A review by davecapp
Diaspora by Greg Egan

For fans of speculative hard Sci-Fi few authors compare with Greg Egan. From the outset this book posits a view of humanity split by its use (and abuse) of technology, with each group evolving or devolving to its core tenants. But as disaster of unimagined proportions threatens everything, the survival of the species becomes key.

Diaspora thus becomes a study of what could be if we were willing to risk it all.

As a side note - this was written almost 20 years ago but the early sections on the evolution of intelligent life
In the polis remain incredibly insightful.