You know you have an obsessive personality when a cousin’s DNA results come in and you put off as many plans as you can for the next 3 days in order to explore them. At least I have some observations to report on the new Ancestry chip as well as more data for my study of the Wold family.
According to Ancestry, this new chip has dropped some less interesting SNPs and replaced them with medically relevant ones as well as ones more useful for determining ancestry composition. The details are at http://blogs.ancestry.com/techroots/customer-testing-begins-on-new-ancestrydna-chip/
GEDmatch only tokenized 455K of the 700K SNPs from that new chip. However when I imported the raw data into a spreadsheet I saw that there were 668,961 lines of data as opposed to the previous 701,495 (then subtract 20 for the header), so not that different a number. New is chromosome 26 which is for the mitochondrial DNA.
My Wold cousin MM is the cousin whose doorstep I arrived on, Ancestry kit in hand, because I really really wanted her results. Those of you who have been to my Triangulation talk or read the article here may have noticed that I had no other cousins tested who are descended from my great-grandmother’s brother Charlie, the one presumed to be Kristine’s great-great-grandad. MM’s test has rectified that although she is descended from a different wife of Charlie’s than Kristine.
Since MM is the half first cousin of Kristine’s grandfather, she and Kristine are half first cousins twice removed. Do they match at the expected level?
According to Blaine’s chart, the average match for a first cousin once removed is 208 cM with a range of 27-415. Therefore a half first cousin once removed should match for half that amount. Here are the results for cousin MM versus Kristine at GEDmatch
|Chr||Start Location||End Location||Centimorgans (cM)||SNPs|
Largest segment = 33.6 cM
Total of segments > 7 cM = 98.5 cM
4 matching segments
Just about the expected amount. Additionally, I find that larger chunks like they have are a good indication of a closer relationship. So we now have another proof that Kristine is a Wold. When I compared cousin MM to all the other Wolds tested however there was quite a wide variation. Here are the totals of segments greater then 7cM for those cousins she matched (most all of them matched)
total cMs relationship who 98.7 half 1st 2R Kristine 63.8 2nd 2R Mike 146.7 2nd 1R Katy 51.2 2nd Kittys Dad 32.3 2nd 1R Kittys brother 18.3 2nd 1R Kitty 35.2 2nd 1R George 80.4 2nd 1R John 19.6 3rd 2R LW
These numbers demonstrate yet again the randomness of DNA inheritance once you get past close family. Katy seems to have more than her share of Wold DNA as she matches everyone at somewhat higher than expected levels.