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The purpose of this page is to discuss the results of the DNA project.
Each group has it's own discussion: Group 1, Group 2, Group 3, Group 4, Group X

Last update: 4 August 2011

Group 1 - Hg I1d1
Halpotype Discussion
This group now has 9 members, 5 of known Irish origin and 4 whose earliest known origins lie in Virginia and South Carolina. The Group 1 participants have a fairly unusual haplotype, there is to date only one 12/12 match with a different surname in any of the available Y-DNA databases online. This is a good thing, as it means that close matches will have a higher significance that would matches for a more common haplotype. According to George Hamilton's analysis of the distribution of repeat values at various STR sites for haplogroup I, the values that make this 12-marker haplotype unusual are DYS390 = 24 (3,2% frequency) and DYS391 = 11 (8,7%). Participant C-6 does have a handful of 12/12 matches since he has the much more common value of 10 at DYS391.

As this group grows larger, we are starting to see more haplotype variance, particularily among the fast mutators DYS 449 and CDY in the 37-marker panel, as well as a significant number of differences in the slower mutating 38-67 marker panel. Since the (de) Courcy surname has a very long history, there is the possibility that some lines will share a common ancestor far back in time and therefore will statistically have a larger GD (genetic distance) to each other. The 38-67 marker panel is showing promise as an indicator as to how closely related the different lines are. The three Irish-origin lines who have tested 67 markers share a deviation from the modal at DYS572 (10 instead of 11) that the southern US-origin lines do not have. The two southern US lines (C-3 and 9) in turn share the off-modal value of 15 at DYS534. Participant C-20, who shares a known common ancestor with C-3, is in the process of being upgraded to 67 markers, it will be very interesting to see if he shares the same value at 534.

The two southern US lines with 67 markers (C-3 and C-9) match each other 66/67 (one mismatch at CDYb), and share the same deviation from the group modal at marker 534 in the 38-67 panel. Members of C-3's line did spend time in South Carolina, and researchers of the two lines have believed there is a possibility that they may be connected, which is supported by the DNA results. Hopefully researchers of these southern US lines will be able to find where they connect using traditional research. Finding the connections between the Irish origin lines will probably be tricky in most cases due to the lack of Irish records, although now that church records for County Cork and Dublin City are being made available online the situation looks a bit brighter.

Y-Halpogroup Discussion
SNP testing has confirmed that the Group 1 members belong to Y-haplogroup I1d1. According to Hg-I expert Ken Nortvedt's system they fall into the I1d-ultra Norse type 1 subgroup. The ultra-Norse variety is strongly associated with Norway geographically, the Type 1 division even more so (way before the use of surnames, however). It is found almost exclusively in Scandinavia and places they colonized, and is rare south of the Baltic and North Seas. (See the I Subclade I1 Project).

Sources indicate that Group 1 is of Irish origin. Historically, the most common haplogroup by far in Ireland is R1b (ca 75%). Haplogroup I is the second most common, at ca 20%. Studies indicate that I1 is the most common of the haplogroup I subclades in France, which is in line with a French origin of the surname. According to Dr. Ken himself, based on their haplotype he would guess that the Group 1 lines are the descendants of an Viking in Ireland or of the Normans. Some researchers have theorized that I1 came to Ireland primarily during two time periods - during the 9th and 10th centuries with the Norse Vikings, and later with the Normans after the use of surnames. Theoretically therefore those Irish I1 with Gaelic surnames would probably be descended from Vikings, while those with non-Gaelic surnames would be descended from Normans. Again, this fits with the traditional history of the Coursey (de Courcy) surname, whose origin is in northern France. It is however far too early to be able to say if this is the genetic signature of the actual Kinsale line, as participants with documented connections to the Kinsale Barony are needed in order to draw any solid conclusions.


Group 2 - Hg J2
This group straddles two surname projects, and actually has a total of 5 members, the additional two being Courson lines who are members of the Corson DNA Project (participants no. 18 and 36, in Division XV). Participant C-4 is no. 31 at the Corson Project, and has agreed to have his results listed here as well in order to highlight the connection between the lines and hopefully encourage more Courseys and Coursons with southern roots to test. Participants C-2 and C-16 have also joined the Corson Project, and are listed there as Nos. 32 and 52, respectively.

This lineage belongs to haplogroup J2, which is found in highest concentration in Western Asia and South Eastern Europe, in other words in the countries to the north and east of the Mediterranean. Its frequency drops dramatically as one moves northward away from that area. Two of the members of this group (C-4 and C-16) have joined the Y-Haplogroup J DNA Project, where they have been placed in a cluster with lines that predominately list Turkey and Italy as their earliest known origin.

