GENEALOGY-DNA-L Archives

Archiver > GENEALOGY-DNA > 2010-02 > 1267056617


From: Grant South <>
Subject: Re: [DNA] Hello Mr. Krahn
Date: Thu, 25 Feb 2010 10:10:17 +1000
References: <9a804091002231904y6e27ed67g287b8f27361b1274@mail.gmail.com><4B84BDFA.40407@familytreedna.com>
In-Reply-To: <4B84BDFA.40407@familytreedna.com>


Dear Thomas,

I think this came through to me by mistake.

All the best

Grant South

On Wed, Feb 24, 2010 at 3:49 PM, Thomas Krahn <> wrote:
> Dear ab10man2,
>
> First I need to mention that I definitely do not have a Dr. title so please
> leave it away before I get into trouble.
> My university degree is Dipl-Ing. Biotechnology from the Technical
> University Berlin
> and I specialized in molecular genetics. This is the subject where I can
> definitely try
> to answer your questions. However I don't feel familiar enough with
> population statistics
> and history (esp. not Arabic or Jewish history) so that I unfortunately
> cannot answer some of your questions.
>
>
> ab10man2 wrote:
>> Hello Dr. Krahn,
>>
>> I hope you get this message doing well. I am sorry to contact you by this
>> e-mail but it is the only one that I found for you. I have tested a
>> y-chromosome test with Family Tree DNA, and it showed my haplogroup to be
>> J1e.
>>
>> Later, I tested the snp l222.2 and it was positive in my kit. These tests
>> confirmed that I have a Semitic Arabic origin in my paternal line.
>>
>> I have been in contact with so many experts and scientists including Mr.
>> Greenspan and Ms. Schrack about the new developments within this haplogroup.
>> I want to say that, honestly, getting answers to my questions from you would
>> be the most perfect way to have them answered for ever..
>>
>> I hope you take a look at them, and provide me with the answers if you would
>> like - for sure.
>>
>>
>> Q1: I know that we now have a newer tree of the haplogroup J1 in ISOGG
>> website. Would you estimate the time of when l222.2 is going to be added to
>> the haplogroups' tree in ftdna.com ?
>>
> This is just a organizational decision that needs to be done by the FTDNA
> management as soon as the IT group has the time to make the modifications
> on the website. I have no influence on this. The GRC lab can't see a
> difference
> whether the order is from a deep clade test or from the advanced orders
> page.
>>
>> Q2: Since we have more than 400 Arabic kits now, have been there any
>> developments in the project WTY ( or WTY2 if it has been started ) in
>> finding new mutations within J1e under l222.2 ? And is l222.2 a back
>> mutation ?
>>
> L222.2 is not a back mutation. It is a parallel mutation.
> L222.1 shows up in E-M2 samples.
> There where several J-L222.2 participants among the WTY participants so far.
> I am not aware of any systematic testing strategy/group that tries to
> divide J-L222.2 further though.
>
>> Q3: Would we have the ability to assign different snp's for each Arabic and
>> Jewish tribe in the future ?
>>
> There are probably enough SNPs on the Y chromosome to find a distinct
> SNP for
> each individual male. The question is rather if members of each "tribe"
> share enough
> markers so that you can identify a clear border around your "tribe"
> definition.
> This I can't answer.
>> Q4:  Is Family Tree DNA having a genetic conference this year ? ( I am
>> asking since we used to hear good news from such conferences).
>>
> I have heard discussions about it but I can't confirm a definitive "yes"
> yet.
> I don't have a date either.
>> Q5: Do you think that we might need to test more markers in the future to
>> determine TMRCA ?
>>
> It depends on what level of resolution and confidence your genealogical
> research requires.
> In general more markers will increase resolution and confidence of a
> TMRCA calculation.
> Especially if we are looking at the time before the surnames and
> genealogical records the resolution
> of the TMRCA calculation is rarely sufficient to draw reliable
> conclusions. With new SNPs we
> may not be able to calculate exact dates, but at least we are able to
> put events into a chronological order.
>
> However if you have genealogical records and are therefore able to
> simply count the generations
> then a 67 marker match is more than enough to confirm this exact TMRCA.
> Then it doesn't even
> matter if you have a few STR mutations or not. The TMRCA won't change
> because the genealogical record
> is more precise. No further testing is necessary in this case.
>> Q6: Do you recommend using: ( trees or calculators ) in finding TMRCA
>> between people that have more than 8 markers difference ?
>>
> No because I can't evaluate how reliable the calculators are. Other
> experts on this list may give you a better informed answer.
>> Q7: Do mutation rates change if we test more people of the same subclade ?
>>
> The mutation rates itself don't change depending on what you test.
> However our measurement value comes closer to the real mutation rate the
> more independent persons we test.
> If we are selecting the testing persons from a distinct subclade then
> we'll approach the mutation rate valid for that specific subclade which
> may be a different mutation frequency than in another subclade.
> Differences are usually small.
> However biochemical reactions are complex systems that can be influenced
> by a huge number of border conditions
>> Q8: Would you recommend that I do the WTY test or not ?
>>
> I don't want to influence you in either direction. If a new SNP may be
> helpful with your personal research you should give it a try.
> If you don't have many matches in the STR database it may be better
> worth to spend the money for testing multiple persons among your
> relatives to get a clearer picture about your genealogy.
>> Q9: Can I rely on 25 markers match or do I need to take 67 markers matches
>> in consideration ONLY?
>>
>>
> This depends on the question that you want to solve. The statistical
> experts on this list may be able to give you quantitative formula on how
> to calculate the number of necessary markers to solve your question at a
> distinct confidence level.
>
> I hope this helps,
>
> Thomas
>
>
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