Haplogroup G, like haplogroups E3b and J2, is thought to have originated in the Middle East, and to have

spread into Europe during the Neolithic. Beyond that, it is somewhat mysterious. According to the Capelli study,

it also occurs in about 2% of the male population in Oban and Stonehaven, which are in Argyll and

Aberdeenshire respectively, and in 4% of the men in Llanidloes in eastern Wales.

One study purported to find haplogroup G at high proportions among the native Gaelic clans of Ulster. These

results suggested that haplogroup G was associated with Q-Celtic speakers who migrated to Ireland and

Britain from continental Europe.

However, the authors of the study later recanted their conclusions, claiming that what they believed was

G was, in fact, a subclade of haplogroup I called I1c. Many G and I haplotypes resemble one another,

and cannot be distinguished without the aid of a SNP test. Hence, many of the matches in Nordic

countries posted in the table below are probably the result of convergence with I haplotypes.

One should also note that G haplotypes with low DYS390 values, such as 21 or 22, can sometimes

be mistaken for E3a haplotypes, which are predominantly African.

Their Neolithic origin suggests that the carriers of the G haplogroup were not among the original inhabitants of the

British Isles. Moreover, the rarity of the haplogroup makes it unlikely that its carriers arrived in great numbers.

Haplogroup G may yet be the genetic remnant of the European Celts who brought the Celtic languages into Britain.

Between 1 and 2 percent of the Border Reiver sample exhibit haplogroup G, which is consistent with the proportion

found in Penrith (Cumbria) and in Morpeth (Northumbria).

A far more likely source of haplogroup G is the multi-ethnic settlement of Roman Britain. Some areas with relatively

high levels of G in Capelli's study, such as those in northern England and eastern Wales, lie where there are comparably

high levels of haplogroups E3b or J/J2. All three haplogroups may have either a Middle Eastern or a Central Asian

origin. E3b and J/J2 are also widespread on both sides of the Mediterranean basin, while G is most common in the

Caucasus - especially Georgia.

Troops from all these areas were stationed at Hadrian's Wall and along the Welsh March.

A recent paper by I. Nasidze et al, entitled "Genetic Evidence Concerning The Origins of North and

South Ossetians", has identified of levels of G in Northern Ossetia ranging from 21 to 75 percent,

depending on the region. Since the Ossetians are considered to be the descendants of the Alans, the

G haplogroup may be construed as a possible marker of Alanic or Sarmatian ancestry when it is

found among Border Reiver descendants. The G haplotype data set of the Nasidze paper, in fact,

contains many signatures similar to the haplotypes displayed here.

Further discussion of the history of haplogroup G, sample G haplotypes and other G-related issues

may be found at this link. Another discussion focusing specifically on the distribution of G and G2

through lands controlled or settled by Sarmatians may be found at this link.

G Haplotype #1

The haplotype below is widespread. Nonetheless, it is interesting that the highest frequency is among the Ossetians,

who are considered the descendants of the Alans and Sarmatians. The Alans accompanied the Visigoths and the Vandals

into Iberia and Gaul, settling in Brittany. Centuries later, some of their descendants joined the Normans in the invasion

of England. The Sarmatians served in the Roman Army in Lancashire and along Hadrian's Wall.

G Haplotype #2

This haplotype exhibits its highest frequency among Italian samples, and also appears in France, Iberia

and Armenia. All of these areas were part of the Roman Empire, suggesting that this haplotype could have

entered Britain through Roman settlement.

This basic haplotype also appeared in the Ossetian data set of the Nasidze paper, so a Sarmatian

or Alanic ancestry is also possible.