What are the motifs in The Valley of Horses: A Novel by Jean M. Auel?

Soul mates are a motif in the story. Ayla is an orphan who was raised by people who are not like herself. Ayla is of an advanced race of human beings while her foster people are of a prehistoric group of humans who will eventually become extinct. Ayla has never felt accepted by these people. In fact, Ayla's foster people feel threatened by her, afraid of what her presence among them might mean to them. Eventually, Ayla is expelled by the Clan because of a natural disaster they blame on her. Ayla is left alone with no knowledge of her own kind and no way of knowing how to find them.