Book Review: Evolution: The Story of Life

Whenever I sit down to write an entry for this blog I remind myself that I might not always speak the same language as the people I am trying to reach. A statement that might be technically accurate, such as "Mammuthus primigenius was a Late Pleistocene proboscidean with a Holarctic distribution", will likely cause nonspecialist readers to go cross-eyed and vow never to visit this blog again. Instead I have to remember what it was like when I began to teach myself about paleontology and evolution. What do those words mean? And how can I quickly and accurately define them without sacrificing the story I am trying to tell?

Admittedly I sometimes forget this principle. I might throw around terms like "Miocene" or "adapid" without fully explaining their meaning. Thankfully Google is always available to assist baffled readers with defining these terms, but regular readers of this blog (and others like it) might find it easier to keep a single source at hand. When it comes to paleontology and evolution there is no shortage of such titles. This year alone has seen the publication of Evolution: The First Four Billion Years, Darwin's Universe: Evolution A to Z, and Prehistoric Life: The Definitive Visual History of Life on Earth, with Douglas Palmer and Peter Barrett's Evolution: The Story of Life due out early next month. This review is about the latter book, an updated version of the classic "Life Through the Ages" treatment.

As an encyclopedia, Evolution: The Story of Life is not meant to be read from cover-to-cover. It is a heavy compendium of information that is organized into several large sections. The first section presents a brief, textbook-like summary of who Charles Darwin was, how fossils are formed, &c. This provides the bare minimum of background to properly understand the rest of the book. It is followed by several larger divisions; one looking at what life was like during particular slices of geologic time, another presenting a drawn-out "tree of life", and a final set of indexes to material found elsewhere in the book.

Paleontology takes center stage in these core sections. Genetics and developmental biology are given a tip of the hat early in the book, but Palmer (author) and Barrett (artist) primarily trace evolution through a series of vignettes restored on the basis of fossil evidence. This is a classic technique, but I have to question its utility.

The succession of illustrations is like a parade of distinct organisms from particular points in time, and little is done to draw the creatures in each habitat group together through evolution. That life changed through time is made abundantly clear, but just how it did so (i.e. through what mechanisms and from which ancestors?) remains obscure in the text. On pages 60-61, for example, the reader is introduced to early, jawless fish, yet not explanation is given as to where those fish came from. I find this lack of explanation strange for a book called Evolution.

For now, though, I will forget about the book that I had expected from the title. What did Palmer and Barrett actually create? The general layout of the "scenes from deep time" made me think of what a Facebook photo gallery for "Life on Earth" might look like. Each scene created by Barrett is bordered by a timescale along the top and detailed boxes and panels along the bottom that correspond to numbers and squares inside each scene. There is a lot of information on each page, not all of it made clear (i.e. page 65 mentions the thylacocephalan Ainiktozoon but just what a thylacocephalan is does not receive comment from the author), but overall this format does serve the intended purpose of showing how life on earth has changed. To the credit of the authors, once life moves onto land they still sample marine habitats, thus mitigating the traditional "onward and upward" vision of evolutionary inertia catapulting life from a simple aquatic monad to humanity.

On page 250 the book changes gears. It goes from being a scrapbook of extinct ecologies to a seemingly endless array of branches arranged to reveal evolutionary relationships. Animals may have received the majority of attention in the previous section, but here single-celled organisms, plants, and other less charismatic organisms are discussed in turn. Again, sometimes technical terms are employed without any explanation of what they mean, but this section of the book can be used in conjunction with the prior one in order to draw connections between organisms previously featured. The actual transitions are not discussed, but together the two sections create a broad sketch of the tree of life.

The last section of the book is a heterogeneous mix of indexes and glossaries. There is a catalog of fossil sites described in the earlier sections, an species index, a listing of various groups of organisms, and a few other handy resources. This is all capped off with a fold-out timeline and a "panoramic view" of all Barrett's scenes from prehistory stitched together into one evolutionary mural.

What audience would most benefit from this book? If you are interested in the mechanisms of evolution, or the "how" questions, this is not the title for you. Instead I would suggest that you pick up Carl Zimmer's new user-friendly textbook The Tangled Bank. If you want an overview of what animals (especially vertebrates) lived during different times during prehistory, however, this is a good compendium to keep handy. It provides a broad and up-to-date outline of what lived where and when, and different portions of the book can be cross-checked with each other to provide more information should you require it. Likewise, if you often read popular science books, watch documentaries, and read evolution blogs but are often left uncertain by technical terms this book might be a worthwhile investment. It allows readers to easily look up details about particular species, localities, and groups of organisms even if the details of evolutionary transformations are almost entirely absent from this book.

Whether Evolution: The Story of Life is a "good" book or not depends entirely upon the needs of the reader. Someone well-acquainted with paleontology might find little in it that they did not already know while someone who has a more casual interest in the subject may consider it a wellspring of useful information. This is a book meant not so much to be read as to be used, and though it is a bit rough in patches Evolution: The Story of Life could certainly be a useful resource for those who want to peek into the prehistoric past.