Friday, November 17, 2006

DNA Genealogy (part 1)

Last week we introduced the idea of Genetic Genealogy. This is the realm of DNA – formally, deoxyribonuclecic acid; informally, the building block of life and your personal zip-code among humanity.

We could look at it from a planetary perspective – all living things are composed of DNA, and each evolved into something a bit different through mutations. Genealogy is, in reality, a microscopic snippet in the evolutionary time spans; but it does echo, or reveal, it.

Evolution is either periodic or forced mutation at the DNA level. In the case of mutation, we see an average, but consistent, change which reveals when a given ancestral line separated – when two lines shared a common ancestor, with all lines reverting to a common ancestor.

At each level, we are the product of our pedigree – all those who went before us – and our parents. More specifically, we are the product of every male in our father’s line and every female in our mother’s line.

To be even more specific, every male is the product of every father in his genetic line, and a woman is the product of every mother in her maternal line. In addition – and this upsets those favoring patriarchal constructs – each of us is also the end result of every mother in our father’s mother’s ancestry.

The “sex” genome, the X (mtDNA) or Y (Y-DNA) chromosome is the thing which marks our direct ancestry. To this add the pedigree genes – those odd pieces of DNA that were passed by every other ancestor and managed to be passed again.

Your pedigree depicts your “tribal” association and link to every other person on the planet. You may think you are Irish, but your genes will tell the history of Ireland and the various invaders; as well as the wives who were ancient captives or slaves from other cultures.

When we do our genealogy we have the opportunity to match the paper trail to our internal zip-code, by enlisting genetic DNA testing.
If you are afraid of your own ancestry – or among those who do not believe in evolution – you don’t want to know. Those who have the curiosity, and really want to know where they came from, must know.

One of the nicest things about the process is that it is a major study area. Thus, there are all kinds of educational organizations looking for database information. This means the possibility of free testing.

One free test I learned about, then utilized, is done by the Sorenson Molecular Genealogy Foundation (SMGF is online Ph 1-800-344-7643), who will provide a free 12 allele – 12 marker – test to anyone who can provide a pedigree with at least one ancestral line that goes back before 1900.

Anyone who participates in building the SMGF database will receive a significant discount on a more expansive test with a certified result.
I’ll cover terminology, and understanding you genetic zip-code, in separate column; for now, the key is that 12 markers matched to the database yields real distant regional family connections, and roughly how long ago you shared a common ancestor.

The free test protocol does not yield a report – you need to check their online database for your surname (no personal identification); and this is great for Y-DNA. I do not suggest SMGF for women who do not plan to take advantage of the discount offer. (To be continued.)

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