Y-DNA: notes on cases with Y-DNA with John Cleary

In his DNA Discoveries presentation on 21 March 2024, John Cleary looked at the way in which Y-DNA may be used for genealogical purposes, explaining the markers and differences, STRs, SNPs, back mutation, mutation trees and many more terms and tactics for using Y-DNA for family history.

Please find the recording below, and the useful links too. 


Useful organisations, companies, definitions provided by John Cleary in his presentation

https://www.familytreedna.com/products/y-dna - the major site offering Y-DNA tests for genealogy

https://help.familytreedna.com/hc/en-us/articles/4402047942799-Add-ons-Upgrades - this is the link if you wish to upgrade your Y DNA test with FamilyTreeDNA to view further markers

https://www.yseq.net - DNA origins project, niche testing site

https://www.yfull.com - Y-chr Sequence Interpretation Service, an analysis company (does not sell tests)

https://freepages.rootsweb.com/~geneticgenealogy/genealogy/yfreq.htm - Leo Little's Reference Resource. John reminded that his had not been updated for a while but was extremely useful for seeing the rarity of an STR

https://www.johngrenham.com - John Grenham's website for Irish research, useful for surname distribution

Three useful terms:

  • WGS Whole Genome Sequencing - John explained that WGS companies are niche so far, but are having the biggest impact in Y-DNA research
  • STR - Short Tandem Repeat - repeating chunks of DNA, the number of these repeats can change over time
  • SNP - Single Nucleotide Polymorphism - a single letter change. FamilyTreeDNA looks at millions of SNPs

https://isogg.org/wiki/Single-nucleotide_polymorphism/en - to learn more about SNPs

http://www.mymcgee.com/tools/yutility111.html - the McGee Ferguson Utility

https://www.jdvsite.com - SAPP tool (Still Another Phylogeny Program)

https://isogg.org/wiki/Surname_DNA_projects - to learn more about surname projects

https://www.familytreedna.com/group-project - to explore FamilyTreeDNA surname projects

https://help.familytreedna.com/hc/en-us/articles/6463909777295-Time-Tree-Guide - to read the guide to Time Tree by FamilyTreeDNA

(With thanks to Michelle Leonard for sorting the links)

To download a pdf document with the useful links, please see click here.