A Spanish TV documentary has claimed that the explorer Christopher Columbus was a Sephardic Jew from Western Europe.

The claim could overturn long-accepted beliefs about the explorer's identity as a Genovese from the Italian peninsula.

The new claims of Columbus' ancestry were presented in a documentary on Spain’s broadcaster TVE called "Columbus DNA: The True Origin," and are the result of work led by forensic researchers Jose Antonio and Miguel Lorente from the University of Granada in Spain. 

But experts have cast doubt on these claims — the results have not been published in a scientific journal and therefore cannot be verified.   

Additionally, experts say it's not possible for genetic analysis to determine Columbus' religion without additional historical context, which Lorente did not provide.

"DNA simply cannot show that someone is or was Jewish (a religious and/or cultural identity, not an ancestry). At most you might show with high probability that someone has relatives today or in the past who were or are Jewish," Iain Mathieson, a geneticist at the University of Pennsylvania in the US, told DW.

Who was Columbus and why is his ancestry a hot topic?

Columbus led the Spanish Empire's exploration of the Americas in 1492, bringing the first European ships to the coastlines of the Caribbean.

For many decades he was celebrated for his "discovery" of the Americas, but Columbus has also become symbolic of the oppression and dispossession of the Indigenous peoples of the Americas by colonial powers.  

Columbus died in Valladolid, Spain, in 1506, but his remains were moved to Cuba in 1795 and then to Seville in 1898. Columbus’ remains were reportedly stored in Seville Cathedral, but some historians have disputed this.  

His birthplace is also disputed by historians. Many claim he is from Genoa in Italy, but others suggest Spain, Portugal, Greece and the British Isles as other possible birthplaces.

Claims of Columbus' Jewish ancestry not verified by other scientists

According to the documentary, the Granada research team’s analysis confirms that Columbus' remains are in fact those in Seville Cathedral in Spain. 

But the analysis also found that Columbus' long-held Italian identity could be incorrect.  

The Granada researchers claim that Columbus' DNA is associated with populations from Western Europe, and with traces of DNA consistent with a Jewish origin. 

"We have DNA from Christopher Columbus, very partial, but sufficient. We have DNA from Hernando Colon, his son, and both in the Y (male) chromosome and in the mitochondrial DNA (transmitted by the mother) of Hernando there are traits compatible with Jewish origin," Miguel Lorente said in the documentary.

But the scientific community has urged caution about this interpretation, as the research has only been presented in the documentary film and not in a peer-reviewed journal, meaning that the results were not scrutinized and checked by other scientists.   

Toomas Kivisild, a geneticist from KU Leuven in Belgium, expressed disappointment that the claims had been presented in the media as research-based facts.  

"The scientific community cannot be certain about these claims. No study has in fact been published, and no facts been made available for scientific scrutiny," Kivisild, who last year supervised the genetic decoding of Ludwig van Beethoven's hair samples, told DW.   

Jose Antonio Lorentes told DW that "the complete and detailed scientific results of the research on what this documentary film on the origin of Columbus is based, will be presented at a press conference in November."  

The data will also be submitted to an academic journal for peer-reviewed publication, he said.

DNA tests alone cannot determine nationality or religion   

Mathieson and Kivisild told DW that it's not possible to determine someone’s nationality or religion from DNA analysis on its own. Nationality and religion are social concepts, and are not encoded in DNA.  

The Granada team reportedly used a genetic test that analyzes an individual's autosomal DNA. Autosomes are the 22 nonsex chromosomes that are inherited from a person's paternal and maternal lines. This gives a high quality of genetic information from which to link a person’s recent ancestry to specific geographic regions.   

But these tests only connect a person's genetic information to that of people currently living in a particular region.   

DNA tests cannot, for instance, say whether a person is Jewish. Rather, they can point to whether a person's genes are linked with people who lived in a certain region who were known to be Jewish from other historical sources.

Researchers don't know what additional information the Granada team used to make the claim that Columbus was Jewish — only that they linked his DNA to Sephardic Jewish communities who lived in Western Europe at the time.   

Kivisild added that the evidence may be based only on mitochondrial DNA and Y chromosome analyses.  

"[This] analysis cannot conclusively support the distinction of Spanish versus Italian or Sephardic Jewish ancestry," he said.

Edited by: Fred Schwaller

The article was corrected to clarify that Columbus first arrived in the Americas in October 1492.