ST. TAMMANY
GENEALOGICAL SOCIETY
Genetic Genealogy
The unraveling of the double-helix DNA structure was first accomplished 50 years ago (April 1953) by scientists James Watson and Francis Crick. They received a Nobel Prize in 1962 for their monumental legacy. Subsequent decoding of the biological blueprint to life has led to breakthroughs in crime investigation, medicine and genealogy. YES, GENEALOGY!
Most of us are now quite familiar with
forensic scientists demonstrating the value of DNA in solving
crimes. DNA
analysis has also been vital in verifying paternity, indicating the likelihood
of inheriting life-threatening or disabling diseases, as well as responsible for
break-troughs in medical research. The same technology can now also be
used by family historians to make physical connections with their ancestors, not
by having centuries-old relatives exhumed, but by a simple comparative analysis
of cheek cells from living descendants of our ancestors.
Family historians often find themselves 'hitting the wall', after thoroughly researching every known and available genealogical record. Researchers may find they are unable to verify genetic links to ancestors, especially when the ancestors in question emigrated from overseas several centuries ago. Records may be incomplete, destroyed or lost. In many cases, our ancestors lives may not have been well documented. Nuances in surname creation and spelling of the surname down through the years may have caused confusion and lost genealogical trails. And finally, oral family histories that we depend on in some cases may be faulty.
In some cases, no matter how much effort, time and money are put into a family history project, the research results in a 'dead end'. Many researchers give up at this point or perhaps wait for dozens of years hoping a missing piece of documentation will show up. Now, thanks to advances in genetic science, the walls are beginning to crack as genealogists turn to DNA analysis to develop confirmed links with their ancestors.
Genetics testing is the greatest new tool available to genealogists since the creation of the Family Tree! After all, DNA is the Gene in Genealogy!
Recently,
it has become increasingly apparent that we are all related, and I don't mean
just those of us with the same surname in our family tree. The question is
not are we related; but how far back in time is our common ancestor.
Some day, the science of genetics is going to use our DNA to help structure our
basic family tree far beyond what we can do with standard generational research
using historical documentation. For our purposes today, DNA testing can
already tell us if one living descendant is related to another living descendant
of a common ancestor via
Y-chromosome testing.
To learn more about the wonderful new world of genetics testing in support of genealogy, please read on. A number of links have been provided below to help you understand why genetics testing is rapidly becoming a great tool for genealogists, to tell you everything you ever wanted to know about genetics and genetics testing, as well as how to participate in a specific Surname DNA Project.
Surname & Regional DNA Projects
Genetics testing in support of genealogical research is now readily available and affordable. In December 2002, Robert B. Noles became the Group Administrator for the Knowles Surname DNA Project. This project involves testing the Y-chromosome DNA for men with the surname Knowles (all spellings) to establish the unique DNA profile for each of the various Knowles genealogical lines (there are dozens of original 'unrelated' Knowles progenitors). Only men have a Y-chromosome. Women have two X-chromosomes, so obviously they cannot be tested for a surname project (Note: a different type of DNA, called mitochondrial DNA (mtDNA) can be tested for both men and women to determine direct female lines of descent). This series of Genetic Genealogy Web pages provide some background concerning why DNA testing is important for genealogists and in the future a summary of the results from tests already conducted will be provided.
DNA projects are now available for over 25,000 unique surnames in over 2,500 individual Surname Projects. And many Regional DNA Projects are being established. A Regional DNA Project has been established for West Florida Parishes (of southeast Louisiana). By joining either an existing Surname or a Regional Project you can:
Obtain tests at reduced rates (over 30% off retail)
Avoid setting up your own Surname or Regional Project
Obtain the assistance from a Project Group Administrator
A Regional Project like the West Florida Parishes Regional Project is a good place to start if your Surname Project has not yet been established. The Surnames link below identifies surnames of interest for the West Florida Parishes Regional DNA Project. The existing surname projects of special interest to descendants of West Florida Parishes Pioneers are available via the link to West Florida Parishes.
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What is DNA ?
Deoxyribonucleic acid (DNA) is the chemical inside the nucleus of all cells that carries the genetic instructions for making living organisms.
What are Chromosomes ?
Chromosomes are paired threadlike ‘packages’ of long segments of DNA contained within the nucleus of each living cell. In humans, there are 23 pairs of chromosomes. In 22 of the pairs, both members are essentially identical in structure, one deriving from the individual’s mother, the other from the father. The 23rd pair is different. In females, the 23rd pair has two like chromosomes called ‘X’. In males, the 23rd is comprised of one 'X' and one 'Y'; two very dissimilar chromosomes. It is these differences in chromosome 23 that determines the sex of an individual at conception.
Why is
the Y-Chromosome
Important to Genealogists ?
The Y-chromosome is passed down from generation to generation (father to son) normally unchanged. The very minor changes that do occasionally occur at random (usually only after many generations) are actually very helpful in assessing the results of the DNA test. The Y-chromosome is the only human chromosome that escapes the continual reshuffling of parental genes with every new generation. It is this unique characteristic of chromosome 23 that makes the Y-chromosome so important for genealogists.
