Are "Trace" Results Meaningless?

[sallyyorks]

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?

[davidft]

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

[sallyyorks]

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?

[davidft]

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

[sallyyorks]

Thanks for your replies david. Very helpful

[Jan_A]

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.

[sallyyorks]

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.

[Jan_A]

"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.

[sallyyorks]

"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