Thumbs, Toes, and Tears: And Other Traits That Make Us Human

The fascinating evolutionary links between six seemingly unremarkable traits that make us the very remarkable creatures we are.
 
Countless behaviors separate us from the rest of the animal kingdom, but all of them can be traced one way or another to six traits that are unique to the human race—our big toe, our opposable thumb, our oddly shaped pharynx, and our ability to laugh, kiss, and cry. At first glance these may not seem to be connected but they are.  Each marks a fork in the evolutionary road where we went one way and the rest of the animal kingdom went another. Each opens small passageways on the peculiar geography of the human heart and mind.
 
Walter weaves together fascinating insights from complexity theory, the latest brain scanning techniques, anthropology, artificial intelligence, cognitive psychology, and robotics to explore how the smallest of changes over the past six million years – all shaped by the forces of evolution -- have enabled a primate once on the brink of extinction to evolve into a creature that would one day create all of the grand and exuberant edifices of human culture.
 
As the story of each trait unfolds, Walter explains why our brains grew so large and complex, why we find one another sexually attractive, how toolmaking laid the mental groundwork for language, why we care about what others think, and how we became the creature that laughs and cries and falls in love.  Thumbs, Toes and Tears is original, informative, and delightfully thought-provoking.Chip Walter is a science journalist, documentary filmmaker, and former CNN bureau chief who has written for Scientific American, Discover, The Economist, and many other publications. He is coauthor (with William Shatner) of I’m Working on That and author of Space Age, the companion book to the primetime PBS series of the same title. Walter is an adjunct professor at Carnegie Mellon University, a senior manager of strategic communications at the University of Pittsburgh Medical Center (UPMC) and lives in Pittsburgh, Pennsylvania, with his two daughters.

Among the countless traits and behaviors that separate us from the rest of the animal kingdom, six stand out—our big toe, opposable thumb, oddly shaped pharynx, and our abilities to laugh, kiss, and cry. Hough seemingly unconnected, they are actually closely linked; each marks a fork in the evolutionary road where we went one way and the rest of the animal kingdom went another.
 
Science journalist Chip Walter tells the story of how these six unique human traits evolved, and his illuminating book provides surprising insights into how we became the remarkable species we are. Drawing on complexity theory, the latest brain scanning techniques, and new insights from fields as diverse as anthropology, neurobiology, and artificial intelligence, Thumbs, Toes, and Tears reveals a creature whose social relationships, sexual behavior, and internal self-image were shaped by its ability to walk upright, make tools, use language, and bond deeply in a dangerous world.

 

As the story of each trait unfolds, Walter explains why our brains grew so large and complex, why we find one another sexually attractive, how toolmaking laid the mental groundwork for language, why we care about what others think, and how we became the creature that laughs and cries and falls in love. Thumbs, Toes, and Tears will give you a new sense of wonder and appreciation for how unique Homo sapiens truly is. 
 
As the story of each trait unfolds, Walter explains why our brains grew so large and complex, why we find one another sexually attractive, how toolmaking laid the mental groundwork for language, why we care about what others think, and how we became the creature that laughs and cries and falls in love. Thumbs, Toes, and Tears will give you a new sense of wonder and appreciation for how unique Homo sapiens truly is.

 "A tremendously accessible overview of the aspect of evolutionary theory that fascinates people most—the part about humans . . . Walter does a fantastic job of synthesizing the primary research of scientists in various fields, from Louis Leaky to Jane Goodall to Stephen Jay Gould . . . For those who haven't read deeply into the subject, this book would be an excellent introduction."—Pittsburgh Magazine "Author Chip Walter takes us on this reasonable and extremely witty and well-written tour of the human body. He explains with insights that are easy for the layman to understand, as well as scientifically based. He can do so because he knows how to communicate to a general audience, having a career that spans not only journalism and documentary filmaking, but also academia—he teaches at Carnegie Mellon University . . . Walter takes us on a tour du corpus that is at once clever and wise. This book is truly noteworthy, for it addresses the emotional from the world of the physical. It builds upon truisms that must exist to arrive at higher plateaus. This reader was engaged, and it left me with many more questions, perhaps to be explored in a future Walter book."—The Decatur Daily "With a story teller's skill Chip Walter urges us to see how great things come from small beginnings. He refreshingly points out that while ideas have consequences, so do big toes, opposable thumbs and four other human traits that, mostly, we take for granted. We may have much in common with the animal world, but thanks to an unlikely collision of seemingly small evolutionary changes something extraordinary happened—the human race. A fascinating read."—Michael S. Gazzaniga, Ph.D. Director, Center for Cognitive Neuroscience, Dartmouth College, and author of The Ethical Brain
 
"Eons ago, we started to stand straight with our big toes, freeing our hands, evolving our thumbs, manipulating our environment, transforming the thoughts in our expanded brains into changed realities. In this brilliant account of how the majestic human enterprise started from these humble beginnings, Chip Walter vividly tells the ambiguous, messy, and utterly fascinating stories that led to our becoming the technology-creating species."—Ray Kurzweil, inventor and author of The Singularity is Near: When Humans Transcend Biology "A science journalist tours a suite of characteristics, both anatomical and behavioral, that typify human beings. Such excursions often concentrate on a single trait (e.g., Craig Stanford's Upright), so Walter is gathering many topics under one roof. Two of them his readers can consult directly: the big toe and the thumb. His discussion covers their functions, considered against the evolutionary advantages they might have conferred on the African savanna. In that vein, Walter presents paleoanthropology and famous fossils such as Lucy. He also directs attention to the applicability of genetics and neurobiology to unique human qualities, especially brain size. Its increase through the series of hominid species guides Walter's exploration of the ramifications of humans' large brain, such as self-awareness, language, and emotion. For those who wonder if talking and crying have evolutionary origins and survival benefits, Walter points to scientists active in researching such questions. A fluid introduction to the development o