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Archiver > GENEALOGY-DNA > 2010-02 > 1267057708


From: Grant South <>
Subject: Re: [DNA] Hello Mr. Krahn
Date: Thu, 25 Feb 2010 10:28:28 +1000
References: <9a804091002231904y6e27ed67g287b8f27361b1274@mail.gmail.com><4B84BDFA.40407@familytreedna.com><c6384e011002241610h5cd82278g4f748c7c2f7b8c31@mail.gmail.com>
In-Reply-To: <c6384e011002241610h5cd82278g4f748c7c2f7b8c31@mail.gmail.com>


I see it's a list reply, mea culpa!



On Thu, Feb 25, 2010 at 10:10 AM, Grant South
<> wrote:
> 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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>


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