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I was aware that AncestryDNA would be reducing the number of DNA matches to something more reasonable (see, for example, When Less is More), so I was fully prepared for a significant reduction in DNA matches for myself and my parents. However, I expected some consistency with what would be done (whether I agreed with it or not), but in my limited experience, this is not what has happened.
As of 19 November 2014, when AncestryDNA made their changes, both my parents and myself had a reduction in the number of matches:
All our known ancestors are from the UK and since the AncestryDNA test isn't yet available in the UK (although it is expected to be available sometime early in 2015), we don't have any shaky leaf hints except with each other, and my father with the cousin discussed below. We also don't have any of the new DNA circles, as I selected Family Tree DNA for testing other relatives (about 25 of them to date); only my parents and I have been tested at all of the "Big 3" testing companies for autosomal DNA (23andMe is the third one).
Before the recent change at AncestryDNA, my father and I each had a shaky leaf hint with Deb, a known 4th cousin of mine (3rd cousin x1 removed for Dad), who for both of us was shown as a low confidence match, with an estimated relationship of 5th-8th cousin. Unfortunately, AncestryDNA doesn't provide any chromosome browser or any other tools tools for us to compare our DNA data on their website. However, because we all uploaded our data to the wonderful FREE website GEDmatch, we were able to see where we had matching DNA with Deb. There is a universal desire across the genetic genealogy community for AncestryDNA to provide information on the matching segments and/or some tools for us to do this ourselves, but they have been totally resistant to providing a chromosome browser or any tools whatsoever. They have purposely provided a "dumbed down" product, as they know that the majority of Ancestry users wouldn't use it; however, it is very disappointing that they refuse to provide any tools for those of us who would understand how to use them. See Chromosome Browser War (Roberta Estes, DNAeXplained, 30 Nov 2014) for a detailed explanation why this is so important – this blog posting also shows the difference between what AncestryDNA doesn't provide compared with the useful and essential tools that Family Tree DNA and 23andMe have available.
Using GEDmatch, I was able to do comparisons with the following kits:
The table below shows the matching DNA on doing one-to-one comparisons on GEDmatch, which illustrates that Dad and I share the identical segment on Chromosome 12, and this applies to whether phased data (see Phasingfor an explanation) are compared or not – we both share 8.5 cM with Deb on Chromosome 12. My paternal uncle shares more DNA with Deb, a total of 30.9 cM across 3 segments (7.4 cM on Chromosome 6, 15.0 cM on Chromosome 9, and the same 8.5 cM segment as Dad and me on Chromosome 12) – he hasn't been tested at AncestryDNA. When doing one-to-one comparisons on GEDmatch (Deb vs. Dad and my phased kit), I also checked using a minimum segment length of 1 cM, rather than the default of 7 cM, which shows we also have another short matching segment (4.3 cM for Dad and 3.7 cM for me) on Chromosome 9 over the same area as the 15.0 cM segment my uncle has, so this is likely to be "real" (IBD). With the addition of the short segments (we don't have any others besides this one), Dad and I share 12.8 cM and 12.2 cM, respectively, and Deb and my Uncle share >30 cM.
- My father formerly had 17,527 matches and now has 1514 matches (91% reduction)
- My mother formerly had 12,469 matches and now has 1441 matches (88% reduction)
- I formerly had 13,898 matches and now have 1720 matches (88% reduction)
All our known ancestors are from the UK and since the AncestryDNA test isn't yet available in the UK (although it is expected to be available sometime early in 2015), we don't have any shaky leaf hints except with each other, and my father with the cousin discussed below. We also don't have any of the new DNA circles, as I selected Family Tree DNA for testing other relatives (about 25 of them to date); only my parents and I have been tested at all of the "Big 3" testing companies for autosomal DNA (23andMe is the third one).
Before the recent change at AncestryDNA, my father and I each had a shaky leaf hint with Deb, a known 4th cousin of mine (3rd cousin x1 removed for Dad), who for both of us was shown as a low confidence match, with an estimated relationship of 5th-8th cousin. Unfortunately, AncestryDNA doesn't provide any chromosome browser or any other tools tools for us to compare our DNA data on their website. However, because we all uploaded our data to the wonderful FREE website GEDmatch, we were able to see where we had matching DNA with Deb. There is a universal desire across the genetic genealogy community for AncestryDNA to provide information on the matching segments and/or some tools for us to do this ourselves, but they have been totally resistant to providing a chromosome browser or any tools whatsoever. They have purposely provided a "dumbed down" product, as they know that the majority of Ancestry users wouldn't use it; however, it is very disappointing that they refuse to provide any tools for those of us who would understand how to use them. See Chromosome Browser War (Roberta Estes, DNAeXplained, 30 Nov 2014) for a detailed explanation why this is so important – this blog posting also shows the difference between what AncestryDNA doesn't provide compared with the useful and essential tools that Family Tree DNA and 23andMe have available.
