In recent years, the new science of Genetic Genealogy has been developed which applies DNA analysis to Genealogy. This measures the changes between parts of the Y-chromosome and how it affects people's descendants. The Y-chromosome is unique to the male line, as are surnames and its DNA type is denoted yDNA. The female line is also studied, but from a different area of the cell called the mitochondria but is not as useful for Genetic Genealogy since there are fewer changes to track and its DNA type id denoted mtDNA. The full set of DNA, called the genome is also available and is called aDNA where the 'a' is for autosomal, i.e. not sex specific DNA. All are useful, but aDNA is most often used to find related people from the last 200 years.

There are two kinds of analysis for yDNA and mtDNA called STR and SNP.

STR was the first developed and the less accurate. The changes occur very often which leads to a lot of uncertainty. It is often used to locate distant relatives within a couple of hundred years.

SNP was developed later and is much more definite. The changes occur seldom and are very rarely repeated. This is not useful for finding cousins (as of now) but is very useful in tracking the movements of peoples and tribes going back hundreds or thousands of years.

When STR and SNP testing is combined with statistical models, the result is better than either part. We will use the SAPP process by David Vance later with very good results.

STR analysis uses PCR testing, which is older, cheaper, and faster. This is often used by the police. SNP used Next Generation Sequencing, which is newer, more expensive, and slower. The result of SNP testing is a symbol denoting the lab who first discovered the SNP and a unique number.

The Easton Hoys are FGC37623 which was discovered in 2015 by the Full Genome Corporation. FGC37623 was discovered in the sample provided by one of the Easton Hoy men as were all SNPs in the sequence FGC37608 through FGC37624. Only in the past few years have other tests matched any of the Hoy SNPs.

• FGC37624 - 2 men
• FGC37613 - 4 men
• FGC37618 - 8 men

The full SNP tree for the Easton Hoys is this:

M269>L23>L51>L11>P312>S461>L21>DF13>DF49>DF23>M222>FGC4077>A725>S676>S679>FGC37618>FGC37613>FGC37623

M269 is the most common haplogroup in western Europe and Family Tree DNA states that the most likely founder estimate is 12,000 BC. The man who is the most recent common ancestor of this line is estimated to have been born around 4350 BCE.

STR testing gives a long set of letters and numbers recording a value on a specific area of DNA. Originally it was twelve numbers, but modern tests can be up to 111 (or more). These results are called Haplotypes and are grouped into Haplogroups of samples which form a tree from a sequence of letters and numbers. These two concepts are united, and an SNP can be assigned to a haplogroup to place it on the tree as seen below.

The full tree for A725 is here:

    SNP      Haplogroup               - Notes
    M173     R1
    M343     R1b
    L754     R1b1                     - Southeastern European - found in Serbia
    L388     R1b1a                    - Villabruna - found in northern Italy
    P297     R1b1a1                   - 13k years before present
    M269     R1b1a1b                  - R-M269 is most common in western Europe.
    L23      R1b1a1b1
    L51      R1b1a1b1a                - Arrived in West Europe from steppe and its main expansion was from the Rhine delta.
    P310     R1b1a1b1a1
    L151     R1b1a1b1a1a              - Corded Ware Culture. Early Corded Ware and Don Yamnaya are basically identical.
    P312     R1b1a1b1a1a2             - Match Single Grave Culture from around the Lower Rhine.
    S461     R1b1a1b1a1a2c            
    L21      R1b1a1b1a1a2c1           - Insular Celtic (Bell-Beaker)
    DF13     R1b1a1b1a1a2c1a          - Rathlin Island (2400BC)
    Z39589   R1b1a1b1a1a2c1a1
    DF49     R1b1a1b1a1a2c1a1a
    S6154    R1b1a1b1a1a2c1a1a1
    S476     R1b1a1b1a1a2c1a1a1a
    DF23     R1b1a1b1a1a2c1a1a1a1
    Z2961    R1b1a1b1a1a2c1a1a1a1a
    M222     R1b1a1b1a1a2c1a1a1a1a1   - The Féini and Ulaidh and Gáilióin, i.e., the Laighin.
    FGC4077  R1b1a1b1a1a2c1a1a1a1a1b
    A725     R1b1a1b1a1a2c1a1a1a1a1b1 - Sloinne Ó hEochaidh                    
                

