AncestryDNA results vs GEDmatch etc..

[Jessie]

Hi Jessie,

I did my ancestryDNA test recently, and to my surprise my only non-trace regions were Britain at 73% and Ireland at 6%. I expected a much greater Irish component given my ancestors include many Gaelic / Highland Scottish as well as Welsh speaking people. My Gedmatch results for the ancestry kit are:

# Population Percent
1 ATLANTIC 27.26
2 NORTH-CENTRAL_EURO 25.27
3 SOUTH_BALTIC 14.91
4 WEST_MED 12.13
5 EAST_EURO 11.02
6 WEST_ASIAN 6.34
7 SIBERIAN 2.08


Finished reading population data. 78 populations found.
13 components mode.

--------------------------------

Least-squares method.

Using 1 population approximation:
1 Orcadian @ 5.320445
2 IE @ 5.557007
3 Cornish @ 5.909720
4 NL @ 6.221287
5 English @ 7.090277
6 West_&_Central_German @ 7.103646
7 Scottish @ 7.127876
8 DK @ 8.676942
9 NO @ 8.865813
10 South_&_Central_Swedish @ 9.470847
11 North_Swedish @ 12.807658
12 AT @ 13.192289
13 FR @ 13.201672
14 HU @ 18.127720
15 South_Finnish @ 21.391369
16 PT @ 21.590019
17 ES @ 21.643776
18 Serbian @ 22.437931
19 PL @ 23.638054
20 North_Italian @ 25.269634

Using 2 populations approximation:
1 50% IE +50% NL @ 4.867750


Using 3 populations approximation:
1 50% IE +25% IE +25% West_&_Central_German @ 4.856452


Using 4 populations approximation:
1 HU + IE + IE + IE @ 4.142177
2 HU + IE + IE + Scottish @ 4.266030
3 AT + IE + IE + IE @ 4.293591
4 HU + IE + IE + Orcadian @ 4.305387
5 AT + IE + IE + Orcadian @ 4.401197
6 HU + IE + Orcadian + Scottish @ 4.437197
7 FR + IE + IE + North_Swedish @ 4.482569
8 HU + IE + Scottish + Scottish @ 4.484679
9 AT + IE + IE + Scottish @ 4.494554
10 HU + IE + Orcadian + Orcadian @ 4.505452
11 Cornish + HU + IE + IE @ 4.518355
12 AT + IE + Orcadian + Orcadian @ 4.542547
13 FR + IE + IE + South_&_Central_Swedish @ 4.571366
14 FR + IE + North_Swedish + Scottish @ 4.606003
15 Cornish + HU + IE + Scottish @ 4.611389
16 AT + IE + Orcadian + Scottish @ 4.612475
17 FR + IE + North_Swedish + Orcadian @ 4.627069
18 AT + Cornish + IE + IE @ 4.627154
19 HU + Orcadian + Orcadian + Scottish @ 4.644990
20 English + HU + IE + IE @ 4.645694

So while they're definitely not exact, our results seem similar enough that I figure I'd have at least a decent fraction of Irish showing on my ethnicity prediction. I'm writing this as support for the argument against AncestryDNA. (But don't get me wrong for some folks it seems fine, after all it did a great job with your prediction).

I think sometimes people take the names of the components too literally. The Great Britain result doesn't translate to not having any "Celtic" or pre-Anglo-Saxon ancestry. You obviously have the bulk of your ancestry from the British Isles so the results are accurate. It is really difficult to separate some of these populations and a papertrail is always better IMO. You should look at the People of the British Isles study if you haven't already. It is very informative. I forgot to add the 2% Great Britain in my results. I'm going off memory as I can't access the info at the moment.