On Friday nights Jews traditionally bless their daughters to emulate Sarah, Rebecca, Rachel, and Leah. But the women these girls actually take after are 4 other women entirely. In a genetic study conducted in 2002, scientists found that 40% of all living Ashkenazi Jews—some 3.5 million—trace their DNA back to 4 “founding mothers” who lived in Central and Eastern Europe over 1,000 years ago. […]