Imagine that you are looking for a book that summarizes our current knowledge of the human nervous system from an evolutionary perspective (featuring the brain, which is its most illustrious constituent). If you stumble upon a text written by Rob DeSalle and Ian Tattersall entitled The brain: Big bangs, behaviors, and beliefs, your quest is likely to be satisfactorily completed. The educational value of this text can be justified on several grounds. Most and foremost, though, what is likely to capture the reader’s attention is the accurate, well-measured, yet engaging, narrative with which evidence-based and theoretical knowledge regarding such an astonishing organ is reported.
Across the entire text, DeSalle and Tattersall recognize that the brain is a complex device whose intricacies are not entirely understood. Furthermore, its known evolutionary history is no more than an array of reasonable conjectures based on converging evidence. The authors face the challenges of portraying such a complex structure and its purported history as if they were constructing a museum exhibition instead of writing a book. In their minds, the target audience seems to be the general public, defined by varied depths of knowledge regarding the nervous system and its phylogeny, but united by a common curiosity and fascination for the unknown. For the selected target audience, steps and details of the currently understood evolutionary history of the human brain are used to inform, clarify and/or augment the authors’ descriptions of the structure and functioning of this astonishing, and yet largely impenetrable, organ. These properties or attributes reflect scientists’ views of the brain as capable of a variety of actions whose value and intricacies go largely unnoticed until damage affects its functioning. The latter then cruelly exposes the hurdles not only of reproducing lost functions in artificial vessels, but also of developing vessels that fit perfectly (i.e., go largely unnoticed by) the rest of the human machinery.
DeSalle and Tattersall explore a variety of standard human brain’s feats, including sensory-perceptual processing, memory, language, consciousness and emotions. They analyze each one regarding the extent to which the same feats are present in other species of the animal kingdom. Both anatomical and physiological analyses are used for comparison purposes. The goal is to embed the human brain in a two dimensional context where differences between/among species (the horizontal axis) are used to understand its development across the extended timeframe of evolution (the vertical axis). The outcome of the authors’ work is an exciting and informative narrative that challenges the reader’s curiosity by offering some answers in the form of conjectures, but mostly by defining the many questions and unresolved issues that the human brain as a black box still poses.
Indeed, the brain remains very much a black box, albeit non-invasive techniques, which can capture its functioning in real time (e.g., functional Magnetic Resonance Imaging, Positron Emission Tomography, and Evoked Related Potentials), and systematic observations of the consequences of brain damage have begun to unlock some of its mysteries. Progress is palpable, but yet to result in a complete playbook that can be simulated in damaged brains to reinstitute lost functions so perfectly that artifacts will be easily mistaken for the original structures. Ironically, current knowledge of the brain resembles in its form the rudimentary drawings used by the authors to illustrate specific brain structures or other relevant information. In ‘The brain: Big bangs, behaviors, and beliefs’, such knowledge is enriched and made less disappointing by its being framed by known facts and speculations about the evolution of the human species (as it is currently conceptualized). Consequently, the human brain appears as an antique artifact, which can be seen and touched, but whose origins, history of use and activities can only be guessed by studying it with other artifacts. The latter are the brains of other species in the animal kingdom, which the authors carefully review for comparison purposes.
I must admit that the drawings used to illustrate specific brain structures or other relevant information are often less than transparent and intuitive, promoting simplicity as the expense of clarity and fine points. I also find the last chapter too short to capture the unknown of human evolution. Yet, The brain: Big bangs, behaviors, and beliefs offers a valuable narrative about the brain through the glasses of evolution, which can benefit and enrich learning in college courses covering a variety of subjects, including not only physical anthropology and evolutionary biology, but also physiological psychology and cognitive neuroscience. Of course, its narrative can be equally valuable to a general readership composed of individuals whose curiosity about the human brain involves the mystery of its phylogenic development. Indeed, the glossary at the end of the book can be useful to both constituencies, filling the knowledge gaps that a reader may have on a specific topic to permit comprehension.
© 2013 Maura Pilotti
Maura Pilotti, Ph.D., Ashford University