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Family Finder Advanced Topics Advanced discussion about Family Tree DNA's Family Finder Product.

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  #41  
Old 31st August 2013, 01:39 PM
josh w. josh w. is offline
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Originally Posted by Javelin View Post
If I read your posts right, actually it's your second largest component on two tests, since you are conflating three different tests.

Also, when you say "I realize that there was a Near Eastern influence on the Mediterranean and on the Caucasus," it's a bit wrong to speak of these components as "influences."

In essence this is algebra with constructed imaginary components based on peak frequencies in populations. No matter where you come from in Eurasia you will have some amount of x + y + z where x = Caucasus y = Near Eastern z = Mediterranean. The question is, how does your distribution of x + y + z differ from those within your population, and how does it compare to the averages of other populations?



This is where we shift from algebra to statistics, and look for individuals' standard deviations away from their group. We can use this approach to prune outliers, for example. Next, we can create an average cluster for different ethnicities, then compare those.

This idea of breaking down genomes into components is quite interesting and potentially useful, but much more on a population level than an individual one. It's also not as if, when you show as "5% something," that means 5% of your ancestry is from that region. Otherwise, pretty much nobody in the world would be from northern Europe.
I guess I wasn't clear . For each of three tests taken individually, southwest Asian was the third largest component. I agree that the identification of my background as Ashkenazi was quite accurate. My only point is that a significant number of my ancestors came from areas other than the Levant. The high percentage for a Caucasian component (30% Eurgenes, 36% Harrapa World, 24% West Asian- Dodecad) was hardly surprising. Both my Y dna and Mtdna lines began near Kurdistan.
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  #42  
Old 31st August 2013, 02:05 PM
ursus ursus is offline
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Originally Posted by Táltos View Post
Thanks for sharing ursus. Now here is another thing that bugs me about PF, why such a high margin of error for some of you guys? That would make me feel that my results are really way off. But then again perhaps that is their way of being truthful that their Population Finder is not that good.
That bugged me also. I started this thread on that topic http://forums.familytreedna.com/showthread.php?t=30115.

I hadn't realized that the numbers changed slightly in the interim.

Last edited by ursus; 31st August 2013 at 02:11 PM.
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  #43  
Old 31st August 2013, 02:17 PM
Javelin Javelin is offline
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Originally Posted by josh w. View Post
I guess I wasn't clear . For each of three tests taken individually, southwest Asian was the third largest component. I agree that the identification of my background as Ashkenazi was quite accurate. My only point is that a significant number of my ancestors came from areas other than the Levant. The high percentage for a Caucasian component (30% Eurgenes, 36% Harrapa World, 24% West Asian- Dodecad) was hardly surprising. Both my Y dna and Mtdna lines began near Kurdistan.
OK. Pretty much nobody in the Near East gets their highest scores as SW Asian except Saudis, so you need to fall back to comparisons.

As I said, you want to find as many Lebanese, Jordanians, Syrians, Druze, Assyrians, Kurds, Cypriots, Egyptians, Palestinians, etc., to compare to as possible, to stack up against as many Ashkenazim as possible, in order to test the hypothesis that Ashkenazim derive from Israel or somewhere near it.

The amount of deviation from this should be a rough indicator of the proportion of non-Near Eastern genes.

Then you want to take this delta (difference) and compare it to various populations to test hypotheses about where the rest of the genes come from. Essentially, where is the "pull" of the difference coming from in what proportion?

It is my perception from this methodology that on average Ashkenazim are something like 60-70% ancestrally Near Eastern, with the rest split between other Mediterranean populations (including Italy but also some Iberian influence probably from Sephardim); what you could call south-central Europe (Germany, northern Italy, France); other West Asian populations such as Kurds, Turks; and some Eastern European ones, probably Ukrainians and Poles but perhaps also Lithuanians.

I don't think this is any great insight, if you know history, but it's important to understand the component approach and what it can and can't offer.
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  #44  
Old 31st August 2013, 02:33 PM
josh w. josh w. is offline
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Originally Posted by josh w. View Post
I guess I wasn't clear . For each of three tests taken individually, southwest Asian was the third largest component. I agree that the identification of my background as Ashkenazi was quite accurate. My only point is that a significant number of my ancestors came from areas other than the Levant. The high percentage for a Caucasian component (30% Eurgenes, 36% Harrapa World, 24% West Asian- Dodecad) was hardly surprising. Both my Y dna and Mtdna lines began near Kurdistan.

I understand that the computer does profile matching. Still doesn't seem strange that PF considers me Near Eastern with a southwestern Asia component of around 15% on average at Gedmatch. Would other Levantine groups demonstrate such a low percentage. The issue is not whether I'm Jewish but whether I'm Levantine as PF has concluded. Do you have any link or source on the 60-70% figure. Was that the PF % or the Gedmatch %. It would beg the question if it were the PF percent since the designation of Near Eastern is what NY Mark and I have challenged. It seems a little high in terms of published research. How could I have been accepted accepted as within profile range.

Last edited by josh w.; 31st August 2013 at 02:46 PM.
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  #45  
Old 31st August 2013, 03:49 PM
NYMark NYMark is offline
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I'm not sure we're challenging the same things. All I'm saying is that for the purposes of people doing genealogical research, it makes a hell of a lot more sense to call Ashkenazim European.

