Some notes which may get you interested in DNA testing...
Genealogy DNA 101 – The easy version
DNA is passed from parents to children.We have virtually the same DNA our ancestors from several hundred years ago had. As we go back in time, some change occurs; and the farther back we go the more change. So if two men have the same DNA test results, they probably have a common ancestor (in the last few hundred years); and if their results differ in several areas, they probably don’t share a common ancestor (within the last thousand years or so).There are tables on the internet which relate the DNA test scores of two men to the range of generations (or years) in which there is probably a common ancestor.Both a DNA “match” and a “mismatch” are informative and can help steer us toward or away from particular research directions.The DNA results also provide an indication of our “deep ancestry,” or which of the main branches of the tree of mankind (from 100-200,000 years ago) we belong to and where our caveman ancestors migrated.
Genealogy DNA 102 – A little harder version
Each DNA has 46 chromosomes. Only men have the “Y” chromosome in their DNA, which is passed from father to son.Scientists have identified certain parts (testing “markers”*) of the Y chromosome which remain virtually unchanged for many generations, and are therefore useful for genealogy purposes. Your male ancestor in the 1700s passed the Y chromosome DNA to all his male descendants.His male descendants today would have the same DNA “markers” as their ancestor, say 6-8 generations ago, or possibly have one marker which changed since the 1700s.Thus the DNA test results of two living male descendants (of the same ancestor living in the 1700s) would be the same, or very close.Alternatively, if two living male descendants have the same, or close, Y-DNA test results, then they certainly have a common ancestor; and if they don’t have close Y-DNA test results, then they don’t have a “recent” common ancestor.Using these facts: if the DNA “matches” we can link surname lines together and focus the research on finding the common ancestor and the link; or, if the DNA does not match closely, we know that we don’t need to keep looking for a common ancestor, and that we should look elsewhere. With good knowledge of the Y-DNA test results for different lines in a SURNAME Project, new test results would tell us which line the donor belongs to.With several well-researched lines which had not been linked before, Y-DNA test results will tell us if there is a link or not. The information is valuable in either case.
* See Genealogy DNA 104 for the reason these “markers” are of no significance (medical, health, genetics, etc.) to anyone except genealogists and anthropologists.
Genealogy DNA 103 – The BARTLETT DNA Project
The BARTLETT DNA Project was started in October 2002, and has grown since then.Here is some key information about this Project:
Y-CHROMOSOME:This project uses the Y-Chromosome, which is only passed from father to son. Therefore, the DNA donor must be a male BARTLETT descendant.
DNA SAMPLE:The sampling method uses a cheek swab, rubbing a "stick" (provided) on the inside of your cheek; and then putting the end of the stick in a little vile (provided) and mailing it back in a mailer (provided). No pain, no blood. It's like brushing your teeth, and the kit provides all you need.
VENDOR/LAB:We are using Family Tree DNA (FTDNA).They use an independent lab (at the University of Arizona – a DNA pioneer) to do the actual DNA analysis, and then FTDNA posts the info on a web site. The lab only knows your Kit number.The lab also stores the DNA sample for 25 years, so you can have other tests done if you want.
FTDNA WEB SITE:www.familytreedna.com. There is some good information on this web site and some links to various articles and all of their SURNAME Project sites.
MARKERS:FTDNA offers 12 and 25 marker tests. This means they "measure" the DNA at various specific points (markers), and the results can be compared with others. You can get either test, or get the 12-marker test and later upgrade to 25-markers. Most of us in this Project selected the 25-marker test because it provides more robust info that will let you refine relationships more precisely. As an example, my DNA test result is:
NOT A MALE BARTLETT?:Females, and descendants who do not descend all the way down a male BARTLETT line, can still participate by finding a brother, uncle or male BARTLETT cousin who can provide a DNA sample and "stand in" for you.
NAME VARIATIONS:The BARTLETT DNA Project is accepting participants with any possible name variation/spelling: BARTLEY, BARKLEY, BERKLEY, etc.We have already linked an established BARTLEY line to a BARTLETT ancestor, and we’re investigating BERKLEY’s who sometimes used BARTLETT.
PROJECT SCOPE:The BARTLETT DNA Project was started to study lines from Colonial Virginia, but is now open to everyone – America, England, Australia, etc.
PROJECT WEB SITE: http://homepages.rootsweb.com/~cst/bartlett/dnachart.htmhttp://homepages.rootsweb.com/~cst/bartlett/dnachart.htm
HOW TO JOIN: Contact Jim Bartlett email@example.com for the link to discounted pricing, or for any questions you might have.
Genealogy DNA 104 – Genetics
DNA provides the key to life.It has 3 thousand million molecules (called “A”, “C”, “T”, and “G”), in 46 chromosomes passed on from the parents.One of the chromosomes, in men, is called “Y”, and it’s only passed from father to son.Each chromosome is roughly 2 percent genes (which hold the keys), and 98 percent binder or “junk”.Scientists have determined that certain specific areas (markers) in this junk DNA rarely changes (perhaps once in 50 generations), and that these markers can be “measured” by the number of times a certain ACTG sequence is repeated.So when this marker is tested for genealogy purposes, we get a number, say 16, which represents the number of repeats at a specific place on the junk part of the Y-chromosome DNA. There is no medical or any other known value to this piece of DNA, much less to the number of times it was repeated.
Because these selected regions of junk DNA change so infrequently, the DNA testing provides a very good DNA tool.For an ancestor about 7 generations ago (for me that would be Thomas BARTLETT c1730-1806), there is about 50 percent probability that there might be one change (in a string of 25 numbers), and about 50 percent probability that there is no change (in the 25 numbers).In other words, we could say half of Thomas BARTLETT’s male descendants 7 generations later would have unchanged DNA markers and would have the exact same DNA scores, and half would have some change and be off by one number (or maybe even two – we’re dealing with probabilities, not absolute equations).
Because of the changes over the past 100-200,000 years, different family lines will have different DNA results.So if two men of the same surname have DNA results that match (24/25 or 25/25) then they share a common ancestor.If the results don’t match (20/25 or less) then they don’t share a common ancestor – at least not within the past several 1000 years.
Genealogy DNA 105 – Links to more infomation
For a lot more information, here are some web links.
http://www.kerchner.com/kerchdna.htmhttp://www.kerchner.com/kerchdna.htm - lots of good links at the end of the homepage.
http://freepages.genealogy.rootsweb.com/~allpoms/genetics.htmlhttp://freepages.genealogy.rootsweb.com/~allpoms/genetics.html - lots of good info
http://blairgenealogy.com/dna/dna101.htmlhttp://blairgenealogy.com/dna/dna101.html - DNA 101 explanation
http://genealogy.about.com/cs/geneticgenealogy/a/dna_tests.htmhttp://genealogy.about.com/cs/geneticgenealogy/a/dna_tests.htm - good article and links
http://www.duerinck.com/surname.htmlhttp://www.duerinck.com/surname.html - a compilation of many surname DNA projects