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For the Corson Cousins newsletter, April 2014
Corson Surname DNA Project
The project currently has 67 participants, 66 of whom have results. The most recent results arrived for Division II.
Results for 37 STR markers for Participant #67 (surname Coursen) arrived, closely matching those of other Division II descendants. This result was as expected, since this participantís brother (#63), father (#48), and two uncles (#39 and #55) are also tested members of the project. Participants in this family cluster are the most closely related in the project, and their results provide an interesting illustration of the randomness of DNA mutations. All five carry a mutation on DYS 635 not carried by other Division II descendants (thus specific to their line), and one of them (#63) has a mutation (on DYS 444) not carried by his father.
This difference in DNA between father and son stands in stark contrast to the lack of difference between my DNA and that of my 7th cousin, once removed. Despite no Corson ancestor in common since Zebulon Corson (1712-1786), we have 111 identical STR markers. (With testing of additional STR or SNP markers, however, differences should eventually be detected.)
Division II participant #39 (one of the uncles) also received results recently from the "Geno 2.0" test of the Genographic Project of National Geographic. This test examines 12,316 SNPs on the Y-chromosome (see this column in the previous issue for description of SNPs). Though Family Tree DNAís "Big Y" test is superseding Geno 2.0 by testing more (and more recently discovered) SNPs, the Geno 2.0 test currently costs 70% less. Thus, it remains a useful mid-level test for those who want to test many SNPs at once without paying for the most expensive test.
Out of the 312 SNPs for which Participant #39 tested positive, two of them (Z59 and CTS8647) have been identified as "downstream" of (i.e., to have arisen more recently than) the SNP previously determined for Division II (M253). Thus, this decreases the size and age of the genetic superfamily to which Division II descendants belong. SNP CTS8647 is estimated to have arisen about 3500 years ago, 1000 years after M253.
Striking while the iron is hot, Participant #39 has ordered tests for an additional 7 "downstream" SNPs. Testing positive for any one of these would further decrease the size and age of Division IIís superfamily, identifying other surnames closely related to Division II. By testing further and further downstream, the ultimate objective is to identify closely related families whose documented genealogies can help us identify where Division II progenitor Cors Janszen came from.
Between issues of Corson Cousins, information about the DNA project is available at the project website.