Chromosomes, Markers & Evolutionary Trees

Let's recap on some of the basic science behind Y-DNA as this will help you understand what you are seeing when you look at your results, and how your results can be applied in practice.

Chromosomes - a closer look

We have 46 chromosomes, arranged in 23 pairs. Each pair has 2 copies, one of which you got from your mother, the other from your father. So for example, you have one paternal chromosome 14 and one maternal chromosome 14. Before you were conceived, your father made a copy of each of his 46 chromosomes but only passed on one copy from each pair to you. Similarly your mother made copies of all her 46 chromosomes but only passed on to you one copy from each pair. In this way the 23 chromosomes you got from your father combined with the 23 from your mother to bring your chromosome quotient back up to the usual 46.

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The 23rd pair is also known as the sex chromosomes. There are two types of sex chromosome - an X and a Y. At conception, if two X chromosomes combine, a female child is produced (XX). If an X and a Y chromosome combine, a male child is produced (XY). Women (XX) only have an X chromosome to pass on to their offspring, whereas men (XY) can pass on either an X or a Y to their offspring. Therefore the man's contribution decides the gender of the child. Women do not have a Y chromosome and so cannot do this particular DNA test.

Thus the Y chromosome is only passed on from Father to Son.  This is why it is perfect for tracing the father's father's father's line and is the main type of DNA used for surname studies. Be aware though that it only assesses this single ancestral line, and if you go back 10 generations, this represents only 1 of your 1024 ancestors (which is equivalent to about 0.1% of your ancestors at that particular level).

Each of our 46 chromosomes consists of a long double-stranded helix of DNA. If we unwrapped it, it would look like a long ladder extending into infinity, or a railway track running from New York to Los Angeles. It's huge. If you untwisted all 46 chromosomes from a single cell, it would stretch for 2-3 metres (6-10 feet). All the untwisted DNA from the human body would stretch to the moon and back several times.

All along the "ladder" are the nucleotide bases, like rungs in the ladder, binding each strand of the helix to the other strand of the helix. The bases are called A, T, C, and G, after the first letters in their respective names - Adenine, Thymine, Cytosine, & Guanine. A only ever binds with T, C only ever binds with G. You can remember this by thinking the straight-sided letters only bind to each other, and the curved letters bind only to each other. Each base pair effectively forms a rung in the ladder.

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Because A only ever binds with T, and C only ever binds with G, if we know the sequence of bases on one strand of the helix, we automatically can tell what bases are on the other strand. Therefore, the sequence of bases along the DNA is only ever written as a single line of letters (e.g. ATCCGAATTGG). The sequence is read from what is called the 5' (5 prime) end of the DNA molecule (and is read toward the 3' end, like reading from left to right).

In each pair of chromosomes, the two copies (maternal and paternal) are virtually identical to each other in terms of size, length, morphology, etc. The exception is the sex chromosome pair, X and Y ... the X chromosome is 3 times bigger than the Y chromosome.

Although each chromosome in a pair is virtually identical, there are subtle differences between the nucleotide bases that run along the entire length. These variations in the bases are called mutations and can be identified because they occur at specific locations along the chromosome. These locations where mutations occur are referred to as DNA "markers". Each marker can be identified because it occurs at a specific position along the chromosome and thus can be given a particular name (e.g. DYS390 or Z255). People who share the same mutation may have inherited it from a shared Common Ancestor, and this is why DNA can be so helpful for genealogy.

A note on terminology: Y-DNA refers to the Y chromosome. Autosomal DNA refers to all the chromosomes EXCEPT the last pair (Pair 23, the sex chromosomes, X and Y - all the other chromosomes are called autosomes, hence autosomal DNA). Mitochondrial DNA refers to the DNA found in mitochondria (the "batteries" that power each cell). For a more detailed introduction to the three types of DNA test and how they are applied in genealogy, watch this YouTube video here.

The different types of DNA marker

There are two types of DNA marker - STR markers and SNP markers.

