DNA TESTING

COYBL25 · July 12, 2017

heatmeiser said:
I want to do my old mans as he insists he can trace his family back from the Doomsday book or some nonsense.

I can't wait to tell him he's 30% Filipino.*

*that was a random nationality picked purely for the luls

Can you let us know what happens when you tell him lol

verreauxi · July 12, 2017

No need to be skeptical of it. But all companies use a reference for an "ancestral" population. The science is good, but the reality of DNA inheritance is messy. Consider that going back 4 generations you have 2x2x2x2=16 ancestors. But so does everyone else. ...this is obviously not sustainable, since there are 7,000,000,000 people on the planet and there cannot have 16x7,000,000,000 ancestors 4 generations ago because the earth's population was smaller in the past, not larger. More simply, what is happening is that people's ancestry lineages combine into common ancestors. This is relatedness. But DNA also changes (mutates) and recombines (large chunks of chromosomes switch places prior to reproduction), which messes up how we can reconstruct ancestry (mitochondria DNA and Y chromosome DNA doesn't do this recombining). If you're looking to find relatives only a few generations back, then just use archival data. If you're trying to find out if you and your sister are full-siblings, use DNA. And if you're trying to find some amount of distant ancestry, then these tests will provide a coarse guide to ethnicity (e.g., % DNA from Africa, East Asia, Middle East, N.America). This is because DNA companies don't have time machines. They have a database of DNA samples called a reference population. Reference populations are samples of DNA from tons of individuals throughout the world. You send them your DNA, they sequence it and compare it to the DNA sequences of their reference populations; if there is a strong match, then they will say something like 59% of your DNA matches with our reference population A...therefore you are 59% A, and 43% B, and so on.

But these reference populations are only "stand-ins" for ancestors, since they come from modern people--people who's own DNA has been changing across generations due to recombining with other people's DNA, mutating, and due to the people's ancestors migrating into new areas--just like your ancestors. So the reference population isn't a very secure estimate of ancestry. For example, say I submit a sample to 23andme and they tell me that I have 79% South Asian DNA ancestry. What this means is that my DNA matches at 79% to their reference population of people who's DNA they got from India. But it is very possible that the South Asian reference population has only recently moved into India in the last 500 years (but 23andme don't know that), from say Afghanistan and Iran, so really while the current reference population lives in India (and to whom I matched), the reference population's ancestors came from somewhere else.

More generally, people use ancestry subjectively, despite what the ancestry tests say. My dad's family is Dutch and Irish. My mom's family is from Hungary. I tend to identify (for arbitrary reasons) with being Hungarian more than being Irish. But it could have been otherwise--had my dad talked up his Irish pride a bit more during my childhood, I might have gotten a Celtic Cross tattoo as a teenager and then later deeply regretted it. Your pedigree could contain a bunch of average people, a thief and a princess. Most people with this pedigree would go around bragging about how they have royal blood. It's very subjective. Putting it more bluntly, look at the rise in "white nationalism" in right-wing fringe groups. There is no such thing as being a true white person in any genetic sense (since everyone is highly related, and Europe in particular has a history of different migrations) but these people, quite arbitrarily, subjectively believe in "whiteness."

heatmeiser · July 12, 2017

verreauxi said:
No need to be skeptical of it. But all companies use a reference for an "ancestral" population. The science is good, but the reality of DNA inheritance is messy. Consider that going back 4 generations you have 2x2x2x2=16 ancestors. But so does everyone else. ...this is obviously not sustainable, since there are 7,000,000,000 people on the planet and there cannot have 16x7,000,000,000 ancestors 4 generations ago because the earth's population was smaller in the past, not larger. More simply, what is happening is that people's ancestry lineages combine into common ancestors. This is relatedness. But DNA also changes (mutates) and recombines (large chunks of chromosomes switch places prior to reproduction), which messes up how we can reconstruct ancestry (mitochondria DNA and Y chromosome DNA doesn't do this recombining). If you're looking to find relatives only a few generations back, then just use archival data. If you're trying to find out if you and your sister are full-siblings, use DNA. And if you're trying to find some amount of distant ancestry, then these tests will provide a coarse guide to ethnicity (e.g., % DNA from Africa, East Asia, Middle East, N.America). This is because DNA companies don't have time machines. They have a database of DNA samples called a reference population. Reference populations are samples of DNA from tons of individuals throughout the world. You send them your DNA, they sequence it and compare it to the DNA sequences of their reference populations; if there is a strong match, then they will say something like 59% of your DNA matches with our reference population A...therefore you are 59% A, and 43% B, and so on.

But these reference populations are only "stand-ins" for ancestors, since they come from modern people--people who's own DNA has been changing across generations due to recombining with other people's DNA, mutating, and due to the people's ancestors migrating into new areas--just like your ancestors. So the reference population isn't a very secure estimate of ancestry. For example, say I submit a sample to 23andme and they tell me that I have 79% South Asian DNA ancestry. What this means is that my DNA matches at 79% to their reference population of people who's DNA they got from India. But it is very possible that the South Asian reference population has only recently moved into India in the last 500 years (but 23andme don't know that), from say Afghanistan and Iran, so really while the current reference population lives in India (and to whom I matched), the reference population's ancestors came from somewhere else.

More generally, people use ancestry subjectively, despite what the ancestry tests say. My dad's family is Dutch and Irish. My mom's family is from Hungary. I tend to identify (for arbitrary reasons) with being Hungarian more than being Irish. But it could have been otherwise--had my dad talked up his Irish pride a bit more during my childhood, I might have gotten a Celtic Cross tattoo as a teenager and then later deeply regretted it. Your pedigree could contain a bunch of average people, a thief and a princess. Most people with this pedigree would go around bragging about how they have royal blood. It's very subjective. Putting it more bluntly, look at the rise in "white nationalism" in right-wing fringe groups. There is no such thing as being a true white person in any genetic sense (since everyone is highly related, and Europe in particular has a history of different migrations) but these people, quite arbitrarily, subjectively believe in "whiteness."

