What can Y chromosome DNA tell us about the Ui Neill

What can Y chromosome DNA tell us about the Ewings?

John McEwan

August 2006

Summary

The majority of the Ewings have a distinctive DNA profile. Variants of this profile are present in perhaps 20% of Irish descent males, especially those found in the North West of Ireland. This profile can be determined in using markers called STRs, but recently the group can also be more easily detected using a SNP called M222. This group has been labeled haplogroup R1b1c7. The origin of this group is under intensive study, but the evidence to date is consistent with being derived from the original hunter-gatherer population that settled Ireland after the last ice age ended 9000 yrs ago. This group achieved its current high frequency, in part, because it appears to be associated with the Ui Neill dynasty founded by Niall Naoighiallach an Irish king who died in 405 AD. This connection is consistent with the Dal Riadic oral history of the origin of the Ewing’s, who are reputedly descended from Ui Neill descendants that settled in Western Scotland about 1000AD, specifically the MacEoghainn clan who settled in Arygll. The DNA evidence to date is inconclusive as to whether the Ewings are descended directly from Niall Naoighiallach himself or his extended Irish “clan relatives”, but it is most likely the latter. However, the evidence is sufficient to strongly suggest that it is unlikely they had Cymric origin. What is lacking is sufficient tested individuals that are supposedly descended from Aodh Anrathan to tie the Ewings to a sub branch of M222. This includes other variants of the Ewing name.

Thus it appears that the Ewings history can be traced back to the prehistoric hunter gatherer period in Ireland, they then moved to Scotland sometime in the first millennium, then moved back to northern Ireland again in the 17^th Century as Scots-Irish, and then finally shifted to the USA.

Introduction

In some situations Y chromosome markers can provide interesting information about your likely ancient origin as well as identifying close paternal relatives. In the last 2 years sufficient information has become available for this to be done with some confidence for a group of people whose origins are clustered mainly in North West Ireland. We will first quickly review these markers and their properties.

The Y chromosome is only inherited by males, and as such follows surnames since they became prevalent and also oral genealogies kept by Scottish and Irish bards. There are two types of markers or variants on this chromosome STRs and SNPs.

STR and SNPs

The standard Y chromosome DNA test measures repetitive DNA markers that vary in length called STRs. These have a relatively high mutation rate changing in length on average every 500 generations. Usually these changes are single steps and they take what is called a “random or drunkards walk”. Normally, around 37 of these markers are used so there should be a mutation in at least one of these markers every 24 or so generations. Since you have to count from both relatives back to the common ancestor, typically 12generations will separate individuals that have a mutation. Over a longer time period these mutations can also occasionally revert to their original state. This variability makes them very useful for genealogy, which typically is looking for relatives in the last 10 generations. They also have another benefit as they can provide an estimate of the age of the group. This is done by examining the variability seen around the original ancestor’s values and using some mathematics based on the estimated mutation rate to calculate the number of generations to a common ancestor for the entire group. However, it does make it difficult to identify distant pre-historical relatives.

Another type of variant is a SNP. This is where a specific base in the DNA is altered; these changes are at a very much lower rate, on average once every 50,000,000 generations. Fortunately, there are many base pairs that can change making them reasonably frequent. For the cases we discuss here though they can be considered unique events. A person with the variant will with a very high chance be descended from the male in which the variant first appeared. SNPs can be combined and form a tree structure called haplogroups all descended from the last common male ancestor at the dawn of time.

Combining together data from SNPs and STRs provides the most informative results. The SNPs track deep ancestry many thousands of years old and the STRs identifies recent branches within the SNP defined groups and based on their diversity the age of the SNP group itself. SNPs results also have another use, they can also help exclude STR results of unrelated ancestral lines that now look similar “just by chance”. This is particularly valuable for border-line cases and when insufficient STRs are used.

