Julie Dash’s “Daughters of the Dust” is a haunting story of a family torn apart by change. Set in 1902, the film unfolds at the sea island family Peazant’s reunion on the beach called Ibo Landing, where a younger generation talks of moving to the mainland and the older generation fights to stay. The beach is paradise but there’s trouble. A wife is pregnant with another man’s child, a sister returning from the North is a prostitute, another is a Christian religious fanatic. In a movie where characters play symbolic roles, these two returning sisters, shaped by their experience in the big cities, are cautionary examples of something pure having been tainted.