To think these DNA ancestry tests make no sense

As an archaeologist, in my humble opinion, the most useful thing aDNA is showing us currently is familial relationships amongst burial groups going back to the Mesolithic and in some cases, like a recent Viking study, two brothers who were buried in different parts of Europe or men having children with several different mothers and vice versa or monogamous relationships. These things are absolutely fascinating and something we could never get at otherwise.

I have seen their comments. It contradicts what they have written in their own paper.

Given that Cakeorwine can't tell the difference between descendants and ancestors....

I also agree that there is a nasty undertone to "ethnically British". I am in a lot of FB groups for people in other countries who have ancestors who came from different parts of the UK and that's something that comes up regularly. They are the "proper Scots/Irish/Welsh/Yorkshiremen", the ones who were there for centuries and left to go to US/Australia. Their descendants are even more Scottish/Welsh than these recent immigrants from the Caribbean or S Asia.

There are a few posters on this thread who clearly know what they are talking about though.

Since when have white supremacists listened to sense?! Look at the shower we have in the UK with their nonsense about indigenous Brits

Oh - and someone needs to tell the Royal Family that who cares if they can trace their line back to William the Conqueror. Many people in the UK can. It's just that accurate records haven't been kept for most people.

"The main thing for me is that these tests have been used widely by racists in the USA who want to prove their white European bloodlines, and nowadays people working in the field assume that their target market is white supremacists. Not a club I want to be part of!"

Someone needs to tell them that they are related to everyone on else on Earth until relatively recently in human evolution.

I don't think you are a tinfoil hat wearer at all <adjusts own shiny crinkly silver hat>

I actually know someone who works in this field and she is adamant that she would never hand over her genomic data to anyone. There's just too much that could be done in the future with it. To say nothing of the fact that they should be paying people for it, not the other way around, since that's the most valuable asset they have.

I am told by her that nothing going back 3 generations persists in the DNA to the extent that they can tell you your precise heritage. Only a few extremely anomalous sequences, apparently, will show you anything useful, unless you really are interested in your great grandparents, whom you most likely knew anyway. But if you didn't - I get the need to know.

The main thing for me is that these tests have been used widely by racists in the USA who want to prove their white European bloodlines, and nowadays people working in the field assume that their target market is white supremacists. Not a club I want to be part of!

That's not what he is saying.

It states that if people alive back then had ancestors alive now, then 1000 years ago, all of those people who still have ancestors today would be able to trace to all people alive now.

It's reckoned that is about 80% of the population alive 1000 years ago still have ancestors alive now

He’s wrong. Not everyone who had children 1000 years ago had grandchildren for example. Plenty of lines died out. It’s really basic stuff like that that calls into question their credibility on extrapolating their research at a population level to individuals.

These are their comments

Researcher uses DNA to demonstrate just how closely everyone on Earth is related to everyone else (phys.org)

Have you read their comments?

"Our research confirmed what Chang suspected—that everybody who was alive in Europe a thousand years ago and who had children, is an ancestor of everyone alive today who has some European ancestry," Ralph said.

@cakeorwine

I've gone to the actual paper your summaries cite:
https://journals.plos.org/plosbiology/article/info%3Adoi%2F10.1371%2Fjournal.pbio.1001555

It include important information missing in your argument. You keep claiming that the research shows that everyone in Europe has Viking ancestry. But there IS variation. The paper says that "Southeastern Europeans, for example, share large numbers of common ancestors that date roughly to the era of the Slavic and Hunnic expansions around 1,500 years ago, while most common ancestors that Italians share with other populations lived longer than 2,500 years ago. " 2,500 years ago. A thousand years before the vikings. What you are saying may be generally true, but it is not universal.

And some more links

Researcher uses DNA to demonstrate just how closely everyone on Earth is related to everyone else (phys.org)

Our research confirmed what Chang suspected—that everybody who was alive in Europe a thousand years ago and who had children, is an ancestor of everyone alive today who has some European ancestry," Ralph said.
Ralph and Coop calculated that these shared segments showed ancestors stretching back some 3,000 years, or 100 generations. This lends support to Chang's calculation that by expanding his model from living Europeans to everyone alive on Earth, an all-ancestor generation would have occurred some 3,400 years ago

"On top of that it was surprising the extent to which you could also see the effects of history in the patterns we found," Ralph said.

