Updated data here.
Thank you to everyone who has contributed data about shared DNA in people with Ashkenazic ancestry! I have 4000 data points to analyze, and that should help the entire genetic genealogy community (I'm still collecting data--you can find out more about the project and how to contribute here).So far I've been going through and finding anomalies in the data and contacting those submitters (if they left email addresses) to clarify some things.
I'm going to do some deeper statistical analysis once I get the data cleaned up, but meanwhile, here is a high-level look at the data so far. This data contains entries regardless of the percentage of Ashkenazi DNA (later posts will break down shared DNA based on how much Ashkenazi ancestry the testers have). This is using very rough data, but I wanted to get some initial information out there to hopefully help inform people while I work on cleaning the data and then analyzing results.
| Relationship | Number of submissions | Min total shared cM | Max total shared cM | Average total shared cM | Min largest segment | Max largest segment | Average largest segment |
| Parent/Child | 154 | 3379 | 3730 | 3524.72 | 203.4 | 284.26 | 269.23 |
| Siblings | 170 | 2246 | 3037 | 2677.77 | 56 | 281.5 | 185.91 |
| Half Siblings | 29 | 1286 | 2167 | 1819.24 | 79.4 | 253.7 | 150.87 |
| Grandparent/Grandchild | 25 | 1368 | 2312 | 1817.57 | 114.5 | 263.7 | 187.27 |
| Great Grandparent/Great Grandchild | 7 | 618 | 1001 | 785.56 | 67 | 126 | 97.93 |
| Great-great Grandparent/Great-great Grandchild | 1 | 511 | 511 | 511 | 88 | 88 | 88 |
| Uncle or Aunt / Niece or Nephew | 201 | 671 | 2303 | 1786.03 | 35 | 268.8 | 125.14 |
| Half Uncle or Half Aunt / Half Niece or Half Nephew | 17 | 763.3 | 1171 | 936.39 | 84.5 | 161.5 | 114.65 |
| Great-Aunt or Great-Uncle / Great-Niece or Great-Nephew | 36 | 363.3 | 2034.6 | 863.1 | 27 | 237.6 | 93.08 |
| Great-Great-Aunt or Great-Great-Uncle / Great-Great-Niece or Great-Great-Nephew | 6 | 620.3 | 1019.5 | 855.52 | 52.1 | 107 | 74.83 |
| First cousins | 310 | 383 | 1475.4 | 923.74 | 18 | 221 | 83.7 |
| First cousins once removed | 433 | 61.2 | 1878 | 493.72 | 15 | 133.2 | 59.7 |
| First cousins twice removed | 51 | 0 | 537 | 263.45 | 0 | 79.1 | 42.4 |
| First cousins three times removed | 10 | 72 | 170.1 | 110.61 | 17 | 52 | 26.94 |
| Half first cousins | 17 | 192 | 841.2 | 511.52 | 24 | 150.7 | 70.48 |
| Half first cousins once removed | 29 | 63.7 | 389.6 | 264.08 | 23 | 114.6 | 52.94 |
| Half first cousins twice removed | 5 | 82.2 | 212 | 156.84 | 36 | 75.5 | 59.97 |
| Half first cousins three times removed | 2 | 34.7 | 54.8 | 44.75 | 9.2 | 10.4 | 9.8 |
| Second cousins | 704 | 42.4 | 698 | 275.19 | 6 | 423 | 47.65 |
| Second cousins once removed | 661 | 0 | 446 | 169.85 | 0 | 565.1 | 37.72 |
| Second cousins twice removed | 104 | 0 | 285.7 | 113.91 | 0 | 78.5 | 29.05 |
| Second cousins three times removed | 18 | 0 | 177 | 99.92 | 0 | 32 | 20 |
| Half second cousins | 68 | 30 | 313 | 153.9 | 11.8 | 85.5 | 37.94 |
| Half second cousins once removed | 85 | 0 | 243 | 87.61 | 0 | 60.5 | 23.84 |
| Half second cousins twice removed | 13 | 0 | 91.8 | 40.43 | 0 | 35.1 | 16.22 |
| Half second cousins three times removed | 2 | 30.5 | 47.9 | 39.2 | 12.3 | 22.8 | 17.55 |
| Third cousins | 346 | 0 | 315 | 116.91 | 0 | 91 | 26.6 |
| Third cousins once removed | 320 | 0 | 211.2 | 78 | 0 | 68 | 20.16 |
| Third cousins twice removed | 43 | 0 | 173 | 65.9 | 0 | 40.8 | 15.67 |
| Third cousins three times removed | 1 | 46 | 46 | 46 | 0 | 0 | 0 |
| Half third cousins | 70 | 0 | 101.9 | 30.04 | 0 | 32.1 | 9.37 |
| Half third cousins once removed | 21 | 0 | 79.3 | 17.65 | 0 | 18.8 | 5.07 |
| Half third cousins twice removed | 1 | 108 | 108 | 108 | 10 | 10 | 10 |
| Fourth cousins | 219 | 0 | 664 | 49.4 | 0 | 55.6 | 13.44 |
| Fourth cousins once removed | 104 | 0 | 146 | 33.76 | 0 | 41.5 | 10.14 |
