Southerton published the book Losing a Lost Tribe: Native Americans, DNA, and the Mormon Church.
[6] However, those who attended Southerton's church disciplinary council contended that the excommunication had nothing to do with the book.
[6] In an interview with Mormon podcast host John Dehlin, Southerton explained that he was prevented from talking about his position regarding the DNA evidence in connection with the Book of Mormon and clarified that the excommunication was not for adultery, but rather for "inappropriate relations with a woman" during a period of time he was separated from his wife in 2003.
He also felt that the 2005 disciplinary action was taken after he had already been inactive in the church for seven years and maintains that the disciplinary actions were a direct result of the publishing of his book but done in such a way to prevent further spread of his position regarding genetics and the Book of Mormon.
[7] In 2014, Southerton co-founded Gondwana Genomics with DNA marker technology licensed from the CSIRO.