What is the advantage of uploading AncestryDNA results to GEDmatch and/or FTDNA? Let me count the ways… Here are my top 10 reasons.
. To get additional Matches. (from other companies, including Matches below thresholds)
. To get Matches with emails. And most at FTDNA have real names; many at GEDmatch have real names.
. To get cooperative Matches. A much higher percentage of folks who test at FTDNA will work with you on genealogy. Same with folks who have taken the trouble to upload to GEDmatch.
. To see the shared DNA segment. This is probably the most important reason, IMO! For each shared segment with a Match, you see the chromosome number, start and end locations, cM value, and number of SNPs included. This is technical DNA info, but it is invaluable to those who utilize the DNA beyond just a list of Matches (who may or may not be related – read on…)
. The shared segment data allows the tester, or a Match, to confirm the segment is a true segment from an ancestor (that the segment is Identical By Descent, IBD) – this is done by Triangulation with other shared segments
. The shared segment data allows the tester, or a Match, to evaluate the segment – a small segment indicates a distant relationship; a large segment, or multiple segments, indicates a closer relationship.
. The shared segment data allows the tester, or a Match, to group segments from Common Ancestors – you will tend to have only one (or very few) different segments from a distant ancestor, and this is where you will find other cousins from that ancestor.
. With Colonial American ancestry (and other endogamous populations), you may have multiple Common Ancestors with a Match. The shared segment data will allow you to determine which ancestor the DNA came from, because all who have the same shared segment data should descend from the same Common Ancestor.
. Admixture (ethnicity, ancestral geography) reports are different at different companies. GEDmatch, in particular, has several utilities with a range of admixture evaluations that target different areas.
. GEDmatch has other utilities, including seeing if your parents were related.
Readers are invited to add other reasons to upload AncestryDNA results to FTDNA and/or GEDmatch in the comments section.
21 Segmentology: Why Upload to GEDmatch or FTDNA by Jim Bartlett 21050611