DNA Testing - Why Not

[DevonCruwys]

It is assertions like this that makes me laugh.
DNA testing is very much in its infancy and is based on tiny samples.
Nothing has as yet been proven as definitive. Babies have been observed being born but when their DNA has been tested it does not match their mother's DNA.

Perhaps in 20 or 30 years things may have changed but now DNA testing is little more than an expensive toy that proves nothing but claims much

Your information is very out of date. What is your source for the claim about babies not matching their mother's DNA? Close relationships such as parent/child relationships can be definitely proven with DNA testing.

Family Tree DNA were selling their Family Finder test for just £40 at Who Do You Think You Are? Live and the AncestryDNA test was just £49. That does not seem expensive to me.

AncestryDNA now have four million people in their database:

https://blogs.ancestry.com/ancestry/

Most British people are getting several thousand matches, including 50 or more fourth to sixth cousins or closer.

[KGarrad]

It is assertions like this that makes me laugh.
DNA testing is very much in its infancy and is based on tiny samples.
Nothing has as yet been proven as definitive. Babies have been observed being born but when their DNA has been tested it does not match their mother's DNA.

Perhaps in 20 or 30 years things may have changed but now DNA testing is little more than an expensive toy that proves nothing but claims much

Your information is very out of date. What is your source for the claim about babies not matching their mother's DNA? Close relationships such as parent/child relationships can be definitely proven with DNA testing.

Family Tree DNA were selling their Family Finder test for just £40 at Who Do You Think You Are? Live and the AncestryDNA test was just £49. That does not seem expensive to me.

AncestryDNA now have four million people in their database:

https://blogs.ancestry.com/ancestry/

Most British people are getting several thousand matches, including 50 or more fourth to sixth cousins or closer.

False news?!

DNA testing for parents CANNOT prove a positive, but can prove a negative.
That is, it can prove that someone is not related.
But if a match is found it is not conclusive that the two people are, in fact, related.

[DevonCruwys]

DNA testing for parents CANNOT prove a positive, but can prove a negative.
That is, it can prove that someone is not related.
But if a match is found it is not conclusive that the two people are, in fact, related.

Are you confusing Y-chromosome DNA testing with autosomal DNA testing?

Modern autosomal tests using 700,000 autosomal SNPs can verify first to fifth degree relationships with almost 100% certainty:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3083094/

With 700,000 SNPs you can definitively confirm parent/child relationships.

[hurworth]

Your information is very out of date. What is your source for the claim about babies not matching their mother's DNA? Close relationships such as parent/child relationships can be definitely proven with DNA testing.

I think Guy is referring to chimerism which is not common.  There has been a couple of instances where a woman's ovaries are from "sister tissue" from the rest of her.  So her baby would be a genetic niece or nephew to the tissue from her mouth swab.

[DevonCruwys]

I think Guy is referring to chimerism which is not common.  There has been a couple of instances where a woman's ovaries are from "sister tissue" from the rest of her.  So her baby would be a genetic niece or nephew to the tissue from her mouth swab.

You may be right. Here's an interesting article I saved about chimerism:

https://www.buzzfeed.com/danvergano/failed-paternity-test-vanished-twin

Note that in these cases it was recommended that additional testing be done at 23andMe (one of the companies that offers genealogical DNA tests) because the consumer tests cover so many more markers than the standard maternity and paternity tests used for legal testing.

[familydar]

So the autosomal test is more restrictive in time than say an MT line?

yes and no, it depends on what you are hoping to find out.

I believe a mitochondrial test will tell you with more or less 100% certainty if you and someone else are descended from the same female, through the female line.  So you will get a match with your mother and maternal aunts, because their mother was your maternal grandmother.  If you have a daughter she will also match.  But the test won't tell you how many generations you have to work back to find out where the divergence happened (the common ancestor).  Could be a hundred years, could be a thousand or more.

An autosomal test will tell you with a fair degree of certainty if you are related to another person, male or female, and how many generations you might need to work back to find the common ancestor, but because your autosomal DNA is a mix of what you inherited from each of your parents, and they from theirs, it gets less certain the further back you go.  Different companies have different views on the number of generations beyond which it's not a lot of help.

Autosomal tests are currently the least expensive of all tests available for family history purposes and are offered by a range of providers.  I've taken an autosomal test and it has identified distant cousins I had no prior knowledge of.  I've not done a mitochondrial one.

DNA testing isn't a shortcut to researching your family tree by traditional methods.  You'll only get matches with people who have done the same test, and in the grand scheme of things only a tiny proportion of the world's population have.  But in time that will grow.  It's a test that keeps giving.

If you go the autosomal route, whichever provider you choose, please do upload your results AND an ancestor tree (with dates and locations) to GEDMatch.  If you test with a company other than FTDNA you can also upload your results and tree to their database for free.  The more places you have your data, the greater the chance of making contact with distant cousins.

best wishes
Jane :-)

[RobertCasey]

Here is why YDNA testing is now producing very good relevant genealogical information as well as having an unbelievable potential in the future to identify the YDNA signature of everyone on your male pedigree chart.

If you are Irish AND test for the second largest Irish haplogroup L226, we are now getting to the point where we can chart how 80 % are actually connected. Just two years ago, all we had was the YSNP branch itself - L226 which was estimated to be around 1,500 years old. Today, we have 47 branches under L226 with another branch being added every couple of weeks. For its older brother, M222 (the largest haplogroup with Irish orgins), this haplogroup is around four times larger than M222.

Of the L226 branches, 15 of 47 are in the genealogical time frame (under 1,000 years old). The O'Brien line now has six genealogical branches (one branch is down to under 200 years). We now know that if you test Y5610 positive, you are a direct descendant of King Brian Boru (this line has been tested by Sir Conor O'Brien, the official title holder of the O'Brien surname whose title has been been documented for each title holder since around 1,000 AD). Here is a chart showing how 78 % of L226 are related to each other (this was only 35 % charted six months ago):

http://www.rcasey.net/DNA/R_L226/Haplotrees/L226_Home.pdf

We are recently making huge strides in certain parts of the tree of mankind. M222 and L226 are much more prolific in Ireland since both are directly linked to the first kings of Ireland that united / conquered all of Ireland. But even the third largest Irish haplogroup, CTS4466, is now growing to a reasonable size and is starting to enter into the major discovery phase of testing. There are dozens of haplogroups that reside in Ireland today that are now at this level or will be by the end of the year.

[CarolA3]

Illegitimate children rarely inherit their father's surname.  DNA doesn't lie, but unfortunately people do.  I remember reading somewhere that as many as 60% of children do not know their biological father.  However, on a subject like this, it's difficult to collect reliable data.

It is assertions like this that makes me laugh.
DNA testing is very much in its infancy and is based on tiny samples.
Nothing has as yet been proven as definitive. Babies have been observed being born but when their DNA has been tested it does not match their mother's DNA.

Perhaps in 20 or 30 years things may have changed but now DNA testing is little more than an expensive toy that proves nothing but claims much

Cheers
Guy

I'm only an onlooker here and not qualified to engage in debate on the rapidly evolving technicalities of DNA testing.

It just struck me as odd that Guy has chosen to take issue with a post that is:
(a) over five years old and therefore probably irrelevant now;
(b) written by a poster who is deceased and therefore unable to explain or modify his statement.

Carol

[Billyblue]

Carol
Guy probably didn't look at the 2011 date.
Guy may not have known that 'a poster' is now deceased. 
Just because someone is deceased is hardly cause not to comment on something they said.
People do it every day - on Ned Kelly, Freud, you name it   

Dawn M