20,000 matches seems very small (I have 90,125 on Ancestry). Perhaps her many potential matches either haven't DNA tested—if the family has been in the US for several generations you would expect more would have—or have tested in different databases (does she have her DNA in other places in addition to Ancestry?).
What kills me is that of the matches she does have, they / their families are so familiar to me because they are the same lines as mine in so many cases. I match many of them as expected. She has a ridiculously high number of matches through the line we are working on, the descendants of her maternal grandfather, and they are all my cousin a bunch of ways, and hers. LOL.
I did notice after I wrote this that she has an unexplained 15% or so German on this side, which is suggestive of a great grandparent who is probably the one we are looking for. Maybe they were a recent immigrant and had few descendants. Germans do indeed have very few matches on Ancestry, so that would make sense... but I'm still left with her other sides, which still have far too few matches to make sense😂
I'm gonna see about looking at the results on other sites, thanks for the reminder. I know she tested elsewhere, but Ancestry makes it so much easier to share than other sites that if I can I kind of just prefer to stay there, but I feel like I have to at least try!
It would be worth looking at MyHeritage if she has DNA tested/uploaded there. If not, it is not possible to upload there anymore but it may be worthwhile testing there. I have quite a large number of German matches on MyHeritage - 5th highest category of matches when filtered by Country
Similar to my dad's maternal matches, his mom is German. He has so few matches on her side, I could only identify one of them who is a first cousin, haha. Most of them are from random parts of the US and must share a common ancestor with us in Germany way back. 😅
I can think of a few theories but none are very satisfying!
- messed up test as you said
- she and, like, hundreds of other people all have something off in their tree. not totally impossible, i guess, especially considering all of these people are, without exception, basically, related to each other a bunch of ways
- the endogamy in this smaller group is fairly intense and happened more recently than e.g. the Acadian endogamy, so they have fewer matches than usual because the only people they match are descendants of a few founding ancestors who happened not to have that many descendants / were too recent in time to have thousands of descendants yet. unsatisfying because those ancestors would have been from an endogamous group so i would still expect them to match the more distant cousins. also she and i share at least 50 ancestors
!?!?! feel free to share this with anybody who may have a clue hahah. it's not easy to find any information about this type of thing and i'm mystified.
I'm jealous. I tested on Ancestry in 2018 and I just hit 10,000 matches. But, I have no deep roots in the US (earliest ancestor came around 1848) which explains my lower amount of matches.
I have a couple of ideas.
1. Are you and this cousin in the same generation? This can change things. My Azorean cousin and I are a generation off. My cousin has twice as many matches as me (20,000 to my 10,000). She also gets a lot of high matches. I don't. She has pages of matches over 100 cM. I have 13 or 14 matches total. Recombination is a funny thing.
2. Even though we share half of each parent's DNA, it does not distribute from our ancestors evenly. Recombination means one cousin might have a huge chunk from an ancestor and another might get a small chunk or no DNA at all depending how far back. The smaller chunk will produce fewer shared matches.
I have an example of this on my de Braga side. 4 known 3rd cousins. A and B are sister and brother. They both match C & D on the de Braga line. I match B, C, & D on the same line, but I share no DNA with A. A is proven through the DNA connection to C & D. However, her brother carries some different blocks than his sister. Those blocks match me.
3. As other's said, there's a hidden ancestor. This could be from an affair, an incorrect spouse, or even a cousin adoption or raising their child's baby.
My suggestion would be is to identify all the matches that you know you share that you can prove, then see what's leftover and see if there is a group of matches that doesn't seem to fit.
20,000 matches seems very small (I have 90,125 on Ancestry). Perhaps her many potential matches either haven't DNA tested—if the family has been in the US for several generations you would expect more would have—or have tested in different databases (does she have her DNA in other places in addition to Ancestry?).
What kills me is that of the matches she does have, they / their families are so familiar to me because they are the same lines as mine in so many cases. I match many of them as expected. She has a ridiculously high number of matches through the line we are working on, the descendants of her maternal grandfather, and they are all my cousin a bunch of ways, and hers. LOL.
I did notice after I wrote this that she has an unexplained 15% or so German on this side, which is suggestive of a great grandparent who is probably the one we are looking for. Maybe they were a recent immigrant and had few descendants. Germans do indeed have very few matches on Ancestry, so that would make sense... but I'm still left with her other sides, which still have far too few matches to make sense😂
I'm gonna see about looking at the results on other sites, thanks for the reminder. I know she tested elsewhere, but Ancestry makes it so much easier to share than other sites that if I can I kind of just prefer to stay there, but I feel like I have to at least try!
It would be worth looking at MyHeritage if she has DNA tested/uploaded there. If not, it is not possible to upload there anymore but it may be worthwhile testing there. I have quite a large number of German matches on MyHeritage - 5th highest category of matches when filtered by Country
My mother has 5,014 matches on ancestry . She was from Germany.
Similar to my dad's maternal matches, his mom is German. He has so few matches on her side, I could only identify one of them who is a first cousin, haha. Most of them are from random parts of the US and must share a common ancestor with us in Germany way back. 😅
Odds of a hidden ancestor, and someone else listed as parentage?
Mucked up lab test?
You get all the best puzzles. (:
lol i just looked again since i've been connecting her lines to wikitree and the relationship finder updated. we now share over 80 ancestors.
For giggles and chuckles, run Forcier-331 against hers
Y'all have 46 common ancestors haha!
I can think of a few theories but none are very satisfying!
- messed up test as you said
- she and, like, hundreds of other people all have something off in their tree. not totally impossible, i guess, especially considering all of these people are, without exception, basically, related to each other a bunch of ways
- the endogamy in this smaller group is fairly intense and happened more recently than e.g. the Acadian endogamy, so they have fewer matches than usual because the only people they match are descendants of a few founding ancestors who happened not to have that many descendants / were too recent in time to have thousands of descendants yet. unsatisfying because those ancestors would have been from an endogamous group so i would still expect them to match the more distant cousins. also she and i share at least 50 ancestors
!?!?! feel free to share this with anybody who may have a clue hahah. it's not easy to find any information about this type of thing and i'm mystified.
I'm jealous. I tested on Ancestry in 2018 and I just hit 10,000 matches. But, I have no deep roots in the US (earliest ancestor came around 1848) which explains my lower amount of matches.
I have a couple of ideas.
1. Are you and this cousin in the same generation? This can change things. My Azorean cousin and I are a generation off. My cousin has twice as many matches as me (20,000 to my 10,000). She also gets a lot of high matches. I don't. She has pages of matches over 100 cM. I have 13 or 14 matches total. Recombination is a funny thing.
2. Even though we share half of each parent's DNA, it does not distribute from our ancestors evenly. Recombination means one cousin might have a huge chunk from an ancestor and another might get a small chunk or no DNA at all depending how far back. The smaller chunk will produce fewer shared matches.
I have an example of this on my de Braga side. 4 known 3rd cousins. A and B are sister and brother. They both match C & D on the de Braga line. I match B, C, & D on the same line, but I share no DNA with A. A is proven through the DNA connection to C & D. However, her brother carries some different blocks than his sister. Those blocks match me.
3. As other's said, there's a hidden ancestor. This could be from an affair, an incorrect spouse, or even a cousin adoption or raising their child's baby.
My suggestion would be is to identify all the matches that you know you share that you can prove, then see what's leftover and see if there is a group of matches that doesn't seem to fit.