Evolving Brains

This is a sweeping examination of evolution's path leading to that mass of gray matter behind your brows. Allman has synthesized a wealth of research in producing this study. He explains in a clear, interesting style how natural selection has spent the last 500 million years tinkering with life to build complex systems from simpler ones. He is a forceful writer, supplementing a fine text with superb illustrative material to build his narrative. It's a refreshing view of natural selection's power of innovation. Allman draws on the detailed research undertaken in recent years that has mapped the brain and detailed its operations. Like all life, beginnings were simple, but small variations among organisms had the potential for important roles. Deep in the Precambrian, floating cells developed appendages leading to hair-like structures we call "cilia". The cilia adopted dual roles: sensing the environment and responding to it. Allman explains how gene duplication led to opportunities for experiments. This process demonstrates how we can track many of steps leading to today's life forms. The original genes are usually still resident, with enhancements providing new functions added over the passing generations. The author's explanation of the workings of chemistry in brain functions is worth close attention. Behaviour is the result of brain activity, but the interactions of various parts and functions of the brain elude simple analysis. One example is the brain chemical [neurotransmitter] serotonin which is found throughout the brain. It's impact gives monkeys their social structure while adding to the risk of suicide in humans. Neurochemistry alone doesn't explain the expansion of the human brain, nor does the author stop there. He goes on to show how bipedalism, diet, language and social behaviour all working in self-reinforcing feedback loops led to the gob of tissue that takes a fifth of our body resources to keep working. Even global climate changes played a role, coming at a time when our species was just prepared to contend with them.The number and impact of revelations in this book are almost beyond counting. The "urban myth" that women live longer than men because of improved health practices has been disproved both by history and anthropology. A study reaching back into the 18th Century demonstrates that women have outlived men at least that long ago. Among the great apes, chimpanzee females also outlive their mates. Orangutans and gorillas have nearly parallel life spans between genders. There are also studies showing how caring fathers have extended life spans. His analysis of the development of colour vision is another novel thesis. Colour perception arose only 40 million years ago, after the demise of the dinosaurs. This raises again, the question of whether the emergence of flowering plants, which were toxic to those creatures, helped speed their demise. While this book is not a light read, it's an informative a

How has the emergence of the super-sized human brain depended on the evolution of a good set of teeth? Why are the stomach and brain closely linked across the brambles of genetic code? This book answers not only those intriguing questions but also many others concerning the emergence of the brain on this planet. Especially fascinating to me was the explanation of the homeobox phenomenon, a process by which very complex mutations can arise in an organism without the mutation risking certain disaster. Being a non-biologist, I found this homeobox material quite fascinating, for it opened my eyes to how evolution could generate incredibly complex features without requiring a hundred trillion years for all the right components to come together all at once. Equally interesting are the many vestiges of our evolutionary past that are still embedded in the way our brains process information. For example, the sectors into which our brains split each of our retinae today for the purpose of signal processing: these are left overs from the days when our ancestors were prey and not predators, back when our ancestors' eyes were mounted to the sides of their heads! In summary, I would like to say that in reading this book, while just sitting in my chair, I felt myself moving up another notch on the evolutionary tree. It gave me a whole new appreciation for the miracle that is the development of brains and conscious life on this planet. A very pleasant read.

John Morgan Allman wrote a book that can be enjoyed by anyone from a psychology 101 student to an accomplished neuropsychiatrist. The evolutionary perspective on the brain not only informs us about its anatomical development, but enlightens us about the process of being human. I dare anyone to read this book and not come away with a deeper appreciation of pet dogs and gormet food.I have found myself delighting my children, friends, and patients with tidbits from Evolving Brains. Allman seamlessly weaves what is known about evolution and brains with his own hypotheses about function and adaptation. This makes for pleasant and stimulating reading, although sometimes the reader is lead unknowingly into the land of conjecture, such as when Allman states that the anterior cingulum is the seat of human self-awareness. Remember, Decartes thought the pineal was the seat of the sole!But for the most part, Allman is right on. If you like brains, don't miss this book!

I enjoyed this review of the current state of knowledge of the human brain, both its various functions and their evolution. Best of all, I shared some of the ideas in it with my 12 year old son. He went away and a day or so later came back to ask me the kind of question that the young inquiring mind frames so well: (referring to the appositional placement of reptilian eyes), "Dad, how can a reptile see two different scenes at the same time?". I had no good answer to this question which was prompted by the discussion of vision in Evolving Brains....so I called Prof. Allman's office. He kindly called me back within the hour to help me with this seemingly simple question. Turns out the answer is not simple. Just let me say that this book evinces the wonderful personality of the author throughout. Highly recommended for those interested in the latest knowledge on the functions of the human brain and how these functions evolved. Geoff Noyes [email protected]

This is a book to savor, to read again and again. After reading it, I found myself looking at the world and our place in it in a new, expanded way. A lot of scientific advances have been made in the past decade or so, and this book brings the reader up-to-date and ties together the advances made in various fields in an interesting, understandable manner. This book was written by a Professor of Biology at Caltech, who obtained his doctorate in anthropology. It has some chapters that take concentration to read, and others that one can breeze through. The pictures and graphics are great (this book will look good on your coffee table). No prior background in biology or anthropology is assumed. Probably what was most useful to me was that I learned a lot about evolution that I hadn't known before. Before reading this book, I thought that I had a basic understanding of evolution, but now I realize that the part I more or less understood was simply that of natural selection (Darwin). By walking the reader through the recent advances in genetics, this book explains in a clear and understandable way HOW NEW SPECIES ARE CREATED. (In my informal polling of knowledgeable friends and relatives, I found no one else who understood how new species are created... of course, with my new knowledge, I explained it to them!) Speaking of which, this book has resulted in some lively and engaging conversations: I now have a seemingly endless source of fascinating insights about humans, about animals, about the brain that I can talk to others about. Take dogs, for example. I have never been much of a dog-lover, but now I more fully appreciate how dogs (having evolved from wolves with the help of humans) and humans have worked together to ensure each other's survival... so now I don't mind it so much when my sister's dog jumps on my couch! Other examples: how the extended family structure (and therefore the role of females in general) has played in the survival of humans. How serotonin and the level of this chemical affects the brain (and thus why Prozac and other anti-depressants are effective). How our 'junk DNA' creates a fossil record of evolution. How our eyes and vision evolved... amazing! I could go on and on with such examples from the book, such wonderful things I learned. With my enhanced understanding I find myself noticing more about babies and how they learn, about animals... and tuning in to the new animal channel on cable more often. This book has excited a curiosity in me, and I want to learn more. I believe that everyone would benefit greatly from reading this book.