To think these DNA ancestry tests make no sense

[CarolineFields]

So you get back a score of 40% Nigerian. Meaning out of the tiny scrap of DNA tested - less than 0.1% -40% of that matches the average population in Nigeria. But if those Nigerians are tested, they won't come back as 100% Nigerian, so 40% of 0.1% matches people who are likely to be told they are 50% not Nigerian?

And if you are in Iceland when you have that test, you are told you are 40% Nigerian, but someone in Australia can be told they are 80% Icelandic due to being compared to you and you cohort?

Traits is not health info - it's things like you're more likely to have blue eyes, lighter skin tone. And weird stuff about whether you are likely to play and intstrument or be a morning person.

It will not say whether you have genes which make you more likely to develop certain medical conditions. You'd have to test through 23 and Me for that, and that company has never been as popular in the UK.

It only tells you where your ancestors were 200 years ago.
I get that.

But it doesn't tell you where you "come from" as those ancestors came from elsewhere.

So it's a bit pointless really - unless you just want to know where your ancestors from 200 years ago were.

I bet a lot of people in the UK could trace one of their ancestors back to an ancestor of King Charles. Or even Prince George - as we can then include the Middleton's ancestors.

Especially if you go back far enough

So we are all related to the Royal Family. And they are related to non Royals.

Well it's not pointless in that many people don't know where their ancestors came from 200 years ago. I think you are underestimating the massive amount of work it could take to document 4 grandparents, 8 g grandparents, 16 gg grandparents, 32, 64, 128 direct ancestors which is the limits of autosomal testing.

Not everyone doing their genealogy has the aim of simply getting as far back as they can, as quickly as possible. For many, i'd say the majority, it's about understanding the lives of these people. Where did they live, what sort of work did they do, what world events did they live through, were they educated, how many children did they have etc etc etc.

Many people underestimate the huge interest in things like ancestral tourism, people coming from North America, Australia or New Zealand to explore the areas in the UK which their ancestors left 150 years ago.

It seems a very arbitrary thing to look at 200 years. Why stop then?

People say "I'm 54% Norwegian, etc" - it doesn't really tell them anything useful except for tracing people who have a common ancestor from the mid 1800s.

Because of the way your DNA recombines, after 4 or 5 generations you have cousins which whom you do not share DNA. And because most people doing a DNA test are not interested in who their relatives were in 1024 AD, they are interested in who their relatives might have been in 1924 or 1824.

As explained upthread, a Y DNA test can get you much further back because the Y chromosome only mutates very slowly. But it's expensive, and men only.

I think your maths is wrong because you are calculating unique individual ancestors when in fact they are shared multiple times over. And often shared not just among large families but in between the same large families over and over again where people tended to stay in the same place over generations.

Exactly, @DubhLinn24 . It's called pedigree collapse and is much more common in some societies than others. The Jewish community is particularly noted for this as marriages happened within a community and often test-takers have higher percentages of shared DNA because their gg grandparents were cousins and their grandparents second cousins or something.

This thread has fascinated me. I don't know enough about genetics to get involved in any of the discussions- but can anyone point me in the direction of the right / most accurate company to use (in their opinion) to get a test done?

I don’t know about the human ones but I did 2 separate dog ones at least 7 years apart and using two different companies.

My vet told me not to bother as they were no good but both tests came back very similar.

The tests could use the same people to process the results and could be complete BS but I felt they were pretty accurate considering they all said the same dog breeds.

i did 3 with different companies for me, my 2 kids AND my husband, all came back the same within 1% at least with all the companies, was quite surprised

Lots of fascinating contributions on this thread.

Yes some people might not know a lot about their heritage... adoption and slavery are obvious reasons that spring to mind, it's not hard to understand why in these circumstances people would value immensely whatever information dna tests can give.

Quite often you find that someone else has drawn up a detailed family tree that you can link to. DH unearthed some very distant relatives in America - they had managed to complete a side of the family tree back to the 1600s using parish records from a tiny area in continental Europe.

#Roastiesarethebestbit · Yesterday 23:46
So we are all descended from Viking’s because 40 generations ago we have more ancestors than people alive at the time? So doesn’t the same logic mean that we are descended from everyone alive at that

You are absolutely correct in that. Assuming you have European heritage, Everyone who was alive a thousand years ago is either your ancestor, or the ancestor of no one, because their line has died out.

