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Archiver > GENEALOGY-DNA > 2010-02 > 1267369890


From: Al Aburto <>
Subject: Re: [DNA] Backbone tests
Date: Sun, 28 Feb 2010 07:12:18 -0800
References: <011301cab855$fc1165d0$8dfae429@saphirconsult.local>
In-Reply-To: <011301cab855$fc1165d0$8dfae429@saphirconsult.local>


Hi Kamel,
Remember that the free backbone test is done _only_ if the haplogroup
_cannot_ be predicted from the haplotype.

I don't know that FTDNA uses 25 or more markers to do its haplogroup
prediction. Since the minimum of 12 markers can be ordered (is ordered
by many) then their haplogroup prediction algorithm _may_ likely be
based on only 12 markers.

I view FTDNA's list of haplogroups determined from the "backbone" test
as their "minimal haplogroup" set.

I think that FTDNA's rules are fair because it seems (I'm not exactly
sure though) that an R1b1b2 person will need to test a similar (or I
suspect even larger) number of SNPs as a J2 person in order to determine
their current deepest known subclades. So R1b1b2 and J2 are good points
to stop for their "minimal haplogroup" assignment.

Clearly the whole process of determining the Y-tree is an evolving one
(as we see from all the L SNPs found recently) and it may be difficult
to keep it always "fair".

FTDNA's philosophy regarding SNP testing seems to be changing too. In
the past in J2 they would test a whole bunch of SNPs (kind of a blind
brute force method) for the Deep Clade-J, but now they seem to have a
more intelligent method avoiding the testing of unnecessary (ancestral)
SNPs as may be possible. Their pricing structure depends upon the
number of SNPs tested in the Deep Clade-J though and the price per SNP
tested seems fairly reasonable.

FTDNA wants to stay in business, and we want them to stay in business
too, but we don't want them to be unfair or even seem unfair in any
way... It doesn't seem to me they are being unfair in any way ...
probably you should write to FTDNA and ask your question below.
Al


> On 2/28/2010 1:11 AM, Kamel AL GAZZAH wrote:
> Hi All
> As per this FTDNA page explaining about backbone tests,
> http://www.familytreedna.com/snp-assurance-program.aspx
> the follwoing haplogroups can be determined throught bqcknbone test
> A, B, C, D, E, E1b1a, E1b1b1, F, G, H, I, J, J1, J2, K, L, M, N, O, P, Q, Q1a3a, R, R1, R1a1, R1b1b2, R2, T
> I have the following questions:
>
> If two particpants pay the same amount of money for 25 markers tets for example, one will know that he is R1b1b2 and the other one will know othat he is only J2, is that fair ?
>
> Kamel
>


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