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General => Ancestral Family Tree DNA Testing => Topic started by: Flattybasher9 on Monday 26 October 15 12:17 GMT (UK)
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Interesting read
http://www.rootschat.com/links/01gcz/
Regards
Malky
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Hi Malky ........ you do find 'em ........... that really puts the cats among the pigeons :o :o
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Not really DNA has never been able to prove paternity, there is always an element of doubt, it can however disprove paternity.
There have been many cases of DNA differences in samples taken from different areas of the body and many different reasons for the differences.
Cheers
Guy
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Thanks Guy...... I am surprised that differences in DNA samples can be obtained from different parts of a body. :o :o
Have the samples been found to vary much? and does it put the whole field of DNA usage into doubt?
Joe .... who is now reflecting on his outlay on DNA. :'( :'(
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Thanks Guy...... I am surprised that differences in DNA samples can be obtained from different parts of a body. :o :o
Have the samples been found to vary much? and does it put the whole field of DNA usage into doubt?
Joe .... who is now reflecting on his outlay on DNA. :'( :'(
I wouldn't be too worried. YDNA and mtDNA testing would be unaffected by this quirk, and autosomal DNA testing - while giving a slightly different result - would still reflect DNA inherited from the same set of parents.
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Has anyone told Jeremy Kyle? :P
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Thanks Guy...... I am surprised that differences in DNA samples can be obtained from different parts of a body. :o :o
Have the samples been found to vary much? and does it put the whole field of DNA usage into doubt?
Joe .... who is now reflecting on his outlay on DNA. :'( :'(
I wouldn't be too worried. YDNA and mtDNA testing would be unaffected by this quirk, and autosomal DNA testing - while giving a slightly different result - would still reflect DNA inherited from the same set of parents.
Thanks Brian that is indeed comforting :) :)
Joe
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Not really DNA has never been able to prove paternity, there is always an element of doubt, it can however disprove paternity.
There have been many cases of DNA differences in samples taken from different areas of the body and many different reasons for the differences.
Cheers
Guy
There was a paternity case in the USA fairly recently where a woman had sex with identical twins within 24 hours. Wanting to prove the paternity of her child she arranged for tests to be taken.
The first result showed that there was a 1 in 10,000 chance this twin was not the father. Unfortunately, the test on the second twin gave the same result!! ::)
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Not really DNA has never been able to prove paternity, there is always an element of doubt, it can however disprove paternity.
There have been many cases of DNA differences in samples taken from different areas of the body and many different reasons for the differences.
Cheers
Guy
There was a paternity case in the USA fairly recently where a woman had sex with identical twins within 24 hours. Wanting to prove the paternity of her child she arranged for tests to be taken.
The first result showed that there was a 1 in 10,000 chance this twin was not the father. Unfortunately, the test on the second twin gave the same result!! ::)
OK, never mind Jeremy Kyle - send for Jerry Springer!
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Fascinating.
I have a friend who was born with a chimera, in her eye. Honestly. It was removed as it started to affect her sight as a child.
Gives me the heeby jeebys thinking about it.
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Not really DNA has never been able to prove paternity, there is always an element of doubt, it can however disprove paternity.
The old-style paternity tests use up to 15 autosomal STR markers. These do indeed leave some element of doubt. This type of test is still used by the courts.
However, a genetic genealogy autosomal DNA test, which look at 700,000 markers across the entire genome, is able to prove paternity and maternity without any element of doubt at all. Indeed there are now a number of examples of adoptees who have taken such a test and have actually been matched with one of their biological parents. With whole genome sequencing and advanced DNA analysis it is now even possible to distinguish between identical twins.
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Are you saying DC that the old '' if you have an identical twin you can get away with murder'' is now no longer possible? Or were you referring to the IT parenting issue?
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Are you saying DC that the old '' if you have an identical twin you can get away with murder'' is now no longer possible? Or were you referring to the IT parenting issue?
I am indeed saying that. Here's the scientific paper:
http://www.sciencedirect.com/science/article/pii/S1872497313002275
The difficulty would be in extracting enough DNA at the crime scene in order to produce a whole genome sequence so that you could detect the rare discriminating variants. There is a forensic company that sells this test but I believe it's very expensive.
