I have just completed a major update of Warburton DNA Project documentation to reflect recent announcements and their impact on the project. This includes re-writing the DNA Project page itself, and several other documents.
The announcement of a new comprehensive test, the Big Y-700, complemented by the Y Tree and its Big Y Block Tree Matching Tool, has transformed the possibilities from DNA testing by making it easier to uncover the story in your Y-chromosome. I have produced a new document, the Warburton DNA Project Overview, to describe the project in the light of these announcements. The document replaces the old DNA Strategy document, and material previously on the DNA Project page.
The new announcements reflect the increased emphasis on SNP tests that I have discussed on a number of occasions over the past year. This is because SNP matches are definitive whilst STR matches are only indicative. A SNP occurred once in a particular individual. Everyone sharing that SNP is descended from that individual, and shares the sequence of preceding SNPs that defines their shared history. An STR match indicates a common ancestor, but because STR mutations are bidirectional it requires additional information, such as a common surname, to verify this. Also STR tests can only indicate very high level SNPs.
For these reasons the Warburton Project’s objectives would be best met if everyone took Big Y-700. But this would be an expensive approach. In reality a very good result can be achieved with a mix of Big Y-700, the original Y-37 STR test, and specific SNP tests.
I have produced a number of scenarios to help guide you to the most useful tests for you:
- Are you linked in a family tree to someone who has taken Big Y? You will share the Big Y result so repeating it will add little value. You may wish to verify your link to the Big Y result with a specific SNP test.
- Are you in a clan which is linked by an STR match to another clan where someone has taken Big Y? You will also share much of the Big Y result, but you will not know exactly where you diverge. A specific SNP test will do this by identifying your most recent shared SNP. However the earlier the shared SNP is, the more benefit will be obtained from another Big Y test. This will identify your later SNPs including your private variants, which will make dating the shared SNP more accurate, Your private variants may also become future branch points. The 700 STR results will provide a second mechanism for dating the common ancestor. In the Warburton DNA Project only members of the Lancashire and Cheshire Groups fall into the first two scenarios. All others are in one of the scenarios below.
- Are you in a group of two or more clans linked by indicative (STR) matches? In this case there is no Big Y result to provide SNPs for comparison. A Big Y test is required to provide these SNPs. However the result of that test is of interest across all the clans, offering an opportunity for cost sharing. You don’t have to be one of the original testers, provided you are confident of your relationship to him. However an upgrade from an earlier STR test will be cheaper. Once the Big Y result is obtained, with you members of the matching clans should then take specific SNP tests to determine the most recent SNP they share with you. This might be one of your personal variants.
- Are you in a clan that has an unmatched STR result, or matches contained within the clan? Here the best option is a Big Y test. There may be evidence that the original result was influenced by a non-paternal event. On the other hand it is possible a 700 year old Warburton clan is still quite small. The Big Y test may result in recent shared SNPs where the other parties have a different surname, giving a clue as to the origin of a non-paternal event. Or there may be no shared SNPs in the last 700 years, supporting the case for an old but small clan.
- Are you in a clan with no DNA result, or not in a published clan. In this case there are two options. A Big Y test will give a definitive result, but it just might turn out to be close to a previous Warburton Big Y result, and so provide little additional information. Starting with a Y-37 test might produce an indicative match, moving you into one of the above scenarios. A Y-37 followed by Big Y is a little more expensive than going straight to Big Y, but if a Y-37 can be followed by a few specific SNP tests it would be a lot cheaper.
In many situations a Big Y-700 result is the best route forward. Big Y-700 is expensive for many people, but the result is valuable for many people. This gives an opportunity for cost sharing. Also some cost relief arrives from the regular sales at Family Tree DNA. The last sale reduced the cost of the earlier Big Y test to below $500.
I propose to facilitate Big Y-700 testing by separating the process of identifying Big Y-700 test candidates from the process of funding the test. We should use the period between sales as follows:
- The scenarios in the Warburton DNA Project Overview will help you decide if you are a test candidate. I have also identified opportunities in the Lancashire and Cheshire Groups where a test is desirable.
- Anyone who believes they are a candidate and is willing to be tested should contact me, stating the extent to which they and their family members are willing to contribute.
- I will publicise (via Posts on the website) the test opportunities and seek further funding from people who will also benefit from the result, and from those in the wider Warburton community willing to contribute.
- The General Fund will be used to collect these contributions.
Other documents have been amended to reflect the change in emphasis on SNP testing, and to remove duplication. Documents affected include:
- DNA and its Uses in Genealogy has been simplified by removing material about my own use of DNA.
- My Use of DNA is a new document containing the bits removed from DNA and its Uses in Genealogy.
- DNA Results Commentary has a slight change of name and is updated to include recent results.
- The Cheshire Group is devoted to the Cheshire Group’s results, and is a commentary on the Cheshire Group Haplotree.
- The Lancashire Group is devoted to the Lancashire Group ‘s results, and is a commentary on a new document, the Lancashire Group Haplotree.
- Notes on the Cheshire Group TMRCA Calculations is material removed from the The Cheshire Group combined with the old Calculating Time to Most Recent Ancestor, which is removed.