James W. Valentine

The book is aimed at graduate biology students, which means it in parts assumes background knowledge I lack, but also that it's reasonably pedagogical and doesn't assume the reader to be a fellow expert either.

Dealing with the physical (marine) environment of the Cambrian and preceding times, animal phylogeny, developmental genetics, and palaeoecology, the book doesn't lend itself to summarization. But I may note a few conclusions the authors come down on: the explosion had a "long fuse", ie. clades originate in the Proterozoic, long before their diversification during the explosion; geochemical changes, esp. the oxygenation of the oceans, were both driving and driven by animal evolution; animal evolution operated under effectively somewhat different rules then than now, as developmental cascades hadn't solidified yet, or rather were just then solidifying; accordingly divergences then really were more abrupt than in later evolutionary history.

Bits of the book were hard going, because as said they assumed background knowledge I didn't have - particularly regarding geochemistry -, but overall I liked it as an up-to-date perspective on the subject. Don't pick it up expecting a picture book of Cambrian critters however! There are some excellent illustrations included, but the emphasis is firmly on the text, and the authors tend to stay on a rather abstract level, discussing higher taxa, or types of genetic pathways, rather than individual species, specimens, or genes.… (más)