This DNA project applies to the English surname Kirtley and its many variants, including Curtley and Kirkley. Since surnames in western cultures are typically handed down from father to son, the focus of this project is on y-chromosome DNA (y-DNA), which is handed down generations the same way. People interested in determining their genetic relationships to others with their same surname are encouraged to join this project by ordering a y-DNA test of at least 37 markers (to be genealogically useful). Your results will grouped with others in the project based on your genetic matches: http://arslanmb.org/yDNA/Bradshaw-DNA-yDNAResults.htm. Those in the same grouping (cluster) likely share a common direct paternal ancestor in historical timeframes.