This book is a stunning compendium of the range of life forms found on our planet. Margulis and Schwartz describe it as "a catalog of the world's living diversity." It is a vividly descriptive assortment of selected examples from the Five Kingdoms of life formulated by R.H. Whittiker. The authors stress how much new knowledge, particularly in the study of unicellular life forms, has been gained in recent years. They explain how classification identifies organisms and show how modern techniques have led to the expansion of life's kingdoms from two to five. A description of prokaryotes and eucaryotes is given, followed by the body of 92 phyla descriptions. The book is arranged to be either studied as a reference or browsed as an introduction to biological forms. Each entry is carefully organized with the type of information [environment, measurement scales, diagrams] in a consistent location.
However, this is more than simply a collection of illustrative examples of various organisms. The most fascinating chapter relates the authors' proposal to modify one of the standard classifications of life - the Protoctists, replacing Whittiker's Protists. "The Kingdom Protoctista is defined by exclusion," they state. "Its members are neither animals, plants, fungi nor procaryotes." Their common characteristics are nucleated cells, some kind of flagellum and live in an oxygenated atmosphere [unlike many unicellular forms which cannot tolerate oxygen. Their argument contends that many multicellular forms are more
directly related to these unicellular forms than they are to other multi-celled organisms. The new classification "also solves the problem of blurred boundaries that arises if the unicellular organisms are assigned to the multicellular kingdoms." They list 27 phyla [of 36 total]with diagrams exhibiting a range of bizarre structures and life cycles.
Another noteworthy entry is Trichoplax adhaerens. Remember the name of this creature - "it is the simplest of animals." Composed of but a few thousand cells, it is a dull gray body just visible to the unaided eye. In looking at the photo and diagram of this creature invokes a sense of wonder - this is, after all, a distance relative living in the nearest aquarium with the shad.
This book is a delight to browse following one of the authors' intents. Their second purpose, using this book as a reference, is even more admirably met. Clear photographs coupled with excellent diagrams, including typical environments of the selected specimens, add visual support to a readable text base. Any reader interested in the way life is structured and seeking insights into evolutionary development would do well to consider this book. It's not an academic text, but conveys a wealth of meaningful information.