| Fourth cousins twice removed | 6 | 0 | 102.4 | 58.57 | 0 | 31.2 | 10.87 |
| Half fourth cousins | 30 | 0 | 80.1 | 24.36 | 0 | 67.9 | 14.22 |
| Half fourth cousins once removed | 6 | 0 | 62.1 | 33.42 | 0 | 62.1 | 21.48 |
| Half fourth cousins twice removed | 1 | 109 | 109 | 109 | 6 | 6 | 6 |
| Fifth cousins | 30 | 0 | 116 | 28.25 | 0 | 22.5 | 4.67 |
| Fifth cousins once removed | 26 | 0 | 129.5 | 39.52 | 0 | 28.1 | 8.19 |
| Sixth cousins | 5 | 0 | 109.5 | 47.82 | 0 | 28 | 11.16 |
| Sixth cousins once removed | 6 | 0 | 113.8 | 76.47 | 0 | 32 | 17.07 |
| Half sixth cousins | 2 | 75 | 114 | 94.5 | 5 | 5 | 5 |
Note that some relationships don't have enough data to really do anything statistically. But as more people enter data, perhaps they will reach that threshold.
Remember, you can still contribute information about your own family's shared DNA to the project. Information on this project and how to participate is here.
Note: I'm on Twitter. Follow me (@larasgenealogy).
This is really interesting, Lara. I haven't checked, but I assume you have---how different are these numbers from the average expected shared cMs/largest segments of non-Ashenazi test takers? Do these numbers reflect what we'd expect from an endogamous population?
ReplyDeleteI hope you get more people to submit. Looking at my own known relatives (whose results I submitted), they all fall near your averages. Thanks for doing this!
The numbers are definitely noticeably higher than the Shared Centimorgan Project for all but the closest relationships. Stay tuned!
DeleteHey Lara, clicked too fast, sorry. Sent you 29 tonight after about 30 yesterday but please delete the first one I sent tonight -- 1/2 sibs, 1810/176/43 100%/100%.
ReplyDeleteGil
Updated. Thanks for contributing!
DeleteHas anyone examined Sephardic DNA?
ReplyDeleteNot that I'm aware of. However, as I mentioned in my initial posting about this project, it's something I'd like to do in the future. First I need to deal with this batch of data though!
DeleteHow can I print this out so it is large enough to see-when I minimize the chart, then screen shot, it is too small. Thanks.
ReplyDeleteSorry, it depends on the specifics of your printer, so I don't know.
DeleteSeveral things:
ReplyDelete1. You can paste this into a google spreadsheet and then sort and recompute to your heart's content. My guess is that you can do this in Excel, too.
2. I'd have loved to have seen double cousins, etc. Quite possibly, separating double first cousins from of "ordinary" first cousins would bring the "ordinary" cousins' results into closer agreement with the general population. I have quite a few double first cousins in my tree, FWIW. (Since you have halves, why not doubles? After all, it's part of what endogamy is all about.)
3. I'd have loved to have seen min, max and avg number of segments. I realize that this isn't as good a matching criterion as maximum segment length, but it could still be useful to eyeball matches on ancestry. For a constant # of cM, I'd expect this to go down as maximum segment size increases.
More stats to come. I just need to find the time.
DeleteHow do you count the number of segments? I am using the chromosome browser in Family Tree DNA. If a segment appears to cross between the left and right hand sides of the chromosome, does that count as one segment or two?
ReplyDeleteOn the upper left where it lists who you are comparing with, it says the number of segments.
DeleteHi Lara, I am curious as to whether data is still being actively collected and results updated. Thanks in advance.
ReplyDeleteYes, I am still collecting data, and I did additional posts after this one (see link at the top of the post). When I have enough new entries (and enough spare time), there will be yet another update.
DeleteMany thanks, Lara. I was aware there was a 2019 update, but wondered about additional progress. This is invaluable work; I hope to encourage members of my local JGS to contribute.
Delete