siblings dna

[greyingrey]

I can. understand, as it says in. one link,  that I may not have the same. Dna results as a cousin, but should siblings have the same ethnicity results, please

[Lisa in California]

I believe due to DNA that we inherit from parents (amounts can vary), and due to a margin of error, etc. our results can be different.  While my brother and I have somewhat similar high percentage results, I have 2% ethnicity from Norway, he has 0%; he has 4% ethnicity from Sweden and Denmark, I have 0%.  I have 5% from Germanic Europe; he doesn’t have any.

My sister-in-law and her two sisters also have varying results.  In their family, I believe the differences are much greater than the minuscule differences between my brother and me.

I’m sure someone will come along who can correctly and eloquently state facts.     (Apologies if I’ve mislead you.)

Added: I don’t know if this is true with others or just something odd on my part, but my brother seems to have inherited a higher percentage of DNA from our paternal side, and I seem to have inherited a higher percentage from our maternal side.  But, perhaps it’s just due to a margin of error in reading results.

[phil57]

I can. understand, as it says in. one link,  that I may not have the same. Dna results as a cousin, but should siblings have the same ethnicity results, please

No, because they can each inherit different segments of their parents DNA, and will almost certainly do so unless they are identical twins, the allocation to ethnicity regions will likely also vary. Bear in mind also that small percentage allocations are more likely to be false or misattributed, and with different segments of their parents DNA, it is quite possible that a very low percentage match which only one sibling has, might just be random "noise". The percentages that you are presented with are probabilities, so an allocation of a few percent can just as easily mean that there is actually no link to that region at all, and the allocation is false, or that the link may be higher.

You are far better off concentrating on overall segment match lengths to identify family relationships. Their accuracy above 15 - 20 cM is pretty much indisputable, unlike ethnicity guesstimates.

[Biggles50]

Do read up on how the likes of Ancestry analyse and manipulate their data to provide their ESTIMATES of Ethnicity, all the info is in Ancestry’s Help files.

Their source database is from a series of known locations that are essentially extrapolated in their data manipulation to produce the results.

In this case size matters, and in the grand order of life the source database is imo too small for reliable accurate results.

As I have quoted dozens of times, my Ancestry produced Ethnicity Estimate from 5 years ago is totally different from what it now shows.

Do take screen capture's of your own current Ethnicity Estimates and compare them in a few years time to what will be presented then.

[Glen in Tinsel Kni]

Plenty of examples on youtube where siblings, twins and triplets have different ethnicity results. Often they are sensationalised stories by news outlets trying to claim dna tests are at best inaccurate and at worst a scam. Few if any bother to explain dna results are estimates and that companies use a database of locations.

[greyingrey]

thank you...I. have learned a lot and am following your tips to learn. more

[TonyV]

Plenty of examples on youtube where siblings, twins and triplets have different ethnicity results. Often they are sensationalised stories by news outlets trying to claim dna tests are at best inaccurate and at worst a scam. Few if any bother to explain dna results are estimates and that companies use a database of locations.

I think that it's more accurate to say that ethnicity estimates are just that i.e. estimates, whereas DNA results are accurate (albeit that low cM matches are quite likely to be false)