Michael Douglas has been left shocked after discovering he is related to Scarlett Johansson. The 79-year-old star appeared on PBS series ‘Finding Your Roots’ to delve into his ancestry, and he was stunned to find out the ‘Black Widow’ star – who he appeared alongside in 2019’s ‘Avengers: Endgame’ – is a “DNA cousin” of his. When told the news on the show, Michael said: “Are you kidding? Oh, that’s amazing. All right. This is cool. This is so cool.” ‘Finding Your Roots’ presenter Henry Louis Gates Jr. delivered the news to Michael, and told him that he and the 39-year-old actress “share identic…