STR stands for Short Tandem Repeat and the key word here is "repeat". An STR marker is a sequence of bases repeated many times (e.g. CATCATCATCAT). In this example, the sequence is CAT and the repeat value of the sequence is 4. When the DNA is being copied before being passed on to any offspring, there are occasional mistakes made in the copying process. So for example, a copying mistake in the CAT sequence above might result in 3 repeats instead of 4, and so the value of that marker may shift from 4 in the parent to 3 in the offspring. This may be the first mistake to be made in this particular marker for many generations, and so not only will the male child differ from his father, grandfather, and great grandfather, but also from all his male siblings and cousins, who will all have a value of 4 for this particular marker.

The second type of DNA marker is the SNP marker, which stands for Single Nucleotide Polymorphism. The key word here is "substitution" - a single base at a specific location changes from what it normally is to a different base (e.g. an A changes to a C or a T or a G). Whereas the STR markers involve several bases in a row, the SNP marker only involves the substitution of a single base.

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Kelly Wheaton has written some excellent blog posts about DNA markers on the Y chromosome. You can read them by clicking here - STR markers & SNP markers.

There are some very important characteristics of STR and SNP markers which are key to understanding how they are applied in surname studies:

• Mutations in STR markers are written as the value of the marker (e.g. 12) whereas mutations in SNP markers are given names (e.g. Z255) or are written as the location on the chromosome followed by the change that occurred in the bases there. For example, 17349992 (G>A) indicates that a G has been replaced by an A at position 17349992.
• The mutation rate of STR markers varies from marker to marker. Some mutate relatively quickly (e.g. 1 mutation every 5 generations) whilst others mutate very slowly (e.g. 1 mutation every 500 generations). Mutations in slow-mutating markers are very good for studying human migration, whereas mutations in fast-mutating markers can be very useful for genealogy research (in the last 500 years or so).
• A big problem with STR markers is that they can mutate back as well as forward. So for example an STR marker may have a value of 4 which changes to a 3 and then back to a 4. The first mutation (4 to 3) may have occurred 1000 years ago, and the second one (3 back to 4) may have occurred 300 years ago. The trouble is that the Back Mutation masks the fact that there was a significant mutation 1000 years ago and this may result in people with the 4 value being assigned to the wrong branch of the human evolutionary tree and hence the wrong family tree!
• Another problem with STR markers is the Parallel Mutation. This happens when two very separate branches of the same family experience the same mutation "in parallel", giving the impression that the two branches are more closely related than they actually are in reality.
• A further problem with STR markers is that it is very difficult to identify a Back Mutation, or a Parallel Mutation. And as a result we don't know how often they occur. We suspect that it happens fairly frequently, perhaps as often as a marker value mutates forward it also mutates back. We really don't know. But such "hidden" back mutations may seriously confound our interpretation of the data and may result in people being placed on the wrong branches of the human evolutionary tree.
• Convergence is the name given to the situation when Back Mutations and Parallel Mutations on STR markers result in people appearing to be more closely related to each other than they actually are. This is a big problem when comparing people at 12 markers, but less of a problem when comparing at higher numbers of markers (e.g. 37, 67, or 111). However, even at 67 markers significant Convergence has been detected.
• On the other hand, SNP markers mutate much more slowly. And because there are so many of them, Back Mutations and Parallel Mutations are extremely rare (and easily spotted). For this reason, when using DNA markers to place people on the human evolutionary tree, SNP markers trump STR markers i.e. more reliance is given to SNP markers than to STR markers.

Y-DNA, Population Migration, & the Human Evolutionary Tree

Because the Y chromosome is passed on virtually unchanged from father to son, and because mutations in the DNA markers along the Y chromosome happen relatively infrequently, it is also an extremely useful tool for studying the last great human migration out of the African Motherland (about 50,000 years ago) that ultimately led to the populating of the entire planet. There is an excellent interactive animation of human migration here, including the various ice ages and the catastrophic eruption of the Mount Toba volcano that almost destroyed Mankind.

