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Archiver > GENEALOGY-DNA > 2002-09 > 1031242080


From: "John F. Chandler" <>
Subject: Re: [DNA] Best DNA Test Labs
Date: Thu, 5 Sep 2002 12:08 EDT
In-Reply-To: roy.w.johnson@worldnet.att.net message <004201c254e1$e2ae6550$4b68550c@brat> of Thu, 5 Sep 2002 07:40:30 -0600


Roy wrote:
> Information I looked up indicated a perfect match with 25 markers indicated
> a 50% probability at 3.6 generations,

No, that sounds like the figure that Relative Genetics used when they
thought they had 24 markers. Since they assume a mutation rate that's
twice as high as everyone else, you have to compensate by doubling the
number of generations they quote. For 25 markers, it comes to 6.9.

> there to a 95% chance at 40 generations. Given the nature of a bell curve,
> I would think you would get a 60-70% probability pretty quickly,

The 70th percentile is at 12 generations.

> Now, how about some advice regarding the labs? I am looking hard at
> FamilyTreeDNA.com right now, since they give a lit of help in coordinating
> the whole thing. Do you know if they are any good, or if not, who is best?

My experience with FTDNA has been entirely positive.

John Chandler

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