23andMe Blog

Robin Smith, 23ndMe Senior Scientist


When did that 2 percent Yakut ancestry make its way into your family tree?
The newest <a href="https://www.23andme.com/dna-ancestry">23andMe Ancestry feature</a> may have the answer for you.
This feature is another first for 23andMe, which broke new ground by offering customers a detailed accounting of their genetic ancestry with the Ancestry Composition report. Customers who have connected accounts with a parent can also see what ancestries were inherited from each side of the family tree. The Ancestry Composition report also allows customers to dig deeper into their genetic ancestry with a genome map of their ancestry. (To learn more about this feature, see the <a href="https://blog.23andme.com/23andme-and-you/23andme-how-to/meet-your-chromosome-painting/">Meet Your Chromosome Painting</a> blog post.)


Now, 23andMe has added a fourth analysis to the report, which we call <a href="https://www.23andme.com/dna-ancestry/">&#8220;Ancestry Timeline.&#8221;</a> This feature allows customers to go back in time and learn approximately when a particular ancestry entered their family tree.

Ancestry Timeline was made possible through pioneering work by 23andMe Research Scientist <a href="https://blog.23andme.com/23andme-research/a-conversation-with-23andmes-kasia-bryc/">Kasia Bryc</a>, whose previous <a href="https://blog.23andme.com/23andme-research/dna-usa-2/">research provided insights into the American melting pot</a>.
<div id="attachment_25230" style="width: 881px" class="wp-caption aligncenter"><img loading="lazy" decoding="async" aria-describedby="caption-attachment-25230" class="wp-image-25230 size-large" src="https://blog-api.23andme.com/wp-content/uploads/2017/04/ancestry_timeline_sarah_antonio-871x1024.png" alt="" width="871" height="1024" srcset="https://blog-api.23andme.com/wp-content/uploads/2017/04/ancestry_timeline_sarah_antonio-871x1024.png 871w, https://blog-api.23andme.com/wp-content/uploads/2017/04/ancestry_timeline_sarah_antonio-255x300.png 255w, https://blog-api.23andme.com/wp-content/uploads/2017/04/ancestry_timeline_sarah_antonio-768x903.png 768w, https://blog-api.23andme.com/wp-content/uploads/2017/04/ancestry_timeline_sarah_antonio-748x880.png 748w, https://blog-api.23andme.com/wp-content/uploads/2017/04/ancestry_timeline_sarah_antonio-1003x1180.png 1003w" sizes="auto, (max-width: 871px) 100vw, 871px" />According their Ancestry Composition results, Sarah is about 25% British &amp; Irish and Antonio is about 20% Iberian. The Ancestry Timeline feature puts these results in a new context. Sarah likely had a recent ancestor (a grandparent, great-grandparent, or 2nd great-grandparent) who was 100 percent British &amp; Irish, while you have to go pretty far back on Antonio&#8217;s family tree to find someone who was 100 percent Iberian (5-8 generations ago.)</div>
23andMe determines your Ancestry Timeline by analyzing the pattern of ancestry in your genome. It looks at both the number and size of segments that derive 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.
An important caveat of the Ancestry Timeline feature is that it assumes that your ancestry from each population originally comes from a single (recent or distant) ancestor.
It also says nothing about where a particular ancestor was born—only their genetics. Therefore, a British &amp; Irish ancestor born in Philadelphia would look the same as one born in Dublin. Ancestry Timeline also has the same limitations as Ancestry Composition, in that it doesn&#8217;t report contributions by recently admixed populations (e.g. &#8220;Mexican&#8221; ancestry is reported as a mixture of European, Native American, and African ancestry) and trace ancestries (e.g. &lt;0.5 percent) should be taken with a grain of salt.


For a more technical explanation of how the Ancestry Timeline feature works, <a href="https://permalinks.23andme.com/pdf/23-14_admixture_date_estimator.pdf">read our white paper</a>.

ancestry timeline

23andMe’s New Ancestry Timeline

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