Population geneticists have been studying the evolution of mutations on the human Y chromosome (and on mitochondrial DNA) for many years and have developed an evolutionary tree based on these mutations (called the Haplotree).  They refer to each of the major branches of the tree as Haplogroups and have named them after the letters of the alphabet (e.g. Haplogroup R, or its subgroup Haplogroup R1b). You can think of a Haplogroup as a group of people with a broadly similar genetic signature.

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As modern humans moved around Africa and then moved out of Africa and spread to different places around the world, the humans who moved to Europe developed a totally different set of mutations to those humans who moved to India or Australia (for example). Thus certain haplogroups are found more commonly in Europe (e.g. R1b, I2b) than in India (e.g. H, L) or Australia (e.g. C, T).

Furthermore, genetic genealogy is a very young science, and more markers are being discovered all the time (thanks to novel tests like the Big Y test from FTDNA). As a result, scientists are still discovering finer and finer sub-branches of the human evolutionary tree, and we are approaching the point where we will discover the finer branching patterns associated with individual surnames (such as those in the Gleason/Gleeson DNA Project).

The old nomenclature for the various branches of the tree used a long string of letters (e.g. R1b1a2a1a2c1e) but this has been superseded by a system that simply puts the main Haplogroup letter followed by the "terminal SNP" (e.g. R-Z255). You can still see both terminologies in use on the ISOGG tree.

The terminal SNP refers to the SNP marker that currently occurs at the end of a branch. The word "currently" is important because as new SNP markers are discovered the current terminal SNP marker is likely to be replaced with a new one, and we will continue to move further and further down the finer branches of the tree until we identify SNP markers that are specific for your own family branch and even single individuals.

This will eventually allow us to reconstruct family trees based on DNA marker mutations. These are sometimes called phylogenetic trees, sometimes cladograms or phylograms, but my favourite is Mutation History Trees because it sounds similar to Family History Trees. The difference between the two is that Family History Trees are constructed using named individuals, whereas Mutation History Trees use DNA markers. It should be possible to superimpose one upon the other and in this way we can look 'beyond the Brick Wall" of individual pedigrees and see where different family branches are likely to connect. This in turn will help focus further documentary research.

There are various groups working on the human evolutionary tree and they have produced their own version of the haplotree:

• The YCC Haplotree is produced by the Y-Chromosome Consortium. This is an academic effort and it is frequently out of date, being surpassed by the ISOGG tree which is updated much more frequently and harnesses the continuous output of genetic genealogists working on Haplogroup Projects (such as the R-Z255 & Subclades Project to which all members of Lineage II in the Gleason/Gleeson DNA Project belong). The most recent update of the YCC tree is from March 2015 but the tree itself is not user-friendly.
• The ISOGG tree is the result of the efforts of ISOGG (the International Society of Genetic Genealogy) who co-ordinates the analysis and interpretation of the findings from various Haplogroup Projects and as a result has developed a much larger tree than the YCC Tree. It too is quickly out-dated as the pace of new SNP marker discovery advances and further sub-branches are discovered. Lineage II members can click here and search (Cmd+F or Ctrl+F) for Z255 to see where this particular sub-branch sits on the main Haplogroup R branch.
• Several of the commercial companies have developed their own haplotrees which at times may be more advanced than the ISOGG tree, and at times less advanced:
• FTDNA tree - this can be accessed from the Haplotree & SNPs page of your personal FTDNA webpage
• YFULL Experimental Tree - YFULL is a company that offers SNP testing and will interpret the results of SNP testing carried out by other companies. This tree is relatively easy to navigate but again requires use of the Find function (Cmd+F or Ctrl+F).
• FGC tree - like YFULL, FGC (Full Genomes Corporation) also offer SNP testing and interpretation. The visual presentation of the tree is not easy to navigate.
• Haplogroup Project Administrators work at the coal face of scientific discovery in relation to the finer branches of their own particular haplogroup project. The R-Z255 & Subclades Haplogroup Project updates its draft tree periodically as new member results come in to the project. You have to sign up to the project to access these updates but here is the most recent update as of July 15th (for members only). It is important to appreciate the pivotal role that Haplogroup Project Administrators are playing in the ongoing discovery of the finer branches of the tree. Surname Project Admins will work closely with Haplogroup Project Admins to advise their project members regarding which tests to take next and why.
• Alex Williamson's "Big Tree" is a tree that specifically focuses on the Haplogroup R-P312 branch of the human evolutionary tree (of which Z255 is a subgroup). Alex has done incredible work placing newly discovered SNP markers in their best estimated position on the tree, and most importantly for us, creating a visual representation that is easy to navigate and makes the current state of the tree so much more understandable. The members of Lineage II feature here too, in the Z255 subsection. There are two interesting features to Alex's tree:
• if you click on the name of any individual, an analysis of their unique genetic signature comes up. Here is the analysis for member N74958 showing his position on the tree, his unique mutations, and his putative haplotype progression (i.e. the estimated progression of his mutations from previous ancestors).
• the Overlay STR Feature allows you to compare the results for all STR markers (one by one) across the whole group. Here it is for DYS439.
• Nigel McCarthy runs the McCarthy DNA Project and has pioneered the development of phylogenetic trees based on a combination of SNP and STR markers. Luckily for us in Lineage II, one particular area of his research is also focussed on the Z255 subclade to which we belong (Group E in his project). We'll be talking a lot about Nigel's work in due course as it is particularly relevant to the next steps in the DNA Project for Lineage II members.

