Article from GenCircles.com
Starting With the
(Becoming a DNA
an article by R. Aaron Underwood
research involves pushing back your ancestry lines, generation by
generation, to discover your ancestors. How would it change your research
approach if you started with the answer - if you knew who from the early
1700's you descended from, for example, but didn't know the details of
how. If that sounds like fun to you and you have $150-$300 burning a hole
in your pocket, read on...
Researching my genealogy
is a hobby I've always done for fun. I like history and there's something
about understanding my personal connections to it that makes it even more
interesting. I make my living from technology, so when I heard that DNA
analysis could be applied to Genealogy... I was curious on a couple of
levels, and decided to get tested. The following essay covers what I've
learned from the experience. Speaking as a lay person, I'm no doubt
over-simplifying and perhaps even unknowingly fudging a fact here or
there. As with all information... consider the source.
DNA are the bits of
biological information we all carry around that makes us unique - the
stuff that determines, out of all the possibilities our bodies have...
which specific set of characteristics an individual is given to work with.
You get roughly half of this stuff from your mom and half this stuff from
your dad, and in turn contribute half of what you got to your children.
Which half? Well, nature loves both trial and error and continuing a good
thing, so some portions are passed randomly, some portions are passed
strictly father to son, mother to son, and mother to son and daughter.
It's these "strict" portions that we're interested in for genealogy
research purposes, because they prove a relationship.
The amount of
information contained in your DNA is huge... even small portions of it
contain enough information to uniquely identify you apart from any other
person. That's what a paternity test is - an analysis of a portion of the
stuff that's passed parent to child. Now for the big ah-ha... if this
stuff is unique between a father and a son, wouldn't it be unique for a
grand-father and a grandson? YES. How about a great-grand-father and a
great-grandson? YES. Now, before you get too excited, observe that this
method of identification only works for one of two grand-fathers I have.
Why? Because the DNA my father and I share obviously isn't shared by my
mother's dad (they're not related biologically at all, or at least I hope
they weren't :-)... so it uses the requires an unbroken chain of the
same-sex to work for identity purposes- either male to male to male or
female to female to female.
Ok, if you're a deep
thinker, at this point you might be wondering... "Hey, if a human male
always passes these same bits to his son, why wouldn't all human males
have the same bits?" Well, it turns out that every so often, nature, who
loves trial and error, randomly tweaks these "strictly passed" bits so
they're ever so slightly different between father and son (or mother and
daughter - I'll explain later why I'm use father-son examples). Over a
long time span, these occasional tweaks add up to some vary diverse bits
diversity is a boon for genealogists... since this rate of change is
rather predictable and steady. In the commonly used male to male DNA bits,
the rate of change is generally one change every 7 or 8 generations. So if
a fellow researcher of my surname and I share the exact same bits, then we
know we likely share a common father in the past 7 or 8 generations. If
our bits are one step different, then it's probably 7-15 generations ago
that we had a common father, etc. Different bits of the DNA do vary at
different rates, so you can get a bit more precise by looking at the
specific bit that's different.
Ok, back to you deep
thinkers... "Wait, if we know the rate of change of these bits of DNA,
couldn't we do a sampling of all current DNA in the world and do some
fancy math to figure out how long it took for it to diverge this much? And
wouldn't that say something about the origins of all of us?" Yes, in
theory. The Seven Daughters of Eve by Bryan Sykes is seen as one of the
seminal books on that subject for lay people, if you're interested.
Getting back to
genealogy... my mom's a Fike. She calls herself a Fike because that was
her name growing up - her identity. She looked like and acted like people
of that name who lived in the area because they were all part of the same
extended family. For DNA identity purposes, my mother's not a FIKE. Why?
Remember DNA identity only works along strictly male or strictly female
lines. FIKE is a surname. Surnames are passed down from male to male to
male. So while my mother has a unique DNA that ties here to her mother (a
DAVIS) and to her mother before her (an ENNIS)... most culture's don't
assign a consistent name to that. To make things tougher for female
research, the strictly passed female to female bits of DNA don't vary much
over time (compared to the male to male bits) so it's harder to pin down
the time frame of a relationship. So most people using DNA for genealogy
purposes are doing so for surname research, which is male to male to
male... the same as those unique "male to male" bits of DNA. That's why I
used father to son examples earlier.
People of the same surname form "surname projects", typically to try and
collect samples of that surnames DNA. With enough samples, patterns emerge
as to how many different "lines" of that surname exist. For example, in
the US, with a surname like Hancock, and 35 or so samples collected, a
pattern showing 3 or 4 original ancestors has emerged. If you're
researching a Hancock, and you can get a male Hancock from your family (or
yourself if it's your surname) to test for you... chance are reasonable
that you'll tie to one of those known ancestors. Now that you know your
original ancestor, you can research from both ends - from the original
ancestor forward, and from your known ancestor backwards. With the
Underwood surname project, it took us 6 samples before we found two people
that were related.
My advice, money and fun
aside, is to seriously consider using DNA testing for your lines where:
a) you have a male by
that surname that can be tested,
b) there's an existing
"surname project" with 20 or more samples already collected,
c) and your surname
isn't Smith or Jones.
Family Tree DNA is
probably the most popular vendor for adhoc surname projects.
Relative Genetics has a
higher end service that's more appropriate for established groups or to
support things like family reunions and such. And there are others...
You'll find there are
different types of test. The male to male test is called a YDNA test, and
it's offered in different depths (typically something like 12 marker, 25
marker and 37 marker). While the 12 marker test is cheaper, it's not very
useful in the surname projects I've described, because 12 markers simply
aren't unique enough to tell you much. I did the 25 marker test, and so
far haven't had any need for more resolution than that, so would suggest
you start with that. Most companies will let you "upgrade" your test later
to include more markers, so you don't have to resample and retest all over
There are a couple of
forms of the test and sampling - from scrapping your cheek with a little
device that looks like a piece of hard felt to a mouth wash that you swirl
and deposit in a vial. You take the sample yourself and it's easy and not
painful in any way. The sample is mailed in and results come back in 4-6
No doubt some people are
worried about the privacy of all this... As you would expect, the
companies that do the analysis for you are very serious about protecting
it and provide a number of safeguards and guarantees. From my perspective,
my DNA is already compromised - I discard it all the time in a variety of
ways. If someone wanted it bad enough, they could take it without me ever
knowing. So my opinion about the privacy of my own DNA is something I
don't really have anyway... but thatís just my opinion.
Iím glad I had my DNA
analyzed. I havenít turned up any related fellow researchers yet, but I
really think itís just a matter of time before I make a connection.
About The Author: R. Aaron Underwood is a software author (the genealogy
product GenSmarts) , living with
his wife and three kids in Long Grove, IL, and has enjoyed Genealogy as a
hobby for the past 30 years. He can be reached at
Email Us for Information
The information on this web site is
for your personal use only. All pages, compilations, transcriptions and
abstracts are protected by copyright law and may not be copied in whole or
in part and published or distributed in any manner without written consent
of the author, contributor and/or webmaster.
Copyright ©, The Power Et AL DNA
and History Project. All Rights Reserved.
Your comments & suggestions are always welcome.
This Page Last Updated
September 23, 2008