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