Children of Time

Very interesting first book I've read by this author, and well worth the read.

Humanity is warring against itself at home while it destroys earth. A faction sends out probes and then terraforming teams to the most promising systems they've found. Headed by Dr. Avrana Kern, the terraforming team arrives at a promising planet which has had early terraforming processes when another faction of idealists set against the idea of terraforming and spreading humanity attacks her group. Ultimately, Dr. Kern is the only surviving member of the expedition, other than the AI of her ship. She is driven to complete her mission, and decides to encode her brain in the ship's computer to ensure she can complete it. Utilizing the cold-sleep facilities, she then directs the AIs in trying to terraform this planet.

The key plan was to utilize a bespoke designed virus customized to uplift mammals into a society, and this virus has been working on the planet for the millenia since the initial terraformers arrived. The virus has unintended side-effects and much of the story is told from the perspective of a race of spiders as they develop from warring beasts to intelligent individuals and then into a full-fledged advanced society.

Just in time to deal with a colony ship sent from a dying earth, containing what is felt to be the last surviving humans.