Some of this is apples and oranges. 23andMe is trying to point people in the direction of where their actual, recent ancestors were born. PF and a lot of the Gedmatch utilities are more geographical/spatial and deep ancestral. It's not right or wrong; it's just a different approach. I could care less whether my Asheknazi roots are ME, Caucasus, East Asian and on and on. I'm happy to know I'm Ashkenazi, and I have European Jewish matches. If that can be further refined, so much the better, but I have my doubts whether that's possible.

I only care about the deep ancestry on either side to the extent that it points me in the direction of my immediate origins. So "Orcadian" sure doesn't cut it. Nor does what actually shows up in my non-ME PF, which is basically all of Europe.

For my money, the real question is: what's useful, and what's going to help people develop a meaningful understanding of their genealogical ancestry, not their roots 1000 or more years ago. That's the information that most of us are paying for. The rest is just academic. . .

Quote:
Originally Posted by josh w. View Post
I understand that the computer does profile matching. Still doesn't seem strange that PF considers me Near Eastern with a southwestern Asia component of around 15% on average at Gedmatch. Would other Levantine groups demonstrate such a low percentage. The issue is not whether I'm Jewish but whether I'm Levantine as PF has concluded. Do you have any link or source on the 60-70% figure. Was that the PF % or the Gedmatch %. It would beg the question if it were the PF percent since the designation of Near Eastern is what NY Mark and I have challenged. It seems a little high in terms of published research. How could I have been accepted accepted as within profile range.
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  #46  
Old 31st August 2013, 04:09 PM
josh w. josh w. is offline
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Quote:
Originally Posted by NYMark View Post
I'm not sure we're challenging the same things. All I'm saying is that for the purposes of people doing genealogical research, it makes a hell of a lot more sense to call Ashkenazim European.

Some of this is apples and oranges. 23andMe is trying to point people in the direction of where their actual, recent ancestors were born. PF and a lot of the Gedmatch utilities are more geographical/spatial and deep ancestral. It's not right or wrong; it's just a different approach. I could care less whether my Asheknazi roots are ME, Caucasus, East Asian and on and on. I'm happy to know I'm Ashkenazi, and I have European Jewish matches. If that can be further refined, so much the better, but I have my doubts whether that's possible.

I only care about the deep ancestry on either side to the extent that it points me in the direction of my immediate origins. So "Orcadian" sure doesn't cut it. Nor does what actually shows up in my non-ME PF, which is basically all of Europe.

For my money, the real question is: what's useful, and what's going to help people develop a meaningful understanding of their genealogical ancestry, not their roots 1000 or more years ago. That's the information that most of us are paying for. The rest is just academic. . .
These issues may not have any resolution. My emphasis on this forum, going back years, has been to note how people from from different ethnic or national groups may have a common genetic connection. It matters if Italian Catholics and Ashkenazim as well as Italkim show some genetic overlap.
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  #47  
Old 31st August 2013, 05:16 PM
Javelin Javelin is offline
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Quote:
Originally Posted by josh w. View Post
I understand that the computer does profile matching. Still doesn't seem strange that PF considers me Near Eastern with a southwestern Asia component of around 15% on average at Gedmatch. Would other Levantine groups demonstrate such a low percentage. The issue is not whether I'm Jewish but whether I'm Levantine as PF has concluded. Do you have any link or source on the 60-70% figure. Was that the PF % or the Gedmatch %. It would beg the question if it were the PF percent since the designation of Near Eastern is what NY Mark and I have challenged. It seems a little high in terms of published research. How could I have been accepted accepted as within profile range.
My view is formed by a consensus of the data presented in a range of studies including Atzmon, Behar, Ostrer, Bray, Tian, etc. If you email the component people themselves they will probably agree with me.
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  #48  
Old 31st August 2013, 06:10 PM
josh w. josh w. is offline
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Originally Posted by Javelin View Post
My view is formed by a consensus of the data presented in a range of studies including Atzmon, Behar, Ostrer, Bray, Tian, etc. If you email the component people themselves they will probably agree with me.
Bray reported 35-55% European admixture. Zoossman-Duskin (2010) reached similar conclusions. Atzmon's study may have provided an underestimate of the European contribution since southern Italians were not included in the study.

I am not sure that we can resolve our differences. I greatly appreciate the conversation
Josh
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  #49  
Old 31st August 2013, 06:22 PM
Táltos Táltos is offline
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Yes I appreciate the conversation as well. Something that might interest everyone to read. http://en.wikipedia.org/wiki/History...ws_in_Calabria

I wasn't even sure which thread to put this one in! They also point to yDNA-G2c as being a link between the two groups. Though I wasn't aware off hand that G2c was found in approx 40% of Ashkenazim? I know yDNA G as a whole is considered on the rare side. One of my FF cousins who has paternal ancestry from Calabria is yDNA G2a, not c. :-/
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  #50  
Old 31st August 2013, 06:54 PM
Javelin Javelin is offline
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Originally Posted by josh w. View Post
Bray reported 35-55% European admixture. Zoossman-Duskin (2010) reached similar conclusions. Atzmon's study may have provided an underestimate of the European contribution since southern Italians were not included in the study.

I am not sure that we can resolve our differences. I greatly appreciate the conversation
Josh
Zoossmann-Duskin's results are widely criticized by Razib Khan and Dienekes as well as most geneticists, as are those of Elhaik. Zoossmann relies mainly on low-resolution mtDNA and low-resolution autosomal DNA, at the expense of high-resolution mtDNA and autosomal studies. Essentially, if you use too few data points you can prove almost anything.

Look, in contrast, at Haber's recent study.

http://2.bp.blogspot.com/-gNGfQ-Y3gN...03316.g002.png
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