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That is a very interesting and welcome development of DNA science.
I assume there are still many further steps to be taken to "prove" the results but it shows how quickly the science is developing.
Cheers
Guy
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I am indeed saying that. Here's the scientific paper:
http://www.sciencedirect.com/science/article/pii/S1872497313002275
Thank you :) As Guy commented its an interesting development
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Not really DNA has never been able to prove paternity, there is always an element of doubt, it can however disprove paternity.
There have been many cases of DNA differences in samples taken from different areas of the body and many different reasons for the differences.
Cheers
Guy
There was a paternity case in the USA fairly recently where a woman had sex with identical twins within 24 hours. Wanting to prove the paternity of her child she arranged for tests to be taken.
The first result showed that there was a 1 in 10,000 chance this twin was not the father. Unfortunately, the test on the second twin gave the same result!! ::)
Lol funny that.
On another note isn't the human body amazing.
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Not really DNA has never been able to prove paternity, there is always an element of doubt, it can however disprove paternity.
There have been many cases of DNA differences in samples taken from different areas of the body and many different reasons for the differences.
Cheers
Guy
There was a paternity case in the USA fairly recently where a woman had sex with identical twins within 24 hours. Wanting to prove the paternity of her child she arranged for tests to be taken.
The first result showed that there was a 1 in 10,000 chance this twin was not the father. Unfortunately, the test on the second twin gave the same result!! ::)
Lol funny that.
On another note isn't the human body amazing.
In 2002 a pregnant American woman was charged with fraud after DNA test showed she was not the mother of her children.
The DNA was taken due to her claim for maintenance payments for the support of her first two children from their father.
Hospital records of her prior births were disregarded, as she was pregnant with her 3rd child the judge ordered a witness to be present at the birth and be witness to blood samples taken from mother and the new infant. These samples showed the mother not to be the mother of her own baby.
It was later proved this was a case of chimerism, (two different sets of DNA present in a persons body).
Cheers
Guy
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Chimerism is incredibly rare. There are only about 30 cases recorded worldwide:
http://abcnews.go.com/Primetime/shes-twin/story?id=2315693
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Is under recording of the condition also a factor?
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Is under recording of the condition also a factor?
That is part of the preoblem, no one really knows as it is expected that individuals only have one set of DNA in there body so further tests are seldom taken.
It could be commonplace or more likely it could be rare
Cheers
Guy
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Over three million people have now taken DNA tests for genetic genealogy purposes. There are thousands and thousands of related individuals in the databases mother/father/child trios, father/son pairs, first cousins, second cousins, etc. If this phenomenon were common we would have heard of it by now.
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Over three million people have now taken DNA tests for genetic genealogy purposes. There are thousands and thousands of related individuals in the databases mother/father/child trios, father/son pairs, first cousins, second cousins, etc. If this phenomenon were common we would have heard of it by now.
Obviously we have heard of it or we would not be discussing it at present.
However.
Three million people is only the same as the population of the city of Manchester.
This means in terms of the population of a country like England it is a tiny sample. less that 6%.
If you think of 3 million in terms of the population of the USA (318.9 in 2014) it is even smaller.
That is what is wrong with all the various claims made by DNA companies; they make claims based on insignificant numbers.
That does not mean the claims are wrong but simply that they cannot yet be justified, they may be in time but as yet they cannot.
Cheers
Guy
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Guy
I don't know why you think you have to test the entire population of the world to draw conclusions from DNA testing. There is a huge body of scientific literature from which we now understand the processes of DNA inheritance. We know that a child receives half of his or her DNA from each parent and that they receive one set of 22 autosomal chromosomes from the mother and another set of 22 autosomal chromosomes from the father. A male will have an X and a Y chromosome. A female will have two X chromosomes. We know that a child shares around 25% of his or her DNA with his grandparents, and around 12.5% of his her DNA with his great-grandparents. This is basic biology. We can use this knowledge to deduce relationships. If you and your father take a DNA test with enough markers and you share the expected amount of DNA with him and you have inherited a complete set of 23 chromosomes from him then we know for sure that he is your father.
