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Author Topic: Y-DNA "Deep Ancestry"  (Read 1183 times)
Ian BEADLE
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« on: January 19, 2013, 09:34:02 PM »

If Y-DNA Analysis shows paternal "deep" ancestry, is there any way of finding more recent paternal DNA information?
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IanB
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« Reply #1 on: January 20, 2013, 07:05:29 AM »

It depends on what you mean by "more recent" ancestry.

There are two types of Y-DNA testing: SNPs (Single Nucleotide Polymorphisms) and STRs (Short Tandem Repeats). SNPs are used for deep ancestry (generally in the range of thousands of years) while STRs are used for comparing individuals who are related since the development of surnames (within the last thousand years).

Depending on how many STRs you test, you can get fairly good resolution (possibly as close as say 4-8 generations ago). The issue with DNA testing is the fact the mutations are random events, and do not happen at regular intervals. You can find two individuals who are exact 111 STR marker matches from each other who are fourth/fifth cousins, and you can find siblings who have 2 or more differences at 111 STR markers.
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Y-DNA - R1b M157.2 (a private/family subclade of Z6/Z352) 111 markers tested

mt-DNA - J1c2g with the following private mutations: 315.1C 522.1A 522.2C C9974T C16256T (FMS tested and submitted to GenBank)

Autosomal - shows as a typical English ancestry. Tested with 23andMe, FTDNA
Alpine
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« Reply #2 on: January 21, 2013, 01:14:01 AM »

It depends on what you mean by "more recent" ancestry.

There are two types of Y-DNA testing: SNPs (Single Nucleotide Polymorphisms) and STRs (Short Tandem Repeats). SNPs are used for deep ancestry (generally in the range of thousands of years) while STRs are used for comparing individuals who are related since the development of surnames (within the last thousand years).

Depending on how many STRs you test, you can get fairly good resolution (possibly as close as say 4-8 generations ago). The issue with DNA testing is the fact the mutations are random events, and do not happen at regular intervals. You can find two individuals who are exact 111 STR marker matches from each other who are fourth/fifth cousins, and you can find siblings who have 2 or more differences at 111 STR markers.

are you sure on the SNP and STR because DNATribes explained it differently.
they stated basically the opposite and STR have a slower mutation rate
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YDna = T1a2b (L446)
MtDNA = H2a1c (haplofind)

wing_genealogist
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« Reply #3 on: January 21, 2013, 05:51:49 AM »

The nature of STRs, where they have a repetition of a sequence (TAGA TAGA TAGA TAGA TAGA TAGA is a small 6 repeat) makes "mistakes" (mutations) relatively common. The numbers referred to in STR results is the number of repeats (which for some markers can get into the 30s and even low 40s).

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Y-DNA - R1b M157.2 (a private/family subclade of Z6/Z352) 111 markers tested

mt-DNA - J1c2g with the following private mutations: 315.1C 522.1A 522.2C C9974T C16256T (FMS tested and submitted to GenBank)

Autosomal - shows as a typical English ancestry. Tested with 23andMe, FTDNA
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