R1b, the North West Irish Variety and M222

The latest Y chromosome tree is available at ISOGG (www.isogg.org/tree) and is shown in Figure 1 below. We will start with haplogroup R1b which is defined by a SNP variant called M343, which first appeared in a male perhaps 30,000 years ago. These people migrated into Europe prior to the start of the last ice age and have been associated with Cro-Magnon man and are best exemplified by cave paintings in Southern France. During the height of the last ice age from 24,000 to 10,000 years ago people in Europe retreated to several refugia probably located in Spain (Iberia), South Eastern France, Italy and the Balkans. By this time another mutation had occurred called M269 and this distinguished them from people now located primarily in the Middle East. It is now thought the people located in South Eastern France, Italy and the Balkans can be identified by 2 further mutations S21 and S28 respectively. However, the exact history of these groups is not clear, what is known is S21 is now frequent in a band of Northern Germany, North Holland and Scandinavia. In contrast, S28 is widespread, but seems to have a focal point in southern Germany near the head of the Danube and some have speculatively associated it with the La Tene Celtic culture.

Figure 1. Summary of the current 2006 YCC R1b haplogroup tree, based on SNP results available to date, with the R1b1c7 group marked.

At the end of the ice age people followed the retreating ice northwards. Those in Iberia moved north beside the ocean and crossed what then was dry land into Britain. It is thought they moved into Ireland crossing the narrow straight between Scotland and Antrim somewhere between 8000 and 7000BC and they probably arrived by boat even though sea levels were lower than today. The hunter gathers of this period lived on a diet of seafood, birds, wild boar, deer and hazelnuts. This period extended up to between 3500 and 4500 BC. The population during this period was very small probably only a few thousand most likely less than 20,000 and concentrated around the coast and estuaries.

It is thought that during this period, due to small population size and relative isolation, a very distinctive STR haplotype emerged and either during the same phase or just prior to its creation a SNP mutation also appeared called M222. The M222 variant appeared in individuals that had the M269 mutation, but not the S21, or S28 mutation. Some have speculated that this group emerged elsewhere and moved to Ireland. If they did they have left little trace in their homeland. Until such evidence is found we are better off assuming the mutation and distinctive STR haplotype emerged in Ireland.

This group was initially identified and described by David Wilson based on STR profile alone as the Northwest Irish haplotype. The expanded group was defined by myself based on a different STR results as R1bSTR19Irish. The different names are used to remind people how they have been estimated.

These variants probably only initially accounted for several clans or tribes in Ireland, but they were successful and subsequently expanded to represent 10-20% of the Irish population. This expansion could have occurred at any time, but most likely during periods of rapid change such as during the introduction of agriculture around 3500 BC or later during the bronze or iron ages. However, by the iron age the population was already several hundred thousand people and rising so any later emergence or expansion of this variant would have required a marked and sustained advantage extending over perhaps 20 or 30 generations. Later dates require even more improbable scenario’s. There are only two potential candidates for such an event, virtual elimination of opponents by warfare or their decimation by disease. The figures in large STR databases suggest this groups make up 20% of R1b haplogroup with Irish male ancestors, 9 percent of Scots, and close to zero in the rest of Britain and Europe.

Recent Irish Study

Recently a group of Irish researchers based in Trinity College in Dublin published a very interesting paper (Moore et al. 2006) looking at SNP and STR profiles of 796 Irish males based on their surname and origin. They did not use the M222 SNP, but used 17 STRs and were able to distinguish a portion of those with the distinctive haplotype described previously which they called IMH. Figure 2 below is the distribution they observed across Ireland. Further study by this group found that it was particularly associated with those who claimed Ui Neill ancestry. In fact they suggested that the modal haplotype was the same as Niall Naoighiallach whose descendants subsequently became the ruling elite in Irish history for nearly 700 years. They also suggested that the current frequency of this haplotype group was due to a reproductive advantage enjoyed by this clan due to their status since that time. This Ui Neill dynasty was discussed in my previous article. In practice many in the group are unlikely to be direct Niall descendants, but a fraction certainly is.