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Guy
I don't know why you think you have to test the entire population of the world to draw conclusions from DNA testing. There is a huge body of scientific literature from which we now understand the processes of DNA inheritance. We know that a child receives half of his or her DNA from each parent and that they receive one set of 22 autosomal chromosomes from the mother and another set of 22 autosomal chromosomes from the father. A male will have an X and a Y chromosome. A female will have two X chromosomes. We know that a child shares around 25% of his or her DNA with his grandparents, and around 12.5% of his her DNA with his great-grandparents. This is basic biology. We can use this knowledge to deduce relationships. If you and your father take a DNA test with enough markers and you share the expected amount of DNA with him and you have inherited a complete set of 23 chromosomes from him then we know for sure that he is your father.
I did not say that.
I did say that to claim everyone's DNA was different everyone in the world would have to be tested.
That stands to reason because if the final person has a DNA match with another person then everyone in the world would not have different DNA.
However you stated
Quote from: DevonCruwys on Today at 15:04:10
"Over three million people have now taken DNA tests for genetic genealogy purposes. There are thousands and thousands of related individuals in the databases mother/father/child trios, father/son pairs, first cousins, second cousins, etc. If this phenomenon were common we would have heard of it by now."
You were inferring that based on the numbers of people tested chimerism was not common. That claim cannot be made as the numbers of people tested is so small as to be insignificant.
You are talking about the equivalent of one city in a country, it could be that in a particular area or a particular group of people chimerism is not only common but the normal state of affairs.
Until more people are tested and indeed until more people have tests from different parts of their bodies that claim cannot be substantiated.
In the example I gave if the woman concerned had DNA from a cervical smear in the first place instead of from blood samples it may not have been discovered she had two sets of DNA in her body.
Take for instance tossing a coin there is a 50 percent chance of a head or a tail being shown.
I tossed a coin 10 times (not a significant number of times).
It fell heads up 7 times and tails up 3 times.
More interestingly the first 5 times in a row it fell heads up.
If I repeated that I would probably get a completely different set of results.
If however I tossed the coin say a thousand times I would expect to find the number of heads would equal or nearly equal the number of tails.
One cannot draw positive conclusions from small samples.
The mechanics of the sampling has to be taken into consideration as well.
I remember in a physics lesson at school our teacher was trying to demonstrate Newton’s Third Law of Motion. (For every action, there is an equal and opposite reaction). He was using a small cart with a sprung captive bolt in it.
The claim was that if he hit the trigger (a round ball on a vertical shaft) the cart would not move in any direction, however every time he did it moved to the right.
Was Newton wrong no, the teacher was applying an additional force to the cart because he was hitting the trigger at a slight angle rather than vertically.
Cheers
Guy
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For genetic genealogy we're looking for people who share segments or markers of DNA with us. There would be no point in doing the tests otherwise. No one is trying to prove that everyone has different DNA. Why would we want to do that? We know that already. Every human on the planet has a slightly different combination of three billion DNA letters. As you saw from the paper I cited, we can now even distinguish between the DNA of identical twins. Over three million people have taken genetic genealogy tests. There are millions and millions of people in police DNA databases all over the world. Those are massive sample sizes.
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“Hear now this, O foolish people, and without understanding; which have eyes, and see not; which have ears, and hear not” Jeremiah 5:21.
Genetic genealogy is based on assumptions set out in theories.
No one is trying to prove that everyone has different DNA. Why would we want to do that? We know that already.”
Do you know that, how do you know that? You are simply accepting a theory.
Every human on the planet has a slightly different combination of three billion DNA letters.
Another claim that cannot be substantiated and in this case can never be substantiated until every person on the planet has their DNA tested and the results compared.
It may prove to be true but at present it is a theory.
As you saw from the paper I cited, we can now even distinguish between the DNA of identical twins.
No I saw the result of an experiment that suggested that but did not prove that.
For example what kind of “Identical twins” where they?
The paper states they were monozygotic but were they monochorionic-monoamniotic or were they monochorionic-diamniotic?
Would the difference between the two types account for the mutation shown in the result?
You see the science is still being extended but there are still questions to answer.
There are millions and millions of people in police DNA databases all over the world. Those are massive sample sizes.
When compared with what ?
When compared with the population of the world (estimated to be 7 billion or so people in 2012) the numbers in all DNA databases combined barely scratch the surface.