The members of this group match each other fairly closely, and probably share a common ancestor born in the early 1700s or late 1600s. Their haplotype is very uncommon, with virtually no matches at Ysearch with a GD of less than 6 with other surnames above 20 markers. Both the Coursey and Courson families are found in the south-eastern US, most predominately Georgia and Alabama. (See the Courson lineages.) All three Courson lines' earliest known origins are in South Carolina, C-2's are in Georgia. The line of Courson participant no. 31 (C-4) is found in Tattnall County, Georgia, which is in the same part of the state as the Courseys. A Coursey line which may be connected to C-2's line is living in Tattnall County during the same time period. There are some researchers who have speculated in a connection between the Coursons and Courseys, the DNA results prove this theory.

Whether Coursey or Courson is the original surname is not known, though Courson seems to be the most likely candidate as more lines carry the name. Courson is generally considered to be of French origin, while Coursey is Irish/French (see below). Haplogroup J2 is very uncommon in Ireland, and although a small cluster does occur in the British Isles, an origin in France or some other Mediterranean county is much more likely for this line.

Any researchers who have more knowledge regarding these lines are grealty encouraged to contact the project administrator.

Coursey: Irish (of Norman origin): habitational name from any of various places in northern France called Courcy, from the Romano-Gallic personal name Curtius (a derivative of curtus 'short') + the locative suffix -acum. Compare Decoursey. (Dictionary of American Family Names, Oxford University Press, ISBN 0-19-508137-4)
Courson: 1. French: habitational name from either of two places named Courson, in Calvados and Essonne, from the personal name Curtenus (a derivative of Latin curtus 'short') + the locative suffix -onem, or from a place in Yonne named with the same personal name + Gaulish dunum meaning 'pride'; later, 'fortress', 'stronghold'. (Dictionary of American Family Names, Oxford University Press, ISBN 0-19-508137-4)


Group 3 - Hg I1
The DeCoursey participant in Group 3 matches 6 other members with variations of the Corson surname in Division II at the Corson DNA Project. The common ancestor of these lines is known to be Jan Corszen, born about 1650. He settled in New Amsterdam, New York, coming there from Recife, Brazil. His ancestry is unknown, but he is theorized to be from the area of France, Belgium or Germany.

The desendants of Jan Corszen have used many different surnames. The surname of participant C-7's line evolved from CORSZEN to CORSA to DECOURSEY. Other branches of the family have used RESER, RACER, CORSAW, deCORSAW and other variants. Other DeCoursey lines of North Carolina and Kentucky are believed to also be descended from Jan Corszen.

Like Group 1, the participant in Group 3 belongs to the I1 haplogroup. They belong to different subclades if I1 (as defined by Ken Nortvedt), however. Group 1 belongs to the I1d-ultraNorse1 sublade, while Group 3 belongs to the I1-AngloSaxon-generic clade. I1-AS dominates I1 in Germany, Netherlands, etc., but also exists in good numbers up in Denmark, Sweden and even Norway. "Anglo-Saxon" does not in this case refer to the British Isles, but homelands of the Angles, Saxons, etc., with a high concentration in north-west Germany.

The genetic distance between the modal haplotypes of the two groups is 12 at 43 markers, which makes it unlikely that they have a common ancestor within a genealogical time frame. Using Dean McGee's Y-DNA Comparison Utility the number of generations back to the MRCA (most recent common ancestor) between the modals of the two groups is about 60 to 123 generations (1800 to 3700 years) at 95% probability, depending on which mutation rates are used. This is in line with Ken Nortvedt's Estimated Ages Back to Clade MRCAs in Y-haplogroup I1, which puts the age of I1-ASgeneric at ca 4000 years and I1d-uN1 at ca 3150 years.


Group 4 - Hg R-M222 (R1b1a2a1a1b4b)
This group has three members, two of whom have a known common ancestor (C-15 and 18). C-15 has had deep clade SNP testing which establishes that he belongs to subclade R1b1a2a1a1b4b (R-M222). Since the two haplotypes in this group are so close to the modal for M222 they are compared to that haplotype in the results table. R-M222, a sublade of R1b1b2, is found in highest concentration in Northwest Ireland, Ulster and Lowland Scotland. It has gained fame through a study done by Trinity College Dublin, Ireland which postulated that it may be the haplotype of the Irish king "Niall of the Nine Hostages". The Group 4 haplotypes are fairly close to the modal values, differing only on 4 and 5 of 67 markers. As a result, there are some fairly close higher level matches to other surnames which are most likely coincindental.

