Results for FTDNA's Cowan YDNA Project home page are presented at
The project current includes 159 Kits, divided into 15 main groups, plus a number of subgroups within some groups. Groups are identified based on similarity of their YDNA marker composition following the single step model, and using a criteria of 14% dissimilarity for exclusion from any given group.
The largest group has been designated "The Seven Brothers" after a designation used by Source:Fleming, 1971. The Seven brothers include 33% of the kits in the project.
The next largest group is the "Pequea Creek Group", closely related to Flemings "Four Brothers". This group contains about 13% of the projects kits. Felmings original "Four Brothers" are now recognized as being a combination of two separate groups that settled close to each other on Pequea Creek and Octoraro Creek, along the Lancaster/Chester County border in Pennsylvania. The group designated in this YDNA project as the "Cowans Gap" group, are believed to represent the portion of the Four Brothers who settled on Octoraro Creek
Kits for whom no YDNA match has been found comprise about 13% of the project.
All other groups individually compose less than 10% of the project, and typically compose less than 3%.
Project kits belong to one of ten different haplogroups. Most (75%) are R1b1a (75%). Kits in R1a1 haplogroup are the next most common (9%), but are confined to a single Project Group, the Knoxville Merchants. No other haplogroup makes up more than 5% of the project.