23andMe has backpedalled from broadcasting the discredited theory that a portion of Ashkenazi Jews are descended from an obscure tribe from the Caucasus.

But that hasn’t stopped members of the “alt-right” from jumping on the news that the giant Silicon Valley genomics company had given credibility to the so-called Khazar theory, which undermines Jews’ perception of themselves as a unitary people and their ties to the Land of Israel.

“Wow,” tweeted Richard Spencer, a major “alt-right” figure and head of the National Policy Institute, a white nationalist think tank.

I always rejected the Khazar theory, as did KMac and Richard Lynn. Perhaps there’s some truth to it.— Richard ☝?Spencer (@RichardBSpencer) August 29, 2017

Andy Kill, a spokesman for 23andMe, wrote in an email yesterday that the inclusion of information about the Khazar theory on 23andMe’s site was done “in error.”

Science questions everything. Khazar origin is a valid hypothesis, with expanding evidence. Zion is a sandcastle of lies.— Jorj McKie [BuSab] (@Malgwyn) August 30, 2017

“We apologize for this material not being struck from the reports before they were released to customers, which should’ve happened in the editing process,” he wrote. “We do not endorse “Khazar theory” and are removing any language referencing the theory from the product today.”

Image by 23andme.com A screenshot of the part of the genetic report that referenced the Khazar theory.

However, the changes to 23andMe’s site were made sometime during the day Wednesday. Users awoke Wednesday morning to see the Khazar theory still displayed on their genetic reports.

David Rodstein, a 23andMe customer who received the report, said he “was saddened” to see that the paragraph about the Khazar theory remained in his report Wednesday morning, calling the company’s use of the theory “disturbing” and “careless.”

“I’m not anti-facts, I say go where the facts say,” Rodstein said. But he added, “If 23andMe is putting that information out, they should have the studies to back it up.”

Last week, some customers of the company’s direct-to-consumer genetic tests were sent updated genetic reports touting research that “suggests that Ashkenazi Jews who belong to your haplogroup may descend from a single male who… may have been a member of the Khazars,” a group that was invaded and destroyed in the 10th century. The updated report was sent to people in the specific genetic sequence called R-M512, or R1a, by geneticists — a sequence shared by 50% of Levite Jews. The update was one of many sent out to 23andMe customers of various genetic groups.

As of Wednesday evening, 23andMe had not commented on why the literature about the Khazar theory was prepared for publication in the first place, or how many of 23andMe’s customers received the genetic report with the inaccurate information. The company said it would not notify customers of the error.

Now there is no mention of the so-called Khazar theory on 23andMe’s site. Instead the company has published information about a nomadic group of people called the Yamnaya, which roamed Central Asia 4,500 years ago. The region ascribed to the Yamanya on 23andMe’s site overlaps with the historical boundary of the Khazar empire, which covers Eastern Ukraine, the Russian Caucasus and western Kazakhstan.

“To put it mildly, I am not impressed by the 23andMe claim,” Mait Metspalu, an Estonian geneticist, wrote in an email. Metspalu is the director of the Estonian Biocentre, a genetics research institute, and was a lead author on a 2013 study that refuted the Khazar theory.

“From the whole genome perspective, which gives a much fuller account of ones genetic heritage, there is no evidence of Khazar genetic ancestry in the Ashkenazi,” he added. He noted that in testing the genomes of people who live in the part of Central Asia ascribed to the Khazars, researchers have not found any genetic evidence that links them directly to Ashkenazi Jews.

“I’m amazed by the simplemindedness of the information they give to their customers,” Metspalu added.

Mark Pitcavage, a senior research fellow at the Anti-Defamation League’s Center on Extremism, said white supremacists and anti-Semitic groups have been promoting the Khazar theory for over a century. Anti-Semitic hate groups like Christian Identity — who trace the origins of white Europeans to the biblical 12 tribes of Israel — have used the Khazar theory since the early 1900s to say that Jews have nothing to do with the Israelites.

“It’s very convenient for them,” he said. “It’s a way to remove Jews from their own identity story.”

Christian Identity groups have often been behind Christian extremist violence in the United States, such as the Ruby Ridge siege in 1992. From those groups, the Khazar theory spread among non-Christian extremist white supremacist groups.

“It started with Christian Identity, and spread to the white supremacist movement,” Pitcavage said. “It’s not uncommon to find other white supremacists refer to Jews as ‘Khazars.’”

https://t.co/qyyEjj8qDI Interesting. I never put much stock in the Khazar theory. But I am always open to change my mind #TheJewishQuestion— White Devil (@WkdWhiteDevil) August 30, 2017

A search for the word “khazar” on 4chan, a site known for being an “alt-right” and white supremacist refuge, reveals 573 results referring to the theory. The theory was also a subject of perennial discussion on the white supremacist sites Stormfront and The Daily Stormer, both of which were removed from the internet in recent weeks after their domain providers dropped them.

While there are prominent historians who have espoused the view that a large portion of the Khazarian population converted to Judaism in the eighth and ninth centuries, it is not possible to confirm whether there are Jews descended from Khazars. Geneticists have pointed out that because we don’t know which Central Asian populations descend from the Khazars, it is impossible to have definite Khazar genetic samples to test against.

“The question is, ‘Could they have mixed with Ashkenazi Jews?’ Yes, that is possible,” Harry Ostrer, a geneticist at Albert Einstein College of Medicine, told the Forward in 2016. “Were they the founders of Ashkenazi Jews? No, that is not possible. The evidence supports shared origins of European Jewry. That has to be accounted for.”

Along with this genetic problem, there is scant historical evidence that any Jewish Khazarians founded, or were absorbed, into Jewish populations in Europe.

“The Khazar ‘problem’ has been a battleground since the mid-19th century in Russian historiography,” Peter Golden, professor emeritus of history, Turkish and Middle Eastern studies at Rutgers University, wrote in an email. “For some (anti-Semitic) Russian historians they have been the source of all evil in medieval and by extension modern Russian history.”

Golden added that the Khazar empire was an amalgam of various Turkic, Iranian and Slavic tribes. It would be exceedingly difficult to know if genes from any of these ethnicities come from members of the Khazar empire or found their way into the Jewish gene pool through another route.

“In short, the evidence for the Khazar origin of Ashkenazic Jewry is not there,” Golden wrote.

Contact Ari Feldman at feldman@forward.com or on Twitter, @aefeldman.