Wonderful Life: Burgess Shale and the Nature of History (Penguin science) [Paperback]

What would life be like if one of the players had never existed? ...like poor old George Bailey who thought everyone would be happier and better off without him.

In this book Gould takes the position that animals that exist today do so primarily because they were lucky during their early evolutionary history, along with having characteristics that allowed them to survive and succeed in their environment long enough to reproduce -- a contingency hypothesis. They turned right instead of left and consequently avoided predation...OR...they turned left instead of right, were eaten, and that was the end of an entire ancestral line.

This book is a must read for anyone interested in ideas surrounding the diversity of early animal life. The book provides an informative overview of what evolution is, how the now famous Burgess shale fossil beds were discovered and studied, and why some of the body plans found amongst the Burgess shale fauna are not found today. There are also excellent drawings of Burgess shale fossils and the animals they may once have been, and a reasonable selection of descriptions of their possible behaviors based on animal form and function.

Gould also recounts ideas others have had about the Burgess shale fauna and its contribution to our understanding of the Cambrian fauna in general.

It's interesting to note that this book was written prior to the discovery of several other Burgess shale-type fossil beds around the world, most notably in China. But, given what Gould had to work with at the time, this is an admirable work.

If this general topic interests you, you may want to take a look at another book -- "The Crucible of Creation" by Simon Conway Morris. Morris' book provides addtional excellent graphic presentations of cambrian fauna, a different explanation of some possible paleo-ecologies of those animals, and a fundamentally different read on why we have the kinds of animals that we have today. Morris also includes information about newly discovered Burgess shale-like fossil beds and specimens.

All in all, Gould's book is a 5-star work. I'd recommend reading it AND Morris' book for a balanced set of different opinions about this important animal group.

I didn't give it more than 3 stars because, scientifically speaking, it stinks. It is by far Goulds worst book.

I would recommend people to read this book, but when you do, try to remember that the taxonomic rank of phylum, contrary to what Gould claims, lacks a definition; that a 'fundamental body plan' is a wholly arbitrary after-the-fact construction; that neither the rank of phylum or 'fundamental body plans' has any whatsoever evolutionary significance; and that no-one knows why or how the animals of Burgess Shale went extinct.

But on to the book. It is, on the surface, about some remarkable fossils found at a place called Burgess Shale.

Gould spends a substantial part of the book expounding how the psychosocial background of the original discoverer, C. Walcott, led him ("preconditioned" is the word Gould uses) to Get It All Wrong when he classified ("shoehorned") the fossils in known phyla, whereas the zeitgeist of the late 20th century allows a group of whacky new researchers to Get It All Right and see that they belong to previously unknown phyla.

One is then treated to a nice exposé of some really interesting fossils, and there's not much to say about them except that most have since the book was published been re-evaluated, and are today classified as velvet worms, arthropods or annelids (still as interesting, but less enigmatic - and ironically much like Walcott first "shoehorned" them).

Why, Gould asks, did essentially all modern phyla arise in a short period in the cambrian, as well as, allegedly, a large number of phyla which today are extinct, when no new phyla have arisen in the subsequent 550 million years? And the extinct phyla, they seem complex and 'seaworthy' enough - surely which phylum lived and which went extinct must have been purely decided by chance? Surely, if we re-played evolution, the world today would be very different?

There are two errors in that line of reasoning. Firstly the most pervasive: the reification of the taxonomic rank of Phylum and of the concept of 'body plan'.

Gould in this book equals the taxonomic rank of Phylum to the concept of 'fundamental body plan': one body plan = one phylum. This is a bit backwards - the rank of phylum is arbitrary and lacks a definition, but is historically (but not always) afforded the most inclusive groups of animals between which interrelationship is unclear. The concept of 'bauplan' or 'fundamental body plan'is similarly wholly arbitrary - a body plan is a collection of traits deemed characteristic for the group, and can be created for any group, regardless of inclusivity: you take a group of species, such as a phylum, determine what is characteristic for the group, and voilá, there's the fundamental body plan.

What does this mean? That neither the rank of phylum nor the concept of 'bauplan'/'fundamental body plan' has any evolutionary significance - and yet this is what Gould bases his argumentation on in this book.

The second error is a logical one, and is that _even if_ Opabinia, Anomalocaris and the others had represented "new" phyla, and _even if_ phylum had been the same as "fundamental body plan", and _even if_ that had meant something from an evolutionary point of view, this isn't support for Goulds view that evolution is stochastic, driven by chance extinctions rather than adaptation.

All we know is that Burgess Shale organisms went extinct - we do not know why. For all we know these organisms were outcompeted, and would be outcompeted again and again if we 're-played' the history of Earth. The support Gould thinks they give his pet theory isn't there.

So, to sum things up - in this book Gould uses psychosocial arguments to dismiss the science of Walcott and support that of Simon Conway Morris; misunderstands what a phylum is; misunderstands what a "fundamental body plan" is; bases his reasoning on misidentified fossils; and draws conclusions which aren't supported by the supplied evidence.

But he does it in a really enthusing way. There's no denying it's a good read.

Simon Conway Morris, the chief "hero" in this book, has since done his best to distance himself from Gould - to the point that he tends to deem it necessary to explain what a phylum is in his articles, and has written the Gould-critical book "Crucibles of creation" (which isn't that great either).