Using GEDmatch, I was able to do comparisons with the following kits:
- My father: GEDmatch kit # A961084
- Me (Sue): GEDmatch kit # A229901 and paternal phased kit # PA229901P1
- 4th cousin Deb: GEDmatch kit # A145432
- My Uncle: GEDmatch kit # F315518
The table below shows the matching DNA on doing one-to-one comparisons on GEDmatch, which illustrates that Dad and I share the identical segment on Chromosome 12, and this applies to whether phased data (see Phasingfor an explanation) are compared or not – we both share 8.5 cM with Deb on Chromosome 12. My paternal uncle shares more DNA with Deb, a total of 30.9 cM across 3 segments (7.4 cM on Chromosome 6, 15.0 cM on Chromosome 9, and the same 8.5 cM segment as Dad and me on Chromosome 12) – he hasn't been tested at AncestryDNA. When doing one-to-one comparisons on GEDmatch (Deb vs. Dad and my phased kit), I also checked using a minimum segment length of 1 cM, rather than the default of 7 cM, which shows we also have another short matching segment (4.3 cM for Dad and 3.7 cM for me) on Chromosome 9 over the same area as the 15.0 cM segment my uncle has, so this is likely to be "real" (IBD). With the addition of the short segments (we don't have any others besides this one), Dad and I share 12.8 cM and 12.2 cM, respectively, and Deb and my Uncle share >30 cM.
| Comparison (GEDmatch #s) | Chromosome | Start Location | End Location | cM | SNPs |
|---|---|---|---|---|---|
| Deb (A145522) vs. Dad (A961084) | 12 | 128881883 | 132276195 | 8.5 | 1072 |
| Deb (A145522) vs. Sue (A229901) | 12 | 128881883 | 132276195 | 8.5 | 1072 |
| Deb (A145522) vs. Sue (PA229901P1) | 12 | 128881883 | 132276195 | 8.5 | 1070 |
| Deb (A145522) vs. Uncle (F315518) | 6 | 123277300 | 130092303 | 7.4 | 1315 |
| 9 | 74117429 | 85135617 | 15 | 2914 | |
| 12 | 128881883 | 132276195 | 8.5 | 1073 |
It is therefore really odd that although Deb has a shaky leaf hint with my father as previously (shown as predicted 5th-8th cousin, with a confidence of moderate), Deb has disappeared from my AncestryDNA match list. Since the longest segment my father and I share with Deb is identical and seems to be above AncestryDNA's minimum segment length to be declared a match of ~6 cM, I'm really puzzled why she isn't on my DNA match list any longer. My parents and I have all been tested at AncestryDNA and linked appropriately on my tree, so AncestryDNA is able to use my fully phased results for identifying appropriate DNA matches. If you have any suggestions for why this has happened, please add a comment below.
The only "logical" explanation I can think of is that maybe AncestryDNA is taking into account gender for determining the length of a segment, although that doesn't make any sense to me when they have my phased data (and I haven't heard any mutterings about this). When I check on Rutger's Map Interpolator, which uses their smoothed v.2 maps (Build 36), the sex averaged result for positions 128881883-132276195 on Chromosome 12 is 8.5 cM, with the Female and Male values being 4.9 cM and 13.7 cM, respectively – so my "female" segment is then well below 6 cM. Ann Turner, one of my favorite responders on the DNA-NEWBIE message board, provided instructions for how to use this interpolator (if you belong to this group, see Message 38320). Using my example:
I was waiting for Deb to "transfer" her AncestryDNA results to Family Tree DNA to see our match lists there before finishing this blog posting. I wasn't surprised to find on FTDNA that Deb and my Uncle are shown as matches, but neither my Dad nor I are. The reason for this is that besides requiring a minimum matching segment of ~8 cM to be declared a match, Family Tree DNA's algorithm also requires that the total matching segments (down to 1 cM) be at least 20 cM, in order to minimize the chance of false-positives. So my issue with AncestryDNA isn't that Deb didn't appear on my match list, but rather why they have appeared to have handled me differently from my father. But all of this emphasizes the importance of everyone uploading their data to GEDmatch, which allows you to select your own criteria for making comparisons between any two individuals (whether they on the "one-to-many" match list on GEDmatch or not).
In addition to uploading AncestryDNA results to GEDmatch, I also highly recommend that everyone also "transfers" their results to Family Tree DNA (only the results are transferred, not your actual DNA sample), so you are fishing in as many DNA ponds as possible. The cost for doing this has been permanently reduced to $39, so for those in the US, the most cost-effective way to be in 2 DNA databases is to test at AncestryDNA (regular price $99 + shipping, but there is currently a sale on until 21 Dec 2014 for $89, and you may be able to find a coupon code for free shipping), then transfer your results to Family Tree DNA (click on FTDNA Autosomal Transfer) for $39 (no sample required, so no shipping). If you have tested at 23andMe, you will be able to upload your results to GEDmatch – however, you won't be able to transfer your results to FTDNA unless you were tested with the V.3 chip; the 23andMe V.2 test (sold prior to November 24, 2010) and the 23andMe V4 test (sold from November/December 2013) are NOT compatible with FTDNA's Family Finder product.
