I had enjoyed reading Stephen Oppenheimer's previous book The Real Eve; even though I disagreed with many of the things written in it, at least it was a thoughtful and informative read, which really tried to interpret and present the best available evidence. Even though Oppenheimer is not a professional geneticist, his book was more thoughtful and "deep" than most of the high-profile figures of the field.
Oppenheimer has a new book out about the origins of the British, and a new article in Prospect magazine:
Given the distribution of Celtic languages in southwest Europe, it is most likely that they were spread by a wave of agriculturalists who dispersed 7,000 years ago from Anatolia, travelling along the north coast of the Mediterranean to Italy, France, Spain and then up the Atlantic coast to the British Isles. There is a dated archaeological trail for this. My genetic analysis shows exact counterparts for this trail both in the male Y chromosome and the maternally transmitted mitochondrial DNA right up to Cornwall, Wales, Ireland and the English south coast.
Further evidence for the Mediterranean origins of Celtic invaders is preserved in medieval Gaelic literature. According to the orthodox academic view of "iron-age Celtic invasions" from central Europe, Celtic cultural history should start in the British Isles no earlier than 300 BC. Yet Irish legend tells us that all six of the cycles of invasion came from the Mediterranean via Spain, during the late Neolithic to bronze age, and were completed 3,700 years ago.
I have mostly accepted the traditional theory of Central European origins of the Celts, even though I know (or care) very little about that subject. I am not sure how Oppenheimer derives them from Southwest Europe, but that idea makes some excellent sense. After all, the Celts were first identified by classical writers in Southwestern, not Central Europe, and that is where their languages survived to this day.
The idea that the Celts were drawn from the same dispersal out of the southeast into southwest Europe is also attractive because it explains readily the commonalities between Celtic and Italic languages; it also harmonizes with the relative lack of DNA "signals" that would link the inhabitants of Western Europe with those of Central Europe. It fits quite well into the emerging picture of Indo-European dispersals out of Southeastern Europe, with Italo-Celts being responsible for maritime pioneer colonization across the northern Mediterranean, Germanics being responsible for northward movements from Central European descendants of the Linearbandkeramik, and Balto-Slavs derived from northeastern movements of the Bronze Age which brought Corded Ware type people into contact with the Finno-Ugric substratum of eastern Europe.
Oppenheimer also addresses the idea of an Anglo-Saxon imposed apartheid in Britain:
Some geneticists still cling to the genocide story. Research by several genetics teams associated with University College London has concentrated in recent years on proving the wipeout view on the basis of similarities of male Y chromosome gene group frequency between Frisia/north Germany and England. One of the London groups attracted press attention in July by claiming that the close similarities were the result of genocide followed by a social-sexual apartheid that enhanced Anglo-Saxon reproductive success over Celtic.
The problem is that the English resemble in this way all the other countries of northwest Europe as well as the Frisians and Germans. Using the same method (principal components analysis, see note below), I have found greater similarities of this kind between the southern English and Belgians than the supposedly Anglo-Saxon homelands at the base of the Danish peninsula. These different regions could not all have been waiting their turn to commit genocide on the former Celtic population of England. The most likely reason for the genetic similarities between these neighbouring countries and England is that they all had similar prehistoric settlement histories.
The orthodox view is that the entire population of the British Isles, including England, was Celtic-speaking when Caesar invaded. But if that were the case, a modest Anglo-Saxon invasion is unlikely to have swept away all traces of Celtic language from the pre-existing population of England. Yet there are only half a dozen Celtic words in English, the rest being mainly Germanic, Norman or medieval Latin. One explanation is that England was not mainly Celtic-speaking before the Anglo-Saxons. Consider, for example, the near-total absence of Celtic inscriptions in England (outside Cornwall), although they are abundant in Ireland, Wales, Scotland and Brittany.
I like the idea that England was not mainly Celtic speaking before the invasion of Anglo-Saxons. For one thing, the native inhabitants of the British Isles were not identified as Celts by the ancient writers; this is puzzling if they were kinsmen of the continental Celts. The existence of Celts in the British Isles is of course proven on linguistic grounds, but their dominance is very speculative. It is probably due to the fact that the Celts are the only identifiable non-Germanic inhabitants of the Isles who have left a linguistic and cultural legacy (to some extent), so pre-Anglo-Saxons are assumed -wrongly- to have been Celtic.