recent Ancestor Locations Go Back Up To 200 Years
23andMe introduced Recent Ancestor Locations to the Ancestry Composition report in 2018. This is a level below the regions. There are currently about 150 Recent Ancestor Locations.
As an example, my region of “Britain & Ireland” includes three locations:
- United Kingdom
- Ireland
- Guernsey
As suggested by the name, the intention is that these locations represent places your ancestors lived in within a more recent span than estimated by the regions.
The timeframe for Recent Ancestor Locations is within the last two hundred years.
How does 23andMe estimate your Recent Ancestor Locations?
The region estimates use reference panels that include public genome studies.
The difference with Recent Ancestor Locations is that the reference panel consists of 23andMe customers with known ancestry from these locations.
If large segments of your DNA match samples within these locations, you are assigned the same location.
But how does 23andMe “know” their customers’ ancestry? They are basing this knowledge on customers’ reported locations of their grandparents. This is why it is a shorter timeframe than the regions.
My verdict on Recent Ancestor Locations
I have tested with Ancestry.com and with MyHeritage. Both companies have similar features to 23andMe’s Recent Ancestor Locations.
You can check out my review of Ancestry’s genetic communities and MyHeritage’s genetic groups.
My experience is that both company’s features are highly accurate when it comes to my Irish heritage. My four maternal great-grandparents come from the same county in Ireland. Ancestry and MyHeritage locked in on a small number of adjacent counties.
In contrast, I am far less impressed with 23andMe. They assign locations across half of Ireland. Then they throw in places in Great Britain from as far north as Edinburgh down to Greater London in the South East of that island.
This bears no relation to my family tree.
How Many Generations Can 23andMe Go Back With DNA Relatives?
The 23andMe list of DNA relatives goes back as far as six generations.
These distant DNA relatives are estimated as 5th cousins, who share 4th great grandparents with you.
This handy table shows you how your more distant cousins fit into your genealogical family tree:
| Cousin | Generations | Great |
| 1st | 2 | grand |
| 2nd | 3 | great |
| 3rd | 4 | 2nd great |
| 4th | 5 | 3rd great |
| 5th | 6 | 4th great |
However, you may only see fourth cousins in your list of DNA relatives. This is because the company puts a cap on the number of DNA matches they show you.
How many generations in the 23andMe Genetic Tree?
23andMe has a feature called the Genetic Tree. This attempts to calculate the position of your DNA relatives in your family tree.
We have a separate article that explains the 23andMe genetic tree.
The furthest DNA relative that 23andMe predicts for me is an estimated 3rd cousin. This would four generations through my 2nd great-grandparents.
Personally, I don’t find this feature particularly useful. But that’s because 23andMe has only placed one DNA relative in my tree. You may find it more enlightening.
How Far Do Other DNA Tests Go Back?
Ancestry.com is 23andMe’s big rival in consumer DNA testing. Both companies do autosomal DNA testing, which means that their timeframes should be broadly similar.
However, Ancestry.com claims its DNA test goes a lot further back in terms of insights. Check out my review of how far back Ancestry DNA tests go. I go into which of their time estimates are more credible than others!
You can also upload your 23andMe DNA results to MyHeritage for free, although you may need to pay a fee to view advanced ethnicity features. Check out our article on how far back MyHeritage goes.
Going Back To Ancient Origins With Your DNA Results
You can upload your 23andMe results for free to the GEDmatch website. This gives you access to a set of tools that explore ancient origins within your DNA.
GEDmatch has a suite of different tools that try to calculate different ancient origins within your results. For example, some estimate percentages of Hunter-Gatherer versus Neolithic Farmer in your DNA.
The site also lets you review your shared DNA with more distant DNA relatives than other sites.
You can get more details on how to use these tools in our review on how far back GEDmatch goes.
