Children of Time

An SF epic, limited (mostly) to one planet but roaming oh so far in time. We follow the evolution of uplifted spiders over a huge span of years, tracking their scientific advances and societal development. Probably loses two stars for getting a little baggy midway and for spending too much time on humans who are neither as cool or interesting as the spiders, but then it gets one back for an ending that is clever and hugely satisfying. A good read.