I had high hopes for this one but unfortunatly my expectations were not met.
Although the concept is interesting I actually found it repetitive and boring. It was a struggle to finish this book and the only thing that kept me going was the hope that there would be some exciting climax.Although the underlying principles of evolution in reality don't "work" towards a climax, this doesn't mean that the story can't.
On a positive note it seems the author has a firm grasp of evolution and uses his knowledge well to imagine creatures that once were and maybe one day will be.
So to summarise : an interesting concept but repetitive and a bit boring. However this is very subjective and if you're interested in evolution, by all means give it a try.