What are you doing it for?

If you are interested in genealogy and already have done work on your family tree, then Ancestry. Or if you are trying to find an unknown sibling/grandparent.

If it's for health and to know if you have a certain gene more likely to cause a health condition, 23 and Me.

If it's purely for "ethnicity result", still Ancestry, but realistically, don't waste your money.

I would reword that and say "Most of us will have Viking descendants, because most of us will eventually have common ancestors - and if you go back a long long time, we all have ancestors from Africa" - and ultimately, we can all go back to bacteria in the pool of life....

Except for those of us who came through the Stargate......

@Gingerkittykat · Today 03:00
CarolineFields · Yesterday 21:59

40 generations ago you have 20 hundred billion ancestors out of a population of 50 million in Europe about a million of whom were Viking, so not only was every European descended from Vikings, but every European is related to every Viking. many times. Many many many many many times! ( and I have rounded those number down!)
There have only been approximately 117 billion people who have ever lived (including people alive now) so it is impossible to have had as many ancestors as you state.

Because that is how many ancestral positions there are in your 'tree'. However, they filled by the same people multiple times over, in other words you are descended from the same people by many different routes, it is called pedigree collapse.

True - but we still have a LOT of ancestors though - and yet there is a smaller pool "at the start"

Imagine what the family tree for every human being would look like when combined!!

The ethnicity bit of the test seems a bit hit and miss. I did it a few years ago on Ancestry and the percentages and countries have been changed a few times since the original test. It is pretty accurate now but I suspect they back up their 'evidence' with who you are matching to.

It accurately has me as 50% of one parent's nationality, then largely English / NW European for the other, with 7% Norwegian. There isn't any Norwegian in the last 200 years on that parent's side, but I think it's normal that British people have a smattering of Norwegian.

I liked doing the test mainly because I like history, and it allowed me to put a family tree together really quickly, as I could see who my matches were.

It changed my life. I'm adopted and didn't know who my father was. I identified his family from AncestryDNA and narrowed it down to him. I have a whole branch of a wonderful family, including a lovely brother and two little nephews who never would have been in my life without it. I also have all the answers I wanted.

@cakeorwine · Today 10:59
Brahumbug · Today 10:47

#Roastiesarethebestbit · Yesterday 23:46
So we are all descended from Viking’s because 40 generations ago we have more ancestors than people alive at the time? So doesn’t the same logic mean that we are descended from everyone alive at that

You are absolutely correct in that. Assuming you have European heritage, Everyone who was alive a thousand years ago is either your ancestor, or the ancestor of no one, because their line has died out.
I would reword that and say "Most of us will have Viking descendants, because most of us will eventually have common ancestors - and if you go back a long long time, we all have ancestors from Africa" - and ultimately, we can all go back to bacteria in the pool of life....

No, absolutely not. Talking about European heritage, We are all descended from everyone alive 1000 years ago who has line if descent extant to this day, that is an absolute fact. So we are all descendants of Charlemagne, Alfred the Great etc. Viking by the way is it an ethnic group, it is a job description!😁

Personally with the rise of the far right across Europe I wouldn't touch this with a barge pole. Much too easy to imagine it being weaponised. Equating origin with nationality is well dodgy. Bits of Europe have changed countries multiple times. What does it mean to be 50 percent Italian if Italy didn't exist until the latter half of the 19th c?

Yes, I found biological members of my family this way.

I was lucky my mum's biological sister was also searching for the same answers so had registered and there was a bio cousin who was a member and was able to give us both answers.

I think there is a lot of luck involved in this process but it is worth a try.

what exactly do you think it means by Celtic? genetically there is no such thing. "Celtic" means a society with produces a certain type of art, and are historically concentrated around Spain

The people used to decide a particular heritage have all their ancestors from that particular area. I've thought about putting my Mum's test in for the West Cornwall group (which we show very clearly), as all her ancestors going back 6-8 generations were born within a small radius. So it's not done on where you live now, e.g. Manchester for my Mum, but where your ancestors are from.

@Gingerkittykat thanks so much. I think I'm going to. Not even sure what I'll do with the info but I feel like I need to see

No idea about the geography ethnic background stuff but I found out my grandad wasn’t my grandad. Got lots of matches of cousins, etc I knew nothing about.