I don't know if this addresses your specific observation, but FTDNA consistently reports lower cM values than GEDmatch and 23andMe. http://isogg.org/wiki/CM#cm_values_per_chromosome Ann Turner On Sat, Oct 24, 2015 at 8:47 AM, Brooks Family via < genealogy-dna@rootsweb.com> wrote: > I thought Jim's & Robert's explanations were good enough for me, but > here's the segment in question again, newly derived this morning: > > Gedmatch: > 9 131,390,868 137,505,316 18.8 1,904 > > ftDNA: > 9 131,456,657 137,335,024 8.85 1,955 > > The relationship is solid. The kit manager had her tree up on ftDNA, > and I had already independently worked the relationship to the MRCAs in > my tree. 4C1R. >
Ann FTDNA must either use a different cM look up table, or the other companies assume some of the gray areas. I've had some segments at 23andMe start at 1 in chromosomes that are usually grayed out at the beginning (typing from a beach chair with my reference data) Jim - www.segmentology.org > On Oct 24, 2015, at 1:15 PM, Ann Turner via <genealogy-dna@rootsweb.com> wrote: > > I don't know if this addresses your specific observation, but FTDNA > consistently reports lower cM values than GEDmatch and 23andMe. > > http://isogg.org/wiki/CM#cm_values_per_chromosome > > Ann Turner >
Without my reference data! Jim - www.segmentology.org > On Oct 24, 2015, at 1:41 PM, Jim Bartlett via <genealogy-dna@rootsweb.com> wrote: > > Ann > > FTDNA must either use a different cM look up table, or the other companies assume some of the gray areas. I've had some segments at 23andMe start at 1 in chromosomes that are usually grayed out at the beginning (typing from a beach chair with my reference data) > > Jim - www.segmentology.org > >> On Oct 24, 2015, at 1:15 PM, Ann Turner via <genealogy-dna@rootsweb.com> wrote: >> >> I don't know if this addresses your specific observation, but FTDNA >> consistently reports lower cM values than GEDmatch and 23andMe. >> >> http://isogg.org/wiki/CM#cm_values_per_chromosome >> >> Ann Turner >> > > > ------------------------------- > 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