PURPOSE The purpose of the Cotton DNA Project is to build a growing database of Y-DNA results from men bearing the Cotton, Cotten, or related surnames (including rarer variants). This data can help identify distinct family lines and determine which branches are connected through a shared male ancestor. As more test results are added, the project aims to differentiate between branches within each family, identify deep ancestral origins, and help researchers make sense of “brick walls” in their paper genealogy. While not a substitute for traditional records, genetic testing can suggest new directions for research, help confirm documented lineages, and disprove mistaken connections. Combined with solid genealogical evidence, Y-DNA testing can be a powerful tool for understanding our shared ancestry. METHOD Y-DNA testing focuses on the Y chromosome, which is passed down from father to son with very little change. Because surnames also traditionally follow the male line, Y-DNA testing is especially useful for surname studies. Over generations, small mutations occur in the Y chromosome, creating unique genetic signatures that can be used to track male-line ancestry. The most common tests today analyze Short Tandem Repeats (STRs) and Single Nucleotide Polymorphisms (SNPs). STR testing provides results useful for matching other men within a genealogical time frame, while SNP testing can place testers on the Y-DNA haplotree and identify deep ancestral branches thousands of years old. Together, STRs and SNPs help clarify both recent and ancient male-line connections. PARTICIPATION We invite any man with the Cotton or Cotten surname, or a close variation (such as Coton, Cottin, Cottone, Cotham, Cottam, etc.), to join the project. Men who suspect they descend from a Cotton/Cotten male in the direct paternal line, even if their surname differs, are also welcome. While women cannot take Y-DNA tests themselves, they can participate by recruiting or sponsoring a male relative from their Cotton/Cotten line — such as a brother, father, uncle, or cousin. As of 2025, over 230 men have tested or are currently testing in the project, with almost 150 of them here at FTDNA. Joining is simple: FamilyTreeDNA sends a cheek swab kit with instructions, and the sample is returned in a pre-addressed envelope. If you’re interested in joining or have questions, please contact the project administrator. We especially encourage new members to consider at least the Y-37 test, with Y-111 or Big Y-700 providing even more detailed information for advanced analysis and placement on the Y-DNA haplotree.