Small segments are one of those instances where testing multiple known relatives is important. I often see where two (or more) have a fairly long segment but their close relative recombined to have 6.8 cM or something of the segment. I realize that not everyone has lots of known relatives available to test, but to the extent that I have done so, I've been able to mark a lot of relatively short segments as IBD because it is clear where recombination took place. That said, I don't go looking for short segments... life is too short for that. However, Genome Mate Pro shows me where the tested relatives are matching a given person, so I can see pretty quickly if two or four people have a big match and another has just a bit of it. Karla On Thu, Dec 3, 2015 at 10:01 PM, ahnen@awest.de via < genealogy-dna@rootsweb.com> wrote: > Yes but it still means that if there was a 8cM ancestral segment and it > gets cut into half the size (just an example, recombination is basically > randomly happening) for the next generation it's still a small portion of > our ancestors DNA. > > However for all testing companies and everyone using the minimum 5, 7 or > even 10 cM rule it doesn't exist anymore. > > But it does exist still. Given the enormous number of IBS/IBC at that > range it doesn't make sense to follow them as a general rule but in case > when a relationship is know from paper trail it makes sense to extend the > search among a group of known cousins further. > > Andreas > > > On Dec 4, 2015, at 05:24, Jim Bartlett <jim4bartletts@verizon.net> > wrote: > > > > Lindsey > > > > Our paper trail means nothing to the DNA. The DNA passes down just the > same for rich/poor, famous/not-so, known relatives/not known. Just because > we know the cousin, doesn't, somehow, change the quality of segments. The > average ratio of IBD/IBS at any cM value will not change. > > > > Jim - www.segmentology.org > > > >> On Dec 3, 2015, at 3:06 PM, Lindsey Britton <lplantagenet@aol.com> > wrote: > >> > >> I will definitely concentrate on the large segments. I was just > wondering whether it was reasonable to assume small segments were likely to > be ancestral, too, once the relationship and common ancestors had been > identified. > >> > >> Lindsey > >> > >> > > ------------------------------- > To unsubscribe from the list, please send an email to > GENEALOGY-DNA-request@rootsweb.com with the word 'unsubscribe' without > the quotes in the subject and the body of the message > -- Karla Huebner calypsospots AT gmail.com

Karla, Thanks for your post and your last sentence is the most important one! > On Dec 4, 2015, at 21:18, Karla Huebner <calypsospots@gmail.com> wrote: > > , so I can see pretty quickly if two or four people have a big match and another has just a bit of it. > > Karla