Showers and Madden spend over haft the book just introducing and counting the young narrator's many ancestors, up to great-great-great-great-etc.-grandparents, before mentioning traits and heredity and describing how Mendel found out through his pea-plant experiments that ""sometimes traits--like red hair and long legs--are not seen in the children. But they might show up again in the grandchildren or great-grandchildren."" If devoting a book to this one scratch-on-the surface will open the way to learning about genetics, okay; but as set down here, especially in Madden's monotonous proliferation of ancestral couples, all those great-great-greats tend mainly to generate clutter. Marginal.