Autosomal DNA problem

[KCW]

Can autosomal DNA be used to definitively prove a family connection?

My great great great grandmother immigrated from Ireland to central Ohio in the later 1840s to early 1850s. I've been able to determine who her mother was from connecting mtDNA on her direct female line to mtDNA of a known direct female line descendent of a woman living near her who I suspected was her mother (and with a verifiable paper trail). My g-g-g-grandmother was noted to be one of seven siblings. I am trying to figure out who they all are but can only prove three of them (proven with paper records etc).

There are two of the seven I have identified through traditional research who I am nearly certain are siblings, but I cannot find paper records proving this. I have autosomal DNA from many of the great grandchildren of my g-g-g-grandmother (in their 90s now). If I an find descendants of the two people I suspect to be siblings of my g-g-g-grandmother, can I used their autosomal DNA to definitively prove they were siblings to my g-g-g-grandmother?

I have a general understanding of how autosomal DNA works, and I suspect there would be an autosomal connection between the known descendants of my g-g-g-grandmother and those that are descended of who I believe to be two of her siblings. Is there a way to prove this definitively though? Someone mentioned triangulation to me, but I don't really understand how this works. Is it possible to examine the segments in chromosome browser? I am a novice (at best) with this as well.

I've had amazing luck with mtDNA and Y-DNA but knowing the ins and outs of autosomal uses is a bit above me at this point. Can someone explain to me if I can use it in my case to prove my theory definitively? Thanks so much for reading and I looking forward to any responses.

Thank you!

[Táltos]

Can autosomal DNA be used to definitively prove a family connection?

My great great great grandmother immigrated from Ireland to central Ohio in the later 1840s to early 1850s. I've been able to determine who her mother was from connecting mtDNA on her direct female line to mtDNA of a known direct female line descendent of a woman living near her who I suspected was her mother (and with a verifiable paper trail). My g-g-g-grandmother was noted to be one of seven siblings. I am trying to figure out who they all are but can only prove three of them (proven with paper records etc).

There are two of the seven I have identified through traditional research who I am nearly certain are siblings, but I cannot find paper records proving this. I have autosomal DNA from many of the great grandchildren of my g-g-g-grandmother (in their 90s now). If I an find descendants of the two people I suspect to be siblings of my g-g-g-grandmother, can I used their autosomal DNA to definitively prove they were siblings to my g-g-g-grandmother?

I have a general understanding of how autosomal DNA works, and I suspect there would be an autosomal connection between the known descendants of my g-g-g-grandmother and those that are descended of who I believe to be two of her siblings. Is there a way to prove this definitively though? Someone mentioned triangulation to me, but I don't really understand how this works. Is it possible to examine the segments in chromosome browser? I am a novice (at best) with this as well.

I've had amazing luck with mtDNA and Y-DNA but knowing the ins and outs of autosomal uses is a bit above me at this point. Can someone explain to me if I can use it in my case to prove my theory definitively? Thanks so much for reading and I looking forward to any responses.

Thank you!

A good starting point would be to review the ISOGG wiki on Autosomal DNA statistics. http://www.isogg.org/wiki/Autosomal_DNA_statistics

If you can find descendants of the supposed siblings, you might be able to prove a relationship. You just have to keep in mind that with each generation the DNA recombines, or in other words becomes diluted so after say five generations there may be no DNA match. However in other cases were certain groups who keep intermarrying the DNA can hang around much longer. Such is the case for people with Ashkenazi or Colonial backgrounds.