While their research showed that Europeans living closer to one another were also more closely related, it revealed that people in Eastern Europe tended to have more shared ancestors than Western Europeans.

"We could really see the demographic effects of the Slavic expansion in Eastern Europe around the time of the fall of the Roman Empire," Ralph said.

"In a population expansion, people are having more children than in a stable population. So, if that larger, expanded generation traces their family back through time there is an increased opportunity that they will have shared ancestors because the pool of potential ancestors is smaller."

It's not a "common ancestor" as such - more to do with common ancestors. i.e. at some point each person alive in Europe was the ancestor of each person alive in Europe now. (although obviously there have been patterns of immigration from other parts of the world in that time).

You could pick any person alive at that point and they would be an ancestor of you.

Imagine in 10,000 years time. Assuming your children have children etc and so on and so on. Could every person on Earth trace a link to you?

Even with pedigree collapse etc, how long would it be before every person alive could trace a direct link to you and to someone else in say Japan alive at this time. Or from you and any other random person alive at the moment.

Again:

Researchers using genomic data place the latter date around A.D. 1000.

And also:

This is illustrated in the 2003 simulation as follows: considering the ancestral populations alive at 5000 BC, close to the ACA point, a modern-day Japanese person will get 88.4% of their ancestry from Japan, and most of the remainder from China or Korea, with only 0.00049% traced to Norway; conversely, a modern-day Norwegian will get over 92% of their ancestry from Norway (or over 96% from Scandinavia) and only 0.00044% from Japan.

Thus, even though the Norwegian and Japanese person share the same set of ancestors, these ancestors appear in their family tree in dramatically different proportions.

A Japanese person in 5000 BC with present-day descendants will likely appear trillions of times in a modern-day Japanese person's family tree, but might appear only one time in a Norwegian person's family tree

A 5000 BC Norwegian person will similarly appear far more times in a typical Norwegian person's family tree than they will appear in a Japanese person's family tree

So some populations will have the same ancestors multiple time from a particular region - a 5000 BC Norwegian person will appear many times in the family tree of a modern Norwegian person - but would only appear maybe once in a Japanese persons family tree - BUT THEY WILL APPEAR

Have you seen the bit where it says genetic studies?

Researchers using genomic data place the latter date around A.D. 1000

People are still saying that they don't have "Viking ancestry" - and yet the study clearly states:

"However, as 1,000 years is about 33 generations, and 233≈1010 is far larger than the size of the European population, so long as populations have mixed sufficiently, by 1,000 years ago everyone (who left descendants) would be an ancestor of every present-day European"

You're ignoring this bit though: "so long as populations have mixed sufficiently"

There have been lots of isolated populations in Europe where there would have been very little mixing. So you cannot assume that there will be common ancestors between say, someone from an island community in the west of Ireland and one from a mountainous village in Transylvania.

I haven't read the full thread sorry but I don't understand why people keep saying Viking when that was an occupation not ethnicity/heritage? Mine shows Scandinavian not Viking.

It's fascinating stuff though. It threw up surprises so I dug deeper. I was surprised to find out lots of Scots in the south/east are of Germanic descent because the Angles settled there and most English people are still Celtic not Anglo Saxon. Go Boudicca lol.

I’m sorry but all the math exercises (no genetic studies) that speculate on a common ancestor for every European or whoever from only thousands of years ago is too much like a new and improved Adam and Eve in the garden of Eden and the world is only 4,000 years old story. I am waiting to see the links to the same sorts of conclusions that aliens stranded a common ancestor on Earth to colonise it. Surely there would be at least an Adam and an Eve? Two common ancestors? Unless the idea is that Adam and Eve were brother and sister and the original ancestor was a woman pregnant with nonidentical twins?

@5Yearsleft
”you’ll need to understand pedigree collapse (she doesn’t). There is a great but lengthy thread that explains why most of us aren’t related to royalty, since “we’re all related to Edward I” is her new claim post-“we’re all Vikings.” It’s here:”

🙌🙌 hear hear. OP also doesn’t understand too how human society is stratified and that meant marriages tended to be within your own demographic of class, religion, ethnicity and so on much more strictly then than today.

