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R Z16526 and Subclades Project

Formerly R-P314 Haplogroup Project
  • 128 members

About us

The first administrators of the McCarthy Surname Study identified, in 2004, a distinct modal haplotype based on the 12 STR marker tests then available. This had the following mutations from the previously identified Western Atlantic Modal Haplotype (WAMH), a term coined by FTDNA:

DYS 390:  24->23 (from 24 to 23 repeats of a base pair motif at this Y-chromosome segment)

DYS 388:  12->13 (a very rare mutation)

DYS 389-2:  29->28 (with DYS 389-1 = 13) , or more accurately expressed a 16->15 mutation in the delta between DYS 389-2 and 389-1, since 389-2 includes the count for 389-1.

Later, the very rare 15->16 at DYF 395S1a and the presence of a majority of other specific mutations were recognised as indicative of this cluster.

An R-L21 Walk through the Y (WTY) on the test kit of 16473 (Martin) late in 2009 identified an SNP associated with this haplotype, a T>C mutation at position 2888672 on the Y-chromosome. This had previously been observed in Haplogroup H and therefore the new discovery was numbered P314.2. We will usually call it P314 on these project pages. The path to this subclade was subsequently determined as R-L21>DF13>DF21>FGC3213>P314.

In 2010, with the benefit of data sets of 67 STRs, the present McCarthy Surname Study Administrator noted that the approximately 30% of McCarthys with the haplotype associated with SNP P314 distinguished themselves from most others with a very rare 12->13 mutation at DYS 617. Soon after, Dr Thomas Krahn, then of FTDNA, spotted another previously unknown SNP very close by while checking McCarthy kit 10119 for SNP P314, an A>T mutation at position 2888632, just 40 bases away from P314. This was labelled L362 (and later L362.2 as this too had been found elsewhere). It fortuitously turned out to only be seen, at that time, in conjunction with SNP P314 plus the 12 ->13 DYS 617 STR mutation. 

With the intoduction of NGS (New Generation Sequencing) testing, such as FTDNA’s Big Y, in 2014, it soon became clear that SNPs P314 and L362 each occurred in long 'bottleneck' periods. A bottleneck occurs where a large number of mutations are observed without any apparent branching from the stem of the lineage. It will often be because insufficient participants with pertinent genetic history have tested deeply enough, but it could truly be that the paternal lineage hung by a thread with only one survivor at the end of the bottleneck period, all other branches having 'daughtered out', i.e. not left any male progeny in a continuing paternal line. In the case of P314 and L362 each bottleneck period contained around 20 SNPs, indicating a likely time period of the order of 1,000 years. However, from our tree constructed speculatively on the basis of STR mutations, it was noticed that there was one distinct branch mid-way through the P314 bottleneck period and a small number of participants with 13 at DYS 617 who appeared to branch off early in the L362 bottleneck period (and most of these in fact subsequently tested negative for L362). NGS testing would have resolved this, but instead testing of a participant from each group with the new R1b-DF21 SNP Pack (which contains over 40 SNPs pertinent to our project and a good number from each of these two bottlenecks) has facilitated progress by breaking each bottleneck into two.

As a consequence, our project now begins with a group of equivalent SNPs comprising Z16526, Z16527, Z16531, Z16535 and Z16832. (SNPs in a bottleneck are said to be "equivalent" because we cannot distinguish one from another in respect of the order in which they occurred). A further three SNPs, Z16524, Z16528 and Z26415, may belong in this group, but have yet to be tested for this purpose. Associated with this grouping of SNPs - and thus occurring in the same time period - are nine STR mutations which include those described above at DYS 390 and DYS 388, and the uncommon 10->11 at DYS 406S1. Subject to subsequent back or further onward mutations at the STR segments, these are common to everyone in our project.

At this point our 'Group 1' breaks away from the stem of the lineage to which the rest of the project belongs, and since Group 1 itself then has six STR mutations in common to all its members, it is anticipated that another SNP bottleneck will be found here if and when several of these members choose to take an NGS test such as Big Y. 

Back on the main stem, there is still a lengthy bottleneck before we see a further flourishing of progeny, and among the mutations in this second bottleneck are SNP P314 and the DYF395S1a and DYS 389-2 STR mutations referenced above.

All these mutations can be seen in diagramatic form in the top left hand section of the R-Z16526 / McCarthy R-L21 Groups B and K phylogenetic tree at www.mccarthydna.wordpress.com/ where it serves the needs of both this project and the McCarthy Surname Study, for which it was originally drawn.


PROJECT NAME CHANGE

"P314" was used to identify this project because from 2011 until 2015 it was found to be positive, where successfully tested, in every kit in which the recognisable haplotype features were seen. However, although it was then included in the National Genographic’s array of over 10,000 SNPs, it soon became clear that the method of testing used by FTDNA on behalf of NG gave unreliable results, which had then to be ignored.

More recently

·        Alex Williamson, the creator of the Big Tree (www.ytree.net/), has noted at least three independent occurrences of P314 under R-P312, including a second under R-DF21.

·        FTDNA withdrew P314 from its catalogue for individual testing, noting it was recurrent, i.e showing up in multiple branches.

·        Another testing company has noted that the region around the location of P314 is very volatile and has similarities with a region of chromosome 6 which could make results unreliable.

.        P314 has failed to give a clear result in the R1b-DF21 SNP Pack test.

.        (Most relevant of all) it was found to be negative in the kit of a Group 1 participant.

Immediately prior to Z16526 and its group of at least four further equivalent SNPs, the line from DF21 is seen to be DF21>FGC3213>Z16532.   A Hatcher who tested Big Y is positive for Z16532 but negative for Z16526 and all its equivalents. His haplotype shows none of the large number of STR mutations associated with the lineage of our interest at all. The project is therefore deemed to begin with Z16526 and its equivalents and Z16526 itself has been selected from this group as suitably representative to replace P314 in headlining our project. We are aware that at some later stage the small bottleneck in which Z16526 is located may also be broken, but will deal with that if and when it arises!


OUR TREE

The aforementioned phylogenetic tree for over 200 Y-DNA participants - not all yet members of our project but whose haplotypes and SNP test data are available in the public domain - remains speculative where only STRs have been tested, and thus testing to 111 STRs greatly increases the confidence in placement thereon. However it is gaining more and more irrefutable definition with SNP testing, and in particular NGS testing such as Big Y. See the Results page for further discussion.

 

MEMBERSHIP CRITERIA

Since this is a Y-haplogroup project it is expected that applicants will have already tested to at least 37 STR markers (e.g with a surname or geographical project) before seeking membership.  Exceptionally, relations of existing members whose paper trail indicates a shared paternal ancestry may order their initial test through the project.

This project is intended for Y-DNA Study only.  Participants will be accepted as long as they have one of the following:

·        a haploytype broadly consistent with that indicated for the main trunk of the tree at www.mccarthydna.wordpress.com/. It is recognised that individuals will have variations on this due to more recent STR mutations (including occasional back-mutations) in their branches, but they should have a reasonable number of the key upstream mutations.

·        a positive (derived) test result for SNP Z16526 or any of its equivalents as shown on our tree, or any SNP further down the tree. (In the event these SNPs are recurrent in other haplogroups, a consistent haplotype would also be a requirement).

Others will be asked to leave the project or should be prepared to accept the Administrators removing them.  If in doubt, please write to one of the Administrators and /or test a suitable SNP before joining.

***NOTE***   P314 is not the same as YP314, which is available for testing at FTDNA. Please contact your Administrators for an alternative source for this test as well as any SNP tests recommended on the Results page which are not available at FTDNA.


Last updated: 21 November 2016