[Here is an interesting study](https://www.independent.ie/opinion/analysis/dna-blueprint-of-the-irish-revealed-26679727.html) which discusses the apparent genetic connection between Basques and the Irish (as well as other ethnically British people).
To wit:
Major genetic surveys of Ireland and Britain have established that the gene pool of both islands is amongst the least diluted in Europe. The genetic evidence shows that three quarters of the ancestors of the Irish and British people were the pioneering settlers who arrived at the end of the last ice age between 17,000 and 8,000 years ago. The inescapable upshot of this is that the Irish are not Celts, any more than the English are Anglo-Saxons.
In fact, both the Irish and the British are Basques, with the Irish significantly more Basque than our neighbours across the pond [i.e., the English], who’ve absorbed more migrations from Europe over the centuries.
[...]
The genetics suggest that, with sea levels low, the Basques simply walked to Ireland, becoming cut off generations later when rising seas created the island we know. Ancient Irish legends say that there were six invasions or migrations from the south many generations before the Celts arrived around 300BC.
The evidence suggests that the Celtic language, fashions and technologies which are supposed to define our Irish heritage, were acquired as cultural accessories in the way that today's Irish schoolkids flounce about under the impression that they're gangsta rappers straight out of Compton or Beverly Hills brat-packers.
The Irish and Basques share by far the highest incidence of the R1b gene in Europe, which has a frequency of over 90% in Basque country and almost 100% along parts of Ireland's western seaboard.
If further proof were needed, there's the physical fact that the Basques are distinguished by a very high incidence of fair (and some reddish) hair, pale skin, blue eyes, and, apparently, sticky-out ears. Sound like anyone you know?
I don't quite believe that the scientists who were involved in this study know as much as they seem to suggest, such as the ideas concerning the ice age, but I do think this is interesting. There is apparently a genetic link between the Basque peoples and the Irish/British peoples. I find this particularly interesting in light of the fact that Sidhartha previously established here on the list that there is a link between the Basque language and Japanese. These Basque folks sure seem to get around!
Is there a possible hollow-earth connection here? If so, what is it?