What do I need to know before getting a DNA test?

[TheBanana]

Before paying for a test, I want to just know as much as possible from you RootsChat members. For example, how will it work? How much information can I expect? Is it going to be accurate? Who do I need to get a sample from (Dad, Mum etc)? And, et cetera.

Thanks! 

[davidft]

A good place to start is by reading the posts at the top of the thread I.e.

Paternal Test (Y-DNA) Links
Introductory Links
Maternal Line (mtDNA) Test Links
Autosomal DNA (atDNA) Test Links   
DNA Science Links

to get an understanding. Then you can ask more specific questions and people can tailor their advice accordingly
 

[Malcolm33]

Before paying for a test, I want to just know as much as possible from you RootsChat members. For example, how will it work? How much information can I expect? Is it going to be accurate? Who do I need to get a sample from (Dad, Mum etc)? And, et cetera.

Thanks! 

     It depends what you want to know from it.     First of all ydna is passed down from father to son but not to daughters.     Secondly mitochondrial dna is only passed down from mother to daughter and to any son but he cannot pass it on to any of his progeny.

      If all you want to know is where your paternal or maternal lines go back to then you only need to have basic dna tests, e.g. just 12 markers in the ydna.   But if you want to check with others with the same surname to see if there is some relationship then you should go for at least 37 markers preferably a hundred.     

      "The Seven Daughters of Eve" and "Blood of the Isles" by Dr Brian Sykes will give you a very good idea how it all works.

       As an example I only had basic tests no more than 12 markers on my ydna.   This returned a result of R1a haplogroup which is sometimes called the 'Viking' group but 50% of males from the Norwegian coast through Eastern Germany, Russia and northern India have the same group.    My maternal dna is T2 and according to Sykes "Seven daughters..." book this means that I have an ancestor who lived by the River Arno in Tuscany 17,000 years ago.    The company also sent me certificates for both tests which list a few people of the same group and mine told me that Kings , George I, Charles I, Prince Philip, Kaiser Wilhelm, Tsar Nicholas and Jesse James have the same ancestor.

       I have also been lucky in that a distant cousin had an extensive test which came up with R1b1a2.    This is the same group as the 18th Dynasty Kings of Egypt, therefore Kings David and Solomon were my cousins.  We have a common ancestor who lived 9,500 years ago near the Black Sea.

      You can also get an autosomnal test which returns a percentage pie graph showing how much you have of various ethnic races.   I am not sure though that these are very accurate.

      One thing that may help you decide are the one name projects.  This page may answer some of your questions - http://freepages.genealogy.rootsweb.ancestry.com/~grantdna/kit-backgrounds.html

[TheBanana]

OK. Thank you for the advice. My current aim is to get geographical data from a DNA test, and to see if I am related to any historical figures and et cetera.

[supermoussi]

OK. Thank you for the advice. My current aim is to get geographical data from a DNA test, and to see if I am related to any historical figures and et cetera.

Check out the Chromo2 Complete test which includes paternal, maternal and autosomal tests:-

http://www.britainsdna.com/products/complete
http://www.britainsdna.com/demos/chromo2

It will be much cheaper than taking the tests separately and includes the most up to date Paternal SNP test there is.

[DevonCruwys]

I suggest you read some of the articles on DNA for beginners which can be found here:

http://www.isogg.org/wiki/Beginners%27_guides_to_genetic_genealogy

Kelly Wheaton's tutorials are particularly recommended.

A DNA test will not tell you that you are related to a historical figure despite what some companies will try and tell you. You will also only get very limited geographical data. See:

http://cruwys.blogspot.co.uk/2013/03/sense-about-genetic-ancestry-testing.html

Make sure you also check out the testing company comparison charts in the ISOGG Wiki:

http://www.isogg.org/wiki

[geno500]

I know I am a old stick in the mud,but having just stumbled on this DNA posting,I feel vindicated for a long held belief that given 80% of the people who do family history are women and given they all seem to follow the female lines for generations in so doing they are researching the entire world,it now seems that these DNA tests bear this out with women only able to pass a gene onto their daughters and to their sons who cannot pass it on,and given a new women is added to the male line when they marry into the family,it would seem that women are searching complete strangers,of course I may have read it wrong,but with few exceptions when you look at the number of names being researched by members of this forum the ones with more than 4 names are nearly always female,still I am sure it keeps a smile on the face of the family history companies.

[trystan]

I feel vindicated for a long held belief that given 80% of the people who do family history are women

Well, if it helps, here on RootsChat, 55% are women.

Trystan

[DudleyWinchurch]

Strange statistics geno500,

As everyone (with possibly a very few exceptions due to recent medical techniques) has exactly one male and one female direct ancestor in each generation, on each line, then, unless all the recent ancestors were previously closely related to each other, there will be approximately 50% of them male and 50% female.

This applies to both males and females. Each individual receives approximately 50% of their genes from each parent.  For males, the proportion of genes received from their mother is slightly higher than 50% due to the comparatively smaller size of the Y chromosome when compared with the X chromosome.

Anyone who has researched beyond their grandparents is likely to have more than 4 family lines to follow. There is the possibility of less names than lines due to co-incidences among these family names but these could be on either male or female lines

Although I only became aware of the fact relatively recently, I had 8 direct ancestors still living at the time of my birth, 2 parents, all 4 grandparents and two great-grandparents, thus giving 5 different family lines (with distinct names) already.