The portion of Alex Williamson's "Big Tree" that deals specifically with members of Lineage II

You may have to read this several times before a lot of the information sinks in but stick with it - it's worth it! Knowing the basics behind the science of Y-DNA and how it can be applied will help you understand a lot of the discussion about SNP testing and Big Y results that will follow in subsequent posts.

Maurice Gleeson

30 July 2015

The Gleeson name in Surname Dictionaries

If you want to get some idea about the possible origin of a particular surname, a Surname Dictionary is a good place to start. There are several surname dictionaries that address the topic of Irish surnames, and perhaps the most well-respected are those of Woulfe and MacLysaght. But do they give us any clues as to the origins of the Irish version of the surname Gleason / Gleeson? Read on ... all will be revealed.

The Rev. Patrick Woulfe (1872-1933), or as he preferred to be known, An tAthair Pádraig de Bhulbh, was born in Cratloe to Seamus Woulfe, a farmer. He became a priest, worked in Limerick, and spent 25 years collecting names, communicating with native Irish speakers and studying the different forms of Gaelic to compile the Irish Names and Surnames dictionary. There are two versions of his book – a small version (138 pages) and a larger version (742 pages). The smaller version was originally published in 1906 and reprinted in 1922 – this is available online in its as original print form from Archive.org here. The larger version was printed in 1923 (reprinted in 1967) and consists of 696 pages, with 46 pages of preliminary text. A digital version of the book is available free of charge online from Library Ireland here. The search feature is very useful and allows you to find any mention of a particular name within the book. Woulfe’s work helped to popularise the use of Irish first-names during the last century and has been an important resource for genealogists. His work was subsequently superseded by that of other scholars, such as Edward MacLysaght.

Woulfe, Patrick. Sloinnte Gaedheal is Gall: Irish Names and Surnames, collected and edited with explanatory and historical notes (1923).

Edward MacLysaght was an interesting character. He lived to be 99 years old (1887-1986) and packed a lot into his lifetime. His father was from Cork, his mother from Lincolnshire, and he was born near Bristol. He went to school in Rugby and then Corpus Christi College, Oxford to study law. But a rugby injury changed his life - he went to Lahinch in Co. Clare and lived in a caravan for 6 months recovering. During this time he developed a love for genealogy, history, and the Irish language, in which he became fluent. He started a pioneer farm in Raheen and introduced electricity 40 years before his neighbours. He also set up local community projects and was deeply involved in the Irish Cultural Revival and the movement for Irish independence. His loyal support of Eamonn de Valera (then member of parliament, and later President of Ireland) resulted in his imprisonment. After independence (1922), he was elected to the Seanad Éireann (the Irish Senate). He later became an Inspector for the Irish Manuscripts Commission (1938), a member of the Royal Irish Academy (1942), Chief Herald of Ireland (1943-1954), Keeper of Manuscripts at the National Library of Ireland (1948-1954), and Chairman of the Irish Manuscripts Commission (1956-1973). It was during this latter period that he wrote his indispensible books on Irish surnames.

