validity of short segment matching

[georgian1950]

I would like to share a blog entry which I recently made giving a new take about short segments:

https://geneticgenealogyoutofthemain...segment-match/

[Gwailo]

Good article Georgian1950. When every other person sharing varying lengths on particular chromosomes come coincidentally from neighbouring locations to where your known family is from there are extremely small odds that the SNPs are landing there by chance. You just haven't got a common ancestor you both know of. I notice that some blocks of SNPs are inherited as a block in many matches which must mean some dna doesn't like or is stubborn to breaking down to smaller segments. I have an 8cm block that I share with more than 200 people from Scotland to Finland and from Nth Ireland to Germany with. Everytime someone matches with main block on that chromosome they nearly always have the same starting and ending SNP location. It's uncanny

[georgian1950]

Good article Georgian1950. When every other person sharing varying lengths on particular chromosomes come coincidentally from neighbouring locations to where your known family is from there are extremely small odds that the SNPs are landing there by chance. You just haven't got a common ancestor you both know of. I notice that some blocks of SNPs are inherited as a block in many matches which must mean some dna doesn't like or is stubborn to breaking down to smaller segments. I have an 8cm block that I share with more than 200 people from Scotland to Finland and from Nth Ireland to Germany with. Everytime someone matches with main block on that chromosome they nearly always have the same starting and ending SNP location. It's uncanny

Thank you Gwailo for your remarks. I've seen what you talking about. Coming up with examples using raw data of that happening would be interesting.