Now while extremely exciting, this study now has to be examined in light of other evidence described above. First they could only classify the group with some difficulty having neither SNP nor extended STR profiles. Secondly, their results were limited to Irish samples. Thirdly they knew nothing of the M222 SNP association with this group. Therefore while the results certainly stand some care is required comparing their results with others. What is likely is the group they defined is only a fraction of the larger group David Wilson, myself or the M222 SNP define.

Figure 2. Distribution of the IMH across Ireland from Moore et al (2006), note it peaks in North West Ireland at close to 17% and is lowest in the south and west of Ireland. They also noted it was relatively frequent in Western and Central Scotland based using 6 marker STR profiles published by previous workers.

The Ewings

So where do the Ewings fit? If a dendrogram (relationship tree) is drawn of all R1b, which shows the major groups as well as all the individuals within the R1bSTR19Irish cluster then almost all Ewings fit in a compact group by themselves. The group is located within the R1bSTR19 cluster, and to date this is also 100% equivalent to having the M222 SNP variant (see Figs 3 and 4). They are at some distance from the modal (or most common value) suggesting they branched off at an early date to many in the group (see table 1). TD is within the same Irish cluster, but in an unrelated region. SL matches a group that is very prevalent in Scotland and almost absent in Ireland and DS, JM and JMc inhabit another extended group. Note a dendrogram shows relationships, and those with the shortest and closely joined branches more closely related. The technique used here is best for relationships that are hundreds to thousands of years old, as there are better methods for recently related individuals. Therefore some care should be exercised assigning degrees of relationship within the major Ewing group. The companion article by David Ewing provides a more in depth summary of the likely recent genealogical relationship.

In theory you can also identify families within the R1bSTR19Irish group that are closely related to the major Ewing group. The McCracken’s and McGhee’s for example. These may be pre-surname relatives. However, at this stage we still not have enough information from Irish and Scots families to be able to easily track the various lineages within the group. I also suspect that to do this reliably will require at least 67 STR markers.

Figure 3. Diagram showing relationships between the R1bSTR19 cluster individual haplotypes (group defined by green bar) and related Ewings (group defined by the brown bar). Those that have been SNP tested positive for M222 are labeled green. Modals for other R1b groups (yellow) are shown as are other Ewings. The bottom branch is outside the R1b haplogroup. For a version which can be viewed at any resolution visit www.oocities.org/mcewanjc/ewing.pdf

Table 1. STR results comparing the modal haplotype of R1b with the R1bSTR19Irish and the Ewing modal. The core Ewing modal is 7 mismatches away from the R1bSTR19Irish modal and 12 mismatches from the R1b modal.

Ysearch Database Configuration - DNA Results Comparison

D
Y
S
3
9
3

D
Y
S
3
9
0

D
Y
S
1
9
/
3
9
4

D
Y
S
3
9
1

D
Y
S
3
8
5
a

D
Y
S
3
8
5
b

D
Y
S
4
2
6

D
Y
S
3
8
8

D
Y
S
4
3
9

D
Y
S
3
8
9
-
1

D
Y
S
3
9
2

D
Y
S
3
8
9
-
2

D
Y
S
4
5
8

D
Y
S
4
5
9
a

D
Y
S
4
5
9
b

D
Y
S
4
5
5

D
Y
S
4
5
4

D
Y
S
4
4
7

D
Y
S
4
3
7

D
Y
S
4
4
8

D
Y
S
4
4
9

D
Y
S
4
6
4
a

D
Y
S
4
6
4
b

D
Y
S
4
6
4
c

D
Y
S
4
6
4
d

D
Y
S
4
6
0

G
A
T
A
-
H
4

Y
C
A
-
I
I
a

Y
C
A
-
I
I
b

D
Y
S
4
5
6

D
Y
S
6
0
7

D
Y
S
5
7
6

D
Y
S
5
7
0

C
D
Y
a

C
D
Y
b

D
Y
S
4
4
2

D
Y
S
4
3
8

R1b

R1bSTR19Irish

Ewing_modal

Distance from reference:

