(Cross posted to Azores, Madeira, and Island Routes lists). I'm waiting to type up my last lecture notes from FTDNA's administrator conference, as they have a couple of missing things that I need to copy from the speakers' slides. The speakers' slides are not yet uploaded to our admin page yet. So I sit here and wait.
So, in the meantime, here's a concept for you that I will talk about later. Identity by State (IBS) versus Identity by Descent (IBD) We are all related through Identity by State (IBS), as we are all human beings. If we compared our DNA to our pet dog, Rover, we'd see absolutely nothing in common, being Rover is a canine. However, in autosomal DNA matching (Family Finder), we are matched up through Identity by Descent (IBD). Blocks of DNA that have been passed down from a common ancestor to us show up in Family Finder and that is how we know we are related. Sounds easy that way. So allow me to now confuse you. :) Last week, you dropped a glass and it shattered. You cleaned it up. Today, you get another glass and you drop it again! It is very easy to pick up the large pieces of glass. They could probably be glued back together if you wanted to. These are the Identity by Descent (IBD) segments. But then you get to the smaller pieces of glass. Some are so small, they are almost like grains of sand. As you get down on the floor, you notice some of the grains from last week's glass. These small grains are the Identity by State (IBS) segments. If you swept all the little grains of glass up, you can't tell which grains belong to which glass. So, when your DNA is run, some very small segments are detected (1 centoMorgan (a genetic unit of measure), 3 cMs)...it is hard to tell if these 1 or 3 cMs are IBS or IBD segments. To keep customers from "rooting out the weeds" a threshhold was established. At FTDNA, you and your match must have a total of 20 cMS AND the longest block must be at 7.75 cMs to be reported to you. If you and your match have 50 cMs and the longest block is 6.91 cMs, it is NOT reported to you. Both criteria was not met. But suppose you KNOW that you and your match are indeed cousins? There are some third party tools out there to help. I need to explore them further in order to advise you properly. I will make a post on that as well. Cheri Mello Family Tree DNA Admin (volunteer) -- For options, such as changing to List, Digest, Abridged, or No Mail (vacation) mode, log into your Google account and visit this group at http://groups.google.com/group/Azores. Click in the blue area on the right that says "Join this group" and it will take you to "Edit my membership." --- You received this message because you are subscribed to the Google Groups "Azores Genealogy" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/azores.