The theories may prove to be accurate but at this stage we do not know.
More experiments need to be undertaken more research needs to be done, that is how science advances.
Even now someone somewhere will be working on their own theory that may confirm an earlier one or may contradict an earlier one.
What you do not seem grasp is I am not contesting the science I am contesting your terminology.
Cheers
Guy
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However you stated
Quote from: DevonCruwys on Today at 15:04:10
"Over three million people have now taken DNA tests for genetic genealogy purposes. There are thousands and thousands of related individuals in the databases mother/father/child trios, father/son pairs, first cousins, second cousins, etc. If this phenomenon were common we would have heard of it by now."
You were inferring that based on the numbers of people tested chimerism was not common. That claim cannot be made as the numbers of people tested is so small as to be insignificant.
You are talking about the equivalent of one city in a country, it could be that in a particular area or a particular group of people chimerism is not only common but the normal state of affairs.
Until more people are tested and indeed until more people have tests from different parts of their bodies that claim cannot be substantiated.
In the example I gave if the woman concerned had DNA from a cervical smear in the first place instead of from blood samples it may not have been discovered she had two sets of DNA in her body.
<snip>
One cannot draw positive conclusions from small samples.
Guy I think you are splitting hairs. It is sound scientific principle to correlate small samples into larger population bases. It is also used in Polling . Where you are correct is the inference '' how to determine best sample size''
But good luck in court trying to fight DNA based on different body region tests :)
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Guy
I agree with you that in science nothing is ever proven, and there is always going to be much more to learn. Theory does in fact have a specific meaning in science:
http://lofalexandria.com/2013/01/fact-vs-theory-vs-law-vs-hypothesis-vs-proof/
However, there is reasonable certainty about many things so that we state them as facts.
While we can't ever prove that a child inherits 50% of its DNA from each of its parents, experiment after experiment has shown this to be the case. The hypothesis has also been confirmed by empirical data from thousands of genetic genealogists who have tested themselves and their parents and see that they too inherit 50% of their DNA from each of their parents.
I don't know all the technical details of the research on identical twins but distinguishing between the DNA of two identical twins is not something that the average genealogist is ever going to need to do.
Genetic genealogy combines genetics and genealogy. The science behind genetics is sound. There is no science behind genealogy. You might have your parents' marriage certificate which states the names of the two fathers but that doesn't prove that these people actually were their biological fathers. With DNA testing we now have a way to test hypotheses like this. You could for example test yourself and a first cousin who should have the same paternal grandfather as you to see if you have share the expected amount of DNA. If you do, then you can be reasonably confident that the information on the marriage certificate is correct.
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Perhaps there is no science behind the way you do genealogy but there certainly is behind the way I carry out my research.
I study the reason behind the records I use to base my research on. I find out why they were created, what information is actually recorded, how it was recorded etc.
I also study the way the records have developed or changed throughout the centuries, both in what they record (and what they do not record) and how they are used.
When I have the information from the records I then experiment with the different combinations of that information to see if my theories hold water or if there are weaknesses in my assumptions. As I know many other genealogists do.
In the end I advance a theory; my tree which is the results of my research and experiments and is open to review by others to test, complying with another principle of science.
My tree is not fact, it is the collated results or my research based on a process of questioning the data recorded in the various historic records available. I do not try to prove the data to be true but try to prove the data to be false.
If I cannot prove the data to be false then I must accept it until further data comes to light.
Which if you look at the flow chart on the page you link to my methods fit very well into what is described there.
In fact that flow chart could actually describe genealogical research.
Definitions of Science
Oxford Dictionary:
The intellectual and practical activity encompassing the systematic study of the structure and behaviour of the physical and natural world through observation and experiment:
Cambridge Dictionary:
(knowledge from) the careful study of the structure and behaviour of the physical world, especially by watching, measuring, and doing experiments, and the development of theories to describe the results of these activities:
Note science does not provide proof of anything, science provides evidence or refutes evidence in exactly the way that good genealogical research does.
While we can't ever prove that a child inherits 50% of its DNA from each of its parents, experiment after experiment has shown this to be the case. The hypothesis has also been confirmed by empirical data from thousands of genetic genealogists who have tested themselves and their parents and see that they too inherit 50% of their DNA from each of their parents.
