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IphonePlus
03-21-2017, 03:32 PM
So I am having trouble interpreting a 23andme's testing. I was thinking of going to get my DNA tested but I am not sure how to interpret results given to other people. I do not understand the genetic "noise" concept, and I was shown a person's test. He is apparently 99% European, but his test said that he <1% South Asian, or less than 1% South Asian, specific ethnicity unspecified. Does this literally mean one of his ancestors was from Thailand/Vietnam or any other countries there ? Or is it just genetic "noise" from the past millennia ? As far as I know he has no recent Asian heritage in his genealogy, and he doesn't know of any in his genealogy either. Is there any way to know how long this portion of his heritage has been in his family ? I want to know if I have any in my heritage, and if I get tested I want to know how long it's been in my bloodline. His composition is as follows :


Asia South <1%

Europe 99%
Great Britain 58%
Europe West 19%
Ireland 11%
Scandanavia 7%
Finland/ Northwest Russia 2%
Europe East 1%
Iberian Peninsula <1%

IphonePlus
03-21-2017, 06:05 PM
Also, thank you in advance for any help :)

Oleg (Rus)
03-21-2017, 07:13 PM
It seems that he has done AncestryDNA test, not 23andme. "South Asian" includes India, Bangladesh, Pakistan, Sri Lanka etc, not Vietnam or Thailand (they both are in Southeast Asia). It's probably the noise, don't take it serious.

IphonePlus
03-21-2017, 07:38 PM
IDK the photograph that he showed me looked like the results from 23andme. What percentage would be considered noise for any ethnicity ? I am not understanding the concept that well.......is it like genes that have been present in his bloodlines since a VERY long time ago ? BTW I love your Belarus flag, Slavic people are awesome, strong, and loyal :)

Oleg (Rus)
03-21-2017, 08:26 PM
These categories are definitely from Ancestry, not from 23andme. In 23andme you can consider everything less than 0.2% noise, for some categories even 1%. Ancestry is not that precise, so even 5-6% can be a noise.

IphonePlus
03-21-2017, 08:45 PM
Okay fair enough. DO you know why Ancestry.com is not accurate ?

Oleg (Rus)
03-21-2017, 08:52 PM
Okay fair enough. DO you know why Ancestry.com is not accurate ?

They are just using a smaller reference sample set, and they don't use broad categories as 23andme do. They are trying to identify all your genes as strictly British/Scandinavian/West-Eu., which is not the best way everytime.

IphonePlus
03-21-2017, 10:18 PM
LOL that is REALLY confusing......so do you think 23andme is better overall ?

Kurd
03-21-2017, 11:28 PM
So I am having trouble interpreting a 23andme's testing. I was thinking of going to get my DNA tested but I am not sure how to interpret results given to other people. I do not understand the genetic "noise" concept, and I was shown a person's test. He is apparently 99% European, but his test said that he <1% South Asian, or less than 1% South Asian, specific ethnicity unspecified. Does this literally mean one of his ancestors was from Thailand/Vietnam or any other countries there ? Or is it just genetic "noise" from the past millennia ? As far as I know he has no recent Asian heritage in his genealogy, and he doesn't know of any in his genealogy either. Is there any way to know how long this portion of his heritage has been in his family ? I want to know if I have any in my heritage, and if I get tested I want to know how long it's been in my bloodline. His composition is as follows :


Asia South <1%

Europe 99%
Great Britain 58%
Europe West 19%
Ireland 11%
Scandanavia 7%
Finland/ Northwest Russia 2%
Europe East 1%
Iberian Peninsula <1%

These percentages whether from AncestryDNA, 23andMe, or FTDNA should not be taken too seriously, since none use ancestral references, meaning that their references themselves are very admixed. So if a European on 23andMe scores 0.5% S Asian (which would be quite unusual), all that really means is that they are slightly more S Asian shifted than the European references they used, which could also imply some recent S Asian admixture, but that does not mean that the subject has only 0.5% TOTAL admixture from S Asia, because, if for example the European references themselves are 5% S Asian admixed (older S Asian gene flow) then the total could be 5.5% S Asian.

To complicate matters 1% S Asian for a European is not the same as 1% S Asian for a W Asian. Whereas the 1% S Asian for a European could translate to 6% total S Asian, if the European references have a 5% S Asian base, the 1% S Asian showing up in a result say for a Kurd or Iranian 23andMe subject could translate to a 16% TOTAL S Asian, since the Middle Eastern references, if they are Iranians, could already have a 15% S Asian base. Therefore, 1% S Asian for a northern European would not be equal to 1% S Asian for say an Iranian or Kurd

What I am seeing in my analysis when I strip down these references into more basal ancient references, eg ENF, Iran N, EHG, WHG, etc is that W Eurasians have much more ASI or E/N Asian total admixture than shown by the genealogical testing. companies using highly admixed modern references.

How much total E/N Asian or ASI is the subject of my next calculator which I have been working on the past few weeks. Here I attempt to unlock hidden E/N/S Asian admixture while at the same time address some of the issues admixture calculators are susceptible to

IphonePlus
03-22-2017, 03:27 PM
Thank you Kurd for your reply !!! Can you provide any sources for your statements ? i just want them for my own records, I really appreciate your help ! You seem so knowledgeable, and it's consoling to get in touch with someone who knows this stuff. If someone tests for, let's say 1% Native American (ancestry.com test, for instance), but one of their relatives has no Native ancestry, did the genes not carry over ? Let's say a Great Uncle gets tested positive for American Indian heritage but his grandniece doesn't have any American Indian heritage...does that mean the genes didn't carry over ?

Thank you for your help !!!

Kurd
03-22-2017, 09:55 PM
Thank you Kurd for your reply !!! Can you provide any sources for your statements ? i just want them for my own records, I really appreciate your help ! You seem so knowledgeable, and it's consoling to get in touch with someone who knows this stuff. If someone tests for, let's say 1% Native American (ancestry.com test, for instance), but one of their relatives has no Native ancestry, did the genes not carry over ? Let's say a Great Uncle gets tested positive for American Indian heritage but his grandniece doesn't have any American Indian heritage...does that mean the genes didn't carry over ?

Thank you for your help !!!

Much of what I posted comes from my own testing and analysis. I have spent alot of time with the various programs such as Plink, ADMIXTURE, Admixtools, Beagle, etc testing various scenarios.

As for the 1%, it is in fact likely that it may not get inherited from some gp or ggp because of the somewhat random process of DNA recombination during meiosis. Also keep in mind that 1% is entirely within the margin of error, or what some call noise, with any allele frequency based admixture program (not 23andMe as they use haplotype segment matching, so there 1% very likely real). Consistent with this, many W and S Asians score 1%+ Amerindian with allele frequency based programs due to shared ancestors of Altaians and Amerindians

Edit: Europeans scoring 1% Amerindian may have something to do with peoples related to Saami and Amerindian origins, because the 1-2% Amerindian in Europeans disappears as soon as I add Saami references to the calculator