MacLysaght, Edward. The Surnames of Ireland. 1957 (sixth edition 1991)

This is a comprehensive list of over 4000 Irish surnames with a short description of each. It includes 1500 surnames not considered in the other books below, which only deal with about 20% of the surnames described in this present book (albeit in a lot more detail). 

MacLysaght, Edward. Irish Families. Their Names, Arms and Origins. 1957 (fourth edition 1985) 

MacLysaght, Edward. More Irish Families. 1970 (first paperback edition 1996, incorporating Supplement to Irish Families, 1964)

These latter two volumes (frequently abbreviated to IF and MIF) give a much more detailed account of many of the most common Irish surnames. Second hand copies can be bought online, usually for quite inflated prices.

Woulfe’s Surname Dictionary

Woulfe’s entry for Gleason / Gleeson as a surname can be found here: 

Ó GLASÁIN—I—O Glassane, O Glessaine, O Gleasan, Glessane, Glissane, Glissawn, Gleason, Gleeson; 'descendant of Glasán' (diminutive of glas, grey); a common surname in all the south of Ireland, especially in Cork, Limerick, Tipperary and Kilkenny; now generally pronounced Ó Gliasáin.

This does not provide us with a huge amount of information relating to the origins of the "clan" but MacLysaght has a lot more information.

MacLysaght’s Surname Dictionary

MacLysaght gives a brief account of the Gleeson surname in his Surnames of Ireland and a much more detailed account in his Irish Families. 

(O) Gleeson Ó Glasáin or O Gliasáin. The anglicized form of this name in Kerry is Glissane. The main sept was located in lower Ormond.

IF Map Tipperary.

(from Surnames of Ireland, p128)

The abbreviation IF refers to his book Irish Families, and Map Tipperary refers the reader to the map in that book on page 222 where the Gleeson name is located just below Lough Derg. The entry in Irish Families is much more informative: 

O'GLISSANE, GLEESON. In spite of its English appearance in it's anglicized form the name Gleeson, never found with the prefix O in English, is that of a genuine Gaelic Irish family. In modern Irish it is O Gliasáin, earlier Ó Glasáin and originally Ó Glesáin. They belong to the Aradh* and their original habitat was Mac Ui Bhriain Aradh's country, that is the country in Co. Tipperary between Nenagh and Lough Derg; but it should be emphasized that the Gleason's are not Dalcassians**; they are of the same stock as the O'Donegans, of the barony of Ara, Co. Tipperary, who were originally of Muskerry, Co. Cork. In the census of 1659 the name is very numerous in north Munster (Counties Tipperary, Clare and Limerick] being then given many spellings, e.g. Glisane, Glison, Glyssane, O'Gleasane, O'Glassane etc. They are still fairly numerous in their home county but are not found much outside Munster. Prior to 1641 the O'Glissanes were very extensive landowners in Co. Tipperary but as such they disappear in the Cromwellian settlement.

Persons of the name have not been prominent in Irish history or literature, but four Irish Gleesons are well known in America, viz. Father William Gleeson, called the "founder of the Church in California"; Edward Blakeney Gleeson, the Rochester millionaire; Frederick Grant Gleeson [1848–1903], the composer; and Mgr.^ Joseph M. Gleason [1869–1942], educator and historian.

(from Irish Families p95)

It's interesting that MacLysaght felt that the Gleesons were not prominent in Irish history - there are lots of examples. In fact, that could be the subject of a subsequent blog post. Submit your candidates now!

