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 Groups Index

All Jam?sons testing the Y-DNA chromosome, fall into just two basic general groups. These are the "I" (eye) or the "R" Haplogroups. Each test result produces, amongst other things, a series of STR[1] numbers, known collectively as that test's DYS[2] profile. Each test can then be compared to another test to determine where matching profiles indicate family groupings

Marker[3] variations within the above mentioned DYS, indicate where different family groups have formed over time, into distinctly different families. These different families within the general Haplogroups are not all that recent. Typically these variations are hundreds and sometimes thousands of years old.

Because of the nature of how the Y-DNA chromosome reveals it's secrets, determining exactly what indicates a different family grouping, traditional genealogical research methods are often required to help identify different families with the same or very similar DYS profiles.

Furthermore, because of the way Jam?son families historically came about, there are many different basically unrelated families. However, because of the anthropological nature of human migrations and Y-DNA (DYS) profiling, all Jam?sons still fall into basically two general groups ("I" and "R" Haplogroups). Because there are, even with the still relatively small number of Jam?sons tested, many different sets of family groups identified, we elect to show these different Haplogroup families separately.

Here are the links to the pages detailing the Y-DNA - DYS profiles:

I - Haplogroup

R - Haplogroup

A further explanation about different Jam?son families and the impact YDNA testing has, can be found here.


[1]      "STR" is an acronym for "Short Tandem Repeat" a scientific term used to identify a series of short term (hundreds of years) markers in Y-DNA testing and analysis

[2]       DYS is an acronym for "DNA - Y-Chromosome - Segment" - and refers to a collection of STR locations, usually along with the number of repetitive returns at that location.

[3]      "Marker" is actually the location on the chromosome and the 'number' within that marker is the number of times it is repeated.

[4]      "SNP" is an acronym for "Single Nucleotide Polymorphism" a scientific term used to identify a series of long term (thousands of years) markers in DNA testing and analysis, usually for the purpose of determining a Haplogroup.