A new paper debunks the claim that Spanish-Americans are significantly crypto-Jewish, i.e., descended from Spanish Jews who hid their Jewish status to blend in, and eventually even forgot their origin.
Ann Hum Biol. 2006 Jan-Feb;33(1):100-11.
Toward resolution of the debate regarding purported crypto-Jews in a Spanish-American population: Evidence from the Y chromosome.
Sutton WK, Knight A, Underhill PA, Neulander JS, Disotell TR, Mountain JL.
Background: The ethnic heritage of northernmost New Spain, including present-day northern New Mexico and southernmost Colorado, USA, is intensely debated. Local Spanish-American folkways and anecdotal narratives led to claims that the region was colonized primarily by secret- or crypto-Jews. Despite ethnographic criticisms, the notion of substantial crypto-Jewish ancestry among Spanish-Americans persists. Aim: We tested the null hypothesis that Spanish-Americans of northern New Mexico carry essentially the same profile of paternally inherited DNA variation as the peoples of Iberia, and the relevant alternative hypothesis that the sampled Spanish-Americans possess inherited DNA variation that reflects Jewish ancestry significantly greater than that in present-day Iberia. Subjects and Methods: We report frequencies of 19 Y-chromosome unique event polymorphism (UEP) biallelic markers for 139 men from across northern New Mexico and southern Colorado, USA, who self-identify as 'Spanish-American'. We used three different statistical tests of differentiation to compare frequencies of major UEP-defined clades or haplogroups with published data for Iberians, Jews, and other Mediterranean populations. We also report frequencies of derived UEP markers within each major haplogroup, compared with published data for relevant populations. Results: All tests of differentiation showed that, for frequencies of the major UEP-defined clades, Spanish-Americans and Iberians are statistically indistinguishable. All other pairwise comparisons, including between Spanish-Americans and Jews, and Iberians and Jews, revealed highly significant differences in UEP frequencies. Conclusion: Our results indicate that paternal genetic inheritance of Spanish-Americans is indistinguishable from that of Iberians and refute the popular and widely publicized scenario of significant crypto-Jewish ancestry of the Spanish-American population.