RootsChat.Com

General => Ancestral Family Tree DNA Testing => Topic started by: sallyyorks on Saturday 04 June 16 15:27 BST (UK)

Title: Are "Trace" Results Meaningless?
Post by: sallyyorks on Saturday 04 June 16 15:27 BST (UK)
This is from Ancestry's FAQs page

"4. What does it mean when my ethnicity results identify 'Trace Regions'?
Most people may have a percentage identified with 'Trace Regions' in their genetic ethnicity results. Trace Regions are regions where the estimated range includes zero and does not go above 15%, or where the predicted percentage is less than 4.5%. Since there is only a small amount of evidence that you have genetic ethnicity from these regions, it is possible that you may not have genetic ethnicity from them at all. This is not uncommon, and as more genetic signatures are discovered with a higher confidence level, we may be able to update these Trace Regions over time."

http://dna.ancestry.co.uk/legal/faq#about-2


Which begs the question, why do they include these trace results at all?
Title: Re: Are "Trace" Results Meaningless?
Post by: davidft on Saturday 04 June 16 16:51 BST (UK)
They tell you what the current state of scientific knowledge allows them to tell you. As they themselves say

and as more genetic signatures are discovered with a higher confidence level, we may be able to update these Trace Regions over time.

so in future they may be able to refine the results with more certainty eg either dropping them altogether or confirming for definite why they are part of your results.

Now ask yourself how would you feel if they had left these traces off and then in a few years came back and said good news we have updated your results and you now have these trace elements too. Would you say oh good more results or say how can I trust them not to come back in a further few years and add more elements
Title: Re: Are "Trace" Results Meaningless?
Post by: sallyyorks on Saturday 04 June 16 17:02 BST (UK)
So in the future they may be able to or they may not be able to confirm the trace results. They may even disregard the trace results in the future all together  ???

So at the moment anything under 15% is not reliable until some time in the future?

Is this why full siblings have different trace results?
Title: Re: Are "Trace" Results Meaningless?
Post by: davidft on Saturday 04 June 16 18:04 BST (UK)
Yes they may be able to confirm or eliminate trace results in future. The science in this area is really not that old.

Full siblings may have different trace results because what is inherited from parents is done so randomly. So although each sibling gets 50% of their genes from each parent they get a 50% that is made up differentlt to their sibling
Title: Re: Are "Trace" Results Meaningless?
Post by: sallyyorks on Saturday 04 June 16 19:21 BST (UK)
Thanks for your replies david. Very helpful
Title: Re: Are "Trace" Results Meaningless?
Post by: Jan_A on Saturday 13 August 16 12:35 BST (UK)
Hello, you also have to remember that with each passing generation, your dna percentage can/will go down.  This is well seen with the Native American's. I have seen people complain that they KNOW they have NA in their blood but it does not show up.  Here is why:  if a full blooded NA marries a white man: their children will be 50% NA. (in theory). SO if that child marries a white man, their children will be 1/4 NA.  Their children marry white men the children at 1/8th and so on through the generations.  This is why I tell people NOT to get scared about the DNA not showing it.  Traits are what is normally passed on (like dark skinned, dark hair, dark eyes etc) more than the Dna (because that can be so random).  So if you do happen to have a trace, I'd be glad it is there and one day you may figure out where the trace comes from.
Title: Re: Are "Trace" Results Meaningless?
Post by: sallyyorks on Saturday 13 August 16 23:22 BST (UK)
Hello, you also have to remember that with each passing generation, your dna percentage can/will go down.  This is well seen with the Native American's. I have seen people complain that they KNOW they have NA in their blood but it does not show up.  Here is why:  if a full blooded NA marries a white man: their children will be 50% NA. (in theory). SO if that child marries a white man, their children will be 1/4 NA.  Their children marry white men the children at 1/8th and so on through the generations.  This is why I tell people NOT to get scared about the DNA not showing it.  Traits are what is normally passed on (like dark skinned, dark hair, dark eyes etc) more than the Dna (because that can be so random).  So if you do happen to have a trace, I'd be glad it is there and one day you may figure out where the trace comes from.

Hi Jan
The ancestry site though specifically states

"Since there is only a small amount of evidence that you have genetic ethnicity from these regions, it is possible that you may not have genetic ethnicity from them at all. This is not uncommon,..."

I take this to mean that the trace results might show ancestry from a certain region or "people", but that that result might be completely wrong.
Title: Re: Are "Trace" Results Meaningless?
Post by: Jan_A on Sunday 14 August 16 12:23 BST (UK)

"Sallyworks", I myself am not too worried about "Trace" origins due to "dirty dna". I look at the main bulk of it as for ancestors.  You'll never really know unless you have documentation of where someone was born and raised etc.  My mom's relatives are convinced that my gg grandfather was German because he spoke Dutch (stupid theory huh?).  One of his living (at 91) students said that he always told people the family was originated from Wales.  My DNA is 50% G. Britain but when I explained that to my mom's cousin - that doesn't matter : we're still German because of the Dutch language.  Stupid huh?