Whilst it is true that a child inherits 50% of their DNA from each parent it is not a simplistic as that. Much of the DNA a child inherits could come from either parent.
This means that after a couple of generations the DNA from one particular ancestor might no longer be found in the DNA of a person.
Science does not prove that one person is a parent but simply advances evidence that it is possible that a certain person could be the parent.
To say otherwise shows you do not understand the meaning of scientific research.
In fact I would go as far to say that to use DNA correctly one would have to not simply accept the analysed results of the DNA but question those results and try to prove them to be false.
But this part of science seems to be lost in your approach to DNA
Cheers
Guy
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Guy
I approach my genealogy in just the same scientific way as you do.
Falsifiablity is one of the foundations of the scientific method but there comes a point when something is so well established that falsifiability isn't necessary. No one is wasting their time trying to falsify the hypothesis that the earth is round or that Mars exists or that grass is green.
I don't think you understand the basics of biology. Scientists have been observing human reproduction for decades by direct observation (eg of cell division under a microscope) so we know exactly how fertilisation takes place, how cells divide and how chromosomes are formed. Yes nature does sometimes play tricks on us and you will sometimes get, say, a female baby born with one X-chromosome instead of two (this is known as Turner's syndrome). But because we understand how the process works we can understand why this has happened, and it would in any case show up in any DNA test.
DNA evidence is just like any other evidence. You have to understand how it works and how to use it responsibly. It's the combination of DNA evidence with genealogical evidence that is often so powerful. On its own DNA doesn't tell you anything. Any good genealogist is going to want to take advantage of any record set going.
If you want to understand how DNA testing is used in combination with other evidence you might like to have a read of the Nature Communications paper on the identification of Richard III:
http://www.nature.com/ncomms/2014/141202/ncomms6631/full/ncomms6631.html
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Guy
I approach my genealogy in just the same scientific way as you do.
Falsifiablity is one of the foundations of the scientific method but there comes a point when something is so well established that falsifiability isn't necessary. No one is wasting their time trying to falsify the hypothesis that the earth is round or that Mars exists or that grass is green.
I don't think you understand the basics of biology. Scientists have been observing human reproduction for decades by direct observation (eg of cell division under a microscope) so we know exactly how fertilisation takes place, how cells divide and how chromosomes are formed. Yes nature does sometimes play tricks on us and you will sometimes get, say, a female baby born with one X-chromosome instead of two (this is known as Turner's syndrome). But because we understand how the process works we can understand why this has happened, and it would in any case show up in any DNA test.
DNA evidence is just like any other evidence. You have to understand how it works and how to use it responsibly. It's the combination of DNA evidence with genealogical evidence that is often so powerful. On its own DNA doesn't tell you anything. Any good genealogist is going to want to take advantage of any record set going.
If you want to understand how DNA testing is used in combination with other evidence you might like to have a read of the Nature Communications paper on the identification of Richard III:
http://www.nature.com/ncomms/2014/141202/ncomms6631/full/ncomms6631.html
Guy
I approach my genealogy in just the same scientific way as you do.
Falsifiablity is one of the foundations of the scientific method but there comes a point when something is so well established that falsifiability isn't necessary. No one is wasting their time trying to falsify the hypothesis that the earth is round or that Mars exists or that grass is green.
Yet another misconception on your behalf the world is not round it is actually a spheriod, but don't let facts get in the way.
I don't think you understand the basics of biology. Scientists have been observing human reproduction for decades by direct observation (eg of cell division under a microscope) so we know exactly how fertilisation takes place, how cells divide and how chromosomes are formed. Yes nature does sometimes play tricks on us and you will sometimes get, say, a female baby born with one X-chromosome instead of two (this is known as Turner's syndrome). But because we understand how the process works we can understand why this has happened, and it would in any case show up in any DNA test.
Unfortuantely there are a number of things about biology and reproduction that science is not certain about, which is why many are still carrying on research into the subject. As those of us with open minds are happy to admit.
DNA evidence is just like any other evidence. You have to understand how it works and how to use it responsibly. It's the combination of DNA evidence with genealogical evidence that is often so powerful. On its own DNA doesn't tell you anything. Any good genealogist is going to want to take advantage of any record set going.
