Thursday, December 13, 2012

Seismic Shift in Genetic Genealogy

It seems like the entire landscape of genetic genealogy has shifted in the last week. What magnitude on the Richter Scale were the shakes that led to this amount of widespread and almost simultaneous change? Only time will tell as to which of theses events will have the most lasting impact.

First we had 23andMe upgrading their "Ancestry Painting" feature. That feature previously had been interesting enough for it to form the central analysis tool for Bryan Sykes to analyze a couple dozen American genomes and generate his recent travelog DNA USA: A Genetic Portrait of America. Now their upgrade to "Ancestry Composition" is much more interesting and informative. The company followed that up with a blockbuster announcement of a permanent reduction of their test to $99. 

Wedged in between these two events National Geographic and explorer in residence, Spencer Wells began to release the first results of their Genographic Project, Geno 2.0.

Then Family Tree DNA (FTDNA) unveiled a major upgrade to their website and their database that will cause all of us who have tested there to reassess our results. All the pieces of the revamped website are not fully funcioning yet but the results are extremely interesting: 
Previously only exact full mitochondrial matches were displayed. Now those within a couple of mutations can also be viewed. This is an extension of similar latitude previously shown in displaying results on partial mitochondrial results.

Y-chromosome results have been re-calibrated and this will change with whom some of those tested match and don't match. Even for those who still match the same individuals, the probabilities of how many generations ago that match occurred are likely to have changed.

Within our Dowell DNA Project we have triangulated 111 marker Y-chromosome results of living descendants of three of the sons of my 6th great-grandfather. Through this process we have been able to reconstruct what the 111 marker DNA signature would have been of Philip Dowell, Sr. who died in 1733. The recent changes in the FTDNA database do not change our overall result. However, they reduce the mutations of some of us who participated  in this process. The chart immediately shows our descendancy from Philip:

Before the re-calibration of the database, the living descendants, who are represented by the lowest boxes in each column, had a combined total of 10 mutations from Philip, Sr. Today they are shown as having 8. From left to right: the descendant of Philip, Jr., still has 2 mutations over the generations. The descendant of John dropped from 6 to 5 mutations. The two of the descendants of Peter, Sr., previously were shown as have 1 mutation each and the third was shown as having no mutations. The revised results show two with no mutations and one still having a single mutation over the generations. Are these revisions significant? They don't change the previously predicted DNA signature of Philip, Sr. However, in borderline cases, it could change whether two men were shown as matches or did not ever show up on each others results pages.

Other 111 marker matches with different surnames, who were previously shown as having a genetic distance of 9 or 10, now show up as having a genetic distance of 5. No new men joined this cluster as a result of the changes in reporting.

The events of the last few days make one think, "Everything I knew about genetic genealogy has changed." But then we haven't heard anything from Ancestry lately. I wonder how long it will take them to try to get back in the spotlight?


  1. I am going to try and find out what Ancestry plan on DNA for WDYTYA in February 2013. I would like to think they are planning something.

  2. Brian,
    With the speed that things seem to be moving, WDYTYA will be a long time out of the spotlight for Ancestry. If it truly is in the company's business plan to expand European testing, one would think they would have a presence there.
    Wonder if they are waiting for RootsTech in March which is essentially on their home court.

  3. This is horrible news to Project ADM.'s because we will have to re-access everyone in their projects, to determine there Matches, again .... with members of over 100, under me It will be a daunting task.

  4. Thank you for highlighting recent developments and linking to more information about them.

    The assumption in your family box chart is a bit of a problem, however. While DNA testing can show who shares common ancestors, an untested ancestor can not be deemed "proved," no matter how well documented a paper trail may be. Even if your Philip Sr. believed those three sons to be his children, that may not have been so.

  5. Geolover,

    Theoretically anything is possible--no matter how improbable it may be. Christening records for the sons exist. They are listed in Philip, Sr.'s will and DNA tests also support the conclusion that these three share a common male ancestor. You don't get much more certainty than this even if you have an affidavit from the biological mother.

    I fully realize that according to scientific method one never PROVES a hypothesis but one can disprove a series of hypotheses that help us close in on the truth. This relationship has, in my opinion, been proved beyond a reasonable doubt. I would consider new evidence if it should be presented to me; but I will not spent one second of my time seeking new evidence when there are so many other relationships that do not begin to reach anywhere near this level of proof.