An Unexpected Result: Genetics Sheds Light on the Spanish Inquisition

With the return of Christian rule to Spain in 1492 after nearly 800 years of Muslim rule, hundreds of thousands of people – both Muslim and Jewish – were faced with the choice of exile, conversion or occasionally even death. Historical accounts estimate that nearly 400,000 Jews and Muslims were expelled from Spain or Portugal within only 100 years.But what about those who didn’t leave?   Many Muslims and Jews converted to Christianity, only to face the scrutiny of the Spanish Inquisition.   Can the descendants of those converts still be found among modern Spanish and Portuguese peoples today?   These very questions were at the heart of the new study by geneticist Mark Jobling and his colleagues at Leicester University.In order to answer these questions, Jobling and his colleagues performed genetic analyses on 1,140 males from the Iberian Peninsula.   They focused on the Y-chromosome DNA, which is passed down from father to son and can be used to trace paternal ancestry.   Jobling and his team found a surprisingly large percentage of DNA types that can be traced back to either Jewish (19.8%) or North African Muslim (10.6%) populations.These levels stand in contrast to historical accounts, which emphasize the expulsion of these two minority groups from Spain and Portugal.   According to Jobling, “These findings attest to a high level of religious conversion (whether voluntary or enforced) driven by historical episodes of religious intolerance.”The genetic evidence lends support to the idea that most Jews and Muslims preferred conversion to Christianity, as opposed to expulsion from the region.   Ultimately, the descendants of those who converted began to integrate into the Christian population.   Today, most of these descendants remain unaware of their ancestors’ religious conversion.The conclusions reached by Jobling and his colleagues illustrate how useful genetic analysis can be in assessing the historical record. Since researchers began using genetics to understand the past about two decades ago, they have focused their attention on prehistoric events such as the origin of the human species in Africa, the migration of people into new territories and the expansion of innovations such as agriculture and pottery.But the gradual accumulation of data now allows scientists to tackle more recent and localized events. Just last month, researchers with the National Genographic Project used the genetic diversity of modern populations around the Mediterranean to piece together Phoenician trade routes from nearly 3,500 years ago.This latest study shows that genetic data can actually be used to test historical claims and assumptions, and even to overturn conventional wisdom. In fact, the results of this research actually contradict some historians’ beliefs about the fate of the majority of Jews and Muslims living in the Iberian Peninsula during the Inquisition.   Clearly, using genetic data to test hypotheses based on historical or archaeological evidence promises to be surprisingly informative in the future.Photograph of “Auto de Fe” by Francisco Ricci from Wikimedia Commons.
  • Hm. That’s assuming the ratios stayed the same, rather than slowly taking over the population. Ja?

  • pp987

    This article may not be taken seriously. It’s been made through extrapolations of scientific and historical data that makes it less than scientific. They used the J2 haplogroup as a marker of jewish heritage, when it is common throughout the mediterranean basin and is credited as a probable neolithic marker (See Lebanon, Greece, Italy). J1, which has half frequency of J2 in jewish population has not been found to be near as common in Iberia. There was no specific jewish haplotypes compared.
    The E3b2 (relative north africa) infusion in iberia may be partly older than the moorish invasion, as many scholars are trying to prove, and the figures about north african admisture in iberia had been analysed before in good studies.
    Actually, this study may deserve better evaluation before being acknowledged in spitoon. You should not post it only beacuse it’s gimmicky. Regards from a genetics fan.

  • Dirk

    Now that I have access to the study, a few comments, and a business suggestion for 23andMe. 🙂

    – As others have already said, there are many populations (Celts, Phoenicians, Greeks, Romans, Visigoths, Arabs, etc.) that contributed people to the Iberian peninsula, but which were ignored in this study.
    – The 19 markers were well chosen; however all samples should have been typed for all of them!
    – This study represents a monumental amount of work, but the conclusions about each haplogroup in the different populations are impaired by the limited resolution of subhaplogroups within formerly-called-E3b, G, I, J, KxP, and R1b. As 23andMe knows, there are many downstream subhaplogroups, each one of which with a distinct distribution in different populations.

    Thus, I do believe there is a market for 23andMe to offer a Y-chromosome-only SNP chip, which tests for all known (including all the ‘private’ ones) Y-SNPs at once! This chip can be marketed to academic researchers and private researchers (Genetic Genealogists). 🙂

  • clipper

    The conclusions reached in this paper are unprecedented and almost certainly overstate the percentage of Iberian males today who are of north African or Jewish genetic origin. This study has been met with disbelief and criticism of its methods. It has no basis in historical fact and the authors have admitted both surprise at the results and disagreement inte se about the validity of their own findings. One, in particular, has said the stated Jewish component (~19%) probably includes a significant number of other likely ethnic peoples, such as Phoenicians, whose genetic signatures are virtually indistinguishable. The Jewish population in Iberia never exceeded 3-5%. Medieval Arab invaders probably constituted a slightly higher percentage. Berbers were far more numerous, but their impact on Iberia, and vice versa, was long and continuous.

    A second study dealing with the genetic similarity of mtDna among southern Spanish and Tunisians, reported here, has noted the genetic flow was from Europe to north Africa, not the other way around, and it took place thousands of years before the Moorish invasion of Iberia in 711 CE. It is entirely possible a similar dynamic was at work in conection with at least a portion of Y chromosome subjects the researchers tested in this project.

    Watch for a public correction or refinement of the conclusions reached here so as to more closely approximate what others have inferred from similar analyses or existing historical sources. It’s only a matter of time.

  • SalidaDelEuro

    20% the jewish population in medieval Spain? ….. please, be more serious.