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Archiver > GENEALOGY-DNA > 2002-08 > 1030375577


From: "James Reynolds Hull" <>
Subject: Re: [DNA] How specific is 12 marker test
Date: Mon, 26 Aug 2002 08:38:00 -0700
References: <003801c24b0f$2395aec0$59383942@nc.rr.com> <5.1.0.14.0.20020826073824.056a1148@mail.verizon.net>


Adding additional comments to the above captioned e-mail; not taking issue
with anybody's comments, but just adding my thoughts to what I have read:

Granted, if one should awake from a deep sleep, and exclaim, "I think I'll
do a 12-marker DNA test!" then he will have some surprises in store. Just
doing a DNA test, for the heck of it, will tell most absolutely squat! Then
to add more confusion, people aimlessly look about to do something with the
numbers, possibly stumbling across someone who says, "Go plug your numbers
in such and such a database to find out who you are related to," then the
person is in for more surprises.

What some at this site, have repeatedly expressed more than once, is that
each person considering doing a DNA test should first begin with a
hypothesis. "I believe I will do a DNA test to prove if I am related to my
surname 5th cousin, and to learn of other surname individuals related to me,
and to determine my oldest known ancestor," could be a way to begin. Then
the numbers can and will take on meaning and can and will prove or disprove
the hypothesis, and possible enable one to strike out in other directions,
when compared to other numbers. Otherwise, additionally expressed on this
site that a DNA test and with no purpose is like "one hand clapping!"

Any DNA test for family genealogy purposes, of course, must be supplemented
with the "grunge" work that absolutely must be done to have the paper
documentary to collaborate the DNA evidence that proves or disproves the
hypothesis.

If one makes a stab at doing the expert reading, then surprises and
wonderment can be substituted with knowledge and preparedness for the
surprises and the numbers; especially somewhat prepared for many other
surnames and numbers that will match, especially if they are as common as
table salt. Additionally, I might add, a 25-marker test can and will help
to refine the 12/12 marker information and does help to put things into
little closer-in-time focus.

Maybe some of the problem is that some of the companies offering family
reconstruction projects [there's the key] are not warning people what DNA
results can and won't do. Maybe each person wanting to do the testing
should be required to give a hypothesis for what it is they want to
accomplish in doing a DNA test. Of course the company should be keeping
their participant's well informed as to what the results mean to each person
based on a hypothesis; and likewise be available for future questions. But,
that is another issue.

regards,

Jim Hull


----- Original Message -----
From: "John S Walden" <>
To: <>
Sent: Monday, August 26, 2002 4:53 AM
Subject: Re: [DNA] How specific is 12 marker test


> At 07:21 AM 8/26/2002 -0400, you wrote:
> >For my money, the 12 Marker Test did not provide an adequate degree of
> >precison on
> >which to base a high confidence genetic genealogical relationship.
>
> RIGHT!
> That is what many people have been saying here on the list.
> The 12 Marker Test cannot PROVE a connection but it can DISPROVE one.
> One can also say that your 12 marker test PROVED you are NOT RELATED to
> thousands and thousands of other men in the data base.
> The 25(or 23) Maker Test cannot PROVE a connection by itself either, you
need
> some other detail in order to believe the match.
>
> Look at it this way
> The 12 Marker test has about a 1000 to 1 chance of just being a random not
> related match
> between two people. But the case you have is not two people it is 10,000
> people.
> You pick one person and take that number look in a 10,000 person data
base.
> You should EXPECT to get 10 matches. More if you have common numbers
> and fewer if you have rarer numbers.
>
> For any given set of 12 marker numbers (unless they are Really Really
rare)
> will have 100,000 other men in the USA with those numbers.
>
> John W
>
>
> ==============================
> To join Ancestry.com and access our 1.2 billion online genealogy records,
go to:
> http://www.ancestry.com/rd/redir.asp?targetid=571&sourceid=1237
>
>

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