Hat tip to Jean for this finding.
Laura Valverde et al., Y-STR variation in the Basque diaspora in the Western USA: evolutionary and forensic perspectives. IJLM 2011. Direct PDF link. [DOI 10.1007/s00414-011-0644-8]
As the authors wisely assess the most important inference we can get from this study is how a colonial population diverges from that of the homeland. The Basque colony in North America is not too large (58,000 in all the USA), albeit significant specially in Idaho, Nevada and to lesser extent California (larger numbers but smaller apportion), and the origin is biased towards a single region: the Northern Basque Country (under French rule).
However the results show that they represent very well the ancestral homeland's haplotypes, only tested in the Southern Basque Country, diverging only somewhat:
|Fig. 1 Median-joining haplotype tree: white European Basque (West), black American Basque|
This is a good example of how a normal colonial population, even if reduced in founders and numbers, behaves in relation to the ancestral one: it retains most of the lineages. No marked founder effects are apparent anywhere.
Our results demonstrate a very high-level of conservation of the Y chromosome haplotypes characteristic of the European autochthonous Basque population among individuals of the Basque diaspora in the Western USA. No signs of founder haplotypes have been found...