Other sources

A third surname resource, that is freely available online, is that of John O'Hart and entitled Irish pedigrees; or, The origin and stem of the Irish nation. However, O'Hart's research is not generally considered to be as good as that of Woulfe and MacLysaght. It was published originally in 1876 and is available in two volumes - click here for Volume 1 and Volume 2. The introduction to both volumes makes for interesting reading. There is a brief entry for Gleeson:

13. O'Breoghan (this name "Breoghan" is considered the root of Brown), O'Glaisin (Glashan, or Gleeson), O'Mictyre and O'Keely were chiefs of Hy-MacCaille, now the barony of "Imokilly," in the county Cork.

Next Steps

So MacLysaght asserts that the Gleeson sept is related to the O'Donegan's and originated in Muskerry, Co. Cork and later became prominent in Aradh, Co. Tipperary, whereas O'Hart asserts that they were chiefs in Imokilly, Co. Cork. Despite all the above, there are some people who disagree with the conclusions of these erudite scholars and would dispute some of the assertions made within the works. This is where DNA comes to the rescue.

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Each of the areas indicated in the above map are associated with a preponderance of certain surnames. These are nicely illustrated in the maps included in MacLysaght's Irish Families (p222) . Surnames associated with the Aradh area include: O Kennedy, O Hogan, O Brien, O Reidy, O Donegan, O Lynch, O Meaghar, O Meara, O Mackey, and O Danagher.

Other online surname distribution map sources include the following:

• Surnames of Ireland map - 4,500 surnames are featured on this map and have been placed in the area where farmers with each surname cluster (based on the 1911 census). Hence each surname is positioned close to where it may have first appeared (assuming that land ownership remained relatively intact over the centuries despite any social mobility that took place). 
• "A geo-genealogy of Irish surnames" - a map showing surnames by county based on the 1890 census with an explanation of how the map was created here. The surnames are not necessarily placed near their ancient clan territories.

From A geo-genealogy of Irish surnames
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We will explore this topic further in a subsequent post but it should be possible to identify the most likely Irish origins of the Gleeson septs of Lineages II and III within the DNA Project by examining the surnames of the closest matches to the members of these groups and through the additional SNP marker testing that is currently being carried out. This will help define on which branch of the human evolutionary tree these Gleeson septs sit, and furthermore, we will be able to determine which other surnames sit on adjacent branches. The surnames most closely related may represent the early neighbours of these particular Gleeson septs, some of whom will be directly related via a common ancestor prior to the advent of surnames, and others who may be associated with an ancient NPE (non-paternity event) where a Gleeson was the father. In this way we will be able to estimate the probability that each Gleeson sept was present in a particular area (i.e. Aradh, Muskerry, Imokilly) and we might even be able to give a rough timescale for their presence there.

Thus, with the advent of DNA testing, we will be in a very strong position to determine the various Irish origins of the Gleeson surname and thus confirm or refute the theories put forth in these surname dictionaries.

Maurice Gleeson

21st July 2015

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* Aradh ... the territory east of the southern part of Lough Derg, now roughly corresponding with the Barony of Owney and Arra, which was previously ruled by the O'Donegans.
** Dalcassian ... people belonging to the sept of Dal gCais
^ Mgr. means Monsignor

A Brief Tour of the Project

The Gleason/Gleeson DNA Project has a number of different resources to help you trace your Gleason/Gleeson ancestry. If you are new to the Project, or even if you are an old hand, here is a useful summary of all the wonderful places you can visit and what each of them has to offer you.

But before we even get to the Project resources, the starting place for most people will be their own DNA results page on FamilyTreeDNA and here is my Dad's results page below as an example.

If you click on Matches under Y-DNA, that will show you what matches you have at different levels of comparison. The picture below shows that my Dad has 2 matches at 111 markers. But I could adjust the number of markers compared by clicking on the dropdown list beside the heading "Markers" (indicated by the red arrow) and choose 67 markers or 37 markers, etc. This will allow me to compare my Dad's results with other people within the FTDNA database who have tested to this particular marker level.

In the first column, the heading is Genetic Distance (GD), and my Dad has a GD of 6 and 9 for his two matches. As we are comparing at the 111 marker level, this can be written as 6/111 and 9/111. Genetic Distance refers to how close or how far away your marker values are when compared to another person. A Genetic Distance of zero means that the values for all of the markers are exactly the same - this is called an exact match.

