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The Runaway Brain: A Review

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Biology 202
2003 Second Web Paper
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The Runaway Brain: A Review

Kate Tucker

Christopher Wills has written a fascinating chronicle of human evolution in a style that will keep the reader glued to the book to find out what happened next. The Runaway Brain is organized into four sections. First Wills addresses The Dilemmas, the many problems that students of evolution encounter mainly from public perception of the subject and from the many prejudices of those involved with the work. The question of where our species first appeared is a particularly contentious one, although it is now widely accepted that the species originated out of Africa. There are, regardless, those who still disagree and especially at first, many dismissed an African origin out of hand. Wills' second main issue is that of the transition to actual "humanity" and if it occurred once or twice. As he discusses in the chapter entitled "An Obsession with Race", those who deride those of African descent often use the multiple origin theory as one that justifies racism. Wills decries this abuse of the science and firmly argues against those that would use evolution to further racist propaganda. He also takes issue with those who insist on believing that all of humanity came from one Eve and one Adam, instead putting forth the theory of the "mitochondrial Eve"; that we all descend from the mitochondrial DNA, but that we do not in fact descent from two individuals.

Wills' own slant on the issue is that humans are involved in a feedback loop which he calls the "runaway brain". Wills claims that humans are unique in that they have culture which has developed. The culture injects an otherwise unknown into the evolutionary process. Humans, Wills says, had advanced brains which allowed them to create a complex culture. The culture challenged their brains and led to more complex brains as the species involved. This process continued to repeat and is still repeating today. This is what Wills claims is driving us towards our ultimate best.

The second section of the book is titled The Bones and tells the story of the archeological remains of the ancestors of humanity. Wills creates a fascinating tale as he describes the lives, feelings and desires of the people involved in finding these bones. Not only does he describe the find and its significance to the understanding of evolution, he also tells the story of the finder making the section more of a human drama than a dry telling of facts. In this section it becomes really apparent that Wills is trying to create an interesting version of evolution that everyone will be interested in reading. In the preface to the book he states that he wants to bridge the gap between scientists and the public and here he does so, mentioning that you might be reading this book while sitting by a fire with your pets. Wills is quite adept at turning the facts of evolution into a story telling process.

After tracing the various archeological finds showing our possible descent from apes, Wills goes on to discuss the genetics of evolution in The Genes. He first describes the basics of genetics, instructing the reader as to the basic nature of genes, alleles, DNA and mutations. He places a very strong emphasis in this section on the fact that mutations are usually neutral, usually having neither a positive or negative influence on the organism. Wills provides the basic genetic knowledge needed to understand how traits can be passed down from generation to generation in a population and in turn how this can alter the makeup of the population.

The final section of the book, The Brain, attempts to discover why the human brain differs from all other animals. As with The Genes, Wills first begins with a description of the basic functioning of the brain and then moves into a more complex analysis of why our brain structure has led us to the more complex abilities we see in human culture today. Wills shows that human brains were not that different from the other organisms that we evolved from originally, but that human brains have become more complex over time. Here again he puts forth his theory of the "runaway brain". He postulates that human culture has created a feedback loop with the complexity of the brain; one leading to an increase in the other and back and forth with our current brain as a result. Hence, the brain has been directed towards as ultimate goal. The goal is the complex structure that we utilize today. This is not, however, the ultimate endpoint for humanity, Wills argues. He claims that evolution is still ongoing today, although we cannot see it at work and will continue in the future.

The Runaway Brain is a highly enjoyable read for anyone interested in evolution. Every fact and discovery is punctuated with a human interest story by telling the history of the discoverer. Every important event is marked with an anecdote explaining the significance in a way that everyone should understand. Wills stated in the beginning that his "goal is to try and close the gap between the scientist's perception of how evolution works and the public's; in essence, to demystify the process of evolution"(xx). In this respect, he has succeeded admirably. The problem with the book, however, is that the sections are quite disjointed. Although the reader will learn a lot about The Bones, The Genes, and The Brain, they are not all tied together in a way which the reader can easily comprehend. The message of the "runaway brain" is also not clear enough. Although Wills refers to it periodically, he does not use the mountain of evidence he presents in this book to back up his theory. As an exploration of how humans evolved to their current complexity, Wills does an admirable job of chronicling but was not so successful at explaining the process.


Wills, Chrisopher. The Runaway Brain: The Evolution of Human Uniqueness. New York: Basic Books, 1993.