What do percentages of ethnicity actually mean

[cardinalcanary]

Hello

Probably been asked before and if so, please point me in the right direction.

Ancestry results indicate an estimated 17% Scandinavian result (5% Irish, 72% British).

I have traced back several generations on most branches and no sign of any Scandanavians or Irish.

17% seems quite high so how many generations do I have to go back to find the Scandinavian roots?

Thanks for your help.

Stephen

[davidft]

They actually mean nothing.

What you are getting when you get an "ethnicity breakdown" is a best guess based on some dubious science and a lot of assumptions.

In my own case I apparently have no British Isles ethnicity and yet my father has nearly 40 per cent. How does that work? And once you have solved that conundrum how come when mine and my fathers data is analysed by a different tester it is possible to get much closer analyses including finding some British Isles inheritance for me.

OK that probably doesn't answer the question in the way you want but what I am saying is don't put too much reliance on the analyses, treat it as a bit of fun and a very broad indicator of possible ethnic inheritance. There are actually some good testimonies on youtube of people revealing their results and how gobsmacked they were with some of the suggested ethnic breakdowns.

Also as you tested with Ancestry they have lots of articles on their site that will answer this and many other DNA related questions so worth a look there

[cardinalcanary]

Thanks. I appreciate it's some guess work and regions overlap. For example, the top range of the estimates say I could be 100% British. How does that reconcile?

There must be something in the 23 strings of letters that suggest Scandinavian.

Will have to see what Ancestry says on their forums.

I was pleased to actually be able to download the info and upload it into My Heritage to get a couple more matches. Can I upload the info anywhere else?

I have actually found a lot of new cousins thanks to the test so it wasn't all bad news.

[davidft]

Yes you can upload to www.gedmatch.com. (its free) I think this site is good in that it has a number of different tools to play around with and you can get several different analyses of your results too - which may help explain things (or confuse them a bit more ... )

Good luck

[cardinalcanary]

Thanks David

I will give it a go.

Best wishes

Stephen

[shellyesq]

It's worth keeping in mind Ancestry's description of their different areas. 

Under Scandinavia, it says "Primarily located in: Sweden, Norway, Denmark  Also found in: Great Britain, France, Germany, Netherlands, Belgium, the Baltic States, Finland" 

Under Ireland, it says "Primarily located in: Ireland, Wales, Scotland  Also found in: France, England"

So really, both of these areas cover Great Britain/England.

[cardinalcanary]

It's worth keeping in mind Ancestry's description of their different areas. 

Under Scandinavia, it says "Primarily located in: Sweden, Norway, Denmark  Also found in: Great Britain, France, Germany, Netherlands, Belgium, the Baltic States, Finland" 

Under Ireland, it says "Primarily located in: Ireland, Wales, Scotland  Also found in: France, England"

So really, both of these areas cover Great Britain/England.

Thanks Shelly.

I think I need to understand the basics of how the assessments are made. Is there something in 1 of the 23 strings of numbers and letters that says Scandinavian, British etc?

[davidft]

Very roughly how ethnicity is determined is comparing your full results over the 23 "strings" with sample populations and indeed as I understand it this is how all the ethnicity predictions from the various different testers is done. So basically what is suggesting you are Scandinavian or whatever is the patterns that occur in like matched people and the degree to which you are Scandinavian is how many of these matches you have. The more matches the higher percentage Scandinavian and so on.

The problem is the sample populations used for the comparison "ethnic groups" can be very small i.e. sometimes even in single digits and yet from that they hope to predict the ethnicity of 7 billion people in the world. Of course this is a new science and so they do not have anywhere near enough backup data to support their sometimes extravagant claims. That said people agreeing to be tested are adding their data to the existing store of knowledge and hopefully over times it will be possible to make more useful predictions. Even then though they will never pick up all of the ethnicities that make up any single person as what we inherit is random and we wipe out some of inheritance within a few generations.

Then as you mentioned previously there are sometimes overlaps in these patterns so the testing companies have to make an "educated guess" as to what ethnic group to put you in so some testers may say put you in British Isles whilst others may put you in say Western and Coastline Europe

A few articles worth a read

http://www.rootschat.com/links/01jr9/  (Ancestry ethnicity predictions)

https://dna-explained.com/2013/10/04/ethnicity-results-true-or-not/

https://ghr.nlm.nih.gov/primer/testing/ancestrytesting (What is genetic ancestry testing?)

[cardinalcanary]

Thanks David

I shall review your recommended links.

My understanding of DNA testing is improving daily.

Best wishes

Stephen