I was merely pointing out how you can GET trace DNA when it dilutes out through generations.
Title: Re: Are "Trace" Results Meaningless?
Post by: sallyyorks on Sunday 14 August 16 14:18 BST (UK)

"Sallyworks", I myself am not too worried about "Trace" origins due to "dirty dna". I look at the main bulk of it as for ancestors.  You'll never really know unless you have documentation of where someone was born and raised etc.  My mom's relatives are convinced that my gg grandfather was German because he spoke Dutch (stupid theory huh?).  One of his living (at 91) students said that he always told people the family was originated from Wales.  My DNA is 50% G. Britain but when I explained that to my mom's cousin - that doesn't matter : we're still German because of the Dutch language.  Stupid huh?

I was merely pointing out how you can GET trace DNA when it dilutes out through generations.

This is probably a stupid question , but how do you know that your "DNA is 50% G.Britain".
The maps I have seen for the results show wide overlapping groups. G.Britain  for example also includes Ireland, France, Belgium and Nordic countries.
The results show little difference between the DNA of north west Europeans. Which is what you would expect after thousands of years of mixing between these people.
I do not see what taking the tests can tell me. Other than that most of my family are from the north west region of Europe. But I already know that most of them are anyway
Title: Re: Are "Trace" Results Meaningless?
Post by: pharmaT on Wednesday 14 September 16 16:10 BST (UK)
Hello, you also have to remember that with each passing generation, your dna percentage can/will go down.  This is well seen with the Native American's. I have seen people complain that they KNOW they have NA in their blood but it does not show up.  Here is why:  if a full blooded NA marries a white man: their children will be 50% NA. (in theory). SO if that child marries a white man, their children will be 1/4 NA.  Their children marry white men the children at 1/8th and so on through the generations.  This is why I tell people NOT to get scared about the DNA not showing it.  Traits are what is normally passed on (like dark skinned, dark hair, dark eyes etc) more than the Dna (because that can be so random).  So if you do happen to have a trace, I'd be glad it is there and one day you may figure out where the trace comes from.

There grandchildren would not necessarily be 25% NA DNA wise. Because what you inherit from each parent is random there is a high chance  what dna you inherit will be skewed towards one grandparents or another.
Title: Re: Are "Trace" Results Meaningless?
Post by: Jan_A on Tuesday 27 September 16 14:37 BST (UK)
In my case, the ancestry.com test gave the "guess" of 50% G. Britain.  I don't wholly believe in their numbers but it gives me a place to begin.

My ggrandfather's family was BELIEVED to be from Germany because he spoke Dutch, not true - many immigrants learned Dutch on the ship ride over.  He was a school teacher and told people that the family was from Wales - which ties back to my dna being GB (This makes me believe I have more GB than thought while growing up).  In that same family line, we have a link to a woman that had a child out of wedlock to a Duke or Earl from Scotland, that child married into my family.  Again that would lead to more GB dna in my family and supports a higher % of dna from that region.

I would never believe in just the numbers, but the locations like GB.  Unlike my mom's cousin searching Germany because he spoke Dutch.

Hope that clears it up, use the DNA as a tool but all tools have flaws.
Title: Re: Are "Trace" Results Meaningless?
Post by: Mike in Cumbria on Tuesday 27 September 16 15:54 BST (UK)
I presume that your cousin knows that they don't speak Dutch in Germany. 

Does he/she mean "Pennsylvania Dutch", which is a dialect of German (from Deutsch)?
Title: Re: Are "Trace" Results Meaningless?
Post by: ReadyDale on Tuesday 27 September 16 17:38 BST (UK)
Hello, you also have to remember that with each passing generation, your dna percentage can/will go down.  This is well seen with the Native American's. I have seen people complain that they KNOW they have NA in their blood but it does not show up.  Here is why:  if a full blooded NA marries a white man: their children will be 50% NA. (in theory). SO if that child marries a white man, their children will be 1/4 NA.  Their children marry white men the children at 1/8th and so on through the generations.  This is why I tell people NOT to get scared about the DNA not showing it.  Traits are what is normally passed on (like dark skinned, dark hair, dark eyes etc) more than the Dna (because that can be so random).  So if you do happen to have a trace, I'd be glad it is there and one day you may figure out where the trace comes from.

There grandchildren would not necessarily be 25% NA DNA wise. Because what you inherit from each parent is random there is a high chance  what dna you inherit will be skewed towards one grandparents or another.
So if the DNA will be skewed to wards one grandparent or another, the figure could be significantly higher than the 25% or significantly lower. And that is just a couple of generations back. Seems that the ethnicity element of DNA testing is just a meaningless sideshow.