Ever since Darwin firmly established the human lineage from the primates with the scientific community, scientists have been debating the how and why of that evolution amongst themselves. Unfortunately, most of those studies have come in science journals that would have limited access to wider, generally less-informed audiences.

Two attempts however, that reversed that trend and stick out the most in recent memory would be Desmond Morris' The Naked Ape of 1967 that gave the human-ape comparison from the human perspective. Then the 1971 book, In the Shadow of Man, by Jane Goodall who reversed that perspective and gave us human-ape comparison from the detailed accounts of chimpanzee social life. We own Jane Goodall much because when she began her detailed studies, she was not aware that she could not attach human names to her non-human subjects. Because of her non-scientific training, (she received her degree after her studies began), she based all her observations on her general knowledge and the obvious connection to human socialization; fortunately, for us, her observations held up under repeated observations from the scientific community.

With The Tree of Origin, we have the best of both worlds. We have a group of well - qualified professionals, all of whom are primotologists, (although they may be linguists, anthropologists, psychologists, and zoologists), that have been brought together under the tutelage and editorship of today's best known intellectual leader in the primate-to-human debate, Frans de Waal. Since the publication of his successful book Chimpanzee Politics, he seems to have taken the lead in advancing our understanding of this transformation from ape to human, and here, he allows his contributors free reign to speculate about the origins of human evolution, but he does so with a major restriction: to write in an accessible, jargon-free style.

In the opening pages of Tree of Origin, de Waal quickly reinforces the current consensus in the nature-nurture debate by reaffirming the mixture of the two: "The current generation of primatologists, however, is quite averse to attempts to squeeze behavior into a simple "learned versus innate" dichotomy. We assume that all behavior in all primates, including our own species, derives from a combination of evolved tendencies, environmental modification, development, learning, and cognition..."In sum, this book is not about our species as a preprogrammed robot destined by its biology to act one way or another...Rather, the goal is to understand human social evolution from the perspective of what we know about the social organization, communication, learned habits, subsistence, reproduction, and cognition of other extant primates." p. 4 & 5.

As for the contributors. Wow! How would you like to host a dinner party with these folks and listen to the group discussion of how to shape the book they were writing: Richard W. Bryne, School of Psychology, University of Saint Andrews, Saint Andrews, United Kingdom; Robin I.M. Dunbar, School of Biological Sciences, University of Liverpool, Liverpool, United Kingdom; William C. McGrew, Dept. of Sociology, gerontology, and Anthropology, Miami University, Oxford, Ohio; Anne E. Pusey, Dept. of Evolution, Ecology, and Behavior, University of Minnesota, Saint Paul, Minnesota; Charles T. Snowdon, Dept. of Psychology, University of Wisconsin, Madison, Wisconsin; Graig B. Stanford, Dept. of Anthropology, University of Wisconsin, Madison, Wisconsin; and Richard W. Wrangham, Dept. of Anthropology, Harvard University,Cambridge, Massachusetts.

Tree of Origin concentrates its look at the primate-human connection through five themes: ecology, sex and reproduction, social organization, social sophistication and cognition, and finally, Hominization; but not all primates are considered. There is strong consensus that we humans had a common ancestor along with the Bonobos and Chimpanzees. As such, to quote de Waal: "Most important, we should keep in mind that the bonobo and the chimpanzee are equidistant from us [humans]. Most biologist consider the general principles of adaptation and natural selection more important than the evolution of a particular species. It is true that the bonobo, by virtue of its close relation to us, is a critical piece in the puzzle of human evolution; but it is really the entire puzzle that science seeks to solve. The most successful reconstruction of our past will be based on a broad, triangular comparison of chimpanzees, bonobos, and ourselves within this larger evolutionary context." p. 68

All of the chapters are well written and presented in a manner that lead us toward a logical progression from primate to human. Anne Pussey enlightens us with her knowledge of chimpanzee social organization followed by de Waal's expertise on bonono and human social comparisons. Karen Strier then chastens us to consider behavior over the entire primate order, followed in chapter four by Craig Stanford who lends considerable weight to his theory that the social importance of meat-eating, and meat-sharing was the foundation of social bonding.

In chapter five we are presented with Richard Wrangham's theory that cooking roots may have greatly influenced the formation of the nuclear family and in chapter six, Richard Byrne wades in with his musings on social and technical forms of primate intelligence. In Chapter seven, Robin Dunbar, reasserts his theory of the relationship between group size and brain neurocortex size. Chapter eight has Charles Snowdon advocating his thoughts on primate communication leading to human language. And, as they say, the best should be left to the last, William McGrew's chapter on cultural primatology is a suitable cap to this fine book.[note the combination of nature and nurture]. To quote McGrew's final words: "Homo sapiens is not the only cultural species of the order Primates. If human culture emerged out of nonhuman nature, then we must seek the intermediate stages of this evolutionary transition if we are to understand more fully our cultural roots. To the traditional approaches of cultural anthropology and archaeology, we must add the wider perspectives of comparative psychology and behavioral ecology. Thus, cultural primatology is a genuinely new synthesis of theory and methods that crosses the disciplinary lines of social and natural science. But our efforts will only be as meaningful as our material: enriching the daily lives of captive primates and preserving the habitats of wild primates is the necessary foundation of productive cultural primatology." p. 254.

These are powerful and wonderful words to conclude a most excellent book that we should include in our personal libraries as we advance our understanding of the gradual and, what appears to be, the true journey of ape to human. This is a excellent book, but I caution beginners that despite its non-technical prose, I recommend reading one of the more basic books first, and then proceed to this mid-level book. The book is highly recommended to all members of the Human Behavior and Evolution Society who, despite their varied disciplines, have a firm grasp on overall evolutionary perspectives.