So my dads talking out of his wagon hole then?

Also, nice post...

Username · July 13, 2017

degsy said:
The test traces Mitochondrial DNA, which only come from your mothers side, so if you - or anybody else is looking to trace their Male line, well you're out of luck...They don't actually spell this out either

What will my results tell me?
Your AncestryDNA results include information about your ethnicity across 26 regions/ethnicities and identifies potential relatives through DNA matching to others who have taken the AncestryDNA test. Your results are a great starting point for more family history research, and it can also be a way to dig even deeper into the research you've already done.

According to their website they no longer just test the mitochondrial DNA but now it includes Autosomal DNA which I think is from both sets of parents, reckon it's worth it??

degsy · July 13, 2017

Username said:
According to their website they no longer just test the mitochondrial DNA but now it includes Autosomal DNA which I think is from both sets of parents, reckon it's worth it??

*shrugs

goldcoastblue - Liverpool Fan Carl Kan · July 13, 2017

verreauxi said:
No need to be skeptical of it. But all companies use a reference for an "ancestral" population. The science is good, but the reality of DNA inheritance is messy. Consider that going back 4 generations you have 2x2x2x2=16 ancestors. But so does everyone else. ...this is obviously not sustainable, since there are 7,000,000,000 people on the planet and there cannot have 16x7,000,000,000 ancestors 4 generations ago because the earth's population was smaller in the past, not larger. More simply, what is happening is that people's ancestry lineages combine into common ancestors. This is relatedness. But DNA also changes (mutates) and recombines (large chunks of chromosomes switch places prior to reproduction), which messes up how we can reconstruct ancestry (mitochondria DNA and Y chromosome DNA doesn't do this recombining). If you're looking to find relatives only a few generations back, then just use archival data. If you're trying to find out if you and your sister are full-siblings, use DNA. And if you're trying to find some amount of distant ancestry, then these tests will provide a coarse guide to ethnicity (e.g., % DNA from Africa, East Asia, Middle East, N.America). This is because DNA companies don't have time machines. They have a database of DNA samples called a reference population. Reference populations are samples of DNA from tons of individuals throughout the world. You send them your DNA, they sequence it and compare it to the DNA sequences of their reference populations; if there is a strong match, then they will say something like 59% of your DNA matches with our reference population A...therefore you are 59% A, and 43% B, and so on.

But these reference populations are only "stand-ins" for ancestors, since they come from modern people--people who's own DNA has been changing across generations due to recombining with other people's DNA, mutating, and due to the people's ancestors migrating into new areas--just like your ancestors. So the reference population isn't a very secure estimate of ancestry. For example, say I submit a sample to 23andme and they tell me that I have 79% South Asian DNA ancestry. What this means is that my DNA matches at 79% to their reference population of people who's DNA they got from India. But it is very possible that the South Asian reference population has only recently moved into India in the last 500 years (but 23andme don't know that), from say Afghanistan and Iran, so really while the current reference population lives in India (and to whom I matched), the reference population's ancestors came from somewhere else.

More generally, people use ancestry subjectively, despite what the ancestry tests say. My dad's family is Dutch and Irish. My mom's family is from Hungary. I tend to identify (for arbitrary reasons) with being Hungarian more than being Irish. But it could have been otherwise--had my dad talked up his Irish pride a bit more during my childhood, I might have gotten a Celtic Cross tattoo as a teenager and then later deeply regretted it. Your pedigree could contain a bunch of average people, a thief and a princess. Most people with this pedigree would go around bragging about how they have royal blood. It's very subjective. Putting it more bluntly, look at the rise in "white nationalism" in right-wing fringe groups. There is no such thing as being a true white person in any genetic sense (since everyone is highly related, and Europe in particular has a history of different migrations) but these people, quite arbitrarily, subjectively believe in "whiteness."

Excellent work but alas I need a much simpler explanation unfortunately, you are clearly on a higher level of smarts than me, A for effort.

Joey66 · July 13, 2017

goldcoastblue said:
Off topic I know but anyone had this done..... had mine done recently somewhat surprised by the results comparatively to other results Ive seen...turns out im 94.8% irish scottish welsh.... who'd of guessed and 5.2% Iberian... kind of always thought I had some exotic blood in me coming from stock from down by the docks like.. nope basically im a Celt..not sure as to how I feel happy or sad..... still working it out

Did you see WATCHDOG last nightlol
its a con!

goldcoastblue - Liverpool Fan Carl Kan · July 13, 2017

Joey66 said:
Did you see WATCHDOG last nightlol
its a con![

no I guess watchdog is on in UK....cos Im not

Joey66 · July 13, 2017

Well they sent in to a firm who asked for a picture of the dog - got it wrong then a cat - then a human - all describing a breed of dog! - It was an utter farce mate be careful where you are sending you DNA sample of your pet a read reviews etc otherwise its money down the drain -
A top DNA animal researcher came on and stated a proper firm can, and should be able to trace the dogs grandparents from a simple DNA swab from your dog - do not send in a picture of your dog is asked for.

goldcoastblue - Liverpool Fan Carl Kan · July 13, 2017

Joey66 said:
Well they sent in to a firm who asked for a picture of the dog - got it wrong then a cat - then a human - all describing a breed of dog! - It was an utter farce mate be careful where you are sending you DNA sample of your pet a read reviews etc otherwise its money down the drain -
A top DNA animal researcher came on and stated a proper firm can, and should be able to trace the dogs grandparents from a simple DNA swab from your dog - do not send in a picture of your dog is asked for.

ru scottish