Participants C-15 and 18 descend from the famed Colonial Coursey family of Maryland's Eastern Shore. They are 67/67 matches to each other, which establishes the genetic signature of their earliest common ancestor, John "Quaker" Corse (b.1701-Hepbourne, Kent County, MD; d.1763-Kent Co, MD; m. Susannah Hanson). John was the third of the four sons of James Coursey/Corse (b. ca 1640 in Dublin, Ireland), who changed the spelling of his surname from "Coursey" to "Corse" when he joined the Quaker Society of Friends. James' father was Henry Coursey of Finglass Parish, Dublin, Ireland. C-15 and 18 are separated from John "Quaker" Corse by 6 and 8 generations, respectively.

The third member of this group (C-19) is descended from a Corse/Cross family of Glasgow, Scotland. The earliest known ancestor of this line is Robert CORSE/CROSS (b. 1640-Glasgow, Lanarkshire, Scotland; d. 4 Apr 1705-Glasgow, Scotland) m. Joanet PEDIE/PEADIE (b. 1643-Glasgow, Scotland; m. 23 Oct 1663-Glasgow; d. 28 May 1687-Glasgow). There is no known link between this family and the Maryland Courseys, on the contrary the Maryland Courseys have always been believed to be connected to the Norman/Irish de Courcy family of Kinsale, County Cork. The genetic distance between C-19 and the MD Courseys is 2, differing only on fast mutators DYS CDY and 534. There is always the possibility that this match is coincidental due to the general closeness between these two haplotypes and the R-M222 modal. However, given the surname connection and the fact that they share 4 of the same deviations from the M222 modal I feel that the match shouldn't be disregarded without further scrutiny. One step in that direction is to find a participant descended from Henry's eldest son Colonel Henry Coursey (b.1628-Dublin,Ireland; d.1695-Talbot County, Maryland) (free test available!), in order to establish that this is indeed the genetic signature of the Maryland Coursey line.

To complicate matters further, a different descendant of Robert CORSE/CROSS (b. 1640-Glasgow, Scotland) has also been DNA tested, his results do not match participant C-19 or any other Cross lines. Thus, further testing of the Glasgow Corse/Cross family is needed.


Group X - Hg R1b
This group has 4 members, all of which have yet to find close matches, in or outside the project. All belong to haplogroup R1b, which is the most common Y-haplogroup in Western Europe. SNP testing has established that member C-17 belongs to the R1b1b2 clade, which is the dominant subclade of R1b in Western Europe. The other 3 members of Group X have tested with AncestryDNA, they unfortunately do not offer haplogroup assignment beyond R1b. Based on their haplotypes, it is very unlikely that any of the members of Group X are M222+ like Group 4.

Since the members of this group have no matches yet, they are compared to the modal for R1b, also known as the Atlantic Modal Haplotype (AMH). None of the haplotypes are particularily close to the R1b modal, the nearest being C-8 at 36/43. This means that they run less risk of having coincidental close matches, which can be an issue with R1b haplotypes since the haplogroup is so common. The most unusual haplotype in this group is C-17, followed by C-11. Neither of these has matches in Ysearch with a GD of less than 4 at higher marker levels (>25). C-8 does have a few close matches at the 25 marker level, but none with a GD under 4 at marker levels >30.


Related Surname Projects:

  • The Corson Surname DNA Project - Group 2 matches two other Courson participants in this project (no. 18 and 36, in Division XV). The participant in Group 3 matches the 6 other members of Division II.
  • The Courson Surname DNA Project - Group 2 matches the participants in this project.
  • The Cross DNA Project - Participant C-19 (Cross) is #190074 in this project. He has no matches there yet, including #153558, who is believed to descended from the same family.

General Y-Halpogroup Info

Y-Halpogroup I Links

Y-Halpogroup J Links

Y-Halpogroup R1b Links


Participating in a Surname DNA Project provides:

  • A report on the participant's genetic DNA, which is very close (and sometimes identical) to the earliest known ancestor
  • A classification of the participant's "deep" ancestry, which gives insight into the prehistoric origins of your surname ancestors
  • A sense of camaraderie with all who participate in the Family Project, which is particularly strong for those who share a genetic ancestry
  • Stimulation to family research and sharing of information
  • A wider sense of identity and relationship, as we begin to realize how much we are a World Family.
  • A chance to compare your genetic ancestry with those of the Surname and the Variant Spellings
  • Locates the genetic matches that do not share your common surname

Group admins

Project Administrators