A team of scientist is undertaking an ambitious project, tracing Jewish genes in order to map the travels of Jews around the world throughout history, the Jerusalem Post reports. They’re doing it in part by collecting DNA samples from volunteers whose parents and grandparents all share the same ethnic background. Eventually, it will yield profiles of what the standard genome looks like for one group of Jews (say, Yemenite) versus another (say, Georgian). That data can help scientists determine the similarities and difference between those different groups—and with the gentile popularions in their areas. “This is our last chance to do this project,” Dr. Eitan Friedman, who specializes in oncogenetics at the Sheba Medial Center in Israel, tells the paper, explaining that intermarriage of Jews from different regions is making it harder to discern distinct demographic shifts.