If you want to understand how DNA testing is used in combination with other evidence you might like to have a read of the Nature Communications paper on the identification of Richard III:
http://www.nature.com/ncomms/2014/141202/ncomms6631/full/ncomms6631.html
Thank you for including the url above, it was something I already know of due to family connection to the Manners family.
However none of this changes the point I have been making.
I repeat: I am not contesting the science I am contesting your terminology.
Cheers
Guy
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There are indeed many millions a DNA samples in police data bases; they can be discounted for Family History purposes are they are highly unlikely to ever be released!
I believe that we must then consider whether the sample DNA that we have of the entire human population is drawn at random. I believe that the sample is definitely skewed, and prominently skewed towards a predominently European population, and is therefore of little value as the 4 billion or more people who are of African and Asian etc. origin are seriously under represented.
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The genetic genealogy bases certainly are skewed towards people of European origin and specifically towards Americans of European origin. However, the fact that there are few people of African and Asian origin is not going to be a problem unless you actually are African or Asian or have some African or Asian ancestry. It also depends on the type of test and who else has tested. Some surname projects are now very mature and have tested someone representing every single living line for the surname so anyone with these surnames who tests is going to find a match unless they're descended from an NPE or they're the last representative of their line.
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Don't we all have some African ancestry? ???
There seems a danger of genealogical DNA becoming a new religion. It's just another tool, of limited use to probably the majority of family history researchers. If anything, it seems better at disproving a family connection than otherwise. All that may change with scientific progress, and once there is a universal DNA database there will be no need for genealogy . . . or RootsChat :'( . . . and we'll all have to find another hobby. Don't imagine that will be soon though . . .
Mike.
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Thank you, to follow on; I am aware that many African Americans descended from slaves have surnames like Washington as that was the name of their original owner; however an African American with a white father and a black or mixed race mother should carry the same Y chromosome as other people with the same surname regardless of their colour; or am I missing somethin?
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Thank you, to follow on; I am aware that many African Americans descended from slaves have surnames like Washington as that was the name of their original owner; however an African American with a white father and a black or mixed race mother should carry the same Y chromosome as other people with the same surname regardless of their colour; or am I missing somethin?
Without having had my morning coffee I will attempt an answer
In your example of white father/owner and black/mixed race , they should carry the Y chromosome of the progenitor. Surnames were adopted/given by slaves as to who owned them. The owner and the progenitor may not be the same person.
So in your example I would use surnames as a localiser and not for genetic disposition. Not every Jefferson is a Jefferson :)
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I believe that the sample is definitely skewed, and prominently skewed towards a predominently European population, and is therefore of little value as the 4 billion or more people who are of African and Asian etc. origin are seriously under represented.
Seriously underrepresented in Africa and Asia AT THE MOMENT. There are plenty of people in China that can afford to do this, and will.
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Agree, and don't forget India. This may well have implications in the UK in at least 2 ways:
1) People of 2nd or 3rd generation descendants of migrants from the sub continent.
2) The connection between Anglo-Indians still living in India, and descendants of those who served the RAJ. This is likely to affect me.
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People in China aren't allowed to send their DNA out of the country. Indians are under-represented in the genetic genealogy databases but I hope that will change over time. If anyone has ancestry from India do join the FIBIS DNA Project:
https://www.familytreedna.com/groups/fibis/about/background
FIBIS also have a lot of free resources on their website.
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thanks for the link very useful
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Further to the DNA list on the FIBIS site does it include Europeans? I ask because it may be the solution to my problem. My 2xgreat grandfather John Luffman b1776 seems to have been illegitimate. All extant known Luffman lines have produced no connection or are extinct in the male line. He was born two miles from Sherborne Dorset (Henstridge Som). However a line of Luffmans recorded on the Lucknow memorial had migrated with the army to India.Records are incomplete but I am really up against it with this brickwall so Indian DNA dara base seems the best(least worst prospect.
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The FIBIS does indeed include Europeans. I believe most of the project members are Europeans rather than Indians. However, they are part of the same FTDNA database so you would have been notified of any matches. The only exception is if someone had restricted their match settings so that they were only seeing matches within a project.
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Thanks, looks like another blank at least for the time being.