For any particular individual, it is a random chance as to
which parent’s chromosome (and its associated DNA) will be inherited. For
example, one or more of the genes in one of the human chromosomes determines the
child's eye color. Brown is dominant over blue, so if the child inherits a brown
eye gene from one parent and a blue eye gene from the other parent, the child
will have brown eyes. Because eye color is a visible characteristic, you may be
able to determine (guess) which parent provided the brown eye gene to the child.
However, in most cases, because the genes are inherited at random in every
generation, for any given characteristic of your makeup, you will typically not
know whether the activated gene in the child came from the mother or the father.
Men can only inherit the Y-chromosome from their father, because the mother doesn't have a Y-chromosome (that's the difference between boys and girls!). A man passes down his surname and his Y-chromosome DNA to his son. In most countries since the middle ages, the surname has been patrilineal. So, here in the 21st century we can test the male Y-chromosome and know with a great deal of certainty the identity of the Y-chromosome that the man's male ancestors had over 500 years ago when surnames were first used. We don't have to dig up our ancestors to test their DNA! In fact, the Y-chromosome deteriorates rapidly after death, so it is unlikely a DNA test could determine one’s Y-chromosome profile for someone who is no longer living (possible only in rare cases).
Who is
Responsible for the Testing
and the Analysis of Results?
Family Tree FDA (FTDNA), a company out of Houston, Texas founded in 2000, is managing the DNA testing for the most Surname and Regional DNA Projects. FTDNA requires only a gentle swab from inside your cheek to obtain a good DNA sample for the test (no blood or needles are required). Testing of the DNA takes about 5 to 6 weeks after the test swab is received by the laboratory. Certified test results are provided to the submitter and to the Project Group Administrator to make the necessary genealogical comparisons. The results of one individual’s tests will not define his direct male ancestors. You need to be able to compare the results from one man's test against the results of another man with a direct line common ancestor to establish the genealogical links.
compare the features provided by
the major companies
supplying genetic genealogy testing
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What Results are Obtained ?
A 12-marker (or 25 or 37-marker) test is conducted on the cells retrieved from your cheek. The more markers tested, the more certain we can be of a match (genealogical link) between two or more participants. Markers are specific loci on the genes within the human chromosome. The 12-markers (or 25 or 37 markers) that are examined have been selected by the 'experts' to best represent the unique nature of the Y-chromosome. The Y-chromosome has many 100s of loci, perhaps several 1,000 all together, but the scientists have been able to narrow down the number to a few loci that they believe are the most meaningful for genealogical test purposes. In other words, when we compare the specific test results for each marker for one man's DNA against other men, we are most likely to determine if there is a recent common ancestor using as few as 12-markers (although 25 and 37 marker tests provide results with greater probabilities). In some cases, the 12-marker test will suffice; however, in some cases, we may need to run a more definitive test using 25 or 37 markers to be very sure of the results. The more markers used for the test, the more likely (higher probability) there is a recent common ancestor when all the markers for both men are tested to be identical (12 for 12, 25 for 25 or 37 for 37) or very nearly identical (11 for 12, 23 for 25 or 34 for 37). Obviously the more markers tested, the higher the cost of the test, although DNA testing for genealogical purposes is now quite reasonable.
The test results by themselves won't mean much to the casual observer. In fact, you can't plug your results into a computer database and have it print out your genealogy. Someday, this may be possible, but not today. That's another whole different story. Anyway, what we can do today is compare a man’s DNA test results with the results of other men who have been tested in the same manner. When the results are an exact match, we know that there is a 99+% probability that the two men tested have a recent common ancestor. So, when we have men with fairly well established genealogies, such as we have for many of the Wiregrass lines, we can then assume an individual’s results represent the Y-chromosome profile for that particular ancestor.
GENOGRAPHIC PROJECT
Spencer Wells, Ph.D., Director, Genographic Project for the National Geographic Society is the population geneticist who has conducted pioneering research using DNA to trace humankind's migratory history. Dr. Wells is currently embarked on a new study, the Genographic Project, to further evaluate the early human migration out-of-Africa some 50 to 60,000 years ago.
Most scientists think humans are descended from a common ancestor, so why do we look so different (the DNA from all humans is 99.9% identical; it's the 0.1% that makes us different)? IBM and the National Geographic Society are searching for the answer to this question by creating a global family tree from human DNA via the Genographic Project. Lead researcher, Spencer Wells is overseeing the gathering of 100,000 samples from native peoples around the world to learn the routes early man took to populate the Earth. Dr. Wells expects some surprises when the results are analyzed by 2010. Dr. Wells tells us, "We all share a common beginning and many similarities. If we remember that, maybe we can reduce the tendency to emphasize our differences."
The general public has been invited to participate in the Genographic project. You can be included in this historic National Geographic Society Project by purchasing a test kit, doing a simple mouth swab and sending it in. In eight weeks, you'll learn about your deep ancestry (results are kept secure). The purchase of the test kit from NGS includes the "Journey of Man" video, by Dr. Wells.
http://www.nationalgeographic.com/genographic
The results received via your participation in the Genographic Project (12 Y-DNA markers) can be transferred to one or two of the FTDNA Surname or Regional DNA Projects. If you already have 12-marker (or more) results via a FTDNA test, you can transfer your results to the NGS Genographic study for a $15 donation.
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