Y-DNA Terms and Acronyms

There are many phrases and terms that may not be familiar to the reader. Here’s a list of those for your benefit when reading.

  • SNP – Single Nucleotide Polymorphism – An alphanumeric also called a Haplogroup. A terminal SNP is the last SNP or Haplogroup in a Y-DNA tester’s Haplotree. For CFS members and FamilyTreeDNA (FTDNA) testers this Haplogroup is found in the FTDNA Clay Group Project matrix (Clay GP matrix). For example, to see the entire Haplotree displayed on a map of John Clay(e)’s ancestor’s migration path go to http:scaledinnovation.com/gg/snpTracker.html?snp=R-BY74161. The CFS currently has 4 testers with this Haplogroup (R-BY74161) in the Clay GP matrix (see a picture of the Clay GP matrix below).
  • TNG – The Next Generation refers to that company that hosts the Clay genealogy database. This Clay genealogy database is located on the web at https://www.clayfswebsite.com/ and contains Clay Branches. TNG Clay genealogy database is organized by geographic regions (i.e. Southern Clays, New England Clays, England Clays, etc.), known as Trees. Within each regional Tree are at least one, but potentially many Clay Branches.
  • Tree – A geographical location that contains Clay Branches.
  • Branch – A Clay line within a regional Tree that has a unique EKCA.
  • EKCA – Earliest Known Clay Ancestor – The earliest known Clay ancestor in a Branch.
  • FTDNA – FamilyTreeDNA refers to that company that hosts the CFS’s surname Clay Y-DNA Group Project database. Its website is at https://familytreedna.com/ where Y-DNA test results are displayed in a matrix and organized by subgroup titles based on Clay genealogy Trees/Branches and dates of MTCCA-G and MRCCA-Y.
  • Southern Clays Tree – TNG Tree containing Branches defined by EKCAs who were first recorded in the British colonies or early United States below NJ, PA and OH.
  • New England Clays Tree – TNG Tree containing Branches defined by EKCAs who were first recorded in the British colonies or early United States above WV, MD and DE
  • England Clays Tree – TNG Tree containing Branches defined by EKCAs who were first recorded in England or the UK
  • Germany Clay Trees – TNG Tree containing Branches defined by EKCAs who were first recorded in Germany
  • MRCCA-G – Most Recent Common Clay Ancestor by Genealogy – The most recent Clay ancestor shared by two or more people in the Clay Genealogy database – express by LocationName (birth year – death year).
  • MRCCA-Y – Most Recent Common Clay Ancestor by Y-DNA – A Y-DNA tester’s terminal SNP/Haplogroup. Where each Haplogroup is also expressed by probable birth year (BY) of the ancestor (the mean of a statistical distribution) and the range of possible BYs (the distribution – having a 95% probability of being within). This BY and range can be very distant in history and not very meaningful for Y-DNA testing levels less than Big-Y. And as more people get tested, more current Haplogroups are created and the date and range move closer and closer to the 20th century. To see an example of John Clay(e)’s terminal Haplogroup (R-BY74161), his Haplotree and the associated BDs and ranges for each Haplogroup in his Haplotree go to http://scaledinnovation.com/gg/snpTracker.html?snp=R-BY74161. When the MRCCA-G BY closely matches the MRCCA-Y By (terminal Haplogroup BY) it identifies an actual Clay ancestor by name for that terminal Haplogroup. Such is the case with John Clay(e) and our four Y-DNA tester’s with Haplogroup R-BY74161.