The most rational and easily defended explanation for the Cambrian explosion I have ever read (although rationality and defensibility do not make it true). It seems so simple now... ( )

Interesting thesis, but poorly presented. The idea - that the Cambrian Explosion was the arms race that followed the evolution of vision - is plausible, and strong enough to transcend its somewhat jumbled presentation here.

Some 'first-book' troubles: an idiosyncratic writing style, for one; but, more seriously, Parker seems to want to shovel in all of paleontology - and maybe everything he knows about everything* - to support the idea; fully half of this book could be cut.

A book on this topic, for this intended audience, really should be footnoted. The photos and illustrations should be credited.

*Why does he spend more than a page talking about facial reconstruction of a human skeleton from biblical Palestine?

Howlers:
p.5: A die has only six possibilities, not eight. (Somebody should have caught this.)
p. 94: Bats do not use radar. (Radar is NOT sonar.) ( )

Interesting, but ultimately frustrating.

Parker's thesis is that what triggered the Cambrian Explosion was the evolution of decent eyes, most likely initially in trilobites. The idea is that with effective vision came effective predation which in turn led to
(a) a period of much more aggressive selection than usual (hence the explosion) and
(b) strong pressure to evolve claws and teeth (to attack) and spikes and shells (to defend) hence visible evidence of the explosion.
To justify this thesis, the bulk of the book discusses general issues of vision and predation, both in modern life and from the paleontological record.
The last few pages put everything together to make the claim.

There are two real problems with the book.
The first is that it's written as a polemic, and as is usually the case, the polemical aspects are of substantially less interest to the audience than they are to the author. This is book designed not just to tell the public what is known, but to enlist them as allies in an academic controversy, and, as an uneducated reader, one's immediate reaction should be to wonder what is being left out because it would dilute the argument.

The second problem is that the author, while perhaps a fine paleontologist (I really don't know) is not at all inclined to math or physics and it shows.
There are frequent little errors of math or physics scattered throughout the book, but that's not the real problem.
The real problem comes in the last few pages where he tries to convince us that the selective pressures to evolve better eyes and to evolve better defence against predators were unlike anything that happened before or since. This may well be true, but it cries out for numbers and quantitative modelling and all we get is plaintive word pictures of how it must have been so.

I assume other paleontologists will study this scenario, and I do hope they will do a decent job of fleshing out the mathematics. ( )