Elon Musk was rushed to the emergency room and needed stitches and a tetanus shot after his brother Kimbal bit off a piece of flesh from his hand during a fight, according to an upcoming biography of the Tesla mogul. According to author Walter Isaacson, Kimbal Musk bit Elon Musk’s hand because he thought his brother was about to punch him in the face while they were both running the startup Zip2 more than two decade ago. An excerpt of Isaacson’s biography was cited by the news site Insider. While co-running Zip2, which provided city guides to newspapers, the two...