I entered into a excel spreadsheet all my 226 matches longest block segments. Then I sorted them by chromosome and segment and matched up the overlapping segments.
The first thing I noticed was that the question was not what ones overlapped, but how few did not overlap.
Some of them can be eliminated by having a minimum of say 5 to 7 cM overlap.
The next question is how many of these overlapping segments are circumstantial (False Positive). If you take the total cM of the 22 chromosomes at 3352 cM and divide it by 7 cM = 479. This means that you can have 479 matches (people) without any one overlapping.
If you have a matches with the longest block of 100 cM you can only have 33.5 people without overlapping. Do I have my math right? This look's like too few people and a high degree of circumstance.
My point here is that you can not use the overlapping longest block as the sole criteria for matching. Many of these matches, especially the small segments are going to be circumstantial.
Any thoughts? Any suggestions on how to refine these overlapping segments?
The first thing I noticed was that the question was not what ones overlapped, but how few did not overlap.
Some of them can be eliminated by having a minimum of say 5 to 7 cM overlap.
The next question is how many of these overlapping segments are circumstantial (False Positive). If you take the total cM of the 22 chromosomes at 3352 cM and divide it by 7 cM = 479. This means that you can have 479 matches (people) without any one overlapping.
If you have a matches with the longest block of 100 cM you can only have 33.5 people without overlapping. Do I have my math right? This look's like too few people and a high degree of circumstance.
My point here is that you can not use the overlapping longest block as the sole criteria for matching. Many of these matches, especially the small segments are going to be circumstantial.
Any thoughts? Any suggestions on how to refine these overlapping segments?
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