Update 2009: Much information has flowed down since the original post, so here are the updates:
Recent studies show a high frequency of M167 in the region of the Val D'Aran in the Pyrenees of Catalonia. There are studies indicating high levels of such in the Pas Valley as well other valleys in Cantabria. The latest frequency maps still point to the eastern stretches of Iberia as a "homeland" for M167. The high frequencies found in the Balearic Islands further concludes the haplogroup must have arisen in somewhere in modern day Catalonia as the numbers are strongest there. Given that M167 is found in the Azores, Canary Islands, Balaeric Islands, Madeira Is., Great Britain, and Ireland would be a good indicator this SNP originates in close proximity to a shoreline. Whether this shoreline is the Bay of Biscay or the Balearic Sea remains to be seen, but it certainly must be one of them. M167 is still a relatively small haplogroup and finding any great numbers of such is important. More research still needs to occur in France to help get better statistics not just for M167, but for all SNP research.
Latest age estimates put M167 at approx. 800 to 1000 BCE. This is relatively close to Hurles 3580 YA/1580 BCE that was estimated. What this does point out, that estimates of 9,700 years ago may be way off. R1b itself is not as old as once claimed being no older than some 18,000 yrs for R1b itself. What does this mean for M167? As it arose in the eastern stretches of Iberia one could only conclude that it coincides with the Iberians and possibly a faint connection with the Celtiberians.
In around this time of 1,000 BC Iberia was founded by Greeks, and Phoenicians, then later Romans. What explains the distribution of the M167 to Britain and Ireland??? One working theory is the Atlantic-Trade Exchange Network of metals, in particular tin. This could explain the population of M167 in Galicia albeit small, as the initial outlier of the network until a different route was chosen through southern France when the Greeks were dominating the trade and avoiding the Phoenician ports at Tartessos/Huelva and Cadiz.
The Greeks claim the friendly encounters between the people of Beleriand (Cornwall/Devon) to foreign merchants as it was no secret of their close associations. Southern and West Ireland was part of this network of metal exchange and by the time of the Romans the network worked itself up by way of the Rhone/Rhein corridor thus possibly explaining the reason why M167 is found in southern Germany, northern France, and western Switzerland.
By the time the Romans arrived to Wales they noted a striking similarity between the Silures and the Iberians as noted by Cornelius Tacitus. Why the myths of Welsh ancestry coming from Spain and the father of the Welsh being Magnus Maximus from Iberia? Why the Irish myths mentioned in the Book of Invasions about the Milesians coming from Spain? And then there is always a possibility of reverse-migrations from Britain/Ireland to Iberia as was such when the Saxons invaded and the Britons in the west made refuge in Britanny. Whatever the case, there is a strong connection with M167 to Britain and Iberia and nothing has yet been proven inconclusively. Even theories of Basque fisherman, Roman Basque Cohorts have no solid proof, though tantalizing they may seem.
I am still researching the true origins of the Yeomans surname and have remained undecided on the possibility that it might have something to do with rivers, streams, or water itself, or just district/canton/hundred - land.