Hi JeffreyRyan.
1st - I've actually written om that for the meme above
imgflip.com/i/5ap1y4 in the comment section.
Here is what I've written:
ON THE JEWS (PART II): ARE THE ASHKENAZI, KHAZARS?
The controversy began with Shlomo Sand with his book, "Inventing the Jewish People" (2009) in which he claimed, through DNA research, that the Ashkenazi which the majority of the worlds Jewry are really descendents of the Khazars, a Turkic people who've converted to Judaism and moved from the kingdom of Khazaria to Eastern and Central Europe.
This presented a number of problems, not only because it contradicted common understanding that the Jews from the maternal standpoint were from Europe, but also brought an excuse for anti-semites to hate the Jews without... being rightly called, "Antisemitic".
While there is some credence to the narrative (after all, there were such a people of Khazaria), in my mind there are a host problems with the conclusion.
First of all, why were most of the Ashkenazi look more European than Khazarian?
Second, if they were Khazarian then there must be visible, cultural traits that wouldn't be original to Jews such as dress, practices, and customs, but nothing was noticed even by the proponents of of the narrative.
Third, according to the critics of the narrative, there were no records of the Khazarian conversion to Judaism.
The Truth: new DNA findings published in Nature Magazine (Oct. 8 2013), proved otherwise. Thus, the Ashkenazim retained their Jewishness.
SOURCES
1. "Are the Ashkennazi Jews Descended from Khazars?" By Sara Ivry
July 3, 2014 • 12:30 PM The Tablet Magazine https://www.tabletmag.com/scroll/178152/are-ashkenazi-jews-descended-from-khazars
2. "Genetic Roots of the Ashkenazi Jews" By Kate Vandell form The Scientists published October 8 2013 the-scientist.com/daily-news/genetic-roots-of-the-ashkenazi-jews-38580