What are the motifs in Children of God: A Novel by Mary Doria Russell?

Genocide haunts Mary Doria Russell's Children of God, but for most of the novel it is based on a false understanding of a shocking behavior involving the two sentient species on the planet Rakhat. A Jesuit mission arrives from Earth, having heard music and expecting high civilizations. They perceive that the Jana'ata are massacring innocent Runa rather than laying claim to a food source that is altogether legal according to planetary custom. Many aged Runa volunteer to become food once their working days are over and are shocked at the thought of wasting good meat. A Jew, Sofia Mendes Quinn, naturally identifying with the underdog, rises up as a Joan of Arc figure to call on the Runa to revolt.