• The list of labs that named the SNPs

The breakthrough for Irish Genetic Genealogy was a paper by Brian McEvoy of Trinity College, Dublin published in 2006. In it he discovered an STR signature that was very prominent from the northwest section of Ireland over to the southwest of Scotland. There were about 65 Irish surnames studied in the paper, and the Haugheys and Dunleavys were included. Haughey is the spelling of Hoy found primarily in Donegal where some Ó hEochaidh migrated to after 1200 under the protection of the Cenél Chonaill. The MacDunveavy were a father and five brothers who were the last kings of Uladh (Ulster) from around 1150 to 1200 when the Normans conquered and dispersed them. The MacDunveavy are recorded as being hereditary physicians to the Cenél Chonaill and were a part of the Hoy family, so they are of interest to us. Both the Haugheys and Dunleavys are almost entirely found in the far southwest of Donegal on the Glencolmcille peninsula. The Cenél Chonaill were based near the present location of Donegal town which is at the other end of the peninsula. See the maps below.

Later Dr. David Wilson discovered the SNP associated with McEvoy's STR signature which was called M222. Two Easton Hoys have been tested and we are M222. Dr. David Wilson and Iain Kennedy of Scotland lead work which lead to the discovery that we are 7 levels below M222 and are FGC30623 which was discovered in our sample.

• Maps of the M222 kits from FTDNA are here.

In 2014 Jim Wilson released data for SNPs below M222 for the first time. Before that there was a huge group of kits lumped together with a strong Donegal tilt which led to the "Niall of the Nine Hostages" idea. Jim's data was a huge breakthrough, but only for the majority Donegal group. Even now, the tree under S659 (DF105) is huge as this is the main Donegal branch. There was still a large group left to be assigned to a new SNP. It is here that Iain and David did their work. They organized the unassigned people and with the help of Thomas and Astrid Krahn of Y-SEQ they found that the SNP of this group was in fact FGC4077 which then led to branches off that including A725 and S676 and S679 below that. Y-SEQ identified A725 and Jim Wilson S676 and S679 (the S is for Scotland, his home).

• The story of the discovery of the A725 Tree

Eventually other branches were found on the FGC4077 tree, and the SAPP process has identified twelve of which A725 is the largest. A725 itself has many sub-trees of which there are 15 at present.

People from the McHarge Project have been present since the time of Iain and David's work and 26 of them are in A725, making them the largest surname group that we have until we found the Burns Project which is now the largest surname project.

Donegal is entirely dominated by non-A725 sub-trees of M222 with only five A725 in the county and those in the same small area of SW Donegal outlined in the 1st row, 3rd column picture below. The SAPP process has identified a branch of A725 which contains these five men as well as five others. A branch of the Sloinne Ó hEochaidh moved to Donegal after 1200 AD.

• Byrne, Francis John (2001), Irish Kings and High-Kings, Dublin: Four Courts Press, ISBN 978-1-85182-196-9
• Brian Patrick McEvoy, First published 2005, Genetic investigation of Irish ancestry and surname history
• James McNish, First published 22 February 2018, "The Beaker people: a new population for ancient Britain", The beaker-people a new population for ancient Britain
• Lara M. Cassidy et al, First published December 28, 2015, "Neolithic and Bronze Age migration to Ireland and establishment of the insular Atlantic genome", Cassidy et al
• Davidski - Eurogenes Blog, Wednesday, January 16, 2019, "Single Grave > Bell Beakers", Single Grave Bell-beakers