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For the Corson Cousins newsletter, January 2012

Corson Surname DNA Project

I have not provided an update on the project in the newsletter since October 2010. The project now has 59 participants, 36 of whom descend from documented 17th-century ancestors in Divisions I, II, III, and IV. Two others descend from a documented 18th-century ancestor (Division VII) and another 6 descend from an unknown 18th-century progenitor (Division XV).

I recently changed the principal DNA testing lab used by the project from (formerly Relative Genetics) to Family Tree DNA (FTDNA). Since purchasing Relative Genetics in 2008, has allowed the DNA tests offered by the lab to stagnate, while FTDNA has continued to offer new, more powerful tests and to improve management tools for project administrators. Consequently, results shown on the Corson DNA project website have been adjusted to reflect marker values used by FTDNA.

The project has experienced quite a bit of activity in the last few months, some from new participants and some from additional tests for existing participants through FTDNA.

Recent Results
Division II

Participant #57 (surname Courson) documents descent from Benjamin Courson, Sr., (c.1746-c.1820), who moved from New Jersey around 1790, settled in Fayette Co., Pennsylvania, about 1792, and moved to Licking Co., Ohio in 1804 (see the article about him in Corson Cousins, April 2011, for more information). Circumstantial evidence suggests that Benjamin descended from Johannes Corssen (1717-1770), grandson of Division II progenitor Jan Corszen (c.1649-1703).

Participant #57's surname and match on 32 out of 32 STR (short-tandem repeat) markers with the other Division II descendants indicate that he and his ancestor Benjamin do indeed descend from Division II. At the moment, we have not identified enough mutations within Division II genetic signatures to indicate from which family line Benjamin descended, but we hope that testing additional markers of several Division II participants will allow us to do so.

Division-III Vroom

Four participants with the Vroom surname (#13, 17, 21, and 56) document descent from Hendrick Vroom (1683-1769), documented grandson of Division III progenitor Cors Pieterszen (1612-1655). We still have not been able to determine whether the Vroom or Corson family line (if either) descends Cors Pieterszen (1612-1655), since each branch of documented descendants has a different genetic signature.

There are, however, ways to work back along the Vroom family tree to help pin down the European origin of the Vroom ancestors. One is to test a documented male-line descendant of another son of Hendrick Corssen Vroom (1653-1690) besides Hendrick, such as Cors (b. ca. 1676), Reyst, and Hans Vroom. If we found a match between one of their male-line descendants (if they exist) and existing Vroom participants, it would push the Vroom genetic signature back one generation.

Another option is explore an alternative hypothesis: that the Vroom participants may descend from a different Vroom family, one that may still exist in the Netherlands. For example, one such line apparently begins in 1543 with another Hendrick Vroom, stonemason and sculptor in Haarlem and ancestor of the famous Vroom painters (Hendrik, b. 1562; Cornelis; Frederik) -- source: Vijf eeuwen Vroom (Five Centuries of Vroom, M.E.Th. van Lunteren-Vroom, 1997, 85 pp). Living Dutch Vrooms who may descend from this progenitor or others have had some online discussions.

With the financial support of other Vroom participants and the CCFHA, Participant #56 “upgraded” his test to 111 STR markers, one of the tests available only from FTDNA. The test results indicate a relatively close match (e.g., 101 out of 111 markers) to a few men with the Boyd surname, who appear to have descended from an 18th-century Ulster-Scots (i.e., Scots-Irish) man with the Boyd surname. The Boyds belong to a genetic sub-group called “U-198”, whose members all descend from a single male-line ancestor who lived a few thousand years ago. Participant #56 also had his genetic signature tested for the U-198 SNP (single nucleotide polymorphism). The result was positive, confirming that he (and thus the other Vroom descendants) belongs to the same genetic sub-group as the Boyds.

The main question is when and where the most-recent common ancestor of the Boyds and Vrooms lived. It is likely that he lived more recently than their common U-198 ancestor. Some think it possible that one family (Boyd or Vroom) descended from the other, a case of “misattributed paternity” in which, for example, a man with the Vroom surname had a father who carried the Boyd surname, but in which the fact was either not known or recorded. Given the 101/111 match and the Vrooms’ well-documented descent from Hendrick Vroom (of at least 7 generations), it is statistically possible that they could share an ancestor who was born as recently as 15 generations ago (lower limit of the 95% confidence interval), that is, about 1637 (assuming 25-year generations); however, this lies at the edge of probability. The most likely time back to the birth of their common ancestor is 23 generations, which would be about 1437, but the upper limit of the 95% confidence interval goes back 35 generations, to about 1137.

So, where might this probably medieval or Renaissance ancestor have lived? Based on other DNA near-matches, he may have lived in what is now the Netherlands or northern Germany. Some of his descendants may have emigrated as Flemish weavers or Huguenots to Scotland or Ireland, where they adopted the Boyd surname, while others remained on the European continent and eventually adopted the Vroom surname.

Pending Results

Possible Division II descendant

Participant #58, with the surname Racer, documents descent from Division II's Teunis Decoursey/Corsa (c.1702-aft.1763) and his son Benjamin Decoursey/Racer. His upcoming results will either be consistent with or refute this documented descent.

Division-III Corson

Three Division III Corson participants (7, 49, and 51) document descent from Cornelius Corssen (1714-1774), three (9, 27, 41) from his brother Benjamin Corssen, Jr. (1718-1774), and one (34) from the as-yet-unattached Daniel Corson (1763-1849). Based on these lineages, their most recent common ancestor is Benjamin Corssen (1686-1740).

As with the Vroom participants, one can work back along the Division III Corson family tree to help pin down the European origin of the Corssen ancestors. One is to test a documented male-line descendant of another son of Cornelis Corssen (1645-1692) besides Benjamin, such as Christian (b. 1676), Jacob (b. 1681), and perhaps Daniel (b. 1690). If we found a match between one of their male-line descendants (if they exist) and existing Division III participants, it would push the Corssen genetic signature back one generation.

The Division III Corson genetic signature has a relatively close match (35 of 37 markers) with some individuals with the Cooper surname from the 19th century, but any relationship between the two family lines is unknown. There is a slightly more distant match (32 of 37 markers) with someone with the Kryger surname, whose progenitor, Gerrit Krijger was born ca. 1710 in the Netherlands. This is consistent with a relationship between Corssen and Kriger further back in time (perhaps several hundred years), perhaps in the region around present-day Netherlands.

Participants #49 and #34 have decided to upgrade to 67 and 111 STR markers, respectively. These tests will help us to identify other near-matching individuals and increase the precision with which we can estimate their relationship to them (i.e., the number of generations back to a common ancestor).

Between issues of Corson Cousins, information about the DNA project is available at the project website or via interim DNA-project e-mail newsletters (you can subscribe at