Who qualifies as a match to you? Anyone whose marker values are sufficiently similar that they meet the criteria set by FTDNA to be declared "a match". And here are those criteria:

• a Genetic Distance (GD) of 0 at 12 markers
• a GD of 2 at 25 markers
• a GD of 4 at 37 markers
• a GD of 7 at 67 markers
• and a GD of 10 at 111 markers

The ISOGG Wiki has a very nice summary of Genetic Distance and the criteria for matching.

However, your own webpage only shows you your own matches - it does not show you other people's matches. And it does not show you matches that fall outside of FTDNA's matching criteria but which may still be relevant to you. For that, you need to visit the Gleason/Gleeson DNA Project website.

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And the most useful page is probably the Results page because this is where you can compare your results to everyone else in the project. Above is a screenshot of the results page.

Explaining the Columns

Reading from left to right across the table ...

• the first column has the Identification Number assigned to each new member as they join the DNA project
• the second column lists their kit number
• the third column records the spelling of their surname (there are several common variants and a few probable NPE's - Non Paternity Events)
• the fourth column list the Earliest Known Ancestor (also known as the Most Distant Known Ancestor) for each member - this could be written as EKA aka MDKA ... don't you just love acronyms!
• the next column records the Haplogroup for each member using both the older "long-form" terminology along with the "terminal SNP" terminology (a Haplogroup is simply a collection of people with a broadly similar genetic signature)
• and thereafter are the values for each marker, one by one, going all the way up to 111 markers (although only the first 37 markers are shown here)

Explaining the Rows

• The first row contains the headers for the columns. Below that is the "Modal Haplotype" for Haplogroup R1b1 which is the Haplogroup to which all three R1b1 Lineages belong. The Modal Haplotype is simply the marker values that occur most frequently within that particular group.
• Below that, is the Modal Haplotype for the group Lineage I. You can see that it differs from the R1b1 Modal Haplotype on a number of markers, indicated by the coloured columns (i.e. orange for marker 391, purple for marker 458, orange again for 447, etc). This in turn differs from the Modal Haplotype for Lineage II, further down the table. The colouring of the differences from the R1b1 Modal Haplotype helps distinguish the unique patterns for each Lineage.
• Each of the subsequent rows contains the details for an individual member - it's as if the Y chromosomes for all of the members are stacked up on top of each other. This makes it easy to compare the values for each of the DNA markers to see if the members in a group match on a particular marker or have a different value. Any differences are again highlighted by coloured squares.

As Project Admins, Judy and I will allocate you to specific groups within the DNA project depending on who you match. So far there are four distinct groups or 'Lineages' within the project. Lineage I members are descended from Thomas Gleson of Cockfield, Suffolk, England (Judy's ancestor), whereas Lineages II & III are Irish groups with origins in Tipperary and Clare respectively. Lineage IV is a small group of people whose origins currently lie within the US. My own particular Gleeson branch belongs to Lineage II.

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Another important page on the website is the Patriarchs Page. This is where we post the pedigree of each project member and as you can see in the screenshot above for Lineage I, it potentially helps in the reconstruction of the family tree of the Common Ancestor associated with each Lineage. All members are encouraged to submit their pedigrees for inclusion on this page. Have a look through it - you may discover your own ancestor there!

The other major resources associated with the Project include this blog and the Gleeson Genealogy Forum on Facebook. This currently boasts 178 members and is a great place for socialising with the other members of the project, sharing information, and making new friends.

And anyone who joins will get a brief "report" of their results courtesy of myself or Judy. This will include an analysis of haplogroup origins, interpretation of matches, what additional projects would be worth joining, and what further DNA testing might prove fruitful for their particular situation.

So do explore the website, this blog, and the Facebook group - there is lots to discover about your Gleason/Gleeson heritage. And come back to this blog often - it will be a repository of knowledge and a log of our ongoing discoveries.

Maurice Gleeson

16th July 2015