By the way:
Please leave a comment if you have any idea why AncestryDNA has kicked my 4th cousin off my match list and yet she still is on my father's. Thank you.
The only "logical" explanation I can think of is that maybe AncestryDNA is taking into account gender for determining the length of a segment, although that doesn't make any sense to me when they have my phased data (and I haven't heard any mutterings about this). When I check on Rutger's Map Interpolator, which uses their smoothed v.2 maps (Build 36), the sex averaged result for positions 128881883-132276195 on Chromosome 12 is 8.5 cM, with the Female and Male values being 4.9 cM and 13.7 cM, respectively – so my "female" segment is then well below 6 cM. Ann Turner, one of my favorite responders on the DNA-NEWBIE message board, provided instructions for how to use this interpolator (if you belong to this group, see Message 38320). Using my example:
- On Rutger's Map Interpolator, select Chromosome 12 on the pull-down list
- For Query, select "physical positions (bp) only"
- In the box, put "128881883 132276195" (or you can put one position on one line and the other on a separate line)
- The output screen will appear as
No. Chr Query_Posn Sex_Ave_cM Female_cM Male_cM
1 12 128881883 167.4464 210.0233 126.4723
2 12 132276195 175.9759 214.8793 140.1783 - Subtract the respective values on row 1 from those on row 2 for Sex_Ave, Female, and Male
I was waiting for Deb to "transfer" her AncestryDNA results to Family Tree DNA to see our match lists there before finishing this blog posting. I wasn't surprised to find on FTDNA that Deb and my Uncle are shown as matches, but neither my Dad nor I are. The reason for this is that besides requiring a minimum matching segment of ~8 cM to be declared a match, Family Tree DNA's algorithm also requires that the total matching segments (down to 1 cM) be at least 20 cM, in order to minimize the chance of false-positives. So my issue with AncestryDNA isn't that Deb didn't appear on my match list, but rather why they have appeared to have handled me differently from my father. But all of this emphasizes the importance of everyone uploading their data to GEDmatch, which allows you to select your own criteria for making comparisons between any two individuals (whether they on the "one-to-many" match list on GEDmatch or not).
In addition to uploading AncestryDNA results to GEDmatch, I also highly recommend that everyone also "transfers" their results to Family Tree DNA (only the results are transferred, not your actual DNA sample), so you are fishing in as many DNA ponds as possible. The cost for doing this has been permanently reduced to $39, so for those in the US, the most cost-effective way to be in 2 DNA databases is to test at AncestryDNA (regular price $99 + shipping, but there is currently a sale on until 21 Dec 2014 for $89, and you may be able to find a coupon code for free shipping), then transfer your results to Family Tree DNA (click on FTDNA Autosomal Transfer) for $39 (no sample required, so no shipping). If you have tested at 23andMe, you will be able to upload your results to GEDmatch – however, you won't be able to transfer your results to FTDNA unless you were tested with the V.3 chip; the 23andMe V.2 test (sold prior to November 24, 2010) and the 23andMe V4 test (sold from November/December 2013) are NOT compatible with FTDNA's Family Finder product.
By the way:
- For a limited time, you can still download a list of your former matches before the culling, so especially in view of my experience here, I strongly recommend you do this while you still have the chance, in case you also had any legitimate matches in the past that you can no longer see. Go to your AncestryDNA Home page and click on SETTINGS (to the right of your picture, with the gear icon), then in the Actions box on the right, click on Download v1 DNA Matches.
- I've found a way to actually print off the detailed and technical Matching White Paper and also to "Learn More about DNA Circles" document. In addition to the latter being really hidden away if you aren't actually in a circle (see Debbie Kennett's blog posting Improved Cousin matching at AncestryDNA, 20 Dec 2014, for instructions for how to locate these), AncestryDNA also makes it extremely difficult to print more than a page of each document. They don't provide a link to a PDF, which could easily be printed off, and also if you try to use [Ctrl + A] to select all on a PC, that doesn't work either. But if you drag with your mouse to select the whole article, you can then copy everything and paste this into a Word document, but make sure you do this using the option to Keep Source Formatting. Virtually all of the formatting copies over very well, including the figures, equations, etc. Much as though I would like to provide an easy link here to the PDF I created myself from the resulting Word document, I didn't want to run the risk of having Ancestry's lawyers coming after me because of copyright issues! [NOTE: Debbie Kennett has posted a much easier way in the Comments section.]
Please leave a comment if you have any idea why AncestryDNA has kicked my 4th cousin off my match list and yet she still is on my father's. Thank you.
