Presentation on theme: "D N A What can it do for us? By Mary Ann Claxton Link to handout for this presentation Thanks to Roberta Estes for part of this presentation."— Presentation transcript:
D N A What can it do for us? By Mary Ann Claxton Link to handout for this presentation Thanks to Roberta Estes for part of this presentation
Alien Ancestors Were your ancestors actually aliens marooned on Earth? Are you sure they were dropped fully grown from the mothership into Tennessee (VA, AL, MS, etc.)? Are you beginning to seriously consider the “born under a cabbage leaf” theory? Do you sometimes ponder the stork stories? Then DNA testing is for you!!!!
What is DNA? DeoxyriboNucleic Acid The instruction code that tells our cells how to build us Almost all of the 20,000-25,000 “marker” genes on the human genome have been mapped and named (numbered) The “markers” on the male, or Y-chromosome are called DNA Y- chromosome Segment (DYS) numbers
3 Kinds of DNA Autosomal Y-Chromosome Mitochondrial
3 Kinds of DNA Autosomal – both parents contribute APPROXIMATELY 50/50 to all offspring [22 chromosomes from each parent located in the NUCLEUS of each cell] 5
3 Kinds of DNA Y-Chromosome – Men only contribute to male-only offspring [DNA] [ 1 chromosome located in the NUCLEUS of each cell] This is the DNA that we use in tracing surname lineage
3 Kinds of DNA Mitochondrial – Women only contribute to both sexes [mtDNA] [many exact copies of 1 chromosome located in the CYTOPLASM of each cell – outside the nucleus] This is the DNA used to trace matrilineal descent (as in Native Americans)
Mitachondrial DNA [mtDNA] Passed only from mother to all children, male and female; females have ONLY this mtDNA. DNA from paternal side [DNA] Passed ONLY from father to son; females do NOT have this DNA. 8
Autosomal DNA from both sides. Approximately 50% from BOTH parents to ALL children. Over time the markers are “diluted” since only PART of the markers from each parent are actually passed on. However... since this DNA is passed to BOTH sexes, it is possible to use this DNA to compare males and females. This is a new test – actually still in trial basis right now. 9
Sample Process Order a DNA sample kit from the processing company (we have used FTDNA, but there are many others) (waiting for results is like watching paint dry... Or “A watched pot never boils...”) Use the “brush” to get a sample of cells from inside your cheek Send the sample to the company and wait........................
Haplogroup? Huh? A haplogroup (from the biological term haploid meaning to share chromosome characteristics) is a group which shares a common set of results for certain DYS markers within the first 12 Currently there are 20 overall groups labeled A through T Each of these groups have subgroups and the subgroups have subgroups, etc., etc. R 1 b 1 is a common haplogroup for western Europe
These are primitive migrations beginning in Africa and spreading out over the other land masses in response to climate change and the resulting habitat change. They follow mitochondrial lines because mtDNA is transferred to both males and females so there is no gap in the sequence. Looking at Y-DNA only can show haplogroups which can be located both historically and geographically, but there can be gaps in tracing lineage when a line “daughters out” and produces no more male descendants.
Mutations Are mutations a bad thing? (Do you really WANT to look like everyone else???) Why do genealogists like mutations? >
No Matches with your Surname? It is possible to have the same surname by coincidence: –Surname was assigned –Surname was purchased > Remember that surnames are a fairly recent feature in history- hundreds of years
Non-Paternity Events Undocumented historic adoptions Step-child takes step-father’s name Orphan trains Pregnancy during war times Illegitimate births – take mother’s name Unwelcome relationships Affairs Recent adoptions NEVER TEST CLOSE RELATIVES! 22
DNA Used in Genealogy is NOT: DNA used in CSI, CSI Miami, NCIS, Court TV, and real criminal cases. The DNA they use is: –Autosomal (CODIS database) –Y chromosome DNA –Mitochondrial DNA DNA used for paternity testing DNA used to identify disaster victims DNA used to find genetic disease or potential for medical problems
Can My DNA be Misused? The government will get my DNA sample –Prevented by privacy laws –Unlikely they will know it exists –Would require a court order –But beyond all that: there are MUCH easier ways for the government to get your DNA. Someone will sell my DNA to an insurance company or make it public –High level of testing company security –Restrictions imposed by consent forms –Great financial risks to the company doing the testing –Insurance companies already have access to your DNA every time you give a blood sample at the Dr.’s office. Some common concerns are:
Can My DNA be Misused? The results can be used against me in some way –Genealogical results are useless for identification purposes –Your results likely match thousands of your cousins –Genealogical DNA is not suitable for criminal identification or disease detection –There would be a chain of custody issues They will clone me –Impossible with the current technology –If perfected, they are not likely to start with cheek cells –Probably only your spouse or your mother would be interested in doing that Some common concerns are:
Tight Guidelines for Security Double safety net: –FTDNA controls the database and test scores –University of Arizona controls the DNA sample Data is released for matching purposes only if release form is signed Individually computer-generated locator ID and matching code for database search only accessible to the customer >
Your Results – What you Get Each testing company presents results in a different format and with differing results Results can vary from a certificate received in the mail, to e-mail results only, to a personal web page My co-administrator for our Claxton/Clarkson/Clarkston project has personally used 8 different testing facilities (in 4 countries) for various purposes >
So what are the outcomes? You can eliminate false leads You can resolve age-old speculations and assumptions Focus on lines that match: work your way forward and backward DNA works hand in hand WITH traditional genealogy Holy Grail: Connect with a line that has documentation back to the year 1000 A.D.! 27
COSTS... Yes they want money – this is America after all! FTDNA price for a kit is cheaper if you order through a surname project Y-DNA tests –12 markers - $99 –25 markers - $124 –37 markers - $149 –67 markers - $239 mtDNA tests –mtDNA - $99 –mtDNA Plus - $149 –mtFullSequence - $279 Autosomal (Family Finder) test - $249
Genographic Project The good news is that once you have your results from your test, you can send your results to the Genographic Project for only $15.00; the kit from National Geographic is $99.00 (but that includes processing).
ON GENEALOGY... You live as long as you are remembered. –Russian proverb Those who forget their past are destined to repeat it. –Robert A. Heinlein We are the children of many sires, and every drop of blood in us in its turn... betrays its ancestor. –Ralph Waldo Emerson Everyone has ancestors and it is only a question of going back far enough to find a good one. –Howard Kenneth Nixon
REFERENCES Human/Chimp DNA compared http://www.newscientist.com/article.ns?id=dn2833 Family Tree DNA http://www.familytreedna.com/default.asp Orphan Trains http://www.outfitters.com/~melissa/ot/ot.html