More on the identical isopoint - the point where everyone who was alive at that point is an ancestor of every human alive now - assuming each of their offspring had children

Identical ancestors point - Wikipedia

The identical ancestors point for Homo sapiens has been the subject of debate. In 2003 Rohde estimated it to be between 5000 and 15,000 years ago.[2] In 2004, Rohde, Olson and Chang showed through simulations that, given the false assumption of random mate choice without geographic barriers, the Identical Ancestors Point for all humans would be surprisingly recent, on the order of 5,000-15,000 years ago.

Ralph and Coop (2013), considering the European population and working from genetics, came to similar conclusions for the recent common ancestry of Europeans

More recently, however, researchers have estimated the European isopoint to be closer to 1000 A.D

However, people will vary widely in how much ancestry and genes they inherit from each ancestor, which will cause them to have very different genotypes and phenotypes

This is illustrated in the 2003 simulation as follows: considering the ancestral populations alive at 5000 BC, close to the ACA point, a modern-day Japanese person will get 88.4% of their ancestry from Japan, and most of the remainder from China or Korea, with only 0.00049% traced to Norway; conversely, a modern-day Norwegian will get over 92% of their ancestry from Norway (or over 96% from Scandinavia) and only 0.00044% from Japan.

Thus, even though the Norwegian and Japanese person share the same set of ancestors, these ancestors appear in their family tree in dramatically different proportions.

A Japanese person in 5000 BC with present-day descendants will likely appear trillions of times in a modern-day Japanese person's family tree, but might appear only one time in a Norwegian person's family tree

A 5000 BC Norwegian person will similarly appear far more times in a typical Norwegian person's family tree than they will appear in a Japanese person's family tree

Note that a person in the population today does not necessarily inherit any genetic material from a given ancestor at the Identical Ancestors Point. For example, a Japanese person may not inherit any genetic material from his Norwegian ancestors. In that case, they are genealogical ancestors but not genetic ancestors. The same goes even for the most recent common ancestor.

So it's likely that if many people in the UK did their family tree, then William The Conqueror would appear in that tree

For some people, he might appear many times. For others, only once. But it's very likely that for most Europeans he would appear

Here's some more reading you can do

On genes, ancestry, and why we’re all descended from royalty | The Bubble

Chang also calculated that everyone of European descent has a common ancestor who lived as recently as around 600 years ago, at the time of Richard II. Bearing this in mind, stories of Danny Dyer’s descent from William the Conqueror and Edward III, or Christopher Lee’s direct ancestry to King Charlemagne seem like hollow claims. Yes, they probably are descended from these prolific figures, but so are all other white Europeans. To add to the redundancy of such assertions, Danny Dyer may possess all of William the Conqueror’s genetic material or none of it, as may anyone.

Humans Are All More Closely Related Than We Commonly Think | Scientific American

Go back a bit further, and you reach a date when our family trees share not just one ancestor in common but every ancestor in common. At this date, called the genetic isopoint, the family trees of any two people on the earth now, no matter how distantly related they seem, trace back to the same set of individuals. “If you were alive at the genetic isopoint, then you are the ancestor of either everyone alive today or no one alive today,” Rutherford says. Humans left Africa and began dispersing throughout the world at least 120,000 years ago, but the genetic isopoint occurred much more recently—somewhere between 5300 and 2200 B.C.,according to Rohde’s calculations.

In fact, even more recent than the global genetic isopoint is the one for people with recent European ancestry. Researchers using genomic data place the latter date around A.D. 1000. So Christopher Lee’s royal lineage is unexceptional: because Charlemagne lived before the isopoint and has living descendants, everyone with European ancestry is directly descended from him. (And every other European at the time who has ancestors)

And think of this - at some point in the future, every parent here will be the ancestor of every human on the planet. If their offspring etc have children

That's what I just did.

Maybe you didn't look at the scientific studies and the one I just linked to

Ok, so no you can’t address those points then. Thought so.

@Ikeatears have you had any offers? It’s the kind of thing I like being sucked into but I haven’t got the time at the moment. There are several Facebook groups though that seem to be full of people loving the challenge.