LeVar Burton got a glimpse into his lineage in “Finding Your Roots” and discovered something about his ancestors that shocked him. The former “Reading Rainbow” host, freedom-to-read advocate and actor knew little about his lineage. He’d been estranged from his father, Levardis Robert Martyn Burton, since he was 11, and his mother, Erma Gene Christian, had been tight-lipped about her own history. Burton said it was “impossible” to get her to open-up about her upbringing.