Re: [Ashkenazi-Q] Re: Advanced Orders Panel
You have my permission to use my DNA sample For your research. My Family Tree DNA number is 115493.
Robert Alan Michelson (Bob)
- Hello all,
I have a question that perhaps someone can answer.
I took the chromosome browser results -- three at a time and downloaded them into Excel for the top 15 "cousin" matches. Then I combined them in one file. I ended up with 532 data lines of names, chromosome number, starting location, ending location, centimorgans and matching SNPS.
Then I sorted them by chromosome first followed by starting location and finally ending location. I came up with a considerable number of locations that are identical with two or more people. The same goes with ending locations. In a number of the data lines, both start and end with the same number, though that is the exception, not the rule.
As an example, these five match me
6 32779081 35439082 2.65 1772 6 32779081 36322469 3.18 1873 6 32779081 36322469 3.18 1873 6 32779081 36322469 3.18 1873 6 32779081 36322469 3.18 1873
The first number is the chromosome then the start, end location, centimorgans and SNPS. My question is whether the testing process tends to cluster starting and ending locations or is the actual locations and in this case 4/5 are identical. Am I wasting my time looking at this?
If anyone is curious I will send the excel file without names so that you can see the data.
See what you do when you are retired and the crafts shops are closed
- Hello Bob,
Family Finder rounds off segments to the nearest block, so these regions have the appearance of identicality, but may not be exactly identical.
In any case, 3.18 cM is a very low amount, and unless you know that you are recently related to someone or your block of this size is adjacent another larger one, I would pay very little attention to any segment under about 6-8 centimorgans.
Finally, it's definitely not a waste of time to analyze the data this way for larger blocks. I have overlapping segments with a known maternal second cousin, and with a suspected paternal 4th cousin once or twice removed (we share an unusual surname). By looking at the overlap by region, I can establish which side of the chromosome pertains to which side of my family. This may also be useful if you have uploaded to gedmatch.com.
- Thanks for your reply. I do have a number of people with 8 or more cM matches and the largest 19.6 is identically matched with three of us.