This is another one of the series about Miles Vorkosigan. The plot summary sounds sort of stupid, but it was a pretty good read. He has a clone twin, made without his knowledge. Evidently the two meet originally in a book I have not read yet. In this one the clone brother steals one of Miles' spaceships and goes on a mission that is a personal crusade of sorts. This goes horribly wrong and it takes the rest of the book to fix everything.
Not only is there an interesting plot, but she uses this book to talk about identity and family and what makes you who you are. This is normal, or at least expected, in a book about clones. What struck me the most was the discussion of "genetics as destiny" that she begins to investigate here and works with more fully in Cetaganda. In talking about power, the men have the obvious, military power, but it is the women, the "grandmothers" who control the marrying and raising of the next generation.
She also has the invention of a "uterine replicator," a means to carry a child to term without the physical risk as an additional cultural manipulation. How would sexual politics change if women didn't have to spend the time physically being pregnant? Since pregnancy is personally awful, I think it would be a great idea, but in our imperfect world it is better that we cannot do such a thing and don't even have a chance of learning how in the near future. I revel in the opportunity to raise my children and I can see the influence I have on them. Those who sacrifice the raising of their children in behalf of their personal achievements do not realize what they are losing.
Mirror Dance. Lois McMaster Bujold. Baen Books. 1995