Interpreting results can be and is often fraught with pitfalls. The dangers in assuming facts not in evidence or are not corroborated with some sort of substantive proof or commonly accepted source often leads to disaster in trying to sort out what the results mean. The major sources of these concerns are:

1.            DNA Testing and Analysis

·        A low number of participants for the particular surname -- thus making any sense of the data by seeing patterns is pointless

·        A low number of DNA markers tested -- in European populations, there is too much commonality in the first twelve markers to be effectively used in individual family research

·        Errors in the testing process caused by laboratory personnel, processes or equipment (it can happen but on a very low frequency)

·        Comparing of results between laboratories who have dissimilar and/or non-standard equipment, processes, scoring methods, or primers (chemicals used to process the DNA sample)

·        Not correctly interpreting and comparing results (inadequate or lack of knowledge of what differences between values on particular markers mean)

2.            Genealogical Analysis

·        Actual facts differing from the traditional, historical, or official accounts due to inaccuracies in the account or recollection of the person who relates it

·        Actual facts differing from the traditional, historical, or official accounts due to downright falsehood or fabrication

·        Confusion between families bearing the same or similar surname when building a family tree

3.            Social and Environmental Intervention or Influences

·        A non-linear event interrupting the supposed genealogical lineage to the 'documented' common ancestor. This could be caused by extra-marital affairs, prime nocte (the medieval right of a manorial lord to bed a newly-married bride on the 'first night' of her marriage), surrogate partners, rape, or other event which caused the father not the be the one stated in the record

·        Fosterage - either traditional fosterage whereby the son of one man is sent to live with another to learn a craft or trade and the birth father dies and the son takes on the surname of the foster-father; or where an adoption (official or not) takes place and the adopted child takes on the surname of the adoptive parents

·        Legal name change - where done, the common reason was to inherit from a person who is not of the original lineage or surname

·        Patriarchal Interruption - where a child is born out of wedlock and the mother's family name is used as the child's surname

·        Very, very rare and not yet proven but must be said here - major divergence due to sudden mutation in a short number of generations possibily caused by diet or environmental changes. This usually happens and often does happen in recombinant DNA (the same DNA that gives us eye color, skin color, etc.) and not in the DNA used for these tests.

     That being said, DNA analysis without having the documentation prior to the testing is not the accepted method. But if you have exhausted your resources, DNA comparison to a large group of people tested can yield clues if one knows how to interpret the matches and the mis-matches in order to rule out people as being close kin.

     One must approach using DNA analysis with genealogy with open honesty and readiness to accept the facts on their face as well as to interpret the results the way they align. Trying to get the DNA to prove a tree may lead to disappointment.

     To explain how to interpret results is very difficult to communicate in a paragraph. But to help make sense of the information for the casual genealogist, I will try to explain the process here.

     Everyone whose results were used in the study (in order to maintain some privacy and to remove bias) was given a kit number when testing and therefore this number was used in place of their name. The people with satisfactory documentation were designated as reference individuals. These people have a 'known' lineage connection to a particular ancestor within the traditional/historical genealogies. From these we compared the results of the samples (either submitted or gleaned out of the two databases offered by FamilyTreeDNA and DNA Heritage). From there we caluclated the Ancestral Result (the estimated result of the most recent common ancestor before any muations). As we had expected, most people (within the two 'clans' that originated the known McManus families) were closely related in some fashion.

     But to break it down further, we identified how individuals differed. On the table of results there are four major groups of markers.

     The first twelve (DYS 393 through DYS 389-II) are considered haplogroup markers. These markers are some of the slowest to mutate as generations are born and you get further away from the common ancestor. This means that any mutation (difference in the numbers) should be seriously looked at and a judgement call made as to whether this means there is no relation, or by chance a chromosome mutated (a little) at some point. So this figured into the decision process.

     The next thirteen markers (DYS 458 through DYS 464d) are the first set of haplotype markers. This is not to be confused with haplogroup - which is related to a larger population than just a family.

     These first two groups form the basis of caculating the 'Ancestral Result'.

     The two groups of twelve after this are additional haplotype markers. The haplotype markers (last thirty-seven on the chart) were helpful in determining sub-groups within the families.

     A pedigree chart was established (and is continuing to be modified based on the need for more - or less - information) to serve as a guide for determining groups and placement of results.

     Here are a summary of the results and some of the details about the sample donors.

Clann Manus Seanadh (McManus)

     The difference in markers show that the most recent common ancestor lived sometime in the late 1500's early 1600's. This could be the person of Ruaidri Maguire who died in 1608 and was the last land holder of Ballymacmanus (Bellisle) in 1607. A more thorough search in the records might yield information that would better explain this relationship in more detail.

Maguires by surname

• FTDna: 143742,N30642, 65848, 21228