"The P78 branch split into two clades A427 and Y7219 some 5,300 years ago, at the time of the Yamna culture in the Pontic Steppe. It is distributed mostly across Central and Northwest Europe, particularly in Poland, Germany and the Netherlands, but also in Romania, Hungary, Scandinavia, Britain, Ireland, France and Italy. Isolated samples have also been found in Greece, Turkey and Armenia. Like the L701 clade, it might well have originated in the Yamna culture and spread with Proto-Indo-European speakers to Central Europe. One branch of A427 is found among Ashkenazi Jews with mostly German surnames, probably through the convertion of Germans to Judaism during the Middle Ages. P78+ matches the I2 Continental 3a clade at Family Tree DNA."

This is posted in the Eupedia entry under I-M223 and I have found this to be true based on reviewing my SNP results... but marvel at how this came to be? Is there more information on this conversion of Germans to Judaism during the Middle Ages? This is the most plausible explanation but I'm wondering if there is anything else available about this possible scenario? Range of dates, location? Anyone? Thanks.