Zero

One

Two

Three+

Figure 4. Magnified view of the diagram above showing the core Ewing group, individuals labeled green have been SNP tested all are positioned based on STR haplotypes

This R1bSTR19Irish connection is consistent with the Dal Riadic oral history of the origin of the Ewing’s, who are reputedly descended from Ui Neill descendants that settled in Western Scotland about 1000AD, specifically the MacEoghainn clan who settled in Arygll. The DNA evidence to date is inconclusive as to whether the Ewings are descended directly from Niall Naoighiallach himself or his extended Irish “clan relatives”, but it is most likely the latter based on their relationship with the modal value of R1bSTR19Irish. However, the evidence is sufficient to suggest that it is now unlikely they originally had a Cymric origin. What are currently lacking in the chain of proof are sufficient tested individuals descended from Aodh Anrathan to tie the Ewings to a sub branch of M222. This includes other variants of the Ewing name.

Thus it appears that the Ewings history can be traced back to the prehistoric hunter gatherer period in Ireland, they then moved to Scotland around 1000 AD, then moved back to Northern Ireland again in the 17^th Century as Scots-Irish, and then finally shifted to the USA.

How believable is the evidence?

This interpretation of the R1bSTR19Irish cluster and M222 is based on extremely new information and is still subject to very robust debate among DNA genealogists. It is so new in fact that only one scientific publication has appeared and it did not use the M222 SNP and extended STR profiles. Like all interpretations it is based on weaving numerous strands of evidence each by themselves of little value and subject to differing interpretations into a solid rope of circumstantial evidence. In short it depends on the following elements:

· Distinctive geographically constrained haplotype clusters only appear when a population goes through an extended bottleneck in relative isolation followed by rapid population expansion. The hunter-gatherer period in Ireland satisfies these conditions as does having a SNP tightly associated with it.

· The variability of the cluster and its distinctiveness, confirmed by SNP testing, means that almost all individuals can be identified based on STR profiles alone. This allows the much larger quantity of STR data to be examined in confidence.

· There is very little evidence for this STR group on the European continent, including Iberia and no SNP evidence to date. It has its highest concentration in Ireland and those whose ancestors can be traced to Ireland. This suggests Ireland is where it originated, and very unlikely that it was part of a ruling elite that conquered Ireland in one of the Celtic invasions.

· The STR variability suggests an age of the larger group that is at least thousands of years old, and when coupled with known population dynamics it suggests an origin prior to the beginning of agriculture.

· Its geographic and surname distribution suggest an origin prior to Niall Naoighiallach. When this is combined with estimates of the variability of the Ui Neill it is consistent with an origin much earlier than when Niall was alive.

What still needs to be done

Like many things it is very difficult to get certainty with these studies. Here are some areas where we lack knowledge.

· Profiles on surname variants. There are few tested Ewing or McEwen surname variants and no McKeown’s from northern island. If 10-20 individuals were available from each of these we would be able to identify whether these surname variants are related, or represent unique surname origins. Given that the Ewings represent a broken clan unique surname origins would not be unexpected.

· More profiles on supposedly related families. These include the Lamonts and other Dal Riadic groups families, if they are truly related they should each have a family branch that is more closely related to the Ewings than just the R1bSTR19Irish group as a whole.

· New SNPs. A current problem is that at least 50% of R1b1c individuals that have no defining R1b1c subgroup SNP. This unclassified group probably consists of several disparate strands perhaps up to 15,000 years old. A SNP that included all those that also had M222 as well as other individuals would more definitively identify the origin of the group prior to the emergence of M222. Currently, we cannot exclude that M222 originated somewhere entirely different than Iberia in some rare or unknown refugia.

Conclusion

The majority of the Ewings are closely related and reside within a Y chromosome group that most likely originated in Ireland at the end of the Ice age. As more evidence is gathered we will be able begin to discern pre-surname relationships, particularly as it relates to the Dal Riadic migration and its relationship with the Ui Neill’s.