Welcome to the COSSAR and CROSSER worldwide DNA project. This project is running in parallel with the established COSSAR and CROSSER surname research study. DNA is a new part of the study but we hope that each will throw light on the other. You can learn more about the genealogy research which underpins this study by visiting the one-name study web site: http://http://www.one-name.org/profiles/cossar.html All COSS_Rs and CROSS_Rs are encouraged to participate in this DNA Project. Men may take part directly. But because women do not have a Y-chromosome they need to find a male relative (father, grandfather, brother, uncle, cousin) to take the test for them. If you have a different surname but believe there is a Cossar or variant in your direct male line, you are also welcome to take part. Women can order an mtDNA test for themselves such as the mtDNA or the mtDNAPlus test to learn about the direct female line - that is, your mother, your mother's mother, your mother's mother's mother, and so on. Testing involves providing a mouth swab sample for analysis by Family Tree DNA. Sampling is painless and involves the use of a swab to collect a small number of cells from the inside of your cheek. Participants administer the test in private at home.