Drawing on a wealth of resource material, Wade builds a comprehensive picture of who we are and where we come from. The "origins" question has been pretty well solved. Darwin's insight that Africa was humanity's home base has been verified in several ways. It is the issue of human traits, their origins and expression, that's in need of clarification. Wade has scoured the research to derive some interesting, and to some, highly disturbing, conclusions.
Writing to his defined audience, Wade's use of Biblical metaphor touches a nerve. It's a useful technique as he opens with 'Genetics & Genesis'. There's no doubt in the reader's mind that 'genetics' will be the guiding theme as this book progresses. Genetics and DNA analysis have 'enriched our view of the past', he notes. He assures us, as well, that the processes they depict are still working to guide us into the future. He lists some of the insights these tools have given us. The clear continuity between 'the ape world of 5 million years ago and the human world that emerged from it' opens the inventory, which includes cultural input and various social factors, why our global dispersal was so rapid, and how language impinged on our development as a species.
Among the more captivating aspects of our evolutionary track is the number alternative paths we might have followed. Wade explains how ape diversity has made discernment of our lineage an onerous task. An indication of what's to follow emerges in a section on why we became 'naked'. The loss of fur meant that exposed skin required protection from the African sun. All humanity's skin cells contain melanin, with variations determined by geographic location. The human diaspora out of Africa led to many variations in our make-up. In many ways, we became different as we wandered the face of the globe. Wade proposes that our migrations were encouraged as much by emerging cognitive skills and development of changed relations between the sexes. Another trigger may have come from 'an ancient gene' - FOXP2. Widespread among mammals, FOXP2 underwent significant changes in our species. It's now known to be a major factor in our language skills. Language, often used as the means to reconcile differences, has also led to changes in our relationships from mates to masses of others. Disputes are subject to the use of deception and aggravation. The result, according to a cluster of researchers Wade has read or interviewed, suggests our capacity to wage war is widespread and of long history. Warfare among chimpanzees implies an inherited trait of deep lineage. The 'cultural' influences merely exacerbate what is already in place.
After explaining how our species distributed itself around the globe, he describes the 'Settlement' process and how it led to agriculture. We take both community and farming as a given today, but it's a very recent alteration from our heritage. Perhaps of more significance is that 'settlements' occurred in widely dispersed sites at various times. The conditions leading to farming and its subsequent changes in human behaviour also were different. What prompted us to take this step? Agriculture resulted in a change from social equality to a hierarchical structure. 'Leaders' were needed for planning and implementation of field use, crop distribution and resource allocation, especially water. It's an interesting facet of this transformation that agriculture emerged where water's availability was dodgy. Religion, whatever its role in hunter-gatherer times, was increasingly important in stable communities. The entire human social structure changed, with new sets of values and choices becoming the norm.
In what will certainly emerge as one the most discussed segments in this book, Wade dedicates a chapter to 'Race'. The issues are based on Wade's emphasis on how much the human genome has changed in recent [at least on an evolutionary scale] times. While the physical characteristics such as skin colour are manifest, there are other, more subtle aspects of what makes groups of us different from others. Among these are those with or lacking a tolerance for lactic acid upon becoming adults. More significantly perhaps, is the discovery that certain medications work better with some groups than others. Health issues such as these are only now being addressed. Much more work is needed and research funding may be challenging some ideological fixations.
Wade's synopsis of human evolution is among the top books issued on the topic in recent years. He has no axes of his own to grind, and blunts some dogmas in passing. The research he describes is wide-ranging. More importantly, much of it relates to how we deal with each other across lines of community, nation and humanity as a whole. While no book on the human track will be complete, nor perhaps of major importance for very long, this one will be worth keeping, and re-reading for some time. [stephen a. haines ' Ottawa, Canada]