National Geographic : 2015 Oct
Us EXPLORE PHOTO: LANDON NORDEMAN. GRAPHIC: MATTHEW TWOMBLY, NGM STAFF siblings Parent Grandparent Great-grandparent Great-great-grandparent Great-great-great-grandparent 1st cousin 2nd 3rd 4th You A JEWISH FAMILY REUNION Of the world’s ten million Ashkenazi Jews, none are more distant than 30th cousins, related to each other by multiple connections. Population genet- icists traced the group back 750 years, or 30 generations, to when a small group of Ashkenazi Jews likely traveled from western Europe to Poland. “The reproducing population at that time was only around 300,” says He- brew University’s Shai Carmi. Scientists think the findings could be useful in studying genetic diseases, particularly ones affecting Jews. —Daniel Stone On college campuses in the U.S . and around the world, pets are lending a paw to stressed-out students. With many collegians reporting depression, anxiety, and other ills—a 2013 study sponsored by the American College Counseling Associa- tion says one in three has used counseling services—school officials arrange “pet therapy” events to spread cheer and fight stress, especially during exams. These aren’t service animals trained to assist people with disabilities; most are the pets of volunteers. Their visits are demonstrably beneficial: Research shows that contact with pets can decrease blood pressure and stress-hormone levels and increase so-called happiness hormones. Mary Margaret Callahan, a director at the nonprofit Pet Partners, considers pet house calls on campus “a great way to support students in being successful.” —L indsay N. Smith Student Rx: Pets Law students at New York University take a study break with dogs brought in by volunteers.