Genetic genealogy is the use of our DNA to identify others that share enough values in common to be identified as presumably related which enables us to document our family tree. This note contains information about Family Tree DNAs family Finder.
It always amazes me how difficult it is for genealogists to get back more then a few generations as they try and document their family tree. Most people know who Grandma was but a surprising number very quickly hit a brick wall by the time they get into the early 1800’s. Until recently the primary method used to connect with unknown ancestors for genealogists interested in genetic genealogy was the Y-DNA test. Using public databases at companies such as Family Tree DNA males were able to compare selected markers of their Y Chromosome to others who shared a common surname. The beauty of Y-DNA was it passed relatively unchanged from father and son for generations. Many have used this tool to get through brick walls in their genealogy research. One of the families I have been researching has been the descendants of Asher Cottrell who was born 1810 in Ohio and Sarah Shaner . We accomplished a number of our goals including verifying the distinct line that shares the relatively uncommon 385b=11 value by using YDNA but we are now using the more advanced autosomal DNA testing.
As helpful as Y DNA is as a research tool its use is limited to direct paternal lines. The problem until recently with using the remaining twenty-two chromosomes which are passed down to both men and women is that they did not remain intact from generation to generation. The mother and fathers DNA combine with each other with each birth event. For example in simple terms the child’s chromosomes now contained half the mothers and half the fathers genes. With each generation they would get split up more and more. This made comparing two individuals almost impossible because which SNP values would you compare ?, how would you know which split up and which did not?. The advances of chip technology to extract DNA values now make it easy and affordable to compare a million or more genetic markers. With modern data processing it is a simple matter to look at two samples of a half million SNPs and search out strands containing blocks of similar DNA. Again keeping it simple we know that a block over a certain length identified as centimorgans is likely passed down intact from a prior generation because it is simply too long a string of matching values to just be a random match.
One way of looking at it is if you were to flip 500 coins and lay them out in a row then flip 500 more directly underneath what are the odds that they would ever be in the exact same sequence , Id say just about none. Well this is my understanding of the premise of autosomal gene testing for DNA purposes. The computer finds and counts the number of 500 or greater pairs between two individuals that match. So for example if two strands of 500 pairs of DNA match then it is understood these match by descent and not by chance. This has added the ability to use autosomal DNA on all of the 23 chromosomes to locate matches. Through research genetic genealogists have also established how long a strand of matched intact DNA should be for each generation removed from the common ancestor. This enables Family Finder to give a predicted degree of relation based on an algorithm that takes into account the longest strand. This can be very helpful in looking for missing relatives.
Update on Cottrell Family Research Free Genetic Genealogy DNA Test fund.
Our free testing has moved on to the new autosomal family finder tests from Family Tree DNA . As of July 1,2011 There are five free tests currently available. I am looking for at least one volunteer each from the Cottrel,Gibson and Toman families. The free test may be available to you if you are a descendant of William Cottrell or Lucy Toman , William Cottrell or Eva Gibson , George Leon Toman or Mary Florence Dickey, or Isaac Newton Gibson or Sophia Schell . I am especially interested in descendants of Owen Cottrell volunteering for the free test . If you are interested in a Free Family Finder test please email me at mark@capeflier.com with your connection and Ill be happy to see if having you test for free would be mutually beneficial for our research. The Free tests are very limited so please contact me sooner rather then later if you are interested.
Taylor Family Genetic Genealogy Project
We have added certain members of the Taylor, Howell and Covey Family from Tell City, Perry County Indiana to our free genetic genealogy test offer please contact me for details.
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Family Finder is a product of Family Tree DNA and more information may be found at
http://www.familytreedna.com/